KR20090090626A - How to send and receive broadcast messages in a wireless communication system - Google Patents

Abstract

A broadcast message transmission method in a wireless communication system is provided. The method includes defining a connection to uplink or downlink information, transmitting a first broadcast message including a count, defining a characteristic of a physical channel, and determining a configuration change count and transmission period corresponding to the count. Transmitting a second broadcast message that includes. In the idle mode, the broadcast message may be received to minimize power consumption, thereby increasing the use time of the terminal.

Description

How to send and receive broadcast messages in a wireless communication system {METHOD OF TRANSMITTING AND RECEIVING BROADCAST MESSAGE IN WIRELESS COMMUNICATION SYSTEM}

The present invention relates to wireless communication, and more particularly, to a method for transmitting and receiving broadcast messages in a wireless communication system.

The Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard provides technologies and protocols to support broadband wireless access. Standardization has been in progress since 1999, and IEEE 802.16-2001 was approved in 2001. It is based on a single carrier physical layer called 'WirelessMAN-SC'. Later, in the IEEE 802.16a standard approved in 2003, 'WirelessMAN-OFDM' and 'WirelessMAN-OFDMA' were added to the physical layer in addition to 'WirelssMAN-SC'. After the completion of the IEEE 802.16a standard, the revised IEEE 802.16-2004 standard was approved in 2004. In order to correct bugs and errors in the IEEE 802.16-2004 standard, IEEE 802.16-2004 / Cor1 was completed in 2005 in the form of 'corrigendum'.

The communication channel between the base station and the terminal is largely composed of a downlink (DL, downlink) channel from the base station to the terminal and an uplink (UL, uplink) channel from the terminal to the base station.

A broadcast message is a downlink message transmitted by a base station to all terminals in a cell. The broadcast message provides the terminal with general information for communicating with the base station, including system information and characteristics of the physical channel. Broadcast messages used in the IEEE 802.16 standard include a downlink channel descriptor (DCD), an uplink channel descriptor (UCD) message, and a MAP message. The MAP message is further divided into a DL-MAP including downlink information and a UL-MAP including uplink information.

In general, a state mode of a terminal may be divided into an idle mode and an active mode. The idle mode is provided to save power and resources of the base station when the terminal has little communication with the base station. In the idle mode, all normal operation operations as well as handover (HO) are stopped, and only downlink synch is set so that only a paging message can be received at a certain interval. . In the idle mode, the UE wakes up at a certain listening interval and receives a paging message or takes an action corresponding to it. In the active mode, the UE continuously communicates with and receives data from the BS. The terminal in the active mode may use a sleep mode to minimize power usage. In the sleep mode, the UE wakes up at a certain availability interval and receives all downlink transmissions in the same manner as in a normal operation.

The broadcast message is information that the terminal should receive in order to receive data from the base station or to transmit data to the base station. Therefore, the terminal receives the broadcast message periodically or occurrence of the event. However, reception of broadcast messages is problematic in idle mode. In the case of a broadcast message transmitted in a relatively large period such as a DCD / UCD message, if the listening period and the transmission period of the DCD / UCD message do not coincide in the idle mode, the UE may remain in standby mode to receive the DCD / UCD message. have. This causes the terminal in the idle mode to wake up for a long time, causing power consumption. There is a need for a method that can receive a broadcast message to reduce power consumption of the terminal.

An object of the present invention is to provide a broadcast message transmission / reception method for reducing power consumption of a terminal in a wireless communication system.

In one aspect, a method of transmitting broadcast messages in a wireless communication system is provided. The method includes defining a connection to uplink or downlink information, transmitting a first broadcast message including a count, defining a characteristic of a physical channel, and determining a configuration change count and transmission period corresponding to the count. Transmitting a second broadcast message that includes.

In another aspect, a method of receiving a broadcast message in a wireless communication system is provided. The method includes receiving a first broadcast message that includes an update indicator and receiving a second broadcast message that is updated according to the indication of the update indicator and periodically transmitted.

Power consumption of the terminal can be prevented by not decoding until the broadcast message is updated. In addition, in the idle mode, the broadcast message may be received to minimize power consumption, thereby increasing the use time of the terminal.

1 is a block diagram illustrating a wireless communication system. Wireless communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.

