KR100957399B1 - Method to operate control sleep mode in a communication system - Google Patents

Abstract

According to an aspect of the present invention, there is provided a method of controlling a sleep mode operation of a mobile terminal in a communication system, wherein the mobile terminal transitions to an awake state in a listening period of a sleep mode; And performing one of the second operation and the third operation, and after the completion of the operation, detecting that data to be transmitted to the base station and data to be received from the base station do not exist. And transitioning to a sleep state, wherein the first operation is a process of receiving data from the base station, the second operation is a process of transmitting data to the base station, and the third operation is data from the base station. Receiving the, characterized in that the process of receiving data from the base station.

Sleep Mode, Awake Mode, Timer

Description

{METHOD TO OPERATE CONTROL SLEEP MODE IN A COMMUNICATION SYSTEM}

The present invention relates to a communication system, and more particularly, to a sleep mode operation control method in a communication system.

In general, a communication system has been developed to provide a service capable of high-speed, high-capacity data transmission and reception to mobile terminals (MSs). A representative example of a communication system is the Institute of Electrical and Electronics Engineers (IEEE) 802.16e communication system. In the IEEE 802.16e communication system, the normal mode operation is to always maintain communication between the MS and the base station (BS).

In the IEEE 802.16e communication system, the MS always monitors the downlink in order to receive data from the BS. This is because the BS always monitors the downlink even when there is no data to transmit to the MS or when the MS has no data to transmit to the BS, so the power consumption of the MS is continued.

In addition, since the IEEE 802.16e communication system considers the mobility of the MS, the power consumption of the MS acts as an important factor for the overall performance of the system, and thus, the sleep mode between the MS and the BS is minimized to minimize the power consumption of the MS. MODE) operation and AWAKE MODE operation corresponding to the sleep mode operation have been proposed. In addition, the MS periodically performs a ranging operation of correcting a timing offset, a frequency offset, and power with the BS in order to correspond to a change in the channel state with the BS.

Next, a message transmission / reception process between the MS and the BS according to the operation of the sleep mode of the communication system will be described with reference to FIG. 1.

1 is a diagram illustrating a process of performing an operation for a sleep mode of a communication system.

Referring to FIG. 1, if the MS 100 is in an awake mode and wants to transition to a sleep mode, the MS 100 transmits a MOB_SLP-REQ (MOBile_SLeeP-REQuest) message to the BS 110 (step 101). Upon receiving the MOB_SLP-REQ message, the BS 110 determines whether to allow a mode transition of the MS 100 to the sleep mode in consideration of the situation of the BS 100 itself and the MS 100. In response to the determination result, a MOB_SLP-RSP (MOBile-SLeeP-ReSPonse) message is transmitted to the MS 100 (step 103). Here, the MOB_SLP-RSP message includes a listening interval parameter. In addition, when there is data to be transmitted by the BS 110 to the MS 100 in the listening section of the sleep mode, the BS 110 sends the MS (the MS) to the MS 100 during the listening period. MOB_TRF-IND (MOBile_TRaFfic-INDication) message including the identifier of 100) may be transmitted.

Upon receiving the MOB_SLP-RSP message from the BS 110, the MS 100 starts a sleep mode operation corresponding to the MOB_SLP-RSP message. Of course, the MS 100 also knows to perform corresponding to the listening interval parameter included in the MOB_SLP-RSP message. In addition, even if the MS 100 is in a sleep mode, when there is data to be transmitted by the MS 100 to the BS 110, the MS 100 may operate in an awake mode immediately in the sleep mode.

If the BS 110 transmits a MOB_TRF-IND message in the listening period of the sleep mode (step 105). In this case, it is assumed that the MOB_TRF-IND message is a message that does not include the identifier of the MS. Since the MOB_TRF-IND message does not correspond to the MS 100, the MS 100 decodes the MOB_TRF-IND message, and then confirms that its identifier is not included, and operates again in the sleep mode. Do this.

When there is data to be transmitted to the MS 100 by the BS 110 in the listening period of the sleep mode after a predetermined time, the BS 110 transmits a MOB_TRF-IND message including the identifier of the MS 100. (Step 107). Since the MOB_TRF-IND message corresponds to the MS 100, the MS 100 decodes the MOB_TRF-IND message, checks that its identifier is included, and transitions to the awake mode. Data is received from the BS 110.

