WO2014207895A1 - Base station device, mobile station device, and communication method - Google Patents

Abstract

This base station device (7), which is connected to a second network (3) via a first network (2), is provided with a detection unit (41, 57, 66) and a connection setting unit (63). The detection unit (41, 57, 66) detects the lengths of packets conveyed between the second network (3) and a mobile station device (10), and in accordance with detection results from the detection unit (41, 57, 66), the connection setting unit (63) transmits, to the mobile station device (10), an instruction signal that sets up a wireless communication connection between the mobile station device (10) and a second base station device (9) that is connected to the second network (3) via a third network (4), said third network (4) being different from the first network (2).

Description

Base station apparatus, mobile station apparatus and communication method

The embodiments discussed herein relate to a base station device, a mobile station device, and a communication method.

Conventionally, a communication system including a mobile station device, a base station device, an IP (Internet Protocol) service network, and other networks connecting the base station device to the IP service network is known. The network between the base station device and the IP service network may be, for example, a private network of a telecommunications carrier that provides a mobile communication service. For example, in LTE (Long Term Term Evolution) defined by 3GPP (3rd Generation Partnership Project), a base station device and an IP service network are connected by a network called EPC (Evolved Packet Core).

As a related technology, for a wireless system that can use different types of resources at the same time, if the degree of congestion of all resources is equal to or greater than a threshold, the wireless system can be used without wasting as much resources as possible periodically. Switching is known (see, for example, Patent Document 1).

A method for managing radio resources for packet data in a radio communication system is known. The method includes allocating radio resources for packet data to be transmitted based on retrieved port numbers and associated statistical models, and at least one general statistical model for traffic Including the stage of building. The traffic characteristics include the number and size of small packets at the start and the number and size of small packets at the end (see, for example, Patent Document 2).

A system and method for learning base determination of semi-persistent scheduling of data packet flow wireless communication are known. A packetized data flow served to a wireless terminal is fully scheduled in the first time period to collect statistics related to the scheduled packet size (Ss) and inter-packet time (Ts). Analysis of the cumulative distribution of {S, T} pairs indicates whether the characteristic packet size (S0) and size variance (D0) are related to the cumulative distribution. The time interval associated with feature size and variance completes the transport format. If the characteristic transport format can be extracted or learned from the accumulated statistics, semi-persistent scheduling is utilized for the packetized flow. The extracted transport format can be used to optimize the scheduling efficiency at the time of handover (see, for example, Patent Document 3).

JP 2010-171520 A Special table 2005-512431 Special table 2010-527208

With the recent increase in traffic of mobile station apparatuses, reduction of congestion occurring in the network between the base station apparatus and the IP service network has become an issue. For example, network congestion is caused by an increase in processing such as packet transmission / reception in a base station apparatus or an apparatus constituting an IP service network, and may be caused by a control signal transmitted / received by a mobile station apparatus. For example, an operating system (OS) operating on a mobile station apparatus, an application, and a radio control signal for performing radio communication transmit a control signal having a relatively short packet length. Network congestion may occur due to frequent transmission of such control signals. Furthermore, due to congestion, the required transmission rate may not be satisfied, or the transmission rate may decrease.

An apparatus or method disclosed in the present specification reduces congestion generated in a network between a base station apparatus and an IP service network, improves a transmission rate by reducing congestion, and satisfies a required transmission rate. Another object of the present invention is to reduce processing in the base station apparatus and the apparatus constituting the IP service network.

According to one aspect of the apparatus, a base station apparatus connected to the second network via the first network is provided. The base station device detects a packet length of a packet transmitted between the second network and the mobile station device, and passes through a third network different from the first network according to a detection result of the detection unit. And a line setting unit for transmitting an instruction signal for setting a wireless communication line between the second base station apparatus connected to the second network and the mobile station apparatus to the mobile station apparatus.

According to another aspect of the device, a mobile station device is provided. The mobile station apparatus detects a size of a packet transmitted between the first base station apparatus and the mobile station apparatus connected to the second network via the first network, and detection of the detection section According to the result, an instruction signal for transmitting line setting information for setting a wireless communication line with the second base station apparatus connected to the second network via the third network different from the first network A line control unit for transmitting to the first base station apparatus, a receiving unit for receiving line setting information, and a line setting unit for setting a wireless communication line between the second base station apparatus according to the line setting information.

According to the apparatus or method disclosed in this specification, congestion occurring in the network between the base station apparatus and the IP service network is reduced. In addition, transmission speed is improved by reducing congestion. Furthermore, the required transmission rate is satisfied. In addition, the processing load on the base station device and the devices constituting the network is reduced.

The objects and advantages of the invention will be realized and attained by means of the elements and combinations shown in the claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

It is explanatory drawing of the structural example of a communication system. It is explanatory drawing of the 1st example of a function structure of a base station apparatus. It is explanatory drawing of the 1st example of a function structure of the PDCP (Packet | Data | Control | Protocol) process part of a base station apparatus. It is explanatory drawing of the 1st example of the detection operation of a small packet. It is explanatory drawing of the 2nd example of the detection operation of a small packet. It is explanatory drawing of the 1st example of a function structure of the RLC (Radio | Link | Link * Control) process part of a base station apparatus. It is explanatory drawing of the 1st example of a function structure of the MAC (Medium * Access * Control) process part of a base station apparatus. It is explanatory drawing of the 1st example of a function structure of a mobile station apparatus. It is explanatory drawing of the 1st example of a function structure of the MAC process part of a mobile station apparatus. It is explanatory drawing of the 1st example of a function structure of the RLC process part of a mobile station apparatus. It is explanatory drawing of the 1st example of a function structure of the PDCP process part of a mobile station apparatus. It is explanatory drawing of the 2nd example of a function structure of a base station apparatus. It is explanatory drawing of the 2nd example of a function structure of the PDCP process part of a base station apparatus. It is explanatory drawing of the 2nd example of a function structure of the RLC process part of a base station apparatus. It is explanatory drawing of the 2nd example of a function structure of the MAC process part of a base station apparatus. It is a sequence diagram for description of the 1st example of operation of a communications system. It is explanatory drawing of a structure of the modification of a communication system. It is a sequence diagram for description of the 2nd example of operation | movement of a communication system. It is explanatory drawing of the 2nd example of a function structure of the MAC process part of a mobile station apparatus. It is explanatory drawing of the 2nd example of a function structure of the RLC process part of a mobile station apparatus. It is explanatory drawing of the 2nd example of a function structure of the PDCP process part of a mobile station apparatus. It is a sequence diagram for description of the 3rd example of operation of a communications system. It is explanatory drawing of the 2nd example of a function structure of a mobile station apparatus. It is a sequence diagram for description of the 4th example of operation of a communications system. It is a sequence diagram for description of the 5th example of operation of a communications system. It is explanatory drawing of the 3rd example of a function structure of a base station apparatus. It is a sequence diagram for description of the sixth example of the operation of the communication system. It is explanatory drawing of the 3rd example of a function structure of a mobile station apparatus. It is a hardware block diagram of an example of a base station apparatus. It is a hardware block diagram of an example of a mobile station apparatus.

<1. Communication system configuration diagram>
Hereinafter, preferred embodiments will be described with reference to the accompanying drawings. FIG. 1 is an explanatory diagram of a configuration example of a communication system. The communication system 1 includes a first network 2, a second network 3, a third network 4, gateway devices 5 and 6, base station devices 7 to 9, and a mobile station device 10. In the following description and accompanying drawings, the gateway device may be referred to as “GW”. The base station apparatus and mobile station apparatus may be referred to as “base station” and “mobile station”, respectively.

The first network 2 and the second network 3 are connected via the GW 5. The second network 3 and the third network 4 are connected via the GW 6. The first network 2 may be, for example, a private network of a telecommunications carrier that provides a mobile communication service.

The base station 7 forms a wireless communication area 11 capable of wireless communication with the mobile station 10 and communicates with the mobile station 10 in the wireless communication area 11 in accordance with a predetermined wireless communication standard. The base station 8 forms a wireless communication area 12 capable of wireless communication with the mobile station 10 and communicates with mobile stations in the wireless communication area 12 according to a predetermined wireless communication standard.

An example of a wireless communication standard may be a 3G (3rd generation) wireless communication standard, LTE, or the like standardized by 3GPP. In the following description, the wireless communication areas 11 and 12 may be referred to as “cell 11” and “cell 12”, respectively.

The base stations 7 and 8 are connected to the first network 2 and transmit data transmitted between the second network 3 and the mobile station 10 via the first network 2. The second network 3 may be an IP service network such as the Internet or a corporate intranet.

The base station 9 forms a wireless communication area 13 capable of wireless communication with the mobile station 10. When the mobile station 10 is located in the wireless communication area 13, the base station 9 is connected to the mobile station 10 in the wireless communication area 13. Communicate according to a predetermined wireless communication standard. An example of the wireless communication standard may be a 3G wireless communication standard, LTE, or the like standardized by 3GPP. In the following description, the wireless communication area 13 may be referred to as “cell 13”.

The base station 9 is connected to the third network 4 and transmits data transmitted between the second network 3 and the mobile station 10 via the third network 4. The third network 4 may be, for example, a private network of a telecommunications carrier that provides a mobile communication service.

The first network 2 and the third network 4 may be private networks of the same communication carrier or may be private networks of different communication carriers. Further, the wireless communication standard that the base stations 7 and 8 follow and the wireless communication standard that the base station 9 follows may be the same standard or different standards.

For example, the base stations 7 and 8 may be macro base stations that form relatively large macro cells, and the base station 9 may be a femto base station that forms relatively small femto cells. For example, the radius of the macro cell is about several kilometers, and the radius of the femto cell is about several tens of meters.

In a modified example, the first network 2 and the third network 4 may be connected to the second network 3 via a common GW 5. That is, the GW 5 may connect the first network 2 and the second network 3 and connect the third network 4 and the second network 3.

In another variation, the third network 4 may be a network that provides services of an Internet service provider. The base station 9 may be an access point of a non-cellular wireless network. The non-cellular radio network may be, for example, a non-3GPP radio network that conforms to a communication standard defined by a standardization organization different from 3GPP. For example, the base station 9 may communicate with the mobile station 10 in accordance with a wireless LAN (Local Area Network) communication standard defined by IEEE (Institute of Electrical and Electronic Engineers) 802.11. For example, the base station 9 may communicate with the mobile station 10 according to WiMAX (Worldwide Interoperability for Microwave Access) defined in IEEE 802.16.

