HK1211773B - Communication devices and methods for network signaling - Google Patents

Description

Communication device and method for network signaling

This application is a divisional application. The name of the invention of the parent application is “Communication device and method for network signaling”, the application date is March 9, 2012, and the application number is 201210060928.X.

Technical Field

Embodiments generally relate to communication devices and methods for network signaling.

Background Art

In wireless communication networks, relay nodes (i.e., relay communication devices) may be used for various reasons, such as expanding coverage areas, more efficient use of radio resources, or improving communication quality. It is desirable to more efficiently notify communication terminals of the presence of such relay nodes.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to like parts throughout the different views. The drawings are not necessarily drawn to scale, emphasis instead generally being placed on illustrating the principles of the invention. In the following description, various embodiments are described with reference to the following drawings, in which:

FIG1 shows a communication system according to an embodiment.

FIG2 shows a communication system according to an embodiment.

FIG3 shows a communication device according to an embodiment.

FIG4 shows a flow chart according to an embodiment.

FIG5 shows a communication device according to an embodiment.

FIG6 shows a flow chart according to an embodiment.

FIG7 shows a communication system according to an embodiment.

FIG8 shows a message flow diagram according to an embodiment.

FIG9 shows a message flow diagram according to an embodiment.

FIG10 shows a communication system according to an embodiment.

FIG11 shows a message flow diagram according to an embodiment.

FIG12 shows a message flow diagram according to an embodiment.

DETAILED DESCRIPTION

The following detailed description is with reference to the accompanying drawings that illustrate by way of illustration the specific details and embodiments in which the present invention may be implemented. These embodiments are described in sufficient detail to enable those skilled in the art to implement the present invention. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the present invention. Because some embodiments may be combined with one or more other embodiments to form new embodiments, the various embodiments are not necessarily mutually exclusive.

FIG1 shows a communication system 100 according to an embodiment.

According to this embodiment, the communication system 100 is configured according to the network architecture of LTE. The communication system 100 may also be configured according to another communication standard, for example, according to UMTS (Universal Mobile Telecommunications System), GSM (Global System for Mobile Communications), CDMA2000 (CDMA: Code Division Multiple Access), or FOMA (Free Mobile Access).

The communication system 100 includes a radio access network (in this example, E-UTRAN (evolved UMTS terrestrial radio access network) according to LTE) 101 and a core network (in this example, EPC (evolved packet core) according to LTE) 102. The E-UTRAN 101 may include base (transceiver) stations (in this example, eNodeBs (eNBs) according to LTE) 103. Each base station 103 provides radio coverage for one or more mobile radio cells 104 of the E-UTRAN 101.

A mobile terminal (in this example, according to LTE, a UE, i.e. User Equipment) 105 located in a mobile radio cell 104 can communicate with the core network 102 and with other mobile terminals 105 via a base station providing coverage (in other words, operating) in the mobile radio cell.

Control and user data are transmitted over the air interface 106 between the base station 103 and mobile terminals located in a mobile radio cell 104 operated by the base station 103 based on a multiple access method.

The base stations 103 are interconnected with each other by means of an X2 interface 107. The base stations are also connected to the core network (evolved packet core) 102 by means of an S1 interface 108, and more specifically to an MME (Mobility Management Entity) 109 and a Serving Gateway (S-GW) 110. The MME 109 is responsible for controlling the mobility of UEs located in the coverage area of the E-UTRAN, while the S-GW 110 is responsible for handling the transmission of user data between the mobile terminals 105 and the core network 102.

The mobile terminal 105 may support several radio access technologies (RATs). For example, the mobile terminal 105 may support various cellular radio access technologies (e.g., GSM, UMTS, LTE) to connect to various cellular communication networks using different radio access technologies as similarly described, such as the LTE communication network and LTE radio access network (E-UTRAN) 101 shown above in FIG. 1 .

The mobile terminal 105 may also support short-range radio access technologies such as Bluetooth and WiFi (eg, IEEE 802.11), for example, to gain occasional access to a short-range communication network.

Typically, cellular communication networks provide, on one hand, almost perfect coverage and availability as well as seamless mobility and a wide variety of offered services, but on the other hand, typically have expensive and limited licensed spectrum for the air interface 106 .

In contrast, short-range radio access technologies such as Bluetooth and WLAN can be used in unlicensed bands, which are free and generally offer more bandwidth and higher throughput per user, such as the ISM (Industrial, Scientific, Medical) bands. Short-range technologies typically have a small coverage area (e.g., less than 100m range) and do not typically provide mobility between different access points, as most access points are not operated by the same operator but by different private entities.

Therefore, both radio access technologies (cellular and short-range) have advantages and disadvantages. According to one embodiment, a concept is used to combine the two main advantages of these two radio access technologies: providing cellular communication services (i.e., communication services provided via a cellular mobile communication system) via license-free spectrum. To this end, so-called opportunistic networks (ONs) are used. This is illustrated in Figure 2.

FIG2 shows a communication system 200 according to an embodiment.

