KR20060040243A - Method for efficiently transmitting and receiveing data between base station and mobile subscriber station in wireless communication system the base station and the mobile subscriber station - Google Patents

Abstract

In the wireless access communication system, the BS informs that the DCD count has changed due to the change of the DCD burst profile encodings corresponding to the DIUC even before the MSS receives the DCD message so that the MSS can receive the DL traffic smoothly. This prevents the DL traffic reception delay occurring when the MSS receives DCD burst profile encodings corresponding to the updated DIUC.

Sleep mode, sleep window, listening window

Description

Efficient data transmission and reception method between a terminal and a base station in a wireless communication system and the terminal and the base station.             

1 is a block diagram illustrating a general broadband wireless communication system;

2 is a diagram illustrating a procedure in which an MSS performs a sleep mode;

3 is a diagram illustrating a case where a conventional MSS receives downlink (DL) traffic;

4 is a diagram illustrating a case in which an MSS receives DL traffic when a DCD count is changed according to DIUC update according to an embodiment of the present invention;

5 is a diagram illustrating a case in which an MSS receives DL traffic when a DCD count changes due to an update of another field except DIUC according to an embodiment of the present invention;

6 is a block diagram of a base station according to an embodiment of the present invention;

7 illustrates a MOB_TRF_IND message according to an embodiment of the present invention;

8 is a view showing in detail the TLV encoded information structure of FIG.

9 is a diagram illustrating an operation in a base station according to an embodiment of the present invention;

10 is a block diagram of a terminal according to an embodiment of the present invention;                 

11 illustrates a DCD burst profile encodings value in a DCD message.

12 is a view showing an operation in a terminal according to an embodiment of the present invention;

The present invention relates to an efficient data transmission and reception method between a terminal and a base station in a wireless communication system, and a terminal and a base station.

1 is a diagram illustrating a configuration of a general broadband wireless communication system. Referring to FIG. 1, each MSS 10, 12 is generally mobile and is connected to the backbone network 30 via a base station (BS) 20, 22, respectively. The MSS 10, 12 allows access between the BS 20, 22 and the subscriber. Base stations (20, 22) provide control, management, and connectivity to the MSS (10, 12). In addition, the backbone network 30 is connected to an Authentication and Service Authorization Server (ASA) 40 for authentication and service authentication of the MSS 10 and 12.

On the other hand, reducing power consumption is very important for MSS supporting mobility. One way to reduce the power consumption of the MSS is to adopt a sleep mode. In the sleep mode, the MSS stops all functions other than the real time clock (RTC) and phase locked loop (PLL), such as the transmit function and the receive function. At this point, the PLL is active so that it can be restarted. In the sleep mode, the MSS wakes up periodically to search for neighbor BSs and to perform ranging or handover. Broadband wireless communication systems, such as the IEEE 802.16e system, utilize this sleep mode to reduce the power consumption of the MSS and allow the MSS to make handover decisions more smoothly.

In more detail, the MSS entering the sleep mode experiences a sleep window and a listening window. The MSS may stop transmitting and receiving data during the frame corresponding to the sleep period, reduce its power, and sometimes return to an awake state to perform periodic ranging. I can go. In addition, the MSS entering the listening window must wake up because it needs to decode the TRF-IND (Traffic Indication) message transmitted from the BS to search for DL traffic granted to the MSS. That is, the MSS needs to transition from the sleep mode to the awake state and return to the state where reception is possible.

The BS shall deliver the traffic indication to the MSS using the broadcast CID during the listening window for the MSS in the sleep mode managed by the BS. Accordingly, when the BS receives the incoming data for a specific MSS operating in the sleep mode, the BS may reach the listening window of the MSS and buffer the DL traffic until the listening window expires. You can, of course, drop such incoming data. Hereinafter, a procedure in which the MSS performs a sleep mode will be described with reference to FIG. 2.

2 is a diagram illustrating a procedure in which an MSS performs a sleep mode.

Referring to FIG. 2, the MSS 10 first transmits a MOB-SLP-REQ message to the BS 20 in step 60 so that it can enter a sleep mode. Upon receiving the MOB-SLP-REQ message, the BS 20 transmits a MOB-SLP-RSP message indicating that the MSS 10 is allowed or denied to enter the sleep mode in step 62. The MSS 10 enters the sleep mode upon receiving the MOB-SLP-RSP message from the BS 20. As described above, the MSS 10 repeatedly experiences the sleep window 70 and the listening window 72 in the sleep mode.