<2. First Example>
FIG. 2 is an explanatory diagram of a first example of the functional configuration of the base station 7. The base station 7 includes a transmission unit 20, a reception unit 21, a MAC processing unit 22, an RLC processing unit 23, and a PDCP processing unit 24. The base station 7 includes a line control unit 25, a line control signal creation unit 26, a line control signal extraction unit 27, and a handover control unit 28. In the following description and accompanying drawings, handover may be referred to as “HO”.

In FIG. 2, the solid connection indicates the data flow, and the dotted connection indicates the control signal flow. The same applies to FIGS. 3, 6 to 15, 19 to 21, 23, 26 and 28.

The transmission unit 20 encodes and modulates a downlink signal transmitted to the mobile station 10 and maps the modulated signal to a channel. The transmission unit 20 converts the signal of each channel into an analog signal, and converts the converted analog signal into a radio frequency signal. The transmission unit 20 amplifies the radio frequency signal and transmits the amplified signal to the mobile station 10 via the antenna.

The receiving unit 21 receives an uplink signal transmitted from the mobile station 10 via an antenna. The receiving unit 21 amplifies the received signal and converts the amplified received signal into an analog baseband signal. The receiving unit 21 performs processing for converting an analog baseband signal into a digital baseband signal, demodulation processing, and decoding processing.

The MAC processing unit 22 performs MAC layer processing of the downlink signal transmitted to the mobile station 10 and the uplink signal received from the mobile station 10. In addition, the RLC processing unit 23 performs RLC layer processing of the downlink signal transmitted to the mobile station 10 and the uplink signal received from the mobile station 10. The PDCP processing unit 124 performs PDCP layer processing of the downlink signal transmitted to the mobile station 10 and the uplink signal received from the mobile station 10.

The MAC processing unit 22, the RLC processing unit 23, and the PDCP processing unit 24 detect, for each logical channel, a packet having a packet length shorter than a predetermined threshold transmitted on the downstream logical channel. In the following description and the accompanying drawings, a packet having a packet length shorter than a predetermined threshold is denoted as “small packet”.

For example, the MAC processing unit 22, the RLC processing unit 23, and the PDCP processing unit 24 identify the logical channel of each packet based on QoS (Quality of Service) class information and Attribute information included in the packet. Small packets may be detected. Further, the identifier of each logical channel may be added to the packet. The MAC processing unit 22, the RLC processing unit 23, and the PDCP processing unit 24 may identify a logical channel based on the identifier of each logical channel added to the packet and detect a small packet for each logical channel.

Note that one or two of the MAC processing unit 22, the RLC processing unit 23, and the PDCP processing unit 24 may detect a small packet, and all of the MAC processing unit 22, the RLC processing unit 23, and the PDCP processing unit 24 Small packets may be detected.

When an application that provides a plurality of different services operates on the mobile station 10, data used in the plurality of different services is transmitted on different logical channels. The service provided by the application may be, for example, an e-mail, a network game, or a packet phone service. For example, the MAC processing unit 22, the RLC processing unit 23, and the PDCP processing unit 24 may detect small packets transmitted by a plurality of different services for each service. In the following description, it is assumed that data transmitted between the mobile station 10 and the second network 3 is data used in the services S1 and S2.

When transmission of a small packet occurs, the MAC processing unit 22, RLC processing unit 23, and PDCP processing unit 24 notify the HO control unit 28 that a small packet has occurred. Upon receiving this notification, the HO control unit 28 determines to perform HO of the mobile station 10 that receives the small packet. The HO control unit 28 requests the line control unit 25 to perform HO of the mobile station 10.

The line control unit 25 that has received the HO implementation request requests the mobile station 10 to measure the radio line quality between the other base stations 8 and 9 in the vicinity. For example, the line control unit 25 requests the line control signal creation unit 26 to create a quality measurement request for causing the mobile station 10 to measure the radio channel quality. The line control signal creation unit 26 creates a quality measurement request and outputs it to the transmission unit 20. The transmission unit 20 transmits a quality measurement request to the mobile station 10.

The mobile station 10 measures the radio channel quality between the base stations 8 and 9 in response to the quality measurement request, and transmits the channel quality information indicating the measurement result of the radio channel quality to the base station 7. The line control signal extraction unit 27 extracts line quality information from the reception signal decoded by the reception unit 21 and outputs the line quality information to the line control unit 25 and the HO control unit 28.

The HO control unit 28 selects the target base station that is the destination of the HO from the other base stations 8 and 9 around the mobile station 10. For example, the HO control unit 28 may select the target base station based on the radio channel quality between the base stations 8 and 9 and the mobile station 10. For example, the HO control unit 28 may select a base station having the best radio channel quality with the mobile station 10.

The HO control unit 28 gives priority to the base station 9 connected to the third network 4 different from the first network 2 over the base station 8 connected to the first network 2 to which the base station 7 is connected. You may choose. In order to select the base station 9 with priority over the base station 8, for example, the HO control unit 28 may add a predetermined added value to the radio channel quality of the base station 9. In the following description, it is assumed that the base station 9 is selected as the target base station.

The line control unit 25 acquires line setting information from the base station 9. The line setting information is setting information used for wireless connection between the mobile station 10 and the base station 9. The channel setting information may include, for example, information for determining a preamble necessary for a random access procedure between the mobile station 10 and the base station 9 and information on the frequency band of the cell of the base station 9.

The line control unit 25 transmits a line setting information request for requesting transmission of line setting information from the base station 9 to the base station 9. The line control unit 25 may transmit a line setting information request via the upper devices such as the GWs 5 and 6 and the second network 3. The line control unit 25 may transmit a line setting information request via the inter-base station interface between the base station 7 and the base station 9.

The base station 9 transmits the line setting information to the base station 7 in response to the line setting information request. The line control unit 25 notifies the mobile station 10 of information specifying the target base station 9 and a HO instruction to the target base station 9. For example, the line control unit 25 requests the line control signal creation unit 26 to create a target base station notification and HO request for notifying the mobile station 10 of information specifying the target base station 9. The line control signal creation unit 26 creates a target base station notification and a HO request and outputs them to the transmission unit 20. The transmission unit 20 transmits the target base station notification and the HO request to the mobile station 10.

The line control unit 25 notifies the mobile station 10 of line setting information. For example, the line control unit 25 outputs the line setting information to the line control signal creation unit 26. The line control signal creation unit 26 generates a control signal including line setting information and outputs the control signal to the transmission unit 20. The transmission unit 20 transmits a control signal including line setting information to the mobile station 10.

Note that the HO control unit 28 may be omitted, and the base station 7 may be modified so that the line control unit 25 executes the above-described operation of the HO control unit 28.

FIG. 3 is an explanatory diagram of a functional configuration of the PDCP processing unit 24. The PDCP processing unit 24 includes a PDCP control unit 30, a compression unit 31, an encryption unit 32, a division / connection unit 33, and a header addition unit 34. The PDCP processing unit 24 includes a header removing unit 35, a reassembling unit 36, a decoding unit 37, an expansion unit 38, and a reordering unit 39. The PDCP processing unit 24 includes a packet length detection unit 40, a small packet determination unit 41, and a threshold storage unit 42.

The PDCP control unit 30 controls the PDCP layer processing by the PDCP processing unit 24. The compression unit 31 compresses the header portion of the downlink data packet received from the host device of the base station 7. The encryption unit 32 encrypts the downstream data packet. The division / concatenation unit 33 generates a packet having a predetermined length L0 by dividing or concatenating the packets. The header addition unit 34 adds a header including a control signal and a sequence number to the packet generated by the division / concatenation unit 33 to generate a PDCP PDU (Packet Data Unit). The header adding unit 34 outputs the PDCP PDU to the RLC processing unit 23. Data for services S1 and S2 are stored in different PDCP PDUs. Note that the sequence number of the header may be omitted.

The header removal unit 35 receives the RLC SDU (Service Data Unit) of the uplink data output from the RLC processing unit 23 as a PDCP PDU. The header removing unit 35 removes the header from the PDCP PDU. The reassembling unit 36 combines the packets from which the header has been removed to assemble an encrypted packet. The decryption unit 37 decrypts the encrypted packet and converts it into a plaintext packet. The decompression unit 38 returns the compressed header included in the plaintext packet to the original header. The reordering unit 39 rearranges the order of the plaintext packets and outputs them as PDCU SDUs to the host device.

The packet length detection unit 40 detects the packet length of the packet before being divided or connected by the dividing / concatenating unit 33. The small packet determination unit 41 determines, for each logical channel, whether the packet transmitted on the logical channel is a small packet based on the detected packet length.

For example, the small packet determination unit 41 compares each packet length of a packet transmitted on the logical channel with the threshold value Lth0 stored in the threshold value storage unit 42. The small packet determination unit 41 may determine that a small packet has been detected on the logical channel when even one packet having a packet length shorter than Lth0 is detected. The threshold value Lth0 may be an upper limit of the packet length of a packet that is not subjected to the division process by the division / concatenation unit 33, for example. For example, the threshold value Lth0 may be the packet length L0 of the packet generated by the dividing / concatenating unit 33.

FIG. 4 is an explanatory diagram of a first example of small packet detection operation. In operation AA, the small packet determination unit 41 initializes the value of the variable n for counting the number of packet length determinations to “0”. In operation AB, the small packet determination unit 41 determines whether or not the value of the variable n is equal to or greater than the upper limit N. The operation ends when the value of the variable n is equal to or greater than the upper limit N (operation AB: Y). If the value of the variable n is not greater than or equal to the upper limit N (operation AB: N), the operation proceeds to operation AC.

In operation AC, the small packet determination unit 41 determines whether or not the packet length Lpn detected by the packet length detection unit 40 is equal to or greater than the threshold value Lth0. When the packet length Lpn is greater than or equal to the threshold Lth0 (operation AC: Y), the operation proceeds to operation AD. If the packet length Lpn is not greater than or equal to the threshold value Lth0 (operation AC: N), the operation proceeds to operation AE.

In operation AD, the small packet determination unit 41 increases the value of the variable n by one. Thereafter, the operation returns to operation AB. In operation AE, the small packet determination unit 41 determines that a small packet has been detected. Thereafter, the operation ends.

Further, for example, the small packet determination unit 41 may detect the occurrence frequency of a packet having a packet length shorter than Lth0 and determine that the small packet is detected according to the occurrence frequency. For example, the small packet determination unit 41 may determine that a small packet has been detected when the number of packets shorter than Lth0 included in a predetermined number of packets is equal to or greater than a threshold value. The small packet determination unit 41 may determine that a small packet has been detected when the proportion of packets shorter than Lth0 in a predetermined number of packets is equal to or greater than a threshold value.

FIG. 5 is an explanatory diagram of a second example of the small packet detection operation. In operation BA, the small packet determination unit 41 sets the value of the variable n for counting the number of packet length determinations and the value of the variable k for counting the number of detections of packets having a packet length shorter than Lth0 to “0”. Initialize to.