The communication system 200 includes a core network 201 corresponding to, for example, the core network 102 shown in FIG. 1 , and a base station 202 corresponding to, for example, one of the base stations 103 shown in FIG. 1 .

The communication network 200 further comprises a first mobile terminal 203 (eg corresponding to the mobile terminal 105 of FIG. 1 ) having a first radio link 204 (eg according to LTE) to the base station 202 , eg via the air interface 106 of the communication system 100 of FIG. 1 .

The communication system 200 also includes one or more second mobile terminals 205. The second mobile terminals are connected to the first mobile terminal 203 via a corresponding short-range RAT second radio link 206. The first mobile terminal 203 operates as a relay mobile terminal. The first mobile terminal 203 is connected to the cellular network via a cellular RAT via a first radio link 204. The first mobile terminal 203 forwards data between the second mobile terminal 205 (also known as an opportunistic network terminal) and the base station 202 (i.e., the cellular communication network of which the base station 202 is a part). As a result, the second mobile terminal 205 can use the communication services provided by the cellular communication network using the unlicensed short-range RAT frequency band. The first mobile terminal 203 and the second mobile terminal 205 can be considered to form an opportunistic network (ON) 207.

The concept of opportunistic networks may be desirable for operators of cellular communication networks because expensive resources from the licensed spectrum (for cellular RAT radio links such as the first radio link 204) are used more efficiently. A user of the second mobile terminal 205 may benefit from accessing communication services provided by the cellular communication network by using the communication services via the opportunistic network 207 at a greater data rate and at a lower cost.

According to one embodiment, the mobile terminal is made aware of the availability of the opportunistic network (eg, aware of the presence of a relay mobile terminal such as the mobile terminal 203 ) so that the mobile terminal can operate as an opportunistic network terminal.

It should be noted that "WLAN access network advertisement" is a method specified by 3GPP (3rd Generation Partnership Project). It can be used to indicate the presence of a WLAN access network and that it provides access to the 3G core network. This information is broadcast by the WLAN access point of the WLAN, or transmitted upon request by a communication terminal. In both cases, the WLAN itself transmits the relevant information. Therefore, a communication terminal that currently has its WLAN transceiver turned off will not be informed of the presence of the WLAN access network and may therefore not be able to benefit from using the WLAN access network.

Furthermore, base stations (eNBs) 103 according to LTE broadcast so-called neighbor cell lists to mobile terminals located in their operating radio cells 104. These lists provide information such as the used frequency bands and radio cell IDs of neighboring radio cells 104. This can be used by mobile terminals 105 to perform measurements on the relevant radio cells 105 to ensure that the mobile terminal 105 always camps on the best radio cell 104 (in terms of signal quality). If this is used to advertise opportunistic networks, then due to the broadcasting technique, all mobile terminals within the coverage area (or at least within the same radio cell 104) will receive the same information about the opportunistic network. Since the coverage area of an opportunistic network is typically very small relative to the coverage area of the base station 103 (i.e., the radio cell 104), many mobile terminals will attempt to access the opportunistic network even if they are not within its coverage area. This can lead to a waste of battery power for the mobile terminals.

According to one embodiment, a network component (e.g., a base station) of a cellular communication network indicates the availability of additional access networks (such as opportunistic networks) to one or more mobile terminals, which would benefit from using the advertised access network. This may include further data about the opportunistic network to facilitate access to the network and the decision of which opportunistic network to select. The advertisement may be mobile terminal specific and only include data about opportunistic networks that are in the vicinity of the mobile terminal and that use a radio technology supported by the mobile terminal.

The mobile terminal may be informed of the availability of additional access networks (eg opportunistic networks) eg by dedicated signaling of "ON advertisement" messages from the base station operating the access network and/or the radio cell in which the mobile terminal is located to the mobile terminal.

Since mobile terminals operating as relay mobile terminals (such as the first mobile terminal 203 in FIG. 2 ) can stop their operation as relay mobile terminals (or, in general, as relay communication devices), or mobile terminals can start their operation as relay communication devices, network components such as base stations (in general, communication devices) can dynamically determine whether the communication device is operating as a relay communication device, for example, based on signals received from the communication device. This is illustrated in FIG. 3 .

FIG3 shows a communication device 300 according to an embodiment.

The communication device 300 includes a detector 301 configured to detect, based on reception of a radio signal from another communication device, whether the other communication device is operating as a relay communication device in a radio cell associated with the communication device.

The communication device 300 further comprises a signalling circuit 302 configured to signal to the communication terminal that the other communication device is operating as a relay communication device if it has been detected that the other communication device is operating as a relay communication device.

In other words, according to one embodiment, a communication device, for example, as part of a cellular communication network, determines whether the communication device is operating as a relay communication device based on radio signals transmitted by the communication device (or also based on the lack of radio signals transmitted by the communication device). The communication device can thereby, for example, determine which relay communication devices are currently operating in a particular geographical area (in this case, a radio cell associated with the communication device, such as a radio cell for which the communication device is responsible (e.g., for control and/or operation). For example, the communication device can periodically (e.g., at predetermined times and/or every predetermined time period) determine which relay communication devices (in other words, which relay nodes) are present in the radio cell. The communication device can then notify one or more communication terminals of the presence of relay communication terminals (e.g., the presence of relay communication terminals of an opportunistic network and, therefore, the presence of an opportunistic network). For example, the communication device can notify one or more communication terminals of the presence of an opportunistic network. This is also referred to below as opportunistic network advertising.