Referring to FIG. 1, a wireless communication system includes a mobile station (MS) 10 and a base station 20 (BS). The terminal 10 may be fixed or mobile, and may be called by other terms such as a user equipment (UE), a user terminal (UT), a subscriber station (SS), a wireless device, and the like. The base station 20 generally refers to a fixed station for communicating with the terminal 10 and may be referred to in other terms such as a NodeB, a base transceiver system (BTS), and an access point. . One or more cells may exist in one base station 20.

Downlink (DL, downlink) means communication from the base station 20 to the terminal 10, uplink (UL, uplink) means communication from the terminal 10 to the base station 20.

The wireless communication system may be an Orthogonal Frequency Division Multiplexing (OFDM) / Orthogonal Frequency Division Multiple Access (OFDMA) based system. OFDM uses multiple orthogonal subcarriers. OFDM uses orthogonality between inverse fast Fourier Transform (IFFT) and fast Fourier Transform (FFT). At the transmitter, data is sent by performing an IFFT. The receiver performs FFT on the received signal to recover the original data. The transmitter uses an IFFT to combine multiple subcarriers, and the receiver uses a corresponding FFT to separate multiple subcarriers.

2 is a block diagram illustrating elements of a terminal.

Referring to FIG. 2, the terminal 50 includes a processor 51, a memory 52, an RF unit 53, a display unit 54, and a user interface unit. , 55). The processor 51 is responsible for transmitting and receiving a physical layer or medium access control (MAC) message. The following data transmission and reception method may be implemented through the processor 51. The memory 52 is connected to the processor 51 to store a terminal driving system, an application, and a general file. The display unit 54 displays various information of the terminal, and may use well-known elements such as liquid crystal display (LCD) and organic light emitting diodes (OLED). The user interface unit 55 may be a combination of a well-known user interface such as a keypad or a touch screen. The RF unit 53 is connected to a processor and transmits and / or receives a radio signal.

3 shows an example of a frame structure. A frame is a sequence of data for a fixed time used by physical specifications. This may be referred to section 8.4.4.2 of the IEEE standard 802.16-2004 "Part 16: Air Interface for Fixed Broadband Wireless Access Systems" (hereafter reference 1).

Referring to FIG. 3, the frame includes a downlink (DL) subframe and an uplink (UL) subframe. Time Division Duplex (TDD) is a method in which uplink and downlink transmissions share the same frequency but occur at different times. The downlink subframe is temporally ahead of the uplink subframe. The downlink subframe starts with a preamble, a frame control header (FCH), a downlink (DL) -MAP, an uplink (MAP) -MAP, and a burst region. A guard time for distinguishing the downlink subframe and the uplink subframe is inserted in the middle part (between the downlink subframe and the uplink subframe) and the last part (after the uplink subframe) of the frame. A transmit / receive transition gap (TGT) is a gap between a downlink burst and a subsequent uplink burst. A receive / transmit transition gap (RTG) is a gap between an uplink burst and a subsequent downlink burst. Slots are the smallest possible data allocation units, defined by time and subchannels. The number of subchannels depends on the FFT size and the time-frequency mapping. The subchannel includes a plurality of subcarriers, and the number of subcarriers per subchannel depends on a permutation scheme. Permutation means mapping logical subchannels to physical subcarriers. In FUSC (Full Usage of Subchannels), a subchannel includes 48 subcarriers, and in Partial Usage of Subchannels (PUSC), a subchannel includes 24 or 16 subcarriers. A segment refers to at least one subchannel set. The bin includes 9 contiguous subcarriers on the OFDM symbol. A band refers to a group of four rows of bins, and an adaptive modulation and coding (AMC) subchannel consists of six contiguous bins in the same band.

The preamble is used for initial synchronization, cell search, frequency offset, and channel estimation between the base station and the terminal. The FCH includes the length of the DL-MAP message and the coding scheme information of the DL-MAP.