Subsequently, BS 20 adjusts to step 64 according to the listening window 72 of corresponding MSS 10 according to the sleepmode pattern negotiated through the MOB-SLP-REQ / MOB-SLP-RSP message. In step 66, the BS 20 informs that there is a corresponding MSS-related message and DL traffic buffered in the MOB-TRF-IND message. At this time, the BS 20 first transmits the DL-MAP to the MSS 10 before transmitting the MOB-TRF-IND message in the listening window. The DL-MAP describes the reception interval in time of each MSS, and the MSSs can know the time interval for receiving data by this DL-MAP.

When the MSS 10 receives the MOB-TRF-IND message, the MSS 10 sees the MOB-TRF-IND message, and if there is a message and DL traffic related to the MSS 10, the MSS 10 transitions to the awake state and becomes available to receive.

Meanwhile, in the broadband wireless communication system, adaptive modulation and coding (AMC) that adaptively applies modulation and coding techniques according to channel conditions between BSs 20 and 22 and MSSs 10 and 12 in each cell 50 and 52. Adopt the method. Accordingly, when the MSS 10, 12 transmits the channel state information to the BS 20, 22, the BS 20, 22 determines the modulation scheme and the coding scheme according to the channel situation to the MSS 10, 12, respectively. You will be informed. BS 20,22 and MSS 10,12 communicate according to the modulation and coding schemes determined in this way. The MSS 10, 12 processes data according to the modulation scheme and the coding scheme determined by the BS 20, 22. In this modulation scheme and coding scheme, the BS 20,22 informs the MSS 10, 12 through a Downlink Channel Descriptor (DCD) message. The DCD message is information indicating a DL channel status and is a broadcast message including an AMC table and system parameters. Information on modulation schemes and coding schemes is included in the AMC table. Downlink Interval Usage Code (DIUC) is an AMC index indicating modulation scheme and coding scheme.

The BS 20, 22 does not transmit the DCD message every frame, but transmits the MSD 10, 12 aperiodically within a predetermined range. Since the DCD message is changed according to channel conditions, a DCD count value for distinguishing each DCD message exists. The DCD count value is included in the DL-MAP and transmitted to the MSS 10, 12. Accordingly, since the MSS 10 and 12 receive the DL-MAP for each listening window, the MSS 10 and 12 may determine whether the DCD message is changed by looking at the DCD count value. In detail, the MSS 10 and 12 determine that the DCD message is changed when the DCD count value obtained in the previous listening window is different from the DCD count value received in the current listening window. In other words, in the sleep mode operation, the MSS 10 decodes the DL-MAP received from the base station during every listening window and maintains information about the DCD count value. However, the MSS 10, 12 may not know whether the change of this DCD message is caused by updating the DCD burst profile encodings corresponding to the DIUC. In other words, since the DCD burst profile encodings, which are indicators for the MSS to operate in the AMC scheme, are set in the DCD message, the DCD count changes when the value is changed. In addition, the DCD count is changed even if a portion of the DCD message other than the DCD burst profile encodings value is changed. Therefore, the MSS 10, 12 may not know what part of the DCD message has changed until it receives a new DCD message.

In sleep mode, continuous DCD message reception is not possible, and the aperiodic transmission of DCD messages makes it difficult to keep pace with sleep-window. Furthermore, since the transmission is performed after a maximum of 10 seconds in the case of a DCD message, when the DCD count is changed in sleep-window, the MSS entering the awake interval must wait for the transmission of the DCD message from the base station for up to 10 seconds. The prior art terminates the sleep mode and receives DL traffic when there is DL traffic for the MSS by the MOB-TRF-IND message. If the DCD / UCD count changes during sleep-window, the MSS does not know what part of the DCD has changed until it receives a new DCD message. Therefore, if the MSS transitions to the normal mode to receive DL traffic on the premise that the DCD count is changed, the DCD burst profile encodings value corresponding to the previously used DIUC may not be correct. Eventually, if DL traffic is received based on the DCD burst profile encodings corresponding to the wrong DIUC, the MSS will not properly decode the DL traffic, leading to continuous data loss. Furthermore, since the base station does not respond with ACK / NACK to the traffic received by the MSS, it determines that the transmission has not been properly performed and attempts to retransmit. This not only causes a waste of radio resources at the base station side, but also generates a situation in which power must be wasted for retransmission requests of data at the MSS side.

3 is a diagram illustrating a case where a conventional MSS receives DL traffic (downlink traffic).