After the data transmission and reception of the MS 100 and the BS 110 are completed, the MS 100 and the BS 110 transmit a MOB_SLP-REQ message and a MOB_SLP-RSP message again to perform a mode transition to the sleep mode again. Give and receive. At this time, the MS 100 and the BS 110 transmit unnecessary messages because the MOB_SLP-REQ message and the MOB_SLP-RSP message are exchanged for the mode transition to the sleep mode. This wastes resources of uplink and downlink and consumes power. In addition, the MS 100 should perform bandwidth ranging by transmitting a BandWidth-REQuest (BW-REQ) message in order to receive the bandwidth for transmitting the MOB_SLP-REQ message to the BS 110. ) Delays the time for the mode transition to the sleep mode.

Meanwhile, the IEEE 802.16e communication system defines the following messages to support the sleep mode operation and the awake mode operation as described above.

(1) MOB_SLP-REQ message

The MOB_SLP-REQ message is a message transmitted to the BS when the MS is in the awake mode and wants to transition to the sleep mode. The MOB_SLP-REQ message includes parameters required for the MS to transition to sleep mode, that is, information elements (IE), and the MOB_SLP-REQ message format is shown in Table 1 below. .

As shown in Table 1, the MOB_SLP-REQ message includes a plurality of IEs.

The management message type is information indicating the type of a message to be transmitted. When the message type is 50, it means the MOB_SLP-REQ message. The number of classes represents the number of power saving classes to be included in the MOB_SLP-REQ message. The definition indicates whether the operation indicates a new power saving class or an existing class. The operation indicates whether to activate or deactivate the power saving class. The power saving class identifier (Power_Saving_Class_ID) represents an identifier for indicating a power saving class indicating a current operation. The start frame number (start_frame_number) indicates a time to activate the corresponding power saving class. The power saving class type (Power_Saving_Class_Type) indicates the type of the corresponding power saving class. The type of the power saving class is as follows.

1) Type 1: Class following the sleep mode operation

2) Type 2: The size of the sleep interval is the initial-sleep window value, that is, the fixed sleep window is maintained continuously, and even if the MOB_TRF-IND message is not received in the listening interval, the message to explicitly disable the sleep mode or A class that continues to sleep unless it receives a header.

3) Type 3: While the Type 1 and Type 2 do not receive a mode transition request message, the device continues to sleep while the Type 3 automatically sleeps after one sleep mode, i.e., one Sleep window. The class that terminates. Mainly used for Management messages or Multicast Traffic.

In addition, the definition indicates whether the link is uplink or downlink. The traffic trigger waken indication (Traffic_Triggered_Wakening_Flag, hereinafter referred to as 'TTWF') applies only to Type 1, which is a type of the corresponding power saving class indicated by Power_Saving_Class_Type described above.

In more detail, the TTWF is used when the MS wants to maintain a sleep mode even when data is generated in a listening period. That is, when the 'TTWF = 0', the MS transmits and receives data during the listening period, and transitions to the sleep mode again at the end of the listening period, that is, at the start of the sleep window. In this case, when the BS wants to transmit a Medium Access Control (MAC) Service Data Unit (SDU) for the corresponding power saving class during the listening period, or the MS transmits a BW-REQ message for the connection for the corresponding power saving class. In case the MS receives the MOB_TRF-IND message including the identifier of the MS from the BS, the MS may end the sleep mode and transition to the awake mode. In addition, the sleep mode may be terminated through a transaction of a MOB_SLP-REQ message and a MOB_SLP-RSP message.

Meanwhile, when the 'TTWF = 1', the MS receives a packet data unit (PDU) from the BS or terminates the sleep mode during the listening period, for example, an MOB_SLP-RSP message or a downlink sleep control extension. Upon receiving a DL Sleep Control Extended Subheader, the MS must exit sleep mode unconditionally and transition to awake mode. In addition, even when data is generated in the MS itself or a management message for terminating the sleep mode, that is, a MOB_SLP-REQ message or a bandwidth request message and an uplink sleep control header is transmitted to the BS, the sleep mode is unconditionally terminated. The mode must be transitioned to wake mode. In other words, when TTWF = 1, if a traffic occurrence or management message occurs during the listening period, the system wakes up to the awake mode.