The IEEE 802.16 standard uses two types of broadcast messages for data exchange between a base station and a terminal. A MAP message defines access to uplink / downlink information in a frame, and a channel descriptor message defines characteristics of a physical channel. The channel descriptor message includes a downlink channel descriptor (DCD) message and an uplink channel descriptor (UCD) message. The count of the MAP message corresponds to the configuration change count (CCC) of the channel descriptor message. For example, in the downlink direction, the UE checks where its data is allocated in the frame through the DL-MAP message, and physically included in the DCD message having the CCC corresponding to the count of the DL-MAP message. Decode the data using the channel characteristics.

DL-MAP is an area where a DL-MAP message is transmitted.

The DL-MAP message is a broadcast message that defines access to downlink information. The DL-MAP message includes a PHY Synchronization Field, a DCD Count, a Base Station ID, and the like. An example of the DL-MAP message format is as follows.

The physical synchronization field includes a frame duration code, a frame number, and the like. The DCD count corresponds to the CCC of a downlink channel descriptor (DCD) message, which defines a downlink burst profile applied to this map. The base station ID identifies the base station.

A downlink channel descriptor (DCD) message is a broadcast message that defines characteristics of a downlink physical channel. The DCD message includes a configuration change count (CCC), a downlink burst profile, and the like. An example of the DCD message format is as follows.

The CCC is incremented by 1 each time the DCD message is updated. For example, when the size of the CCC is 8 bits, the value of the CCC is increased by 1 modulo 256.

The downlink burst profile defines the characteristics of the physical layer associated with the downlink interval usage code (DIUC). DIUC is a code identifying the downlink burst profile. The downlink burst profile includes parameters such as a modulation type, a forward error correction (FEC) code type, a preamble presence, and the like.

The downlink burst is an area where data transmitted from the base station to the terminal is transmitted. The base station transmits data using the downlink burst profile defined in the DCD message having a CCC value corresponding to the DCD count value included in the DL-MAP message. The terminal receives data using a downlink burst profile defined in a DCD message having a CCC value corresponding to the DCD count value included in the DL-MAP message.

The UL-MAP is an area in which the UL-MAP message is transmitted. The UL-MAP message is generated at the base station by allocating a connection to an uplink channel. The UL-MAP message includes a UCD Count, an allocation start time, and the like. An example of the UL-MAP message format is as follows.

The UCD count has a value corresponding to a configuration change count (CCC) of an uplink channel descriptor (UCD) message. The allocation start time is a valid start time of uplink allocation defined by the UL-MAP message.

An uplink channel descriptor (UCD) message is a broadcast message that defines characteristics of an uplink physical channel. The UCD message includes a CCC, an uplink burst profile, and the like. An example of the UCD message format is as follows.

The CCC is incremented by 1 each time the UCD message is updated. For example, when the size of the CCC is 8 bits, the value of the CCC is increased by 256 by 1 module. The uplink burst profile defines the characteristics of the physical layer associated with the uplink interval usage code (UIUC). UIUC is a code for identifying an uplink burst profile. The uplink burst profile includes parameters such as a modulation type, an FEC code type, a preamble length, a randomizer seed, and the like.

The uplink burst is an area in which data transmitted from the terminal to the base station is transmitted. The terminal transmits data using an uplink burst profile defined in a UCD message having a CCC value corresponding to the UCD count value included in the UL-MAP message.

4 is a flowchart illustrating a process of updating a DCD message of a UE in an active mode.

Referring to FIG. 4, a DL-MAP message having a DCD count value of i is referred to as DL-MAP (i), and a DCD message having a CCC value corresponding to the DCD count is represented as DCD (i). The first terminal entering a new cell receives a DCD message for connection with a base station and stores the DCD message. In order to monitor whether the DCD message is updated, the terminal decodes the DCD message whenever the DCD message is received and checks whether the CCC is changed. If the CCC has changed, the DCD message has been updated. In this case, the terminal stores the updated DCD message.

The base station transmits the DCD (i) to the terminal (S110).

The base station transmits the DL-MAP (i) to the terminal (S120). DL-MAP (i) applies a downlink burst profile defined in DCD (i) since the DCD count is i.

The base station transmits data (i) to the terminal (S125). Data i is a burst to which DCD (i) is applied. The base station transmits data i using the downlink burst profile defined in DCD (i). The terminal receives the data i using the downlink burst profile defined in the DCD (i).

The base station transmits the DL-MAP (i) to the terminal (S130).