Referring to FIG. 3, the MSS 10 and 12 first receive a DL-MAP in a listening window and then receive a MOB_TRF_IND message. When the MSS 10, 12 determines that there is DL traffic (downlink traffic) to be received with reference to the MOB_TRF_IND message, the MSS 10, 12 terminates the sleep mode and enters the normal mode to receive the DL traffic. However, if the DCS count value included in the received DL-MAP is different from the DCD count value recognized before the sleep mode, the MSS 10, 12 receives the DL until the MSS 10, 12 acquires the updated DCD message. The data loss interval T occurs because the traffic cannot be received. If the MSS knows in advance that the above-described change factor of the DCD count value is not due to the change of the DCD burst profile encodings corresponding to the DIUC, the above DL traffic transmission delay can be prevented. In the present invention, the DCD count is changed in advance because the DCD burst profile encodings value corresponding to the DIUC is changed so that the MSS can receive DL traffic in advance, the DCD burst profile encodings value corresponding to the DIUC updated MSS The present invention proposes a method for improving the delay of receiving DL traffic.

Accordingly, the present invention provides a wireless communication system including a base station and a mobile MSS that can reduce the loss interval of the received data according to the reception delay of the DCD message.                         

In addition, the present invention provides a method for reducing the loss interval of the received data according to the reception delay of the DCD message in the base station or mobile MSS of the wireless communication system.

According to an embodiment of the present invention for achieving the above object, in a wireless access communication system, a MOB_TRF_IND message for transmitting downlink traffic related information for a terminal performing a sleep mode is transmitted, but the MOB_TRF_IND message is transmitted down. A MOB_TRF_IND message generating unit including updated DIUC update information reflecting change information of any one of a modulation technique and a coding technique for link traffic, and configuring the updated DIUC update information in a type, length, and value encoding format; It includes a transmitter for transmitting the MOB_TRF_IND message. The terminal may receive the MOB_TRF_IND message and demodulate the downlink traffic to be transmitted according to the updated DIUC update information. In addition, the updated DIUC update information is composed of a DIUC value and the corresponding FEC code type.

An embodiment of the present invention for achieving the above object is a method in at least one base station for communicating with a predetermined terminal in a wireless access communication system, the DCD count according to a change in the modulation technique and coding technique used to communicate with the predetermined terminal And generating a MOB_TRF_IND message including TLV encodings to indicate that the value has been updated.

Another embodiment for achieving the object of the present invention is a method for transmitting a MOB_TRF_IND message for transmitting downlink traffic-related information for a terminal performing a sleep mode in a wireless access communication system, the MOB_TRF_IND message is to be transmitted Generating a MOB_TRF_IND message including updated DIUC update information reflecting change information of any one of modulation and coding techniques for downlink traffic, and configuring the updated DIUC update information in a type, length, and value encoding format; And transmitting the MOB_TRF_IND message.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

In an embodiment of the present invention, the MSS is notified of the updated DIUC by notifying that the DCD count has changed due to the change of the DCD burst profile encodings corresponding to the DIUC even before the MSS receives the DCD message so that the MSS can receive DL traffic smoothly. Do not delay receiving DL traffic to receive corresponding DCD burst profile encodings.

Specifically, according to an embodiment of the present invention, the BS includes the TLV encodings related to DIUC_update in the MOB-TRF-IND message to inform the MSS that the DCD count has changed due to the change of the DCD burst profile encodings corresponding to the DIUC. TLV encodings indicate that the DIUC in the DCD message has changed. Here, the TLV type format refers to an encoding format consisting of a type, a length, and a value. For example, when TLV encodings related to DIUC_update are added to the MOB-TRF-IND message, this indicates that the DCD count has been updated by changing the DCD burst profile encodings value corresponding to DIUC, and the TLV encodings are not included in the MOB-TRF-IND message. If not, it indicates that the DCD count has not been changed in relation to the DCD burst profile encodings corresponding to the DIUC.

According to an embodiment of the present invention, when the MSS receives the DL-MAP and MOB-TRF-IND messages from the BS in the listening window, the DCD count of the received DL-MAP is equal to the DCD count of the DL-MAP received in the previous listening window. In other cases, it is referred to whether TLV encodings are included in the MOB-TRF-IND message. When the MOB-TRF-IND message includes the TLV encodings related to DIUC_update, the MSS determines that the DCD count is updated by changing the DCD burst profile encodings value corresponding to the DIUC. At this time, the MSS receives the DCD again without receiving DL traffic based on the DCD burst profile encodings value corresponding to the previously used DIUC since the DCD burst profile encodings value of the DIUC has been changed but is not known. DL traffic transmitted from the base station is received on the basis of the DIUC-FEC code type pair in the DIUC_update included in the TLV encodings in the modified MOB-TRF-IND message. The BS may begin transmitting to the MSS in order of smallest data size, which may continue until the MSS receives the DCD message. When the MMS receives the DCD message, it receives DL traffic based on the DCD burst profile encodings corresponding to the newly updated DIUC, and then normal data is received.