As described above, the TTWF is used when the MS maintains the sleep mode as Type 2 of Type 1, which is a type of the power saving class, and transmits and receives data during the listening period.

The initial sleep window (Initial-sleep Window) represents the start value to start the sleep period, the Listening Window (Listening Window) represents the requested listening period. The maximum value of the sleep interval is determined through two parameters, a final sleep window base and a final sleep window exponent, the maximum sleep window value being (final-sleep). window base) * 2 ^ (final-sleep window exponent). In addition, the number of sleep connection identifiers (Number_of_Sleep_Connection IDs) indicates the number of unicast CIDs corresponding to the corresponding power saving class.

(2) MOB_SLP-RSP message

The MOB_SLP-RSP message is transmitted to the MS or indicates an unsolicited instruction, including whether the BS allows a mode transition to the sleep mode in consideration of the situation of the BS itself and the MS. This message is sent to the MS. The MOB_SLP-RSP message includes parameters required for the MS to operate in a sleep mode, that is, IEs, and the MOB_SLP-RSP message format is shown in Table 2 below.

As shown in Table 2, the MOB_SLP-RSP message includes a plurality of IEs. The MOB_SLP-RSP message is also a message transmitted based on the basic CID of the MS.

The management message type is information indicating the type of a message to be transmitted. When the message type is 51, it means the MOB_SLP-RSP message. The length (Length_of_Data) of the data represents the number of bytes of the power saving class. Sleep Approved (Sleep_Approved) indicates whether or not to request the activation or deactivation of the corresponding power saving class of the MS. Here, when the value of Sleep_Approved is '1' and the operation value is '1' (activation), the Sleep_Approved value includes Start_frame_number, the value of Sleep_Approved is '1', and the Definition value is '1'. ', Power_Saving_Class_Type, Direction, initial-sleep window, listening window, final-sleep window base, final-sleep window exponent, TRF-IND required, TTWF and the like. Here, the TRF-IND required is applied only to the power saving class Type 1, and indicates that the BS should transmit at least one MOB_TRF-IND message to the MS at every listening interval.

(3) MOB_TRF-IND message

The MOB_TRF-IND message is a message that the BS transmits to the MS during a listening interval, and indicates whether there is data to be transmitted to the MS by the BS. The MOB_TRF-IND message is a message transmitted in a broadcast or multicasting manner, unlike the MOB_SLP-REQ message or the MOB_SLP-RSP message. The MOB_TRF-IND message format is shown in Table 3 below.

As shown in Table 3, the MOB_TRF-IND message is a message indicating whether there is data to be transmitted by the BS to the MS, and the MS receives the MOB_TRF-IND message during the listening period so that the MS itself can receive the MOB_TRF-IND message. A determination is made whether to transition from sleep mode to awake mode or to keep the sleep mode.

If the MS transitions to the awake mode, the MS confirms frame synchronization. At this time, if the frame sequence number expected by the MS does not match, the MS may request retransmission of lost data in the awake mode. Meanwhile, even when the MS does not receive the MOB_TRF-IND message or the MOB_TRF-IND message during the listening period, a negative indication, for example, a message indicating that there is no data to be received by the MS is received. If so, the MS can keep the sleep mode.

Meanwhile, the MOB_TRF-IND message also includes a plurality of IEs. The management message type is information indicating the type of a message to be transmitted. When the message type is 52, it means the MOB_TRF-IND message. FMT indicates whether a format of the MOB_TRF-IND message uses a slip identifier (SLPID: SLeeP IDentifier) bitmap format or an SLPID format.

(4) Downlink Sleep Control Extended Subheader

The downlink sleep control extension subheader is a subheader that the BS transmits to the MS to activate or deactivate a power saving class. The format of the downlink sleep control extension subheader is shown in Table 4 below.

As shown in Table 4, since the IE of the downlink sleep control extension subheader has been described in the MOB_SLP-RSP message, a detailed description thereof will be omitted.