In operation BB, it is determined whether or not the value of the variable n is greater than or equal to the upper limit N. The operation ends when the value of the variable n is equal to or greater than the upper limit N (operation BB: Y). If the value of the variable n is not greater than or equal to the upper limit N (operation BB: N), the operation proceeds to operation BC.

In operation BC, the small packet determination unit 41 determines whether or not the packet length Lpn detected by the packet length detection unit 40 is greater than or equal to the threshold Lth0. When the packet length Lpn is greater than or equal to the threshold value Lth0 (operation BC: Y), the operation proceeds to operation BE. If the packet length Lpn is not greater than or equal to the threshold value Lth0 (operation AC: N), the operation proceeds to operation BD. In operation BD, the small packet determination unit 41 increases the value of the variable k by one. Thereafter, the operation proceeds to operation BE.

In operation BE, it is determined whether or not the value of the variable k is greater than the threshold value kth. When the value of the variable k is larger than the threshold value kth (operation BE: Y), the operation proceeds to operation BG. When the value of the variable k is not larger than the threshold value kth (operation BE: N), the operation proceeds to operation BF.

In operation BF, the small packet determination unit 41 increases the value of the variable n by one. Thereafter, the operation returns to operation BB. In operation BG, the small packet determination unit 41 determines that a small packet has been detected. Thereafter, the operation ends.

For example, the small packet determination unit 41 may determine that a small packet has been detected when the number of packets shorter than Lth0 included in the packets detected within a certain period is equal to or greater than a threshold value. The small packet determination unit 41 may determine that a small packet has been detected when the proportion of packets shorter than Lth0 in the packets detected within a certain period is equal to or greater than a threshold value. When transmission of a small packet occurs, the small packet determination unit 41 notifies the HO control unit 28 that a small packet has occurred.

FIG. 6 is an explanatory diagram of a functional configuration of the RLC processing unit 23. The RLC processing unit 23 includes an RLC control unit 50, a division / connection unit 51, a header addition unit 52, a reordering unit 53, a header removal unit 54, and a reassembly unit 55. The RLC processing unit 23 includes a packet length detection unit 56, a small packet determination unit 57, and a threshold storage unit 58.

The RLC control unit 50 controls the RLC layer processing by the RLC processing unit 23. The division / concatenation unit 51 receives the downlink data PDCP PDU output from the PDCP processing unit 24 as an RLC SDU. The division / concatenation unit 51 generates a packet having a predetermined length L1 by dividing or concatenating the received RLC SDU. The header adding unit 52 adds a header including a control signal and a sequence number to the packet generated by the dividing / concatenating unit 51 to generate an RLC PDU. The header adding unit 52 outputs the RLC PDU to the MAC processing unit 22. Data for services S1 and S2 are stored in different RLC PDUs. Note that the sequence number of the header may be omitted.

The reordering unit 53 receives the MAC SDU of the uplink data output from the MAC processing unit 22 as an RLC PDU. The reordering unit 53 rearranges the order of the RLC PDUs and inputs them to the header removal unit 54. The header removing unit 54 removes the header from the RLC PDU. The reassembling unit 55 combines the packets from which the header has been removed to assemble a PDCP PDU. The reassembling unit 55 outputs the PDCP PDU to the PDCP processing unit 24.

The packet length detection unit 56 detects the packet length of the packet before being divided or connected by the division / concatenation unit 51. The small packet determination unit 57 determines, for each logical channel, whether the packet transmitted on the logical channel is a small packet based on the detected packet length.

For example, the small packet determination unit 57 compares each packet length of the packet transmitted on the logical channel with the threshold value Lth1 stored in the threshold value storage unit 58. The small packet determination unit 57 may determine that a small packet has been detected on the logical channel when even one packet having a packet length shorter than Lth1 is detected. For example, the small packet determination unit 57 may detect the occurrence frequency of a packet having a packet length shorter than Lth1 and determine that the small packet is detected according to the occurrence frequency.

The threshold value Lth1 may be the upper limit of the packet length of a packet that is not subjected to the division process by the division / concatenation unit 51, for example. For example, the threshold value Lth1 may be the packet length L1. When transmission of a small packet occurs, the small packet determination unit 57 notifies the HO control unit 28 that a small packet has occurred.

FIG. 7 is an explanatory diagram of the functional configuration of the MAC processing unit 22. The MAC processing unit 22 includes a MAC control unit 60, a multiplexing unit 61, a retransmission control unit 62, a radio channel setting control unit 63, and a demultiplexing unit 64. The MAC processing unit 22 includes a packet length detection unit 65, a small packet determination unit 66, and a threshold storage unit 67.

The MAC control unit 60 controls the MAC layer processing by the MAC processing unit 22. The multiplexing unit 61 receives the RLC PDU of the downlink data output from the RLC processing unit 23 as a MAC SDU. The multiplexing unit 61 multiplexes control data and user data transmitted through different logical channels. For example, the data of service S1 and service S2 are multiplexed. The multiplexing unit 61 further generates a packet having a predetermined length L2 by dividing or concatenating data.

The retransmission control unit 62 adds a header including a control signal and a sequence number to the packet generated by the multiplexing unit 61 to generate a MAC PDU. The retransmission control unit 62 temporarily stores the MAC PDU. Note that the sequence number of the header may be omitted.

The radio channel setting control unit 63 creates a control signal for setting a radio channel between the base station 7 and the mobile station 10. The MAC control signal may be added to the MAC PDU as a header. As an example of the wireless line setting, the wireless line setting control unit 63 executes a random access procedure. After the above processing is performed, the MAC PDU is output from the MAC processing unit 22 to the transmission unit 20.

The retransmission control unit 62 receives the error determination result of the uplink data reception signal from the reception unit 21. When there is no error in the received signal, the retransmission control unit 62 outputs an acknowledgment (ACK: ACKnowledge) to the transmission unit 20. When there is an error in the received signal, the retransmission control unit 62 outputs a negative response (NACK: Negative ACKnowledge) to the transmission unit 20.

The demultiplexing unit 64 disassembles the MAC PDU that is the packet received by the receiving unit 21 into logical packets and distributes the data to each service. The demultiplexer 64 assembles the MAC SDU by concatenating the decomposed data for each logical packet. The demultiplexer 64 outputs the MAC SDU to the RLC processor 23.

The packet length detector 65 detects the packet length of the packet before being multiplexed by the multiplexer 61. The small packet determination unit 66 determines, for each logical channel, whether or not the packet transmitted through the logical channel is a small packet based on the detected packet length.

For example, the small packet determination unit 66 compares each packet length of the packet transmitted on the logical channel with the threshold value Lth2 stored in the threshold value storage unit 67. The small packet determination unit 66 may determine that a small packet has been detected on the logical channel when even one packet having a packet length shorter than Lth2 is detected. For example, the small packet determination unit 66 may detect the occurrence frequency of a packet having a packet length shorter than Lth2 and determine that the small packet is detected according to the occurrence frequency.

The threshold value Lth2 may be an upper limit of the packet length of a packet that is not subjected to the division process by the multiplexing unit 61, for example. For example, the threshold value Lth2 may be the packet length L2. When transmission of a small packet occurs, the small packet determination unit 66 notifies the HO control unit 28 that a small packet has occurred.

When the MAC processing unit 22 does not detect a small packet, the packet length detection unit 65, the small packet determination unit 66, and the threshold storage unit 67 may be omitted. When the RLC processing unit 23 does not detect a small packet, the packet length detection unit 56, the small packet determination unit 57, and the threshold storage unit 58 may be omitted. When the PDCP processing unit 24 does not detect a small packet, the packet length detection unit 40, the small packet determination unit 41, and the threshold storage unit 42 may be omitted.

Further, as the threshold values Lth0, Lth1, and Lth2 to be compared with the detected packet length, the shortest value among the predetermined values L0 to L2 may be used, or a value unrelated to the predetermined values L0 to L2 is used. Also good.

FIG. 8 is an explanatory diagram of a first example of the functional configuration of the mobile station 10. The mobile station 10 includes a receiving unit 70, a transmitting unit 71, a MAC processing unit 72, an RLC processing unit 73, a PDCP processing unit 74, and an application processing unit 75. The mobile station 10 includes a line control signal extraction unit 76, a line control unit 77, a line control signal creation unit 79, and a quality measurement unit 78.

The receiving unit 70 receives a downlink signal transmitted from the base station 7 via an antenna. The receiving unit 70 amplifies the received signal and converts the amplified received signal into an analog baseband signal. The receiving unit 70 performs processing for converting an analog baseband signal into a digital baseband signal, demodulation processing, and decoding processing.

The transmission unit 71 encodes and modulates the uplink signal transmitted to the base station 7, and maps the modulated signal to the channel. The transmission unit 71 converts the signal of each channel into an analog signal, and converts the converted analog signal into a radio frequency signal. The transmission unit 71 amplifies the radio frequency signal and transmits the amplified signal to the base station 7 via the antenna.

The MAC processing unit 72 performs MAC layer processing of the upstream signal transmitted to the base station 7 and the downstream signal received from the base station 7. The RLC processing unit 73 performs RLC layer processing of the uplink signal transmitted to the base station 7 and the downlink signal received from the base station 7.

The PDCP processing unit 74 performs PDCP layer processing of uplink data transmitted to the base station 7 and downlink signals received from the base station 7. The application processing unit 75 performs information processing in the application layer for providing the service S1 and the service S2 to the user.

The line control signal extraction unit 76 extracts a quality measurement request from the reception signal decoded by the reception unit 70 and outputs the quality measurement request to the line control unit 77. The line control unit 77 that has received the quality measurement request causes the receiving unit 70 and the quality measurement unit 78 to measure the radio channel quality between the base stations 8 and 9. The quality measuring unit 78 measures, for example, SIR (Signal-to-Noise-Ratio), SNR (Signal-to-Noise-Ratio), RSRP (Reference-Signal-Received-Power), RSRQ (Reference-Signal-Received-Quality)) as the radio channel quality. The quality measurement unit 78 outputs the measurement result to the line control unit 77.

The line control unit 77 converts the measurement results into discrete values and outputs them to the line control signal creation unit 79. The line control signal generator 79 generates line quality information indicating the measurement result and outputs the line quality information to the transmitter 71. The transmission unit 71 transmits the line quality information to the base station 7.

The line control signal extracting unit 76 extracts the target base station notification, HO request, and line setting information transmitted from the base station 7 from the received signal decoded by the receiving unit 70.