The communication device 300 may further include a list generation circuit configured to generate a list of other communication devices operating as relay communication devices in the radio cell.

For example, the list generating circuit is configured to include other communication devices in the list if it has been detected that the other communication devices are operating as relay communication devices.

The communication device may include update circuitry configured to update the list in response to detecting that one of the other communication devices in the list has exited operation as a relay communication device.

The updating circuit is, for example, configured to update the list at predetermined points in time and/or to update the list periodically.

According to one embodiment, detecting whether another communication device is operating as a relay communication device in a radio cell based on reception of a radio signal from the other communication device includes determining whether the other communication device has exited operation as a relay communication device or has started operation as a relay communication device.

According to one embodiment, detecting whether another communication device is operating as a relay communication device in a radio cell based on reception of a radio signal from the other communication device includes: determining whether an expected signal is received from the other communication device, and if the expected signal is not received from the other communication device, deciding that the other communication device is not operating as a relay communication device.

According to one embodiment, detecting whether another communication device is operating as a relay communication device in a radio cell based on reception of a radio signal from the another communication device includes detecting whether a message indicating that the another communication device has started operating has been received from the another communication device.

The communication device may further include a radio receiver configured to receive a radio signal from the relay communication device.

According to one embodiment, the operation as a relay communication device is an operation as a relay communication device between the communication device and the communication terminal.

For example, the operation as a relay communication device is an operation as a relay communication device that communicates with the communication device using a first radio technology and communicates with the communication terminal using a second radio technology.

The first radio technology is, for example, a wide area network radio technology and/or a cellular mobile communication network radio technology.

The second radio technology is, for example, a local area network radio technology and/or a short-range radio technology, for example, a WLAN radio technology or a Bluetooth radio technology.

The communication device is, for example, a component of a mobile communication network.

According to one embodiment, the communication device is a base station operating a radio cell.

The communication terminal may be a subscriber terminal of a mobile communication network.

The other communication device may be a communication terminal (eg, a subscriber terminal of a mobile communication network).

According to one embodiment, the other communication device is a subscriber terminal of a mobile communication network.

In an embodiment, a "circuit" may be understood as any kind of logic implementation entity, which may be a dedicated circuit or a processor that executes software stored in memory, firmware, or any combination of memory and firmware. Thus, in an embodiment, a "circuit" may be a hardwired logic circuit or a programmable logic circuit such as a programmable processor, for example, a microprocessor (e.g., a Complex Instruction Set Computer (CISC) processor or a Reduced Instruction Set Computer (RISC) processor). A "circuit" may also be a processor that executes software, such as any kind of computer program (e.g., a computer program using a virtual machine code such as, for example, JAVA). According to alternative embodiments, any other kind of implementation of the corresponding functionality, which will be described in more detail below, may also be understood as a "circuit."

According to one embodiment, the communication device 300 executes the method shown in FIG. 4 .

FIG4 shows a flow chart 400 according to an embodiment.

Flowchart 400 illustrates a method for network signaling.

In 401 , based on reception of a radio signal from another communication device, it is detected whether the other communication device is operating as a relay communication device in a radio cell related to the communication device.

In 402 , if it has been detected that the other communication device is operating as a relay communication device, a signal is sent to the communication terminal that the other communication device is operating as a relay communication device.

FIG. 5 shows a communication device 500 according to an embodiment.

The communication device 500 includes a memory 501 and a determination circuit 502, wherein the memory 501 stores a list of communication devices operating as relay communication devices in a radio cell associated with the communication device, and the determination circuit 502 is configured to determine, for the communication terminal, one or more communication devices from the communication device list that can be used by the communication terminal as relay communication devices based on information about the communication terminal.

The communication device 500 further comprises a signaling 503 circuit configured to signal information about the determined one or more communication devices to a communication terminal.

According to one embodiment, in other words, a communication device (e.g., a component of a cellular mobile communication network such as a base station) notifies a communication terminal of the presence of a relay communication device that can be actually used by the communication terminal by filtering a list of relay communication devices stored in the communication device based on information about the communication terminal (e.g., based on attributes of the communication terminal (e.g., according to capabilities or location of the mobile terminal)).

According to one embodiment, the determining circuit is configured to determine, from the list of communication devices, those one or more communication devices that can be used by the communication terminal as relay communication devices based on information about radio capabilities of the communication terminal.

For example, the communication device comprises a receiver configured to receive information, for example from a communication terminal.

The communication device 500 executes the method shown in FIG. 6 , for example.

FIG6 shows a flowchart 600 according to an embodiment.

Flowchart 600 illustrates a method for network signaling.

In 601 , a list of communication devices operating as relay communication devices in a radio cell associated with the communication device is stored.