As described above, in the sleep mode operation of the IEEE 802.16e communication system, the power saving class Type 1 maintains the sleep mode when the MS receives the MAC SDU in the listening interval from the BS corresponding to the TTWF, Or you can disable it. However, when the MS intends to maintain the sleep mode, a time point for transitioning to the sleep mode again after the listening period ends is not clearly proposed. In addition, the TTWF is initially set in a MOB_SLP-REQ message and a MOB_SLP-RSP message transmitted and received by the MS and the BS. However, a situation in which the TTWF needs to be changed may occur while performing the sleep mode operation, and an operation for changing the TTWF has not been specifically proposed.

Accordingly, an object of the present invention is to provide a sleep mode operation control method in a communication system.

Another object of the present invention is to provide a sleep mode operation control method for reducing resource waste in a communication system.

Another object of the present invention is to provide a sleep mode operation control method for reducing power consumption of an MS in a communication system.

In accordance with another aspect of the present invention, there is provided a method of controlling a sleep mode operation of a mobile terminal in a communication system, wherein the mobile terminal transitions to an awake state in a listening period of a sleep mode, and in the awake state. Performing, by the mobile terminal, any one of a first operation, a second operation, and a third operation; and after performing any one operation, data to be transmitted to the base station and received from the base station If it is detected that data does not exist, the method includes transitioning to a sleep state, wherein the first operation is a process of receiving data from the base station, and the second operation is a process of transmitting data to the base station. The third operation is a process of receiving data from the base station and receiving data from the base station. do.

According to another aspect of the present invention, there is provided a method of controlling a sleep mode operation of a base station in a communication system, the method including recognizing that the mobile terminal is in an awake state in a sleep mode, and the mobile terminal is in an awake state. After recognizing that the base station performs any one of the first operation, the second operation, and the third operation, and after performing any one operation, data to be transmitted to the mobile terminal And detecting that there is no data to be received from the mobile terminal, the base station includes recognizing that the mobile terminal has transitioned to a sleep state, and the first operation is a process of transmitting data to the mobile terminal. The second operation is a process of receiving data from the mobile terminal, and the third operation is performed by the mobile terminal. And transmitting data and receiving data from the mobile terminal.

According to another aspect of the present invention, there is provided a method of controlling a sleep mode operation of a mobile terminal in a communication system, the mobile terminal including a variable listening interval indicator for transitioning from an awake state to a sleep state. Transmitting a first message to a base station, maintaining a sleep state, reaching a listening interval, and transitioning to an awake state; and in response to the variable listening interval indicator in the awake state, a first operation; And performing a second operation or a third operation, wherein the first operation is a process of receiving data from the base station, and the second operation is a process of transmitting data to the base station. The third operation is a process of receiving data from the base station and transmitting data to the base station. And a gong.

According to another aspect of the present invention, there is provided a method of controlling a sleep mode operation of a base station in a communication system, the method including: receiving a first message including a variable listening interval indicator from the mobile terminal; Transmitting a second message including the variable listening section indicator to the mobile terminal in response to the first message; and recognizing that the mobile terminal has reached a listening section and has reached an awake state while maintaining a sleep state. Thereafter, a process of performing any one of a first operation, a second operation, and a third operation corresponding to the variable listening interval indicator, wherein the first operation is a process of transmitting data to the mobile terminal. The second operation is a process of receiving data from the mobile terminal, and the third operation is the mobile terminal. To transmit data, and is characterized in that the method comprising the steps of: receiving data from the mobile terminal.

As described above, the present invention proposes a sleep mode operation control method and system in consideration of power consumption reduction in a communication system, and operates a timer proposed in the present invention to control the sleep mode operation between the MS and the BS to consume power. Has the advantage of reducing

Hereinafter, the operation principle of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The present invention proposes a sleep mode operation control method in a communication system. In particular, the present invention proposes a sleep mode operation control method in which a timer is operated after data transmission and reception is completed to immediately enter a sleep mode if data transmission and reception are not performed even if the timer exceeds the threshold set by the timer. In particular, although the present invention describes a sleep mode operation control method using an IEEE 802.16e communication system as an example, the sleep mode operation control method proposed in the present invention can be applied to other communication systems as well as the IEEE 802.16e communication system. Of course.

The present invention proposes an operation in which one MS and BS controls sleep mode operation in a communication system. However, the communication system can be applied to the sleep mode operation control method proposed by the present invention even when there are a plurality of MSs.