FIG. 9 is an explanatory diagram of a first example of a functional configuration of the MAC processing unit 72. The MAC processing unit 72 includes a MAC control unit 80, a retransmission control unit 81, a demultiplexing unit 82, a multiplexing unit 83, and a radio channel setting control unit 84.

The MAC control unit 80 controls the MAC layer processing by the MAC processing unit 72. The demultiplexer 82 decomposes the MAC PDU, which is a packet received by the receiver 70, into logical packets and distributes the data to each service. The demultiplexer 82 assembles the MAC SDU by concatenating the decomposed data for each logical packet. The demultiplexer 82 outputs the MAC SDU to the RLC processor 73.

The multiplexing unit 83 receives the uplink RLC PDU output from the RLC processing unit 73 as a MAC SDU. The multiplexing unit 83 multiplexes control data and user data transmitted through different logical channels. For example, the data of service S1 and service S2 are multiplexed. The multiplexing unit 83 further generates a packet having a predetermined length L3 by dividing or concatenating data.

The retransmission control unit 81 adds a header including a control signal and a sequence number to the packet generated by the multiplexing unit 83 to generate a MAC PDU. The retransmission control unit 81 temporarily stores the MAC PDU. The retransmission control unit 81 receives the error determination result of the downlink data reception signal from the reception unit 70. When there is no error in the received signal, retransmission control section 81 outputs an acknowledgment (ACK) to transmission section 71. When there is an error in the received signal, retransmission control section 81 outputs a negative response (NACK) to transmission section 71. Note that the sequence number of the header may be omitted.

The radio channel setting control unit 84 executes a random access procedure in the frequency band of the cell of the base station 9 specified by the channel setting information using the preamble determined by using the channel setting information received from the base station 7, and the mobile station 10 and a base station 9 are established. For example, the wireless channel setting control unit 84 may execute a non-contention based random access procedure. Thereafter, the line control unit 77 shown in FIG. 8 performs HO for changing the connection destination of the mobile station 10 to the base station 9.

FIG. 10 is an explanatory diagram of a first example of a functional configuration of the RLC processing unit 73. The RLC processing unit 73 includes an RLC control unit 90, a reordering unit 91, a header removal unit 92, a reassembly unit 93, a division / connection unit 94, and a header addition unit 95.

The RLC control unit 90 controls processing of the RLC layer by the RLC processing unit 73. The reordering unit 91 receives the MAC SDU of the downlink data output from the MAC processing unit 72 as an RLC PDU. The reordering unit 91 rearranges the order of the RLC PDUs and inputs them to the header removal unit 92. The header removal unit 92 removes the header from the RLC PDU. The reassembling unit 93 combines the packets from which the header is removed to assemble a PDCP PDU. The reassembling unit 593 outputs the PDCP PDU to the PDCP processing unit 74.

The division / concatenation unit 94 receives the uplink CPPD PDU output from the PDCP processing unit 74 as an RLC SDU. The division / concatenation unit 94 generates a packet having a predetermined length L4 by dividing or concatenating the received RLC SDU. The header adding unit 95 adds a header including a control signal and a sequence number to the packet generated by the dividing / concatenating unit 94 to generate an RLC PDU. The header adding unit 95 outputs the RLC PDU to the MAC processing unit 72. Data for services S1 and S2 are stored in different RLC PDUs. Note that the sequence number of the header may be omitted.

FIG. 11 is an explanatory diagram of a first example of a functional configuration of the PDCP processing unit 74. The PDCP processing unit 74 includes a PDCP control unit 100, a header removal unit 101, a reassembly unit 102, a decoding unit 103, an expansion unit 104, and a reordering unit 105. The PDCP processing unit 74 includes a compression unit 106, an encryption unit 107, a division / concatenation unit 108, and a header addition unit 109.

The PDCP control unit 100 controls the PDCP layer processing by the PDCP processing unit 74. The header removing unit 101 receives the RLC SDU of the downlink data output from the RLC processing unit 73 as a PDCP PDU. The header removal unit 101 removes the header from the PDCP PDU. The reassembling unit 102 combines the packets from which the header has been removed to assemble an encrypted packet. The decryption unit 103 decrypts the encrypted packet and converts it into a plaintext packet. The decompressing unit 104 returns the compressed header included in the plaintext packet to the original header. The reordering unit 105 rearranges the order of the plaintext packets and outputs them to the application processing unit 75 as PDCU SDUs.

The compression unit 106 compresses the header portion of the uplink data packet output from the application processing unit 75. The encryption unit 107 encrypts the uplink data packet. The division / concatenation unit 108 generates a packet having a predetermined length L5 by dividing or concatenating the packets. The header adding unit 109 generates a PDCP PDU by adding a header including a control signal and a sequence number to the packet generated by the dividing / concatenating unit 108. The header adding unit 109 outputs the PDCP PDU to the RLC processing unit 73. Data for services S1 and S2 are stored in different PDCP PDUs. Note that the sequence number of the header may be omitted.

FIG. 12 is an explanatory diagram of the functional configuration of the base station 9. The base station 9 includes a transmission unit 120, a reception unit 121, a MAC processing unit 122, an RLC processing unit 123, and a PDCP processing unit 124. The base station 9 includes a line control unit 125, a line control signal creation unit 126, and a line control signal extraction unit 127.

The transmission unit 120 encodes and modulates a downlink signal transmitted to the mobile station 10 and maps the modulated signal to a channel. The transmission unit 120 converts the signal of each channel into an analog signal, and converts the converted analog signal into a radio frequency signal. The transmission unit 120 amplifies the radio frequency signal and transmits the amplified signal to the mobile station 10 via the antenna.

The receiving unit 121 receives an uplink signal transmitted from the mobile station 10 via an antenna. The receiving unit 121 amplifies the received signal and converts the amplified received signal into an analog baseband signal. The receiving unit 121 performs processing for converting an analog baseband signal into a digital baseband signal, demodulation processing, and decoding processing.

The PDCP processing unit 124 performs PDCP layer processing of the downlink signal transmitted to the mobile station 10 and the uplink signal received from the mobile station 10. FIG. 13 is an explanatory diagram of a functional configuration of the PDCP processing unit 124 of the base station 9. The PDCP processing unit 124 includes a PDCP control unit 130, a compression unit 131, an encryption unit 132, a division / concatenation unit 133, and a header addition unit 134. The PDCP processing unit 124 includes a header removing unit 135, a reassembling unit 136, a decoding unit 137, an expansion unit 138, and a reordering unit 139.

The functions of the PDCP control unit 130, the compression unit 131, the encryption unit 132, the division / concatenation unit 133, and the header addition unit 134 are the same as the PDCP control unit 30, the compression unit 31, the encryption unit 32, and the division / concatenation shown in FIG. The functions of the unit 33 and the header adding unit 34 may be the same. The functions of the header removing unit 135, the reassembling unit 136, the decrypting unit 137, the decompressing unit 138, and the reordering unit 139 are the header removing unit 35, the reassembling unit 36, the decrypting unit 37, the decompressing unit 38, and the like shown in FIG. The function of the reordering unit 39 may be the same.

Refer to FIG. The RLC processing unit 123 performs RLC layer processing on the downlink signal transmitted to the mobile station 10 and the uplink signal received from the mobile station 10. FIG. 14 is an explanatory diagram of a functional configuration of the RLC processing unit 123 of the base station 9. The RLC processing unit 123 includes an RLC control unit 150, a division / concatenation unit 151, a header addition unit 152, a reordering unit 153, a header removal unit 154, and a reassembly unit 155.

The functions of the RLC control unit 150, the division / connection unit 151, the header addition unit 152, and the reordering unit 153 are the same as those of the RLC control unit 50, the division / connection unit 51, the header addition unit 52, and the reordering unit 53 shown in FIG. It may be the same as the function. The functions of the header removing unit 154 and the reassembling unit 155 may be the same as the functions of the header removing unit 54 and the reassembling unit 55 shown in FIG.

Refer to FIG. The MAC processing unit 122 performs MAC layer processing of a downlink signal transmitted to the mobile station 10 and an uplink signal received from the mobile station 10. FIG. 15 is an explanatory diagram of a functional configuration of the MAC processing unit 122 of the base station 9. The MAC processing unit 122 includes a MAC control unit 160, a multiplexing unit 161, a retransmission control unit 162, a radio channel setting control unit 163, and a demultiplexing unit 164.

The functions of the MAC control unit 160, multiplexing unit 161, retransmission control unit 162, radio channel setting control unit 163, and demultiplexing unit 164 are the same as those of the MAC control unit 60, multiplexing unit 61, and retransmission control unit 62 shown in FIG. The functions of the radio line setting control unit 63 and the demultiplexing unit 64 may be the same.

Refer to FIG. The line control unit 125 receives the line setting information request transmitted from the base station 7. The line control unit 125 may receive the line setting information request via the higher-level devices such as the GWs 5 and 6 and the second network 3. The line control unit 125 may receive a line setting information request via the inter-base station interface between the base station 7 and the base station 9.

The line control unit 125 transmits the line setting information to the base station 7 in response to the line setting information request. The line control unit 125 may transmit the line setting information via a host device such as the GWs 5 and 6 and the second network 3 or the interface between base stations.

Also, the line control signal creation unit 126 generates a signal for controlling the wireless line between the base station 9 and the mobile station 10 and transmits the signal to the mobile station 10 via the transmission unit 120. The channel control signal extraction unit 127 extracts a signal for controlling the radio channel between the base station 9 and the mobile station 10 from the reception signal decoded by the reception unit 121.

15 receives the preamble transmitted from the mobile station 10, executes a random access procedure, and establishes a wireless line between the mobile station 10 and the base station 9. The line control unit 125 illustrated in FIG. 12 performs HO for changing the connection destination of the mobile station 10 to the base station 9.

FIG. 16 is a sequence diagram for explaining a first example of the operation of the communication system 1. In operation CA, data of services S1 and S2 are transmitted between the base station 7 and the mobile station 10. In operation CB, the base station 7 detects transmission of a small packet in the service S2. Operation CB corresponds to the operation of any of the small packet determination units 41, 57 and 66.

In operation CC, the base station 7 decides to perform HO of the mobile station 10. The operation CC corresponds to the operation of the HO control unit 28. In the operation CD, the base station 7 transmits information on the other base stations 8 and 9 around the base station 7. In operation CE, the base station 7 issues a quality measurement request for causing the mobile station 10 to measure the radio channel quality between the base station 8 and the mobile station 10 and the radio channel quality between the base station 9 and the mobile station 10. Send. Operations CD and CE correspond to the operations of the line control unit 25 and the line control signal creation unit 26.