In 602 , based on the information about the communication terminal, one or more communication devices that can be used by the communication terminal as relay communication devices are determined for the communication terminal from a list of communication devices.

In 603, information about the determined one or more communication devices is signaled to the communication terminal.

It should be noted that, where applicable, embodiments described in the context of one of the communication devices are analogously valid for the other communication device and methods for network signaling, and vice versa.

For example, the communication device 300 and/or the communication device 400 corresponds to the base station 202 of the communication system 200 shown in Figure 2, and will be notified of the presence of a relay communication device (for example, the presence of the first mobile terminal 203) and therefore the presence of a mobile communication terminal of an opportunistic network corresponding to one of the second mobile terminals 205.

According to one embodiment, in the communication system 200, the transmission of the signaling regarding the presence of the first mobile terminal 203 is triggered during normal operation of the second mobile terminal 205, for example:

- when a second mobile terminal 205 having no ongoing connection (i.e. in idle mode) is entering a radio cell operated by the base station 202 and transmits a tracking area update message to the base station 202. This approach is advantageous because it does not add delays in the connection setup to the opportunistic network when the second mobile terminal 205 wants to establish a connection.

- When the second mobile terminal 205 which has no ongoing connection (i.e. is in idle mode) wants to establish a connection and transmits a connection request message to the base station 202. In this case, the opportunistic network advertisement message is sent in the following example case:

o After receiving the connection request message. This instructs the second mobile terminal 205 to establish a connection towards the opportunistic network. With this method, no handover is required and thus the signaling overhead can be reduced.

o After the connection towards the base station 202 is established by the second mobile terminal 205. The second mobile terminal 205 performs a handover to the opportunistic network after receiving the message. With this method, no delay in connection setup is added.

- When an opportunistic network is newly established or the properties of the opportunistic network have changed and the new or changed opportunistic network is made known to the base station 202. Thus, the second mobile terminal 205 may select a more suitable opportunistic network if it is available.

According to one embodiment, the opportunistic network advertisement message sent to inform the second mobile terminal 205 of the presence of the relay communication device contains the following data to facilitate access to the communication network and to decide which opportunistic network to select:

-ON type (e.g., "IEEE 802.11n", "Bluetooth", ...)

-ON-ID

-ON name (human-readable, e.g., SSID in case of IEEE 802.11)

- Frequency bands used by opportunistic networks

- Information related to the currently offered Quality of Service (QoS), i.e. an indication of the class of communication offered (e.g. VoIP, media streaming, etc.)

- The password required to access the opportunistic network

- an indication of the current load (e.g. number of connected mobile terminals, average unoccupied resources, available QoS, etc.)

- Auxiliary data for verification of encryption methods and/or digital signatures

- Relaying the position/location of the first mobile terminal 203 .

According to one embodiment, base station 202 stores and maintains a list of opportunistic networks currently operated by base station 202 (e.g., by serving mobile terminals operating as relay communication devices). For each opportunistic network, the data required for ON advertisement messages is stored in a separate dataset. When a new opportunistic network is operated by base station 202, the new dataset is added to the list. If a relay mobile terminal 203 leaves the cell or ceases operating as a relay communication device, the entry is deleted. Some stored parameters are periodically updated by the opportunistic network (e.g., parameters related to current resource occupancy) or updated after a change (e.g., if access parameters have changed), while other portions of the opportunistic network dataset remain static, such as the ON-ID.

The base station 202 may generate an ON advertisement message separately for each second mobile terminal 205. For example, only opportunistic networks that are in the vicinity of the second mobile terminal 205 and support the short-range technology used by the second mobile terminal 205 are included in the ON advertisement message for the second mobile terminal 205. This saves resources for signaling and prevents the second mobile terminal 205 from attempting to access an opportunistic network that is currently inaccessible.

By using the advertising process according to the embodiment, the second mobile terminal 205 can use the idle mode process from the cellular communication system when it is in idle mode, and can use the opportunistic network when it is in connected mode. Therefore, the second mobile terminal 205 can benefit from the lowest power consumption and permanent availability due to very good cellular coverage in idle mode, and when the opportunistic network is available, the second mobile terminal 205 can benefit from greater data rates, lower costs and lower power consumption in connected mode.

According to an embodiment, the second mobile terminal 205 does not need to permanently scan for opportunistic network availability. However, the second mobile terminal 205 may use the opportunistic network any time the opportunistic network is available.

In the following, an example of opportunistic network advertising for connection setup is described with reference to FIG. 7 .

FIG7 shows a communication system 700 according to an embodiment.

Communication system 700 includes a core network 701 corresponding to core network 102 shown in FIG. 1 , for example, and a base station 702 corresponding to one of base stations 103 shown in FIG. 1 connected to core network 701 via an MME 703 corresponding to MME 109 shown in FIG. 1 .

The communication system 700 also includes a first mobile terminal 704 (e.g., corresponding to the mobile terminal 105 of FIG. 1 ), which has a first radio link 705 to the base station 702, e.g., via the air interface 106 of the communication system 100 of FIG. 1 . As similarly described above with reference to FIG. 2 , the first mobile terminal 704 operates as a relay communication device for the first opportunistic network 706, the second opportunistic network 707, and the third opportunistic network 708.