In the present invention, the MS and BS first transmit a MOB_SLP-REQ (MOBile_SLeeP-REQuest) message and a MOB_SLP-RSP (MOBile_SLeeP-ReSPonse) message in order to transition to the sleep mode. The sleep mode includes a sleep period and a listening period. When the MOB_SLP-REQ message and the MOB_SLP-RSP message are transmitted and received, the sleep mode determines the time to enter the sleep mode, the length of the sleep period, and the length of the listening period. In addition, the state that consumes power due to data transmission or reception between the MS and the BS or the standby state is defined as an awake state, and the state in which the MS does not transmit or receive data to or from the BS to reduce power consumption is in a sleep state. It is defined as

According to the present invention, the BS and the MS enter a sleep mode and are in a sleep period. The BS and the MS enter an awake state in a listening period. When the transmission and reception does not occur, the operation when the transition to the sleep state must be proposed.

Data transmission and reception between the MS and the BS assumes that the BS performs data transmission to the MS after sending a MOB_TRF-IND message to the MS. However, the data transmission method and system for reducing power consumption, which will be proposed later in the present invention, can also be applied to the case of transmitting and receiving data without transmitting the MOB_TRF-IND message.

Next, an operation for transmitting data by the BS in the communication system according to the first embodiment of the present invention will be described with reference to FIG. 2.

2 is a diagram illustrating an operation for a BS to transmit data in a communication system according to an embodiment of the present invention.

Referring to FIG. 2, the BS and the MS first transmit and receive the MOB_SLP-REQ message and the MOB_SLP-RSP message to enter the sleep mode, the length of the sleep period, and the length of the listening period. And the MS enters the sleep mode. Since the sleep mode entry process is the same as the prior art, a description thereof will be omitted. The present invention assumes that the length of the sleep interval is 8 frames and the length of the listening interval is determined to be 2 frames through the transmission and reception of the MOB_SLP-REQ message and the MOB_SLP-RSP message between the MS and the BS. It is also assumed that the frames are listed from # 0 to #N (201). The BS recognizes that the MS is in the sleep period of the sleep mode from frame # 0 to frame # 7. When entering the frame # 8, the BS recognizes that the listening interval has been reached, and the BS has data to transmit to the MS and transmits a MOB_TRF-IND message including the identifier of the MS in the frame # 8 (203). . The BS sends data to the MS immediately after transmitting the MOB_TRF-IND message (205). Or when the BS transmits the MOB_TRF-IND message to the MS, after the MS recognizes the MOB_TRF-IND message, if the MS has data to transmit to the BS, the data is transmitted to the BS. (205). The MS sends and receives the data and operates timer T1 to zero.

The timer T1 is a timer that recognizes when the MS has no data to be received from the BS and the MS also has no data to transmit to the BS. In addition, although the MS has no data to be received from the BS, it is also applicable when there is data to be transmitted by the MS to the BS. In addition, although the MS has data to be received from the BS, it is also applicable when the MS has no data to transmit to the BS. Therefore, the timer T1 may know that the timer is reset to 0 when data transmission and reception between the BS and the MS occur. After the data is transmitted and received, it is assumed that the BS completes data transmission to the MS in frame # 11, and data reception from the MS to the BS is completed. Accordingly, if there is no data to be transmitted to the MS and no data to be received from the MS to the BS in frame # 12, the MS sets timer T1 to enter a sleep state to 1 (207). ).

The present invention assumes that the threshold value of the timer is set to a value corresponding to four frames. Then, the timer T1 increases from 1 to frame # 12 to frame # 15. When the BS has no data to transmit to the MS and no data to be received from the MS until the frame exceeds 4 frames, which is the threshold value of the timer T1, the MS immediately enters the sleep state. After that, the next data transmission and reception is performed in the next listening section. Since the operation in the listening section is the same as described above, the description thereof will be omitted.

Next, an operation for transmitting data by the MS in the communication system according to an exemplary embodiment of the present invention will be described with reference to FIG. 3.