In operation CF, the mobile station 10 measures the radio channel quality between the base station 8 and the mobile station 10 and the radio channel quality between the base station 9 and the mobile station 10. The operation CF corresponds to the operation of the quality measurement unit 78. In operation CG, the mobile station 10 transmits channel quality information indicating the measurement result of the radio channel quality to the base station 7. Operation CG corresponds to the operations of the line control unit 77 and the line control signal creation unit 79.

In operation CH, the base station 7 selects the base station 9 as the target base station. The operation CH corresponds to the operation of the HO control unit 28. In operation CI, the base station 7 transmits a line setting information request to the base station 9. The operation CI corresponds to the operation of the line control unit 25.

In operation CJ, the base station 9 transmits the line setting information to the base station 7 in response to the line setting information request. Operation CJ corresponds to the operation of the line control unit 125. In operations CK and CL, the base station 7 transmits a target base station notification and line setting information to the mobile station 10. Operations CK and CL correspond to the operations of the line control unit 25 and the line control signal creation unit 26.

In operation CM, the mobile station 10 and the base station 9 establish a wireless channel between the mobile station 10 and the base station 9 by executing a predetermined channel setting procedure, and connect the connection destination of the mobile station 10 to the base station 9. Implement HO to be changed. The operation CM corresponds to the operations of the wireless line setting control units 84 and 163 and the line control units 77 and 125. In operation CN, data transmission of services S1 and S2 starts between the base station 9 and the mobile station 10.

According to the present embodiment, it is possible to switch from the first network 2 to the third network 4 the network that transmits the data of the service S2 that generates a small packet that causes congestion. For this reason, it is possible to reduce the congestion of the first network 2 that is the switching source. By reducing congestion, the transmission rate is improved and the required transmission rate can be satisfied. In addition, it is possible to reduce processing in the network or processing in the devices constituting the network.

In the above embodiment, the MAC processing unit 22, the RLC processing unit 23, and the PDCP processing unit 24 detected the transmission of small packets on the downlink logical channel. Instead of or in addition to this, the base station 7 may be modified such that the MAC processing unit 22, the RLC processing unit 23, and the PDCP processing unit 24 detect small packets in the uplink. The same applies to other examples and modifications described below.

Next, an example of HO that switches the connection destination of the mobile station 10 from the cellular radio network to the non-cellular radio network when a small packet is detected in data communication with the mobile station 10 will be described.

FIG. 17 is an explanatory diagram of a configuration of a modified example of the communication system 1. The base station 7 is a base station of a cellular radio network that operates according to LTE, for example. The third network 4 is, for example, a WiMAX access service network, and the base station 9 is a WiMAX access point. The second network 3 and the third network 4 are connected via the GW 5. When the base station 7 detects a small packet by data communication with the mobile station 10, the base station 7 performs HO to change the connection destination of the mobile station 10 to the base station 9.

FIG. 18 is a sequence diagram of an operation for switching the connection destination of the mobile station 10 from LTE to WiMAX. In operation DA, the data of the services S1 and S2 are transmitted between the GW 5 and the mobile station 10 via the base station 7.

In the operation DB, the base station 7 detects the transmission of a small packet in the service S2. The operation DB corresponds to one of the operations of the small packet determination units 41, 57, and 66. In operation DC, the base station 7 decides to measure the radio quality between the base station 9 and the mobile station 10 which are WiMAX access points. Operation DC corresponds to the operation of the HO control unit 28.

In operation DD, the base station 7 transmits information on the base station 9 to the mobile station 10. In operation DE, the base station 7 transmits to the mobile station 10 a quality measurement request for causing the mobile station 10 to measure the radio channel quality between the base station 9 and the mobile station 10. Operations DD and DE correspond to the operations of the line control unit 25 and the line control signal creation unit 26.

In operation DF, the mobile station 10 measures the radio channel quality between the base station 9 and the mobile station 10. Operation DF corresponds to the operation of the quality measurement unit 78. In operation DG, the mobile station 10 transmits channel quality information indicating the measurement result of the radio channel quality to the base station 7. Operation DG corresponds to the operations of the line control unit 77 and the line control signal creation unit 79.

In operation DH, the base station 7 selects the base station 9 as the HO destination. Operation DH corresponds to the operation of the HO control unit 28. In operation DI, the base station 7 transmits to the mobile station 10 channel setting information of the radio channel for HO to the base station 9. An example of transmission of the line setting information may be transmission of an “RRC CONNECTION RECONFIGURATION” message that is a wireless line reconfiguration message. The operation DI corresponds to the operations of the line control unit 25 and the line control signal creation unit 26. In operation DJ, the base station 7 transmits “HANDOVER COMMAND” instructing HO to switch the mobile station 10 to the base station 9. Operation DJ corresponds to the operations of the line control unit 25 and the line control signal creation unit 26.

The mobile station that has received “HANDOVER COMMAND” starts HO from LTE to WiMAX. In operation DK, the mobile station 10 transmits “HANDOVER REQ” requesting HO to the base station 9 to the base station 9. In operation DL, the base station 9 determines HO by the mobile station 10 and reserves a radio resource for a radio channel between the mobile station 10 and the base station 9. In operation DM, the base station 9 notifies the mobile station 10 of a response message “HANDOVER RSP” to “HANDOVER REQ”.

In operation DN, the mobile station 10 transmits a “HANDOVER IND” message notifying that the mobile station 10 performs HO to the base station 9 to the base station 9. In operation DO, the mobile station 10 switches the radio access used for communication with the second network 3 from LTE to WiMAX.

In operation DP, the mobile station 10 accesses the base station 9 by an access procedure unique to WiMAX. In operation DQ, the setting of the GW 5 is changed, and a path between the GW 5 and the mobile station 10 is newly set. In operation DR, data of services S1 and S2 are transmitted through the base station 9 between the base station 9 and the mobile station 10.

According to the modification, when a small packet is detected in the data communication of the mobile station 10 that communicates via the cellular wireless network, the connection destination of the mobile station 10 can be switched to the non-cellular wireless network. it can. For this reason, the congestion which generate | occur | produces in a cellular radio | wireless network can be reduced. By reducing congestion, the transmission rate is improved and the required transmission rate can be satisfied. In addition, it is possible to reduce the processing in the cellular radio network or the processing in the devices constituting the network.

The present modification has been described on the assumption that the base station 9 operates according to WiMAX. However, the base station 9 may make another non-cellular wireless network (for example, wireless LAN) after making necessary design changes. The present invention can also be applied to a form that is an access point. Similarly, in the following other embodiments and modifications, the connection destination of the mobile station 10 may be switched from the cellular radio network to the non-cellular radio network.

<3. Second Embodiment>
Please refer to FIG. The MAC processing unit 72, the RLC processing unit 73, and the PDCP processing unit 74 of the mobile station 10 detect transmission of small packets on the uplink logical channel for each logical channel. Any one or two of the MAC processing unit 72, the RLC processing unit 73, and the PDCP processing unit 74 may detect a small packet, and all of the MAC processing unit 72, the RLC processing unit 73, and the PDCP processing unit 74 are small packets. May be detected. When transmission of a small packet occurs, the MAC processing unit 72, the RLC processing unit 73, and the PDCP processing unit 74 notify the line control unit 77 that a small packet has occurred.

FIG. 19 is an explanatory diagram of a second example of the functional configuration of the MAC processing unit 72 of the mobile station 10. Components similar to those shown in FIG. 9 are denoted by the same reference symbols as those used in FIG. The MAC processing unit 72 includes a packet length detection unit 85, a small packet determination unit 86, and a threshold storage unit 87.

The packet length detection unit 85 detects the packet length of the packet before being multiplexed by the multiplexing unit 83. The small packet determining unit 86 determines, for each logical channel, whether or not the packet transmitted on the logical channel is a small packet based on the detected packet length.

For example, the small packet determination unit 86 compares each packet length of the packet transmitted through the logical channel with the threshold value Lth3 stored in the threshold value storage unit 87. The small packet determination unit 86 may determine that a small packet has been detected on the logical channel when even one packet having a packet length shorter than Lth3 is detected. For example, the small packet determining unit 86 may detect the occurrence frequency of a packet having a packet length shorter than Lth3 and determine that the small packet is detected according to the occurrence frequency.

The threshold value Lth3 may be an upper limit of the packet length of a packet that is not subjected to the division process by the multiplexing unit 83, for example. For example, the threshold value Lth3 may be the packet length L3. When transmission of a small packet occurs, the small packet determination unit 86 notifies the line control unit 77 that a small packet has occurred.

FIG. 20 is an explanatory diagram of a second example of the functional configuration of the RLC processing unit 73 of the mobile station 10. Constituent elements similar to those shown in FIG. 10 are assigned the same reference numerals as those used in FIG. The RLC processing unit 73 includes a packet length detection unit 96, a small packet determination unit 97, and a threshold storage unit 98.

The packet length detection unit 96 detects the packet length of the packet before being divided or connected by the division / concatenation unit 94. The small packet determination unit 97 determines, for each logical channel, whether the packet transmitted on the logical channel is a small packet based on the detected packet length.

For example, the small packet determination unit 97 compares each packet length of the packet transmitted through the logical channel with the threshold value Lth4 stored in the threshold value storage unit 98. The small packet determination unit 97 may determine that a small packet has been detected on the logical channel when even one packet having a packet length shorter than Lth4 is detected. For example, the small packet determination unit 97 may detect the occurrence frequency of a packet having a packet length shorter than Lth4 and determine that a small packet has been detected according to the occurrence frequency.

The threshold value Lth4 may be an upper limit of the packet length of a packet that is not subjected to the division process by the division / concatenation unit 94, for example. For example, the threshold value Lth4 may be the packet length L4. When transmission of a small packet occurs, the small packet determination unit 97 notifies the line control unit 77 that a small packet has occurred.

FIG. 21 is an explanatory diagram of a second example of the functional configuration of the PDCP processing unit 74 of the mobile station 10. Constituent elements similar to those shown in FIG. 11 are denoted by the same reference numerals as those used in FIG. The PDCP processing unit 74 includes a packet length detection unit 110, a small packet determination unit 111, and a threshold storage unit 112.

The packet length detection unit 110 detects the packet length of the packet before being divided or connected by the division / concatenation unit 108. The small packet determination unit 111 determines, for each logical channel, whether a packet transmitted through the logical channel is a small packet based on the detected packet length.

For example, the small packet determination unit 111 compares each packet length of a packet transmitted through the logical channel with the threshold value Lth5 stored in the threshold value storage unit 112. The small packet determination unit 111 may determine that a small packet has been detected on the logical channel when even one packet having a packet length shorter than Lth5 is detected. For example, the small packet determination unit 111 may detect the occurrence frequency of a packet having a packet length shorter than Lth5 and determine that the small packet is detected according to the occurrence frequency.