The base station updates the DCD message, and transmits a DCD (i + 1) to the terminal (S140). DCD (i + 1) is a DCD message with CCC i + 1. Since the CCC has changed, the terminal stores the DCD (i + 1). In this case, the terminal does not discard the already stored DCD (i), but continues to store.

The base station transmits data (i) to the terminal (S145). The terminal receives the data i using the downlink burst profile defined in the DCD (i).

The base station transmits the DL-MAP (i) to the terminal (S150). The base station retransmits the DCD (i + 1) to the terminal (S160). The base station transmits data (i) to the terminal (S165). The terminal receives the data i using the downlink burst profile defined in the DCD (i). When the DCD message is updated, to ensure that each terminal in the cell receives the updated DCD message at least once, the base station schedules the transmission of the DCD message. For example, the base station does not change the DCD count of the DL-MAP message until two updated DCD messages are transmitted.

The base station transmits the DL-MAP (i + 1) to the terminal (S170). DL-MAP (i + 1) applies a downlink burst profile defined in DCD (i + 1) because the DCD count is i + 1. Thereafter, the terminal may discard the existing DCD (i) in the buffer.

The base station transmits data (i + 1) to the terminal (S175). The terminal receives data i + 1 using a downlink burst profile defined in DCD (i + 1).

The base station transmits a DCD (i + 1) to the terminal (S180). The terminal decodes the DCD (i + 1) and checks whether the CCC is changed.

5 is a flowchart illustrating a process of updating a UCD message of a UE in an active mode.

Referring to Figure 5, the base station transmits the UCD (i) to the terminal (S210).

The base station transmits the UL-MAP (i) to the terminal (S220). Since the UL-MAP (i) has a UCD count of i, the uplink burst profile defined in UCD (i) is applied.

The terminal transmits data (i) to the base station according to the allocation information defined in UL-MAP (i) (S225). The terminal transmits data (i) using an uplink burst profile defined in UCD (i).

The base station transmits the UL-MAP (i) to the terminal (S230).

The base station updates the UCD message, and transmits the UCD (i + 1) to the terminal (S240).

The terminal transmits data (i) to the base station according to the allocation information defined in UL-MAP (i) (S245). The terminal transmits data (i) using an uplink burst profile defined in UCD (i).

The base station transmits the UL-MAP (i) to the terminal (S250). The terminal transmits data (i) to the base station (S255). The base station retransmits UCD (i + 1) to the terminal (S260). The UE decodes the UCD (i + 1) and checks whether the CCC is changed.

When the UCD message is updated, in order to ensure that each terminal in the cell receives the updated UCD message at least once, the base station schedules the transmission of the UCD message. Herein, the base station does not change the UCD count of the UL-MAP message until two updated UCD messages are transmitted, but does not limit when to change the UCD count of the UL-MAP message. .

The base station transmits the UL-MAP (i) to the terminal (S270). Since the UL-MAP (i) has a UCD count of i, the uplink burst profile defined in UCD (i) is applied.

The terminal transmits data (i) to the base station by using the allocation information defined in the UL-MAP (i) (S275).

The base station transmits the UL-MAP (i + 1) to the terminal (S280). Since the UL-MAP (i + 1) has changed the UCD count to i + 1, the UL-MAP (i + 1) applies an uplink burst profile defined in UCD (i + 1). Thereafter, the UE may discard the existing UCD (i) in the buffer.

The terminal transmits data (i + 1) to the base station (S285). The terminal transmits data (i + 1) using an uplink burst profile defined in UCD (i + 1).

The base station transmits the UCD (i + 1) to the terminal (S290). The UE decodes the UCD (i + 1) and checks whether the CCC is changed.

In downlink transmission, the terminal should always check the MAP message, but does not always need to check the entire channel descriptor message. This is because the characteristics of the physical channel are defined once and then continue to use the same unless there is a separate update. Therefore, the terminal checks whether the CCC of the channel descriptor message is changed, and if the CCC is not changed, it is not necessary to check the remaining part of the channel descriptor message.

6 is an exemplary diagram illustrating an example of a process of updating a channel descriptor message of a terminal in an idle mode.