First, with reference to FIGS. 4 and 5, a case in which the MSS receives DL traffic according to the update of the DIUC or the update of other fields except the DIUC will be described.

4 is a diagram illustrating a case in which an MSS receives DL traffic when a DCD count is changed according to a DIUC update according to an embodiment of the present invention, and FIG. 5 is an update of other fields except DIUC according to an embodiment of the present invention. The MSS receives DL traffic when the DCD count changes.

4 and 5, the MSS receives DL-MAP and MOB_TRF_IND messages for each listening window (listen window1 and listen window2). The MSS looks at the DCD counter of the received DL-MAP to determine whether the DCD message has changed. 4 and 5, when the MSS determines that the DCD message has changed in the state of receiving the DL-MAP in the listening window 2, the MSS has a DCD count value (DCD count = N) obtained in the listening window 1, which is the previous listening window. The DCD count value (DCD count = N + 1) received in the listening window 2 which is the current listening window is compared. The MSS determines that the DCD message has changed if the previous DCD count value is different from the current DCD count value. If the MSS is the same, the MSS determines that the DCD message has not been changed.

When the MSS determines that the DCD message has been changed as a result of the DCD count value comparison, the MSS determines whether the DCD burst profile encodings corresponding to the DIUC has been changed by checking whether TLV encodings are included in the MOB_TRF_IND message. The DIUC update indicator has two values. In FIG. 4 and FIG. 5, when the TLV encodings are included, the DCD count is updated by changing the DCD burst profile encodings value corresponding to the DIUC, and when the TLV encodings are not included, the DCD Indicates that the count has not changed in relation to the DCD burst profile encodings corresponding to DIUC.

Meanwhile, the MSS refers to the MOB_TRF_IND message to determine whether there is download traffic it should receive. The MSS may determine that there is data to be downloaded to itself by looking at the traffic indication bit of the MOB_TRF_IND message. When the MSS determines that there is data to be downloaded, the MSS terminates the sleep mode, transitions to the normal mode, and receives corresponding download traffic from the BS.

In this case, when the MSS determines that the DIUC of the DCD message is changed by performing the operation as stated above, the MSS receives the download traffic based on the DIUC-FEC code type pair of DIUC_update included in the TLV form in the modified MOB-TRF-IND message. do. That is, the MSS does not receive DL traffic based on the DCD burst profile encodings value corresponding to the previously used DIUC, and modifies the DL traffic transmitted from the base station until the DCD message is received again. Received based on the DIUC-FEC code type pair. At this time, the DIUC-FEC code type pair is 9 bits in total, indicating the DIUC value from the MSB (Most Significant Bit) to 4 bits, and the remaining lower 5 bits indicate the FEC code type corresponding to the DIUC.

Here, the DIUC value and the corresponding FEC code type value are set based on DCD burst profile encodings in the DCD message most recently transmitted by the base station. This continues until the MSS receives the DCD message. When the DCD message is transmitted, the MSS receives DL traffic based on the DCD burst profile encodings corresponding to the newly updated DIUC, and then normal data is received.                     

Referring to FIG. 4, the MSS receives DL traffic based on the DIUC-FEC code type pair in the MOB-TRF-IND message in the section indicated by a and newly updated DIUC in the section indicated by b after receiving the DCD message. DL traffic is received based on the corresponding DCD burst profile encodings.

In addition, if the MSS determines that the DCD count has been updated when DL traffic is received but is not related to DIUC, DIUC_update is not included in the TLV form. Therefore, the MSS uses the DL based on the DCD burst profile encoding value of the previously received DCD message. Receive traffic

Referring to FIG. 5, the MSS receives DL traffic in a DIUC corresponding to N in a DCD count in a section indicated by c, and DL based on a DCD burst profile encodings value corresponding to a newly updated DIUC in a section indicated by d. Receive traffic Next, the configuration and operation of the base station according to the embodiment of the present invention will be described. 6 is a block diagram of a base station according to an embodiment of the present invention. Referring to FIG. 6, the base station 600 according to an embodiment of the present invention includes a DL-MAP generator 620, a MOB-TRF-IND message generator 630, and a transmitter 640.