The threshold value Lth5 may be an upper limit of the packet length of a packet that is not subjected to the division process by the division / concatenation unit 108, for example. For example, the threshold value Lth5 may be the packet length L5. When transmission of a small packet occurs, the small packet determination unit 111 notifies the line control unit 77 that a small packet has occurred.

When the MAC processing unit 72 does not detect a small packet, the packet length detection unit 85, the small packet determination unit 86, and the threshold storage unit 87 may be omitted. When the RLC processing unit 73 does not detect a small packet, the packet length detection unit 96, the small packet determination unit 97, and the threshold storage unit 98 may be omitted. When the PDCP processing unit 74 does not detect a small packet, the packet length detection unit 110, the small packet determination unit 111, and the threshold storage unit 112 may be omitted.

Further, as the threshold values Lth3, Lth4, and Lth5 to be compared with the detected packet length, the shortest value among the predetermined values L3 to L5 may be used, or a value unrelated to the predetermined values L3 to L5 is used. Also good.

Refer to FIG. When the MAC processing unit 72, the RLC processing unit 73, and the PDCP processing unit 74 notify the line control unit 77 of the occurrence of a small packet, the line control unit 77 causes the line control signal generation unit 79 to detect the small packet. Requests creation of a small packet detection notification to be notified. The line control signal creation unit 79 creates a small packet detection notification and outputs it to the transmission unit 20. The transmission unit 20 transmits a small packet detection notification to the base station 7.

Refer to FIG. The line control signal extraction unit 27 extracts the small packet detection notification from the reception signal decoded by the reception unit 21 and outputs the small packet detection notification to the HO control unit 28. Upon receiving this notification, the HO control unit 28 determines to perform HO of the mobile station 10. The HO control unit 28 requests the line control unit 25 to perform HO of the mobile station 10. Subsequent operations are the same as those in the first embodiment.

FIG. 22 is a sequence diagram for explaining a third example of the operation of the communication system 1. In operation EA, data of services S1 and S2 are transmitted between the base station 7 and the mobile station 10. In operation EB, the mobile station 10 detects transmission of a small packet in the service S2. Operation EB corresponds to one of the operations of small packet determination units 86, 97, and 111.

In operation EC, the mobile station 10 transmits a small packet detection notification to the base station 7. Operation EC corresponds to the operations of the line control unit 77 and the line control signal creation unit 79. In operation ED, the base station 7 determines to perform HO of the mobile station 10 in response to the small packet detection notification. Operation ED corresponds to the operation of the HO control unit 28. The operations EE to EO are the same as the operations CD to CN shown in FIG.

According to the present embodiment, it is possible to switch from the first network 2 to the third network 4 the network that transmits the data of the service S2 that generates a small packet that causes congestion. For this reason, it is possible to reduce the congestion of the first network 2 that is the switching source. By reducing congestion, the transmission rate is improved and the required transmission rate can be satisfied. In addition, at least the processing in the first network 2 can be reduced.

According to the present embodiment, the detection process of small packets generated by the service used in the mobile station 10 is distributed to each mobile station 10. For this reason, it is possible to avoid an increase in the load on the base station 7 in order to detect small packets.

In the above embodiment, the MAC processing unit 72, the RLC processing unit 73, and the PDCP processing unit 74 detected the transmission of a small packet on the uplink logical channel. Instead of or in addition to this, the mobile station 10 may be modified such that the MAC processing unit 72, the RLC processing unit 73, and the PDCP processing unit 74 detect small packets on the downlink. The same applies to other examples and modifications described below.

<4. Third Example>
FIG. 23 is an explanatory diagram of a second example of the functional configuration of the mobile station 10. Constituent elements similar to those shown in FIG. 8 are denoted by the same reference numerals as those used in FIG. The mobile station 10 includes a HO control unit 88.

When transmission of a small packet occurs, the small packet determination unit 86 of the MAC processing unit 72, the small packet determination unit 97 of the RLC processing unit 73, and the small packet determination unit 111 of the PDCP processing unit 74 indicate that a small packet has occurred. The HO control unit 88 and the line control unit 77 are notified. The HO control unit 88 and the line control unit 77 request the base station 7 for HO.

For example, the HO control unit 88 determines to perform HO of the mobile station 10. The HO control unit 88 requests the line control unit 77 to perform HO of the mobile station 10. The line control unit 77 that has received the HO implementation request requests the line control signal creation unit 79 to create an HO request for requesting HO. The line control signal creation unit 79 creates a HO request and outputs it to the transmission unit 71. The transmitter 71 transmits a HO request to the base station 7.

Refer to FIG. The line control signal extraction unit 27 extracts a HO request from the reception signal decoded by the reception unit 21 and outputs the HO request to the line control unit 25. The line control unit 25 that has received the HO request determines whether to approve the mobile station 10 to perform HO in accordance with a predetermined condition. When approving the implementation of HO, the channel control unit 25 measures the radio channel quality between the mobile station 10 and other base stations 8 and 9 in the same manner as in the first embodiment. Request. Subsequent operations are the same as those in the first embodiment.

FIG. 24 is a sequence diagram for explaining a fourth example of the operation of the communication system 1. In operation FA, data of services S1 and S2 are transmitted between the base station 7 and the mobile station 10. In operation FB, the mobile station 10 detects transmission of a small packet in the service S2. Operation EB corresponds to one of the operations of small packet determination units 86, 97, and 111.

In operation FC, the mobile station 10 determines to perform HO of the mobile station 10. Operation FC corresponds to the operation of the HO control unit 88. In operation FD, the mobile station 10 transmits a HO request to the base station 7. Operation FD corresponds to the operations of the line control unit 77 and the line control signal creation unit 79. In operation FE, the base station 7 authorizes the mobile station 10 to perform HO. The operations FF to FP are the same as the operations CD to CN shown in FIG.

According to the present embodiment, it is possible to switch from the first network 2 to the third network 4 the network that transmits the data of the service S2 that generates a small packet that causes congestion. For this reason, it is possible to reduce the congestion of the first network 2 that is the switching source. By reducing congestion, the transmission rate is improved and the required transmission rate can be satisfied. In addition, at least the processing in the first network 2 can be reduced.

According to the present embodiment, the small packet detection process and the HO execution determination process that occur in the service used by the mobile station 10 are distributed to each mobile station 10. For this reason, the load of the base station 7 for detecting small packets and determining whether to perform HO is reduced.

<5. Fourth Embodiment>
In this embodiment, the mobile station 10 that has detected the small packet selects the target base station and notifies the base station 7 of it. The line control signal extraction unit 76 extracts information on the other base stations 8 and 9 around the base station 7 from the reception signal decoded by the reception unit 70.

The information of the base stations 8 and 9 may include identification information of the base stations 8 and 9, for example. Moreover, the information of the base station 8 may include information for identifying that the first network 2 to which the base station 8 is connected and the first network 2 to which the base station 7 is connected are the same network, for example. The information on the base station 9 may include, for example, information for identifying that the third network 4 connected to the base station 9 and the first network 2 connected to the base station 7 are different networks. The line control signal extraction unit 76 outputs information on the other base stations 8 and 9 to the line control unit 77.

The line control unit 77 that has received the HO implementation request causes the reception unit 70 and the quality measurement unit 78 to measure the radio channel quality with the base stations 8 and 9. The quality measuring unit 78 measures the radio channel quality and outputs the measurement result to the HO control unit 88.

The HO control unit 88 selects the target base station that is the destination of the HO from the other base stations 8 and 9 around the mobile station 10. For example, the HO control unit 88 may select the target base station based on the radio channel quality between the base stations 8 and 9 and the mobile station 10. For example, the HO control unit 88 uses the base station 9 connected to the third network 4 different from the first network 2 rather than the base station 8 connected to the first network 2 to which the base station 7 is connected. You may choose preferentially.

The HO control unit 88 notifies the line control unit 77 of information on the base station 9 selected as the target base station. The line control unit 77 outputs information on the base station 9 to the line control signal creation unit 79. The line control signal creation unit 79 creates a HO execution request designating the target base station 9 as a wireless line control request, and transmits the request to the base station 7 via the transmission unit 71.

Refer to FIG. The line control signal extraction unit 27 extracts a radio line control request from the reception signal decoded by the reception unit 21 and outputs the radio line control request to the line control unit 25. The line control unit 25 determines whether to approve the mobile station 10 to perform HO according to a predetermined condition.

The line control unit 25 acquires line setting information from the base station 9 and transmits it to the mobile station 10 in the same manner as in the first embodiment when approving the implementation of HO. Subsequent operations are the same as those in the first embodiment.

FIG. 25 is a sequence diagram for explaining a fifth example of the operation of the communication system 1. In operation GA, the base station 7 transmits information of other base stations 8 and 9 around the base station 7 to the mobile station 10. Operation GA corresponds to the operation of the line control unit 25. In operation GB, data of services S1 and S2 are transmitted between the base station 7 and the mobile station 10.

In operation GC, the mobile station 10 detects transmission of a small packet in the service S2. The operation GC corresponds to one of the operations of the small packet determination units 86, 97, and 111. In operation GD, the mobile station 10 determines to perform HO of the mobile station 10. Operation GD corresponds to the operation of the HO control unit 88.

In operation GE, the mobile station 10 measures the radio channel quality between the base station 8 and the mobile station 10 and the radio channel quality between the base station 9 and the mobile station 10. Operation GE corresponds to the operation of the quality measurement unit 78. In operation GF, the mobile station 10 transmits channel quality information indicating the measurement result of the radio channel quality to the base station 7. Operation GF corresponds to the operations of the line control unit 77 and the line control signal creation unit 79.

In operation GG, the mobile station 10 selects the base station 9 as the target base station. Operation GG corresponds to the operation of the HO control unit 88. In operation GH, the mobile station 10 transmits a radio channel control request to the base station 7. Operation GH corresponds to the operation of the line control signal creation unit 79.

In operation GI, the base station 7 determines to approve the HO implementation of the mobile station 10 according to a predetermined condition. The operations GJ and GK are the same as the operations CI and CJ shown in FIG. The operations GL to GN are the same as the operations CL to CN shown in FIG.

According to the present embodiment, it is possible to switch from the first network 2 to the third network 4 the network that transmits the data of the service S2 that generates a small packet that causes congestion. For this reason, it is possible to reduce the congestion of the first network 2 that is the switching source. By reducing congestion, the transmission rate is improved and the required transmission rate can be satisfied. In addition, at least the processing in the first network 2 can be reduced.

According to the present embodiment, the detection process of small packets generated in the service used in the mobile station 10, the HO execution determination process, and the target base station selection process are distributed to each mobile station 10. For this reason, the load of the base station 7 for these processes is reduced.