Referring to FIG. 6, the terminal operates in an unavailable interval or listening interval in an idle mode. The unused section is a section in which no data is transmitted and received by lowering the power, and the listening section is a section in which the terminal wakes up for data reception. In the idle mode, the terminal receives a broadcast message during the listening interval to check whether data is transmitted and / or received. The transition to the idle mode is performed by the terminal requesting the transition to the idle mode with a DREG-REQ (De-registration Request) message to the base station, or the terminal receives a DREG-CMD (de / reregister command) message from the base station. Is done.

During the unavailable period, the terminal may scan the neighbor base station or reselect the preferred base station. However, the terminal cannot receive downlink data or transmit uplink data.

During the listening period, the terminal may wake up and receive a broadcast message. If the received broadcast message is a channel descriptor message, the terminal may check the CCC of the channel descriptor message and check whether it is updated. However, since the channel descriptor message is not always transmitted, the channel descriptor message updated during the unavailable period may not be received. To this end, the IEEE 802.16 standard provides broadcast control pointers. The broadcast control pointer is included in the DL-MAP message and transmitted, and includes information on a frame in which a channel descriptor message updated to the terminal is transmitted. The following is an example of an information element (IE) of a broadcast control pointer.

The DCD_UCD transmission frame refers to a frame in which the DCD and / or the UCD are transmitted.

The terminal receiving the broadcast control pointer during the listening interval wakes up and receives the channel descriptor message even if the period in which the frame indicated by the broadcast control pointer is transmitted belongs to an unusable interval. If the decoding of the channel descriptor message succeeds, the terminal enters into an unavailable period again.

The channel descriptor update process of the idle mode terminal of FIG. 6 may be applied to the channel descriptor update process of the sleep mode terminal. In this case, the listening interval of FIG. 6 is an availability interval of the sleep mode.

7 is an exemplary diagram illustrating another example of a process of updating a channel descriptor message of a terminal in an idle mode.

Referring to FIG. 7, a terminal receiving a broadcast control pointer during a listening interval wakes up and receives a channel descriptor message even if a period in which a frame indicated by the broadcast control pointer is transmitted belongs to an unusable interval.

The channel descriptor message may not be received or the decoding of the received channel descriptor message may fail. At this time, the terminal should continue to decode all subsequent frames until it successfully receives the updated channel descriptor message without waking down the power. In other words, the terminal must stay awake. Only after receiving a successfully updated channel descriptor message will it return to normal idle mode.

The terminal receives the channel descriptor message through a frame indicated by the broadcast control pointer. However, if the terminal does not successfully receive the updated channel descriptor message, it should continue to wait in the reception state. This may cause unnecessary battery consumption of the terminal.

The process of updating the channel descriptor of the idle mode terminal of FIG. 7 may be applied to the process of updating the channel descriptor of the sleep mode terminal. In this case, the listening section of FIG. 7 is an available section of the sleep mode.

8 illustrates a broadcast message transmission method according to an embodiment of the present invention.

Referring to FIG. 8, the base station sends a MAP message, that is, a DL-MAP message and / or a UL-MAP message, to the terminal (S310). The base station sends a DCD message having a CCC corresponding to the DCD count of the DL-MAP message to the terminal (S320). The DCD message includes information about a DCD interval. The DCD period is a period during which a DCD message is transmitted.

The base station sends a DL-MAP message and / or UL-MAP message to the terminal (S330), the base station sends a UCD message having a CCC corresponding to the UCD count of the UL-MAP message to the terminal (S340). The UCD message contains information about the UCD Interval. The UCD period is a period during which UCD messages are transmitted. The base station explicitly informs the terminal of the transmission period of the channel descriptor message so that the terminal can receive the channel descriptor message every transmission period.

The base station sends a DL-MAP message and / or UL-MAP message to the terminal (S350). The base station sends a DCD message to the terminal every DCD cycle (S360). The base station sends a UCD message to the terminal every UCD cycle (S370).

Various methods can be used to include the transmission period in the channel descriptor message. The following table shows an example of a format of a DCD message including a DCD period.

The following table shows an example of a UCD message format including a UCD cycle.

The position or size of the DCD period and the UCD period shown in the above tables are merely exemplary, and those skilled in the art may include the DCD period and the UCD period in the DCD / UCD message in various ways. For example, the DCD / UCD period may be included in the form of TLV (type / length / value) encoded information of the DCD / UCD message. In addition, the DCD / UCD period is not always included in the DCD / UCD message, but may be selectively included when necessary.