The base station 600 receives channel state information from the MSS to adaptively determine a modulation technique and a coding technique and transmit the determined modulation technique and the coding technique to the MSS through a DCD message. In this case, the base station 600 describes modulation and coding technique information through DCD burst profile encodings of the DCD message.

First, the DL_MAP generation unit 620 of the base station 600 generates the DL_MAP including the DCD message count value. As mentioned above, the DCD count value identifies each DCD message. Thus, when the DCD message changes, the DCD count value also changes. The DL_MAP generation unit 620 receives the DCD count value whenever a DCD message is generated. The DL_MAP 620 generator 620 generates a DL_MAP including the provided DCD count value and provides the DL_MAP to the transmitter 640.

The MOB_TRF_IND message generator 630 includes the DIUC_update in the TLV form in the MOB-TRF-IND message to indicate that the DCD count has changed due to a change in the DCD burst profile encodings value corresponding to the DIUC. That is, when the MOB_TRF_IND message generator 630 determines that the DCD burst profile encodings value corresponding to the DIUC of the AMC table has been changed, the MOB_TRF_IND message generator 630 sets TLV encodings related to DIUC_update accordingly. The MOB_TRF_IND message generator 630 generates a MOB_TRF_IND message including TLV encodings.

In addition, the MOB_TRF_IND message generator 630 generates a MOB_TRF_IND message including a modulation or code type for DL traffic to be transmitted later and information indicating whether there is downlink traffic in each MSS. The MOB_TRF_IND message generator 630 provides the generated MOB_TRF_IND message to the transmitter 640. The transmitter 640 transmits the DL-MAP and MOB_TRF_IND messages provided from the DL-MAP generator 620 and the MOB_TRF_IND message generator 630 to the MSS according to the standard.

Then, if the base station 600 does not transmit the DCD message until the MSS enters the normal mode and receives the DL traffic, the base station 600 starts transmitting to the MSS in the order of the smallest data. It persists until the MSS receives the DCD message.

7 illustrates a MOB_TRF_IND message according to an embodiment of the present invention. Referring to FIG. 7, the MOB_TRF_IND message according to an embodiment of the present invention includes a TLV encoded information field 650 and a Traffic Idication Bitmap field 660 indicating whether downlink traffic exists in each MSS.

In the embodiment of FIG. 7, the TLV encoded information field 650 indicates that the DCD count has been updated by changing the DCD burst profile encodings corresponding to the DIUC. Referring to FIG. 8 to describe the TLV encoded information field 650 of the MOB_TRF_IND message according to an embodiment of the present invention in detail. The TLV encoded information field 650 includes a DIUC-FEC code type pair of DIUC_update encoded in a TLV format, the format of which is illustrated in FIG. 8.

As shown in FIG. 8, the DIUC-FEC code type pair includes a total of 9 bits, 4 bits from the MSB represent the DIUC value, and the remaining lower 5 bits represent the FEC code type corresponding to the DIUC. For example, when 9 bits are composed of '001000010', the upper 4 bits, that is, '0010', means 2 in decimal, which means DIUC No. 2, and the lower 5 bits, that is, '00010' also indicates 2 and FEC code. It means that type is 2. In this case, referring to FIG. 11, which is a diagram illustrating a DCD burst profile encodings value in a DCD message, if the FEC code type is 2, it corresponds to (16-QAM (CC) 1/2) in FIG. 11. Therefore, when '001000010' is allocated to the DIUC-FEC code type pair, it can be seen that the FEC code type corresponding to DIUC No. 2 is changed to (16-QAM (CC) 1/2). As such, the DIUC-FEC code type pair informs modulation or code type for downlink traffic to be transmitted later.

On the other hand, the configuration of the base station according to the embodiment of the present invention described above can be changed by those skilled in the art. For example, the DL-MAP generator 620 and the MOB_TRF_IND message generator 630 may be implemented as one component having these functions. Therefore, the present invention is not limited by the base station configuration according to the above-described embodiment.

Next, the operation of the base station according to the embodiment of the present invention will be described.

9 is a diagram illustrating an operation in a base station according to an embodiment of the present invention. In the following description, the base station 600 is described as interworking with one MSS, but those skilled in the art will understand that the base station 600 interoperates with a plurality of MSSs.