<6. Fifth embodiment>
FIG. 26 is an explanatory diagram of a third example of the functional configuration of the base station 7. Constituent elements similar to those shown in FIG. 2 are assigned the same reference numerals as those used in FIG. The base station 7 includes a line addition processing unit 180.

When a small packet occurs, the small packet determination unit 66 of the MAC processing unit 22, the small packet determination unit 57 of the RLC processing unit 23, and the small packet determination unit 41 of the PDCP processing unit 24 indicate that a small packet has occurred in the service S2. To the line addition processing unit 180 and the line control unit 25. The line addition processing unit 180 determines to add a new wireless line that transmits the service S2. The line addition processing unit 180 requests the line control unit 25 to add a new wireless line.

In order to add a new wireless line for transmitting the data of the service S2, the line control unit 25 is connected to the mobile station 10 between the other base stations 8 and 9 in the same manner as in the first embodiment. Request to measure radio link quality. The line control signal extraction unit 27 extracts line quality information from the reception signal decoded by the reception unit 21, and outputs the line quality information to the line control unit 25 and the line addition processing unit 180.

The line addition processing unit 180 selects a base station connected to the mobile station 10 through a new wireless line from the base stations 8 and 9 around the mobile station 10. Hereinafter, a base station newly connected via a wireless line is referred to as an “additional base station”.

The line addition processing unit 180 may select an additional base station based on the radio line quality between the base stations 8 and 9 and the mobile station 10, for example. For example, the line addition processing unit 180 may select an additional base station having the best radio channel quality with the mobile station 10. The line addition processing unit 180 gives priority to the base station 9 connected to the third network 4 different from the first network 2 over the base station 8 connected to the first network 2 to which the base station 7 is connected. May be selected.

When the base station 8 or 9 has a plurality of unit communication bands, the line addition processing unit 180 may select a unit communication band to be used for a new wireless line. An example of the unit communication band may be a carrier component (CC: Carrier Component) used in LTE-Advanced standardized by 3GPP.

For example, the line addition processing unit 180 may select a unit communication band to be used based on the radio line quality for each unit communication band between the base stations 8 and 9 and the mobile station 10. For example, the line addition processing unit 180 may select a unit communication band with the best wireless line quality. The line addition processing unit 180 has a base connected to a third network 4 different from the first network 2 than the unit communication band of the base station 8 connected to the first network 2 to which the base station 7 is connected. The unit communication band of the station 9 may be preferentially selected. In the following description, it is assumed that the base station 9 is selected as the additional base station.

The line control unit 25 acquires line setting information from the base station 9 as in the first embodiment. The line control unit 25 gives information for specifying the additional base station 9, information for identifying the logical channel for transmitting the data of the service S1, and an instruction to add a new radio line with the additional base station 9 to the mobile station 10 is notified. For example, the line control unit 25 sends information for designating the additional base station 9, information for identifying the logical channel for transmitting the data of the service S2, and a new radio line to the line control signal creation unit 26. Requests creation of a radio link addition notification containing instructions to add. The line control signal creation unit 26 creates a wireless line addition notification and outputs it to the transmission unit 20. The transmission unit 20 transmits a wireless line addition notification to the mobile station 10. Further, the line control unit 25 notifies the mobile station 10 of line setting information as in the first embodiment.

Refer to FIG. The line control signal extraction unit 76 of the mobile station 10 extracts the additional base station notification and the line setting information transmitted from the base station 7 from the reception signal decoded by the reception unit 70. The radio channel setting control unit 84 shown in FIG. 9 executes a random access procedure in the frequency band of the cell of the base station 9 specified by the channel setting information, using a preamble determined using the channel setting information received from the base station 7. Then, a radio channel is established between the mobile station 10 and the base station 9.

The line control unit 77 shown in FIG. 8 transmits the base line to the service S2 in which data is transmitted on the logical channel designated by the wireless line addition notification while the existing line between the base station 7 and the service S1 is assigned. A newly added logical channel is allocated to the station 9. For example, the line control unit 77 assigns the carrier component of the base station 7 to the service S1, and performs carrier aggregation that assigns the carrier component of the base station 9 to the service S2.

When the logical channel specified by the radio channel addition notification is a downlink channel, the receiving unit 70 receives the data of the service S1 on the existing channel with the base station 7 and receives a new one with the base station 9. The data of service S2 is received through a simple wireless line. When the logical channel specified in the radio channel addition notification is an uplink channel, the transmission unit 71 transmits the data of the service S1 through the existing channel with the base station 7 and newly transmits with the base station 9. The data of service S2 is transmitted over a simple wireless line.

In some cases, uplink and downlink data transmission make a pair. For example, uplink and downlink data transmissions by the same application operating on the mobile station 10 may be paired. The line control unit 77 switches the radio channel used for one of the uplink and downlink data transmissions that make a pair to a new radio channel between the base station 9 and the radio channel used for the other data transmission. It may be switched to a new wireless line with the base station 9.

For example, the line control signal creation unit 26 of the base station 7 identifies the data transmission logical channel that forms a pair with the data transmission in addition to the information for identifying the data transmission logical channel in which the small packet is detected. Information may be added to the wireless line addition notification. The line control unit 77 of the mobile station 10 assigns a logical channel that uses a newly added wireless line to the base station 9 to a service that uses a pair of logical channels specified by the wireless line addition notification. The line control unit 25 of the base station 7 may identify a logical channel for data transmission that makes a pair, for example, based on application information transmitted from the mobile station 10.

When uplink and downlink data transmission make a pair, the same QoS class may be assigned to these data transmission packets. When a small packet occurs in data transmission that is paired with data transmission to which a high-quality QoS class is assigned, the high-quality QoS class is also applied to the transmission of small packets, which may cause congestion due to the transmission of small packets. is there.

By switching the radio channel used for the pair of uplink data transmission and downlink data transmission to a new radio channel, congestion of the first network 2 due to occurrence of small packets on one link can be prevented. By reducing congestion, the transmission rate is improved and the required transmission rate can be satisfied. That is, at least processing in the first network 2 can be reduced. In addition, by switching both the radio channel used for uplink data transmission and downlink data transmission to a new radio channel, transmission caused by uplink and downlink data transmission via different networks A delay difference can be avoided.

FIG. 27 is a sequence diagram for explaining a sixth example of the operation of the communication system 1. In operation HA, data of services S1 and S2 are transmitted between the base station 7 and the mobile station 10. In operation HB, the base station 7 detects transmission of a small packet in the service S2. Operation HB corresponds to one of the operations of the small packet determination units 41, 57, and 66.

In operation HC, the base station 7 determines to add a new wireless line. Operation HC corresponds to the operation of the line addition processing unit 180. Operations HD to HG are the same as operations CD to CG in FIG. In operation HH, the base station 7 selects an additional base station. Operation HH corresponds to the operation of the line addition processing unit 180.

In operation HI, the base station 7 transmits a line setting information request to the base station 9. Operation HI corresponds to the operation of the line control unit 25. In operation HJ, the base station 9 transmits line setting information to the base station 7 in response to the line setting information request. Operation HJ corresponds to the operation of the line control unit 125.

In operations HK and HL, the base station 7 transmits a radio channel addition notification and channel setting information to the mobile station 10. Operations HK and HL correspond to the operations of the line control unit 25 and the line control signal creation unit 26.

In operation HM, the mobile station 10 and the base station 9 establish a radio channel between the mobile station 10 and the base station 9 by executing a predetermined channel setting procedure. The mobile station 10 allocates the newly added logical channel to the service S2 while allocating the existing line with the base station 7 to the service S1.

In operation HN, the base station 7 and the mobile station 10 transmit data of the service S1. In operation HO, the base station 9 and the mobile station 10 transmit data of service S2.

According to the present embodiment, of the services S1 and S2 accompanied by the data transmission of the mobile station 10, the network that transmits only the data of the service S2 that generates a small packet can be switched from the first network 2 to the third network 4. It becomes. For this reason, the congestion of the first network 2 that is the switching source can be reduced. By reducing congestion, the transmission rate is improved and the required transmission rate can be satisfied. On the other hand, the occurrence of congestion in the third network 4 can be reduced by not switching the network that transmits the data of the service S1 to the third network 4. By reducing congestion, the transmission rate is improved and the required transmission rate can be satisfied. In addition, at least the processing in the third network 4 can be reduced.

Note that the mobile station 10 may detect small packets as in the second embodiment. The line addition processing unit 180 of the base station 7 may determine to add a new wireless line in response to the small packet detection notification from the mobile station 10.

<7. Sixth embodiment>
FIG. 28 is an explanatory diagram of a third example of the functional configuration of the mobile station 10. The same reference numerals as those used in FIG. 23 are attached to the same constituent elements as those shown in FIG. The mobile station 10 includes a line addition processing unit 181. When transmission of a small packet occurs, the small packet determination unit 86 of the MAC processing unit 72, the small packet determination unit 97 of the RLC processing unit 73, and the small packet determination unit 111 of the PDCP processing unit 74 indicate that a small packet has occurred. This is notified to the line addition processing unit 181 and the line control unit 77.

The line addition processing unit 181 determines to add a new wireless line that transmits the service S2. The line addition processing unit 181 and the line control unit 77 request the base station 7 to add a new wireless line.

For example, the line addition processing unit 181 determines to add a new wireless line that transmits the service S2. The line addition processing unit 181 requests the line control unit 77 to add a new wireless line. Receiving the line addition request, the line control unit 77 requests the line control signal creation unit 79 to create a line addition request for requesting addition of a new wireless line. The line control signal creation unit 79 creates a line addition request and outputs it to the transmission unit 71. The transmission unit 71 transmits a line addition request to the base station 7.

Refer to FIG. The line control signal extraction unit 27 of the base station 7 extracts a line addition request from the reception signal decoded by the reception unit 21 and outputs the line addition request to the line control unit 25. The line control unit 25 that has received the line addition request determines whether to approve the addition of a new wireless line in accordance with a predetermined condition. When approving the implementation, the channel control unit 25 requests the mobile station 10 to measure the radio channel quality between the other base stations 8 and 9 in the same manner as in the fifth embodiment. . Subsequent operations are the same as those in the fifth embodiment.

According to the present embodiment, of the services S1 and S2 accompanied by the data transmission of the mobile station 10, the network that transmits only the data of the service S2 that generates a small packet can be switched from the first network 2 to the third network 4. It becomes. For this reason, the congestion of the first network 2 that is the switching source can be reduced. By reducing congestion, the transmission rate is improved and the required transmission rate can be satisfied. On the other hand, the occurrence of congestion in the third network 4 can be reduced by not switching the network that transmits the data of the service S1 to the third network 4. By reducing congestion, the transmission rate is improved and the required transmission rate can be satisfied. In addition, at least the processing in the third network 4 can be reduced.