The base station may inform the user equipment through a separate message without including the DCD / UCD period in the DCD / UCD message. For example, the DCD / UCD period may be sent in a MAP message, or may be sent with other data.

9 is a flowchart illustrating a DCD message update process of a terminal in an active mode according to an embodiment of the present invention.

Referring to FIG. 9, the base station transmits a DCD (i) to the terminal. At this time, the base station may inform the terminal of the DCD period through the DCD (i). The base station transmits DL-MAP (i) to the terminal. DL-MAP (i) applies a downlink burst profile defined in DCD (i) since the DCD count is i. The base station transmits data i to the terminal. The terminal receives the data i using the downlink burst profile defined in the DCD (i). The base station transmits DL-MAP (i) to the terminal.

In the DCD period, the base station transmits DCD (i). At this time, the terminal does not need to decode the DCD (i) (indicated by a dotted line). This is because, if the DL-MAP message including the same DCD count is being transmitted, it is known that the same DCD message as the previously received DCD message. The base station then transmits DL-MAP (i + 1). Since the DCD count has changed from i to i + 1, the UE can recognize the update of the DCD message. The base station transmits data i to the terminal.

The base station transmits the updated DCD (i + 1) to the terminal in the DCD period. Since the CCC has been changed, the terminal decodes the DCD (i + 1), and stores the DCD (i + 1). The DCD count of the received DL-MAP message is set to i + 1, and data is received using DCD (i + 1).

The terminal checks whether the DCD message is updated through the CCC corresponding to the DCD count. Since the DCD message is transmitted periodically, the base station and the terminal can know when the updated DCD message is transmitted. Therefore, since the updated DCD may be applied to the data immediately after receiving the updated DCD message, the terminal may immediately discard the existing DCD (i) after receiving the updated DCD message.

10 is a flowchart illustrating a process of updating a UCD message of a terminal in an active mode according to an embodiment of the present invention.

Referring to FIG. 10, the base station transmits UCD (i) to the terminal. At this time, the base station may inform the UE of the UCD period through the UCD (i). And, the base station transmits UL-MAP (i) to the terminal. Since the UL-MAP (i) has a UCD count of i, the uplink burst profile defined in UCD (i) is applied. The terminal transmits data (i) to the base station. The terminal transmits data (i) using an uplink burst profile defined in UCD (i). The base station transmits the UL-MAP (i) to the terminal.

In the UCD period, the base station transmits UCD (i). At this time, the UE does not need to decode UCD (i) (it is indicated by a dotted line). This is because, if a UL-MAP message including the same UCD count is being transmitted, it can be seen that it is the same UCD message as the previously received UCD message. And, the base station transmits UL-MAP (i + 1). Since the UCD count has changed from i to i + 1, the UE can recognize the update of the UCD message. The terminal transmits data (i) to the base station.

In the UCD period, the base station transmits the updated UCD (i + 1) to the terminal. Since the CCC has changed, the terminal decodes UCD (i + 1) and stores UCD (i + 1). The UCD count of the received UL-MAP message is set to i + 1, and data is transmitted using UCD (i + 1).

The UE checks whether the UCD message is updated through the CCC corresponding to the UCD count. Since the UCD message is transmitted periodically, the base station and the terminal can know when the updated UCD message is transmitted. Therefore, since the updated UCD can be applied to the data immediately after receiving the updated UCD message, the UE can discard the existing UCD (i) immediately after receiving the updated UCD message.

11 is an exemplary diagram illustrating a process of updating a channel descriptor message of a terminal in an idle mode according to an embodiment of the present invention.

Referring to FIG. 11, a terminal receiving a broadcast control pointer during a listening interval wakes up and receives a channel descriptor message even if a period in which a frame indicated by the broadcast control pointer is transmitted belongs to an unusable interval. The broadcast control pointer contains information about the DCD or UCD period. The DCD or UCD period represents the transmission period of subsequent DCD or UCD messages.

The following table shows an example of a format of a broadcast control pointer including a DCD or UCD period (DCD_UCD interval).