Referring to FIG. 9, when a predetermined MSS is in a sleep mode, the base station 600 buffers traffic transmitted to the MSS without transmitting or receiving data with the MSS. In the sleep mode, the sleep window and the listening window are alternately present. The base station 600 determines whether it is a sleep window in step 680. If the sleep window is in the sleep mode, the base station 600 determines whether the DCD burst profile encoding value has changed in step 682. In other words, the base station 600 determines in step 682 whether the DCD burst profile encodings value corresponding to the DIUC has changed. If the determination result is changed, the base station 600 sets the DIUC-FEC code type pair of the DIUC_update in the TLV form to indicate that the DCD count has changed due to the change of the DCD burst profile encoding value corresponding to the DIUC in step 684, and includes the MOB_TRF_IND. Create a message. At this time, the base station 600 includes a modulation or code type for downlink traffic to be transmitted later in the MOB_TRF_IND message, and information indicating whether there is downlink traffic in each MSS. Here, the above-described operation may be performed by the MOB_TRF_IND message generator 630 in the base station 600.

Subsequently, the base station 600 determines whether a listening window has been reached in step 686. If the listening window arrives, the base station 600 proceeds to step 688, and transmits DL-MAP and MOB_TRF_IND messages to the MSS through the transceiver 640.

Next, the configuration and operation of the MSS according to the embodiment of the present invention will be described.

10 is a block diagram of an MSS according to an embodiment of the present invention. Referring to FIG. 10, the MSS 700 according to an embodiment of the present invention includes a receiver 710, a DCD burst profile encodings change monitoring unit 720, and an FEC code type setting unit 730. The MSS 700 alternately repeats the sleep window and the listening window in the sleep mode.

Referring to FIG. 10, the MSS 700 receives a DL-MAP and a MOB-TRF-IND message from a base station in a listening window through the receiver 710. Then, the DCD burst profile encodings change monitoring unit 720 of the MSS 700 determines whether the DCD count of the received DL-MAP is different from the DCD count of the DL-MAP received in the previous listening window. I think it is. If the DCD count value is changed, the DCD burst profile encodings change monitoring unit 720 updates the DCD count by changing the DCD burst profile encodings value corresponding to the DIUC when the DCD count value is changed and the TLV encodings are included in the MOB-TRF-IND message. Determine if If the DCD count is updated by the change of the DCD burst profile encodings corresponding to the DIUC, the DCD burst profile encodings change monitoring unit 720 provides the FEC code type setting unit 730 to it.

The FEC code type setting unit 730 receives a notification from the DCD burst profile encodings change monitoring unit 720 that the DCD count has been updated by a change in the DCD burst profile encodings value corresponding to the DIUC. Set its own FEC code type according to the code type pair. That is, the FEC code type setting unit 730 sets a modulation scheme and a coding scheme when receiving DL traffic. If the FEC code type setting unit 730 receives a new DCD message, the FEC code type setting unit 730 sets its FEC code type according to the DCD burst profile encodings corresponding to the DIUC. When the MSS 700 determines that there is DL traffic to be received with reference to the MOB_TRF_IND message, the MSS 700 enters a normal mode and receives DL traffic based on the configured FEC code type.

When the MSS 700 determines that the modulation or coding scheme of DL traffic has been changed by checking whether the TLV type DIUC_update, that is, TLV encodings, is included in the MOB_TRF_IND message, the MSS 700 refers to the DIUC-FEC code type pair of the DIUC_update. A device (not shown) for decoding DL traffic is included.

On the other hand, the configuration of the MSS according to the embodiment of the present invention described above can be changed by those skilled in the art. For example, the AMC change monitoring unit 720 and the FEC code type setting unit 730 receive the MOB_TRF_IND message and check whether the TLV encodings are included and according to the DIUC-FEC code type pair of the TLV encodings according to the test result. It may be replaced by a device for decoding the DL traffic. Therefore, the present invention is not limited by the MSS configuration according to the above-described embodiment.

12 is a diagram illustrating an operation in an MSS according to an embodiment of the present invention. Referring to FIG. 12, when the MSS 700 receives the DL-MAP and MOB-TRF-IND messages in a listening window in the sleep mode, the MSS 700 determines whether the DCD count of the DL-MAP has changed in step 810. At the same time, the MSS 700 refers to the MOB_TRF_IND message to determine whether there is DL traffic to be transmitted to it, that is, whether the Traffic Indication Bitmap is positive. If there is no change in the DCD counter and the Traffic Indication Bitmap indicates negative (00), the MSS 700 proceeds to step 820 to maintain a sleep state after ending the listening window. In contrast, if there is no change of the DCD counter and the Traffic Indication Bitmap indicates a positive value (01), the MSS 700 proceeds to step 830 to terminate the listening window and enter the normal mode. The MSS 700 then receives DL traffic based on the DCD burst profile encoding value of the DCD message previously received in step 831.