The opportunistic networks 706 , 707 and 708 include a second mobile terminal 709 .

The communication system 700 further comprises a third mobile terminal 710, which in this example is the mobile terminal that is to be informed of the presence of the opportunistic network.

The communication system 700 is a cellular communication system conforming to the 3GPP Release 8 communication standard, for example. The second mobile terminal 709 is equipped with a short-range transmission module according to IEEE 802.11n for communicating with the corresponding relay mobile terminal 704.

According to one embodiment, opportunistic network advertising is performed at connection setup time. The corresponding message flow is shown in FIG8 .

FIG8 shows a message flow diagram 800 according to an embodiment.

The message flow diagram 800 occurs between a mobile terminal 801 corresponding to the third mobile terminal 710 and a base station 802 corresponding to the base station 702 .

Assume that mobile terminal 801 in Figure 2 is in idle mode and wants to establish a connection to core network 701 (e.g., for internet browsing). Therefore, in 803, mobile terminal 801 transmits message 804 to base station 802, wherein message 804 is an RRC Connection Request message, which includes two additional parameters: i) the current location of mobile terminal 801 (position, speed, and direction of movement), and ii) the ON-capabilities of mobile terminal 801 (i.e., a list of supported short-range technologies including further details (e.g., supported versions and maximum data rates). Mobile terminal 801 is unaware of the existence of the opportunistic network at this point in time.

In 805, upon receiving message 804, base station 802 checks whether at least one opportunistic network is currently operating within its coverage area. To this end, base station 802 stores an ON list (i.e., access details for each currently operating opportunistic network (opportunistic network type, opportunistic network name, frequency band, etc.)) and the location of the relay mobile terminal for that opportunistic network. In this example, based on the hypothetical scenario shown in FIG7 , this check is positive, as three opportunistic networks 706, 707, and 708 are assumed to be currently operating within the coverage area of base station 802. To provide more accurate advertising, base station 802 only advertises opportunistic networks that are or will be in the vicinity of mobile terminal 801 and are using a short-range technology supported by mobile terminal 801. Therefore, base station 802 uses the current location, speed, and direction of movement of mobile terminal 801, as well as the opportunistic network capabilities, received in 803. In this example, the base station 802 selects the first opportunistic network 706 and the second opportunistic network 707 because the first opportunistic network 706 and the second opportunistic network 707 are close to the mobile terminal 801 in this example and use short-range technologies supported by the mobile terminal 801. Therefore, the base station 802 decides to advertise the selected opportunistic networks to the mobile terminal 801.

Accordingly, in 806 , the base station 802 sends an ON advertisement message 807 to the mobile terminal 801 with information on how to access the selected opportunistic network and on the current load of said opportunistic network.

In 808, after receiving the ON Advertisement message, the advertisement process ends. Mobile terminal 801 may attempt to connect to one of the opportunistic networks indicated in the received message. It may use the information about the current load included in ON Advertisement message 807 to select an opportunistic network. For example, it may select an opportunistic network that offers more unoccupied resources. In another example, it may use the indication of the communication class to select a suitable opportunistic network.

The process shown in Figure 8 is well suited for non-time-critical connection setup. The process can be implemented with very little signaling, thereby saving resources of the cellular communication network.

According to one embodiment, the opportunistic network advertisement is performed after setting up a connection with the base station 702. The corresponding message flow is shown in FIG9.

FIG9 shows a message flow diagram 900 according to an embodiment.

The message flow diagram 900 occurs between a mobile terminal 901 corresponding to the third mobile terminal 710 and a base station 902 corresponding to the base station 702 .

Assume that the mobile terminal 901 is initially in idle mode and wants to establish a connection to the core network 701 (eg, for internet browsing).

Therefore, in 903, the mobile terminal 901 sends a message to the base station 902, which is an RRC Connection Request message including two additional parameters, namely i) the current location of the mobile terminal 901 (position, speed and direction of movement) and ii) the opportunistic network capabilities of the mobile terminal 901 (i.e. a list of supported short range technologies including further details such as supported versions and maximum data rates). It is assumed that the mobile terminal 901 is not aware of the existence of the opportunistic network at this point in time.

In 905 , the base station 902 establishes a communication connection towards the mobile terminal 901 (eg, as usual).

In 906 , after the connection is established, base station 902 checks whether at least one opportunistic network is currently operating within its coverage area. To this end, base station 902 stores an ON list (i.e., access details (opportunistic network type, opportunistic network name, frequency band, etc.) for each currently operating opportunistic network) and the location of the corresponding relay mobile terminal 704. According to the scenario assumed in this example, as shown in FIG7 , this check is positive, as three opportunistic networks 706 , 707 , and 708 are assumed to be currently operating. To provide more accurate advertising, base station 902 only advertises opportunistic networks that are or will be in the vicinity of mobile terminal 901 and are using short-range technologies supported by mobile terminal 901. To this end, base station 902 uses the current location, speed, and direction of movement of mobile terminal 901, as well as the opportunistic network capabilities, received in 903 . In this example, base station 902 selects the first opportunistic network 706 and the second opportunistic network 707 because they are close to mobile terminal 901 and use supported short-range technologies. Therefore, the base station 902 decides to advertise the opportunistic network to the mobile terminal 901 .