The above table is merely an example, and a person skilled in the art may include information about a DCD or UCD period in a broadcast control pointer in various ways.

Even if the channel descriptor message is not received or the decoding of the received channel descriptor message fails, the UE knows when the next channel descriptor message is transmitted through a DCD or UCD period. Therefore, the terminal lowers the power and enters into an unavailable section.

The UE wakes up in the next DCD or UCD transmission period and receives a channel descriptor message. Although the terminal fails to receive the channel descriptor message through the frame indicated by the broadcast control pointer, the terminal may not wake up continuously and wake up in the next transmission period to receive the channel descriptor message. Therefore, power consumption of the terminal can be minimized.

The process of updating the channel descriptor of the idle mode terminal of FIG. 11 may be applied to the process of updating the channel descriptor of the sleep mode terminal. In this case, the listening section of FIG. 11 is an available section of the sleep mode.

12 is an exemplary view illustrating a broadcast message transmission method according to another embodiment of the present invention.

Referring to FIG. 12, the base station sends a DCD message every DCD period. After the UE receives and decodes the DCD message, it is not necessary to decode the DCD message periodically transmitted from the base station until the DCD message is updated. The DCD message indicated by the dotted line indicates that the terminal does not need to decode because it is not updated.

The DL-MAP message may include an update indicator (hereinafter referred to as an UI) to inform the update of the DCD message (from DCD (i) to DCD (i + 1)). The UI informs whether a subsequent DCD message is updated. For example, if the size of the UI is 1 bit, '1' may indicate that the DCD message has been updated, and '0' may indicate that the DCD message has not been updated. The terminal receives and decodes the subsequent updated DCD message only when it is confirmed that the subsequent DCD message is updated through the UI of the DL-MAP message.

After the base station receives the updated DCD (i + 1), the base station transmits data (i + 1) to which the DCD (i + 1) is applied.

Since the UE knows the DCD period, it can always predict in which frame the DCD message will be transmitted. The terminal decodes the DCD message only after confirming whether the DCD is updated through the UI included in the DL-MAP message. The DCD message is not received until the update of the DCD is indicated by the UI of the DL-MAP. Therefore, power consumption of the terminal due to decoding of the DCD can be reduced.

13 is an exemplary diagram illustrating a broadcast message transmission method according to another embodiment of the present invention.

Referring to FIG. 13, the base station sends a UCD message every UCD period. After the UE receives and decodes the UCD message, the UE does not need to decode the UCD message periodically transmitted from the base station until the UCD message is updated. The UCD message indicated by the dotted line indicates that the UE does not need to decode it because it is not updated.

The UL-MAP message may include a UI to inform the update of the UCD message (DCD (i) to DCD (i + 1)). The UI informs whether the subsequent UCD message is updated. For example, if the size of the UI is 1 bit, '1' may indicate that the UCD message has been updated, and '0' may indicate that the UCD message has not been updated. The terminal receives and decodes the subsequent updated UCD message only when it is confirmed through the UI of the UL-MAP message that the subsequent UCD message has been updated.

After receiving the updated UCD (i + 1), the terminal transmits data (i + 1) to which the UCD (i + 1) is applied to the base station.

Since the UE knows the UCD period, it can always predict which frame the UCD message will be transmitted through. The UE decodes the UCD message only after confirming whether the UCD is updated through the UI included in the UL-MAP message. The UCD message is not received until the update of the UCD is indicated by the UI of the UL-MAP. Therefore, power consumption of the terminal due to decoding of the UCD can be reduced.

14 is an exemplary view illustrating a broadcast message transmission method according to another embodiment of the present invention.

Referring to FIG. 14, unlike the embodiment of FIG. 12, after the DCD (i + 1) is received, the updated DCD is not applied immediately, but after waiting for the DCD transition interval, the updated DCD is applied to the data. Apply. Also, the changed DCD count is applied to the DL-MAP after the DCD transition interval expires. The DCD transition interval may inform the UE in advance by the base station.

15 is an exemplary view illustrating a broadcast message transmission method according to another embodiment of the present invention.

Referring to FIG. 15, unlike the embodiment of FIG. 13, the updated UCD is not applied immediately after receiving the UCD (i + 1), but waits for the UCD transition interval, and then updates the updated UCD to the data. Apply. Also, the changed UCD count is applied to the UL-MAP after the UCD transition interval expires. The UCD transition interval may inform the terminal in advance to the terminal.