3 is a diagram illustrating an operation for transmitting data by an MS in a communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the BS and the MS first transmit and receive the MOB_SLP-REQ message and the MOB_SLP-RSP message to enter the sleep mode, the length of the sleep period, and the length of the listening period. And the MS enters the sleep mode. Since the sleep mode entry process is the same as the prior art, the description thereof will be omitted. The present invention assumes that the length of the sleep period is 8 frames and the length of the listening period is determined to be 2 frames through the transmission and reception of the MOB_SLP-REQ message and the MOB_SLP-RSP message between the MS and the BS. It is also assumed that the frames are listed from # 0 to #N (301). The MS recognizes that the frame is a sleep period of the sleep mode from frame # 0 to frame # 7, and transitions to the sleep mode. When entering the frame # 8, the MS recognizes that the listening interval, and the MS transmits an uplink bandwidth allocation request message (UL-BW-REQ) to the BS in the frame # 8.

The MS transmits the UL-BW-REQ message and transmits data that should be sent to the BS. In addition, if there is data to be received from the BS to the MS in the listening period, the data is also received to the MS (305). The MS sends and receives the data and operates timer T1 to zero. The timer T1 is a timer that recognizes when the MS has no data to receive from the BS and the MS also has no data to transmit to the BS. In addition, although the MS has no data to be received from the BS, it is also applicable when there is data to be transmitted by the MS to the BS. In addition, although the MS has data to be received from the BS, it is also applicable when the MS has no data to transmit to the BS. Therefore, the timer T1 may know that the timer is reset to 0 when data transmission and reception between the BS and the MS occur. After the data is transmitted and received, it is assumed that the MS completes data transmission to the BS in frame # 11, and data reception from the BS to the MS is completed.

When there is no data to be transmitted to the BS and no data to be received from the BS by the MS in frame # 12, the MS sets the timer T1 to enter a sleep mode to 1 (307). The present invention assumes that the threshold value of the timer is set to a value corresponding to four frames. Then, the timer T1 increases from 1 to frame # 12 to frame # 15.

The MS enters a sleep mode when there is no data to be transmitted to the BS and no data to be received from the BS until it exceeds four frames, which is the threshold value of the timer T1. Thereafter, the next data transmission and reception is performed in the next listening period. Since the operation in the listening section is the same as described above, the description thereof will be omitted.

Next, an operation sequence of the MS in the communication system according to an embodiment of the present invention will be described with reference to FIG. 4.

4 is a diagram illustrating an operation of an MS in a communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 4, first, in step 401, the MS already exists in the sleep period of the sleep mode, enters the listening period, waits for data from the BS, and proceeds to step 403. In step 403, the MS receives and decodes a MOB_TRF-IND message from the BS. In step 405, the MS checks whether the MS's own identifier is included in the MOB_TRF-IND message. If the identifier of the MS is included, the process proceeds to step 409. If the identifier of the MS is not included, the process proceeds to step 407. If the MS identifier is included, the process proceeds to step 409 to receive data from the BS and proceeds to step 411. If the identifier of the MS is not included, the MS proceeds to step 407 to check an uplink-buffer, checks whether the MS itself has data to transmit to the BS, and checks the MS itself. If there is data to be transmitted, the flow proceeds to step 409. In step 409, the MS transmits data to the BS and proceeds to step 411.

In step 411, the MS operates the timer T1 to 0 as soon as data transmission and reception between the MS and the BS is performed, and proceeds to step 413. In step 413, the MS checks whether there is data to be transmitted or received in the next frame and proceeds to step 415. If data transmission / reception between the MS and the BS is completed and there is no data for the MS to transmit to the BS and there is no data to be received from the BS to the MS, the timer T1 is incremented to 1 and the process proceeds to step 419. . If the timer T1 set by the MS reaches the preset threshold in step 419, the MS proceeds to step 421. In step 421, the MS transitions to the sleep mode and terminates. If there is data to be transmitted to the BS by the MS in step 415, and there is data to be received by the MS from the BS, the process proceeds to step 409 again to perform data transmission and reception, and the following steps are as described above. Will be omitted. If there is no data to be transmitted to the BS by the MS in step 407, the MS immediately proceeds to step 421 and goes to sleep and ends.

Next, the operation sequence of the BS according to the embodiment of the present invention will be described with reference to FIG. 5.

5 is a diagram illustrating an operation of a BS according to an embodiment of the present invention.