On the other hand, if there is a change in the DCD counter and the Traffic Indication Bitmap indicates negative, the MSS 700 proceeds to step 840 to terminate the listening window and maintains an awake state at step 842. MSS 700 then awaits reception of a new DCD message at step 844. If a DCD message is received, the MSS 700 proceeds to step 846 to remain in a sleep state. The MSS 700 knows through the DCD counter that the DCD message has changed and remains awake until the DCD message is received even in the sleep mode.

Finally, if there is a change in the DCD counter and the Traffic Indication Bitmap indicates positive, the MSS 700 proceeds to step 850 where the DCD count corresponds to the DIUC by referring to the inclusion of TUC encodings related to DIUC_update in the MOB-TRF-IND message. It is determined whether the updated DCD burst profile encodings have been updated.

Subsequently, if the DCD count has been updated by changing the DCD burst profile encodings value corresponding to DIUC, the MSS 700 itself according to the TLV encodings in the MOS-TRF-IND message, ie, according to the DIUC-FEC code type pair, in step 852. Set the FEC code type. MSS 700 then exits the listening window in step 854 and enters normal mode. Subsequently, the MSS 700 receives DL traffic according to the corresponding DIUC-FEC code type pair in step 856.

 The MSS 700 then determines in step 858 whether it receives a DCD message from the base station. When the DCD message is received, the MSS 700 proceeds to step 860 and sets its FEC code type according to the DCD burst profile encodings value corresponding to the DIUC in the received DCD message. The MSS 700 receives DL traffic based on the FEC code type set in step 862.

In the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

As described above, according to the present invention, it is possible to minimize data loss caused by the base station sending data to the MSS while the MSS waits for the DCD message, and to eliminate the retransmission procedure caused by the MSS not receiving the data correctly. Reduces DL traffic buffering overhead and increases the efficiency of MSS radio resource usage.

In addition, according to the present invention, the DCS count is informed to the MSS in advance of being updated due to the change of the DCD burst profile encodings corresponding to the DIUC and the FEC code type, thereby inducing smooth DL traffic reception. In addition, when the DCD count is updated by changing a value other than the DCD burst profile encodings value corresponding to DIUC, DL traffic can be normally received using the DCD burst profile encodings value corresponding to the previously known DIUC. Furthermore, unnecessary power consumption caused by the MSS performs a request for retransmission of unreceived data.

 Therefore, the present invention generally has an effect in that the MSS can smoothly perform AMC operations related to data reception in a sleep state and thereby maximize the efficiency of radio resources.

Claims (25)