16 is a diagram illustrating a broadcast message transmission method according to another embodiment of the present invention.

Referring to FIG. 16, the base station informs the transmission number N of the updated DCD in the terminal. Here, N = 2 is illustrated, but N may be set to an integer greater than or equal to one. The terminal applies the updated DCD to the data after receiving the DCD (i + 1) by the number of transmissions N. Accordingly, the time when DCD (i + 1) is applied to data and / or DL-MAP is a DCD period * N, which is called a DCD update indication period.

17 is a diagram illustrating a broadcast message transmission method according to another embodiment of the present invention.

Referring to FIG. 17, the base station informs the transmission number N of the updated UCD in the terminal. Here, N = 2 is illustrated, but N may be set to an integer greater than or equal to one. The terminal receives the UCD (i + 1) by the number of transmissions N and then applies the updated UCD to the data. Accordingly, the time when UCD (i + 1) is applied to data and / or UL-MAP becomes a UCD period * N, which is called a UCD update indication period.

All of the above functions may be performed by a processor such as a microprocessor, a controller, a microcontroller, an application specific integrated circuit (ASIC), or the like according to software or program code coded to perform the function. The design, development and implementation of the code will be apparent to those skilled in the art based on the description of the present invention.

Although the present invention has been described above with reference to the embodiments, it will be apparent to those skilled in the art that the present invention may be modified and changed in various ways without departing from the spirit and scope of the present invention. I can understand. Therefore, the present invention is not limited to the above-described embodiment, and the present invention will include all embodiments within the scope of the following claims.

1 is a block diagram illustrating a wireless communication system.

2 is a block diagram illustrating elements of a terminal.

3 shows an example of a frame structure.

4 is a flowchart illustrating a DCD message update process of a UE in an active mode.

5 is a flowchart illustrating a process of updating a UCD message of a UE in an active mode.

6 is an exemplary diagram illustrating an example of a process of updating a channel descriptor message of a terminal in an idle mode.

7 is an exemplary diagram illustrating another example of a process of updating a channel descriptor message of a terminal in an idle mode.

8 illustrates a broadcast message transmission method according to an embodiment of the present invention.

9 is a flowchart illustrating a DCD message update process of a terminal in an active mode according to an embodiment of the present invention.

10 is a flowchart illustrating a process of updating a UCD message of a terminal in an active mode according to an embodiment of the present invention.

11 is an exemplary diagram illustrating a process of updating a channel descriptor message of a terminal in an idle mode according to an embodiment of the present invention.

12 is an exemplary view illustrating a broadcast message transmission method according to another embodiment of the present invention.

13 is an exemplary diagram illustrating a broadcast message transmission method according to another embodiment of the present invention.

14 is an exemplary view illustrating a broadcast message transmission method according to another embodiment of the present invention.

15 is an exemplary view illustrating a broadcast message transmission method according to another embodiment of the present invention.

16 is a diagram illustrating a broadcast message transmission method according to another embodiment of the present invention.

17 is a diagram illustrating a broadcast message transmission method according to another embodiment of the present invention.

Claims (8)

In the broadcast message transmission method in a wireless communication system, Defining a connection to uplink or downlink information and transmitting a first broadcast message comprising a count; And Defining a characteristic of a physical channel and transmitting a second broadcast message comprising a configuration change count and a transmission period corresponding to the count. The method of claim 1, And wherein the second broadcast message is a channel descriptor message. The method of claim 1, And displaying whether or not the second broadcast message is updated as the count is changed. The method of claim 1, And the first broadcast message includes an update indicator indicating whether the second broadcast message is updated. The method of claim 1, And the first broadcast message is a MAP message. The method of claim 5, wherein The MAP message comprises a broadcast control pointer including a transmission period of the second broadcast message. In the broadcast message receiving method in a wireless communication system, Receiving a first broadcast message comprising an update indicator; And And receiving a second broadcast message updated according to the indication of the update indicator and periodically transmitted. The method of claim 7, wherein And after the second broadcast message is updated, data using the updated second broadcast message is further received after the transition period has elapsed.

Images