In 907 , the base station 902 sends an ON advertisement message 913 with information about the selected opportunistic network (opportunistic network type, opportunistic network name, used frequency band) and information about measurements of the opportunistic network (e.g. periodicity of measurements and when measurements are reported) to the mobile terminal 901 .

After receiving the ON advertisement message, the mobile terminal 901 starts performing measurements on the advertised opportunistic network and reports the measurement results as a measurement report 909 to the base station 902 in 908 .

If the measurement results meet one or more specific criteria (e.g., the measured signal quality is above a specific level), base station 902 decides to hand over the connection to an opportunistic network 706, 707, 708 that meets the one or more criteria. Further criteria may be considered, such as the current load of the opportunistic network 706, 707, 708. It is assumed that all criteria for handover are met. Therefore, at 910, base station 902 transmits a handover command message 911 to mobile terminal 901. Handover command message 911, for example, includes access details for the selected opportunistic network (in this example, first opportunistic network 706).

In 912, the mobile terminal 901 connects to the opportunistic network indicated in the received message.

The process shown in FIG. 9 is well-suited for time-critical connection setup, since there is no additional delay during the connection setup.

It should be noted that in the embodiments described above with reference to Figures 8 and 9 , it is assumed that the mobile terminal 801, 901 initiates the connection setup. However, the methods according to these embodiments are also similarly applicable to situations where the communication network initiates the connection setup, for example, when incoming data from the mobile terminal 801, 901 arrives at the core network 701. In this case, a paging message is received by the mobile terminal 801, 901 before the RRC connection request message is transmitted. Thereafter, the process may be performed as described above with reference to Figures 8 and 9 , respectively.

In the following, an embodiment in which ON advertisement for a mobile terminal is performed in an idle mode of the mobile terminal is described with reference to FIG. 10 .

FIG10 shows a communication system 1000 according to an embodiment.

The communication system 1000 includes, for example, a core network 1001 corresponding to the core network 102 shown in Figure 1, a first base station 1011 and a second base station 1002 corresponding to two of the base stations 103 shown in Figure 1, which are connected to the core network 1001 via, for example, an MME 1003 corresponding to the MME 109 shown in Figure 1.

The communication system 1000 also includes a first mobile terminal 1004 (e.g., corresponding to the mobile terminal 105 of FIG. 1 ), which has a first radio link 1005 to the second base station 1002, e.g., via the air interface 106 of the communication system 100 of FIG. As similarly described above with reference to FIG. 2 , the first mobile terminal 1004 operates as a relay communication device for the first opportunistic network 1006, the second opportunistic network 1007, and the third opportunistic network 1008.

The opportunistic networks 1006 , 1007 , 1008 include a second mobile terminal 1009 .

The communication system 1000 further comprises a third mobile terminal 1010, which in this example is the mobile terminal to be informed of the presence of the opportunistic network.

The communication system 1000 is, for example, a cellular communication system compliant with 3GPP Rel 8. The second mobile terminal 1009 is, for example, equipped with a short-range transmission module according to IEEE 802.11n for communicating with the corresponding relay mobile terminal 1004.

The message flow according to one embodiment is shown in FIG. 11 .

FIG11 shows a message flow diagram 1100 according to an embodiment.

The message flow diagram 1100 occurs between a mobile terminal 1101 corresponding to the third mobile terminal 1010 , a base station 1102 corresponding to the second base station 1002 , an MME 1103 corresponding to the MME 1003 , and an HLR (Home Location Register) or HSS (Home Subscriber Server) located in the core network 1001 .

Assume that mobile terminal 1101 is in idle mode and enters the coverage area of base station 1102 (eg leaves the coverage area of first base station 1011 as indicated by arrow 1012 in FIG10 ). Assume that base station 1102 is currently operating three opportunistic networks 1006 , 1007 and 1008 .

Since the tracking area has changed, the mobile terminal 1101 performs a tracking area update and transmits a corresponding tracking area update (TAU) request message 1106 to the base station 1102 in 1105 .

In 1107, the base station 1102 processes the tracking area update request message 1106 as usual by forwarding it to the relevant MME 1103. Furthermore, in 1108, it obtains the opportunistic network capabilities of the mobile terminal 1101 by querying the HLR/HSS 1104. To this end, the HLR/HSS stores the opportunistic network capabilities (i.e., a list of supported short-range technologies including further details, such as supported versions and maximum data rates) for each mobile terminal 1101. In this example, the mobile terminal 1101 supports IEEE 802.11n.