In a wireless access communication system, A generation unit for generating a MOB_TRF_IND message including TLV encodings for indicating that the DCD count for identifying each DCD message has been changed due to any one of modulation and coding techniques of downlink traffic; And a transmitter for transmitting the MOB_TRF_IND message. The apparatus of claim 1, wherein the modulation and coding techniques are indicated by DCD burst profile encodings corresponding to Downlink Interval Usage Code (DIUC). 2. The apparatus of claim 1, wherein the MOB_TRF_IND message includes a DIUC-FEC code type pair for indicating a modulation or code type for downlink traffic to be transmitted later in TLV encodings. 2. The apparatus of claim 1, further comprising: receiving the MOB_TRF_IND message and checking whether TLV encodings are included in the received MOB_TRF_IND message. 5. The method of claim 4, wherein if it is determined that the modulation technique or coding technique of downlink traffic is changed by checking whether TLV encodings are included in the MOB_TRF_IND message, the modulation or code type for downlink traffic to be transmitted after the TLV encodings. The apparatus further includes a device for decoding downlink traffic by referring to a DIUC-FEC code type pair for indicating.  2. The apparatus of claim 1, further comprising: determining whether the DCD count has changed due to a change in the DCD burst profile encodings value by checking whether TLV encodings are included in the MOB_TRF_IND message. The method of claim 1, wherein the MOB_TRF_IND message further comprises a field indicating whether each terminal has downlink traffic, And a transmitter configured to generate a DCD message including a DCD count value and to transmit aperiodically. 8. The method of claim 7, wherein the terminal receiving the DCD message and the MOB_TRF_IND message, if the previous DCD count value and the current DCD count value is different, and recognizes that there is downlink traffic to receive, to receive the next DCD message The downlink traffic received before is decoded by referring to a DIUC-FEC code type pair for indicating a modulation or code type for downlink traffic to be transmitted after the TLV encodings of the MOB_TRF_IND. 9. The apparatus of claim 8, wherein the DIUC-FEC code type pair consists of 9 bits, and the 9 bits comprise an upper 4 bits representing a DIUC and a lower 5 bits representing an FEC code type corresponding to the DIUC. The terminal of claim 7, wherein the terminal receiving the DCD message and the MOB_TRF_IND message receives a changed DCD message when it recognizes that a previous DCD count value and a current DCD count value are different and that there is no downlink traffic to receive. The device characterized in that the sleep mode is performed again after the update. 8. The method of claim 7, wherein the terminal receiving the DCD message and the MOB_TRF_IND message, if the previous DCD count value and the current DCD count value is the same, and recognizes that there is downlink traffic to receive, refer to the existing DCD message To perform downlink traffic decoding 10. The method of claim 8, wherein the terminal receiving the DCD message and the MOB_TRF_IND message, if the previous DCD count value and the current DCD count value is the same, and if there is no downlink traffic to receive, it performs a sleep mode again. Device characterized in that. In at least one base station for communicating with a predetermined terminal in a wireless access communication system, A DL-MAP generation unit for generating a DL-MAP describing a reception interval in time of the terminal, including a DCD count value for identifying each DCD message; And a MOB_TRF_IND message generator for generating a MOB_TRF_IND message including TLV encodings for indicating that a DCD count value has been updated according to a change in a modulation technique and a coding technique used to communicate with the predetermined terminal. The base station according to claim 13, further comprising a transmitting unit receiving DL-MAP and MOB_TRF_IND messages from the DL-MAP generating unit and the MOB_TRF_IND message generating unit and transmitting the DL-MAP and MOB_TRF_IND messages to the terminal. In at least one base station for communicating with a predetermined terminal in a wireless access communication system, Generating a DL-MAP including a DCD count value identifying each DCD message; And generating a MOB_TRF_IND message including TLV encodings for indicating that a DCD count value has been updated according to a change of a modulation technique and a coding technique used to communicate with the predetermined terminal. The method of claim 15, further comprising transmitting the DL-MAP and MOB_TRF_IND messages to the terminal. A terminal for communicating with a base station in a wireless access communication system, A receiving unit which receives a MOB_TRF_IND message from the base station in a listening window in a sleep mode; It is determined whether the DCD count value of the DL-MAP has been changed, and if the DCD count value has been changed, the DCD count changes the DCD burst profile encodings value corresponding to the DIUC by referring to the inclusion of TLV encodings in the MOB-TRF-IND message. A DCD burst profile encodings change monitoring unit to determine whether or not it has been updated by If the DCD count value is changed according to the change of the AMC table, it is according to a DIUC-FEC code type pair for indicating a modulation or code type for downlink traffic to be transmitted after TLV encodings in the MOB-TRF-IND message. And a FEC code type setting unit for setting a FEC code type of the terminal. 18. The terminal of claim 17, wherein when the UE determines that there is DL traffic to be received with reference to the MOB_TRF_IND message, the UE enters a normal mode and receives DL traffic based on the set FEC code type. 18. The terminal of claim 17, wherein the DIUC-FEC code type pair consists of 9 bits, and the 9 bits comprise an upper 4 bits indicating a DIUC and a lower 5 bits indicating an FEC code type corresponding to the DIUC. In a wireless access communication system, Sends a MOB_TRF_IND message for transmitting downlink traffic-related information for the terminal performing the sleep mode, The MOB_TRF_IND message includes updated DIUC update information reflecting change information of any one of a modulation technique and a coding technique for downlink traffic to be transmitted. A MOB_TRF_IND message generating unit configured to configure the updated DIUC update information in a type, length, and value encoding format; And a transmitter for transmitting the MOB_TRF_IND message. 21. The apparatus of claim 20, wherein the terminal receives the MOB_TRF_IND message and performs demodulation on downlink traffic to be transmitted according to the updated DIUC update information. The apparatus of claim 21, wherein the updated DIUC update information comprises a DIUC value and a corresponding corresponding FEC code type. In a wireless access communication system, a method for transmitting a MOB_TRF_IND message for transmitting downlink traffic-related information for a terminal performing a sleep mode, The MOB_TRF_IND message includes updated DIUC update information reflecting change information of any one of a modulation technique and a coding technique for downlink traffic to be transmitted. Generating a MOB_TRF_IND message for configuring the updated DIUC update information in a type, length, and value encoding format; Transmitting the MOB_TRF_IND message. 24. The method of claim 23, wherein the terminal receives the MOB_TRF_IND message and performs demodulation on downlink traffic to be transmitted according to the updated DIUC update information. The method of claim 24, wherein the updated DIUC update information comprises a DIUC value and a corresponding corresponding FEC code type.

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