According to the present embodiment, the detection process of small packets generated by the service used in the mobile station 10 is distributed to each mobile station 10. For this reason, it is possible to avoid an increase in the load on the base station 7 in order to detect small packets.

Note that the line addition processing unit 181 may select an additional base station based on the measurement result of the quality of the radio channel between the base stations 8 and 9 by the quality measuring unit 78. The selection operation of the additional base station by the line addition processing unit 181 may be the same as the selection operation of the additional base station by the line addition processing unit 180 of the fifth embodiment, for example. The line control signal creation unit 79 creates a line addition request for requesting addition of a new wireless line with the selected additional base station 9 and transmits the request to the base station 7 via the transmission unit 71.

Refer to FIG. The line control signal extraction unit 27 of the base station 7 extracts a line addition request from the reception signal decoded by the reception unit 21 and outputs the line addition request to the line control unit 25. The line control unit 25 determines whether to approve the addition of a new wireless line according to a predetermined condition. The line control unit 25 acquires line setting information from the base station 9 and transmits it to the mobile station 10 in the same manner as in the fifth embodiment when approving the addition of a new wireless line. Subsequent operations are the same as those in the fifth embodiment.

In the above description, the functional configuration diagrams of FIGS. 2, 3, 6 to 15, 19 to 21, 23, 26, and 28 are configurations related to the functions described in this specification. Shown in the center. The base stations 7 and 9 and the mobile station 10 may include other components than the illustrated components. The series of operations described with reference to FIGS. 4, 5, 16, 18, 22, 24, 25, and 27 may be interpreted as a method including a plurality of procedures. In this case, “operation” may be read as “step”.

<8. Hardware configuration>
The hardware configurations of the base stations 7 and 9 and the mobile station 10 will be described below. FIG. 29 is a hardware configuration diagram of an example of the base stations 7 and 9. The base station devices 7 and 9 include a processor 200 such as a CPU (Central Processing Unit), a storage device 201, an LSI (Large Scale Integration) 202, a wireless processing circuit 203, and a network interface circuit 204. In the following description and accompanying drawings, the network interface may be referred to as “NIF”.

The storage device 201 includes a non-volatile memory, a read-only memory (ROM: Read Only Memory), a random access memory (RAM: Random Access Memory), a hard disk drive, and the like for storing computer programs and data. Good. The processor 200 performs user management processing other than the processing performed by the LSI 202 described below and operation control of the base stations 7 and 9 in accordance with the computer program stored in the storage device 201.

The LSI 202 performs baseband signal processing related to encoding and modulation of signals transmitted to and received from the mobile station 10, demodulation and decoding, communication protocol processing, and scheduling. The LSI 202 may include an FPGA (Field-Programming Gate Array), an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processing), and the like.

The wireless processing circuit 203 may include a digital / analog conversion circuit, an analog / digital conversion circuit, a frequency conversion circuit, an amplification circuit, a filter circuit, and the like. The NIF circuit 204 includes an electronic circuit for communicating with an upper node apparatus via a wired network using a physical layer and a data link layer.

The above operations of the transmission unit 20 and reception unit 21 of the base station 7 and the transmission unit 120 and reception unit 121 of the base station 9 are realized by the cooperation of the LSI 202 and the wireless processing circuit 203, for example. The operations of the MAC processing unit 22, the RLC processing unit 23, and the PDCP processing unit 24 of the base station 7 are realized by the LSI 202, for example. The above operations of the MAC processing unit 122, the RLC processing unit 123, and the PDCP processing unit 124 of the base station 9 are realized by the LSI 202, for example.

The operations of the line control unit 25, the line control signal creation unit 26, the line control signal extraction unit 27, the HO control unit 28, and the line addition processing unit 180 of the base station 7 are realized by the processor 200, for example. The above operations of the line control unit 125, the line control signal creation unit 126, and the line control signal extraction unit 127 of the base station 9 are realized by the processor 200, for example.

FIG. 30 is a hardware configuration diagram of an example of the mobile station 10. The mobile station 10 includes a processor 210, a storage device 211, an LSI 212, and a wireless processing circuit 213. The storage device 211 may include a nonvolatile memory, a read-only memory, a random access memory, and the like for storing computer programs and data.

The processor 210 executes operation control of the mobile station 10 other than the processing performed by the LSI 212 described below and an application program for processing user data, according to the computer program stored in the storage device 211.

The above operations of the receiving unit 70, the transmitting unit 71, and the quality measuring unit 78 are realized by the cooperation of the LSI 212 and the wireless processing circuit 213. The above-described operations of the MAC processing unit 72, the RLC processing unit 73, and the PDCP processing unit 74 are realized by the LSI 212, for example. The operations of the application processing unit 75, the line control signal extraction unit 76, the line control unit 77, and the line control signal creation unit 79 are realized by the processor 210, for example.

It should be noted that the hardware configuration shown in FIGS. 29 and 30 is merely an example for explaining the embodiment. Any other hardware configuration may be adopted for the base station and the mobile station described in the present specification as long as the operations described above are executed.

All examples and conditional terms contained herein are intended for educational purposes only to assist the reader in understanding the present invention and the concepts provided by the inventor for the advancement of technology. And should not be construed as being limited to the examples and conditions set forth above, as well as the configuration of the examples herein with respect to showing the superiority and inferiority of the present invention. Is. While embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions and modifications can be made thereto without departing from the spirit and scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Communication system 2 1st network 3 2nd network 4 3rd network 5, 6 GW
7, 8, 9 Base station 10 Mobile station

Claims (17)

A base station device connected to the second network via the first network,
A detection unit for detecting a packet length of a packet transmitted between the second network and the mobile station device;
A wireless communication line between the second base station apparatus connected to the second network via the third network different from the first network and the mobile station apparatus is set according to the detection result of the detection unit An instruction signal to be transmitted, a line setting unit for transmitting to the mobile station device;
A base station apparatus comprising: The base station apparatus according to claim 1, wherein the line setting unit transmits the instruction signal to the mobile station apparatus when a packet length of the packet is equal to or less than a threshold value. 2. The base according to claim 1, wherein the line setting unit transmits the instruction signal to the mobile station apparatus when the number of times that the packet length of the packet is equal to or less than a threshold value is equal to or greater than a predetermined number. Station equipment. The line setting unit transmits the instruction signal to the mobile station apparatus when a ratio of the number of packets having a packet length equal to or less than a threshold value among a predetermined number of the plurality of packets is equal to or greater than a predetermined ratio. The base station apparatus according to claim 1. The line setting unit transmits the instruction signal to the mobile station apparatus when the number of packets having a packet length equal to or less than a threshold value among the packets detected in a predetermined period becomes equal to or greater than a predetermined number. The base station apparatus according to claim 1. 6. The base station apparatus according to claim 1, wherein the instruction signal instructs a handover to switch a base station apparatus connected to the mobile station apparatus to the second base station apparatus. The detection unit detects a packet length of each packet for each logical channel;
The instruction signal transmits a packet of a logical channel in which a packet having a packet length longer than a threshold is detected through a wireless communication line between the base station device and the mobile station device, and a packet having a packet length equal to or less than the threshold is detected. 6. An instruction to switch a wireless communication line that transmits a packet of a logical channel to a wireless communication line between the second base station apparatus and the mobile station apparatus, The base station apparatus according to one item. 2. The base according to claim 1, wherein the detection unit detects a frequency at which a packet length of a packet transmitted between the second network and the mobile station apparatus is equal to or less than a predetermined packet length. Station equipment. The detection unit detects a frequency at which a packet length of a packet transmitted between the second network and the mobile station device for each logical channel is equal to or less than a predetermined packet length,
The instruction signal transmits a packet of a logical channel whose frequency is less than a threshold over a wireless communication line between the base station apparatus and the mobile station apparatus, and transmits a packet of a logical channel whose frequency is equal to or higher than the threshold. The base station apparatus according to any one of claims 1 to 5, wherein an instruction is given to switch a radio communication line to a radio communication line between the second base station apparatus and the mobile station apparatus. 10. The selection unit according to claim 1, further comprising a selection unit that selects the second base station device based on radio channel quality between the base station device and the mobile station device. Base station device. A mobile station device,
A detecting unit for detecting a size of a packet transmitted between the first base station apparatus connected to the second network via the first network and the mobile station apparatus;
Line setting for setting a wireless communication line with the second base station apparatus connected to the second network via a third network different from the first network according to the detection result of the detection unit A line control unit for transmitting an instruction signal for transmitting information to the first base station device;
A receiving unit for receiving the line setting information;
A line setting unit for setting a wireless communication line with the second base station device according to the line setting information;
A mobile station apparatus comprising: A measurement unit for measuring a radio channel quality between a base station device and the mobile station device;
The mobile station apparatus according to claim 11, further comprising a selection unit that selects the second base station apparatus based on the radio channel quality. The mobile station apparatus according to claim 11 or 12, wherein the line control unit executes a handover for switching a base station apparatus connected to the mobile station apparatus to the second base station apparatus. The detection unit detects a packet length of each packet for each logical channel;
The line control unit transmits a packet of a logical channel in which a packet having a packet length longer than a threshold is detected through a wireless communication line between the first base station apparatus and the mobile station apparatus. 14. The wireless communication line for transmitting a packet of a logical channel in which a packet is detected is switched to a wireless communication line between the second base station apparatus and the mobile station apparatus. The mobile station apparatus according to the item. The said detection part detects the frequency from which the packet length of the packet transmitted between the said 2nd network and a mobile station apparatus becomes below a predetermined packet length, The movement of Claim 11 characterized by the above-mentioned. Station equipment. The detection unit detects a frequency at which a packet length of a packet transmitted between the second network and the mobile station apparatus is not more than a predetermined packet length for each logical channel;
The line control unit transmits a packet of a logical channel whose frequency is less than a threshold over a wireless communication line between the first base station apparatus and the mobile station apparatus, and a packet of a logical channel whose frequency is equal to or higher than the threshold. The mobile communication device according to any one of claims 11 to 13, wherein the mobile communication device instructs to switch a wireless communication channel for transmitting a signal to a wireless communication channel between the second base station device and the mobile station device. Station equipment. A mobile station device connected to a base station device connected to the second network via the first network, and a first step of detecting a packet length of a packet transmitted between the second network;
In accordance with the detection result of the first step, a wireless communication line between the second base station apparatus and the mobile station apparatus connected to the second network via a third network different from the first network A second step to set,
A communication method comprising:

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