At 1109, base station 1102 checks whether at least one opportunistic network using a short-range technology supported by mobile terminal 1101 is currently operating in its coverage area. To this end, base station 1102 stores a list of opportunistic networks (i.e., access details (opportunistic network type, opportunistic network name, frequency band, etc.) for each currently operating opportunistic network) and the location of the corresponding relay mobile terminal 1104. According to the scenario shown in FIG10 , since three opportunistic networks 1006, 1007, and 1008 are assumed to be currently operating and using IEEE 802.11n, this check is positive. Therefore, base station 1102 decides to advertise these opportunistic networks to mobile terminal 1101. To provide more accurate advertising, base station 1102 only advertises opportunistic networks that are or will be in the vicinity of mobile terminal 1101. To this end, at 1110, base station 1102 transmits a location request message to mobile terminal 1101 to obtain mobile terminal 1101's current location, speed, and direction of movement.

In 1112, the mobile terminal 1101 answers the location request 1111 by transmitting its location, speed and direction of movement to the base station 1102 using a location notification message 1113. It obtains this data by using, for example, GPS (Global Positioning System) or cellular-based positioning methods.

Based on the received location information, base station 1102 selects an opportunistic network that is in the vicinity of mobile terminal 1101 or that can be expected to be in the vicinity of mobile terminal 1101 based on its current direction of movement. In this example, base station 1102 selects first opportunistic network 1006 and second opportunistic network 1007. At 1114, base station 1102 sends access details of the selected opportunistic network (at least one of the following parameters: opportunistic network type (e.g., IEEE 802.11n), opportunistic network name, frequency band, password required for access, an indication of the current load (e.g., number of connected mobile terminals 1101, average unoccupied resources, available QoS, etc.)) to mobile terminal 1101 using an ON advertisement message 1115.

The advertisement process ends after the mobile terminal 1101 receives the ON advertisement message 1115. In 1116, the mobile terminal 1101 has two options: the mobile terminal 1101 may immediately attempt to connect to one of the opportunistic networks indicated in the received ON advertisement message 1115, or the mobile terminal 1101 may store the access details and attempt to connect to one of the opportunistic networks if a connection to the core network 1001 is required. The decision of the mobile terminal 1101 as to which opportunistic network to connect to may depend on the received access details.

The method described with reference to FIG11 is well suited for situations where the mobile terminal 1101 has not temporarily changed its distance from the advertised opportunistic network (e.g., where the mobile terminal 1101 and the opportunistic network (i.e., at least the corresponding relay mobile terminal 1004) are both located on the same bus or train).

In the following, an embodiment in which opportunistic network advertising is performed after the opportunistic network list is changed is described with reference to FIG. 12 .

FIG12 shows a message flow diagram 1200 according to an embodiment.

The message flow occurs between the first mobile terminal 1201 , the second mobile terminal 1202 and the base station 1203 .

In 1204, the base station 1102 detects a change in the opportunistic network being operated. This may be:

● The opportunistic network ceases to operate (e.g. because the corresponding relay mobile terminal is no longer willing or able to provide a connection to the cellular mobile communication network for mobile terminals using the opportunistic network, is no longer willing or able to operate as a relay node for the base station 1102, or because the relay mobile terminal has left the radio cell operated by the base station).

● Opportunistic networking begins operations.

• Relaying mobile terminals to report changes in access properties (eg location, number of mobile terminals using the opportunistic network, amount of free resources, changed maximum bit rate of the cellular radio link, ...).

In 1205 , the base station 1102 updates an entry in a list of opportunistic networks, eg, an entry in a list of opportunistic networks available in a radio cell operated by the base station 1102 .

In 1206, base station 1102 selects one or more mobile terminals for which opportunistic network advertisements should be transmitted, and determines which type of opportunistic network advertisement should be transmitted (with access details or with measurement configuration). If base station 1102 wishes to decide whether a mobile terminal should access a particular opportunistic network, base station 1102 selects an opportunistic network advertisement with measurement configuration. If base station 1102 wishes for the mobile terminal to independently decide to access a particular opportunistic network, base station 1102 selects an opportunistic network advertisement with access details. Only mobile terminals that are in, or can be expected to be in, the vicinity of the opportunistic network that caused the update in 1205 and that support the short-range technology used by the opportunistic network that caused the update in 1205 are selected. Furthermore, not all changes are reported by base station 1102. In this example, opportunistic network advertisements are transmitted only when an opportunistic network begins operating.

In the following, it is assumed that the opportunistic network starts operating and the base station 1102 selects the first mobile terminal 1201 and the second mobile terminal 1202 because the first mobile terminal 1201 and the second mobile terminal 1202 are in the vicinity of the opportunistic network and support the short range technology of the opportunistic network.

The base station 1102 determines that the first mobile terminal 1201 should decide for itself when and whether to connect to the opportunistic network. The second mobile terminal 1202 should report measurement results of the opportunistic network so that the base station 1102 can decide when the second mobile terminal 1202 should connect to the opportunistic network. Therefore, the base station 1102 transmits a first opportunistic network advertisement message 1212 with access details of the opportunistic network to the first mobile terminal 1201 in step 1207.

In 1208 , the first mobile terminal 1201 connects to the opportunistic network.

Furthermore, in 1209 , the base station 1102 transmits a second ON advertisement message 1210 with a measurement configuration for the opportunistic network to the second mobile terminal 1202 .

In 1211, the second mobile terminal 1202 starts measuring the opportunistic network and reports the results to the base station 1102, as indicated in the received second ON advertisement message 1210. If the measurement report meets certain criteria (e.g., the signal level of the opportunistic network is above a certain threshold), it is decided by the base station 1102 to transmit a handover command.

While the present invention has been particularly shown and described with reference to certain embodiments, it will be understood by those skilled in the art that various changes in form and details may be made thereto without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is therefore indicated by the appended claims and all changes that come within the meaning and range of equivalents of the claims are therefore intended to be embraced.

Claims (24)

1. A device used in a communication apparatus, the device comprising: The detector is configured to: Detecting whether the first UE is operating as a relay UE based on at least one radio signal from the first user equipment (UE), and Detecting requests associated with network connectivity via a relay UE based on at least one radio signal from a second UE; and A signaling circuit coupled to the detector, the signaling circuit being configured to: When the first UE operates as a relay UE, it sends a signal to the second UE to notify the second UE of information that facilitates the second UE's selection of the first UE based on the network connectivity of the second UE via the first UE. 2. The device according to claim 1, wherein the information is associated with the location of the first UE. 3. The device according to claim 1, further comprising: Storage circuitry, adapted to store information associated with multiple UEs operating as relay UEs. 4. The device according to claim 1, The first UE and the second UE operate in the Evolved Universal Mobile Telecommunications System Terrestrial Radio Access Network (E-UTRAN). 5. The device according to claim 4, further comprising: A list generation circuit is configured to generate a list of other UEs operating as relay UEs in a radio cell, wherein the list generation circuit is configured to include a first UE in the list if a first UE is detected operating as a relay UE. 6. The device according to claim 4, The device is included in the LTE network. 7. The device according to claim 4, further comprising: An update circuit is configured to update the list in response to detecting that one of the other UEs in the list has exited as a relay UE. 8. The device according to claim 7, The update circuit is configured to update the list at predetermined time points. 9. The device according to claim 1, In order to detect whether the first UE is operating as a relay UE based on at least one radio signal from the first UE, the detector is configured to determine whether the first UE has exited operation as a relay UE or has started operation as a relay UE. 10. The device according to claim 1, In order to detect whether the first UE is operating as a relay UE based on at least one radio signal from the first UE, the detector is configured to: Detect whether the expected signal has been received from the first UE, and When the expected signal is not received from the first UE, the first UE is considered not to operate as a relay UE. 11. The device according to any one of claims 1 to 10, further comprising: A receiver configured to receive signals associated with a relay UE. 12. A device included in a user equipment "UE", the device comprising: The signaling circuit, which is: Send a request to the communication device related to network connectivity via the relay UE, and Based on the request, information is received from the communication device to facilitate the selection of a relay UE for network connectivity; and Processor, which: Selecting a relay UE based on the received information, and Controls the establishment of links with the selected relay UE based on network connectivity. 13. The device according to claim 12, wherein: The signaling circuit sends the request according to the first radio access technology "RAT", and The processor controls the establishment of the link with the relay UE according to the second RAT. 14. The device of claim 13, wherein the first RAT includes communication via a cellular communication protocol, and the second RAT includes communication via a short-range communication protocol. 15. The device according to any one of claims 12 to 14, wherein the information associated with the relay UE includes information associated with the location of the relay UE. 16. A method performed in a communication device, the method comprising: The communication device detects whether the first UE is operating as a relay UE based on at least one radio signal from the first user equipment (UE). The communication device detects a request associated with network connectivity via the relay UE based on at least one radio signal from the second UE; and When the first UE operates as a relay UE, the communication device sends a signal to the second UE to notify information that facilitates the selection of the first UE based on network connectivity via the first UE. 17. The method of claim 16, wherein the information is associated with the location of the first UE. 18. The method of claim 16, further comprising: The communication device stores information associated with multiple UEs that are instructed to operate as relay UEs. 19. The method of claim 16, wherein the first UE and the second UE operate in the Evolved Universal Mobile Telecommunications System Terrestrial Radio Access Network (E-UTRAN). 20. A device used in a communication apparatus, the device comprising: A means for detecting whether a first user equipment (UE) is operating as a relay UE based on at least one radio signal from a first user equipment (UE); A means for detecting a request associated with network connectivity via a relay UE based on at least one radio signal from a second UE; and A means for signaling to a second UE, when the first UE is operating as a relay UE, information for facilitating the selection of the first UE based on network connectivity via the first UE. 21. The device of claim 20, wherein the information is associated with the location of the first UE. 22. The apparatus of claim 20, further comprising: A means for storing information associated with multiple UEs operating as relay UEs. 23. The apparatus of claim 20, wherein the first UE and the second UE operate in the Evolved Universal Mobile Telecommunications System Terrestrial Radio Access Network (E-UTRAN). 24. At least one computer-readable medium including instructions that, when executed by a device, cause the device to perform the method according to any one of claims 16 to 19.