First, an operation when there is data to be transmitted to the MS by the BS will be described.

Referring to FIG. 5, first, in step 501, the BS checks whether there is data to transmit to the MS. If there is data to be transmitted to the MS by the BS, the process proceeds to step 503. In step 503, the BS includes the identifier of the MS in the MOB_TRF-IND message and proceeds to step 505. In step 505, the BS waits for a listening section and proceeds to step 507. In step 507, the BS transmits a MOB_TRF-IND message to the MS and proceeds to step 509. In step 509, the BS transmits data to the MS and proceeds to step 511. In step 511, the BS transmits data to the MS and simultaneously operates the timer at 0 and proceeds to step 513. In step 513, the BS checks whether there is data to be transmitted or received in the next frame for data transmission and reception between the BS and the MS. If there is no data to be transmitted to the MS in step 515, the flow proceeds to step 517. In step 517, the BS sets the timer T1 to increase by one from the value set in the previous step, and proceeds to step 519. In step 519, the BS checks whether the timer T1 reaches a threshold value. If the timer reaches the threshold value, the BS proceeds to step 521. In step 521, the BS recognizes that the MS has transitioned to the sleep state and terminates.

Secondly, the process of receiving data from the MS to the BS will be described.

Referring to FIG. 5, if the BS recognizes that there is no data to transmit to the MS in step 501, it proceeds to step 523. In step 523, the BS waits for a listening interval and proceeds to step 525. In step 525, the BS transmits a TRF-IND message not including the identifier of the MS and proceeds to step 527. In step 527, the BS waits for uplink traffic in the listening period and proceeds to step 529. If there is no data reception from the MS to the BS in step 529, the process proceeds to step 531. In step 531, the BS checks the next frame whether there is data to be transmitted or received, and proceeds to step 533. If the listening period is finished, the process proceeds to step 521 and recognizes that the MS has transitioned to the sleep state. If the listening period is not completed in step 533, the BS proceeds to step 529 to wait for uplink traffic from the MS.

If there is data reception from the MS to the BS in step 529, the process proceeds to step 511. Since the following steps have been described above, the description thereof will be omitted.

Although not shown in the drawings of the present invention, a sleep mode operation control method and system using a timer T2 and a timer T3 will be described.

BS and MS transmit and receive the MOB_SLP-REQ message and the MOB_SLP-RSP message to enter the sleep mode, the length of the sleep period, and the length of the listening period when the data transmission and reception occurs for the first time. After determining, the terminal enters the sleep mode. Since the sleep mode entry process is the same as the prior art, a description thereof will be omitted. The BS is present in the sleep period and recognizes that the listening period is the listening interval. The BS transmits a TRF-IND message to the MS during the listening interval, and the BS transmits data to be sent to the MS. At this time, the timer T2 and the timer T3 are operated to zero. The timer T2 is a timer for determining that the MS has no data to receive from the BS or that the BS has no data to send to the MS. The timer T3 is a timer for determining that the MS has no data to transmit to the BS or that the BS has no data to receive from the MS.

The timer T2 and the timer T3 operate at zero at the same time when the data is transmitted and received. When the MS proceeds to the next frame and the MS has no data to receive from the BS or the BS has no data to transmit to the MS, the timer T2 increases from 0 to 4 frames which are preset thresholds. Similarly, when proceeding to the next frame, if the MS has no data to transmit to the BS or if the BS has no data to receive from the MS, the timer T3 increases from 0 to 4 frames, which is a preset threshold. When both the timer T2 and the timer T3 recognize that the data transmission / reception is not performed even if the timer exceeds the four frames which are preset threshold values, the timer T2 and the timer T3 immediately enter the sleep mode and are in the sleep mode.

Next, in the second embodiment, the sleep mode scheme described in the first embodiment is a power saving class type in which Traffic_Triggered_Wakening_Flag (hereinafter referred to as 'TTWF') included in the MOB_SLP-REQ message and the MOB_SLP-RSP message is '0'. How to apply to (Power_Saving_Class_Type) 1 will be described.

Here, the TTWF is used when the MS wants to maintain a sleep state even though data occurs in a listening period. That is, in the second embodiment, the listening period is fixed, and the data transmission / reception may be performed during the listening period while repeating the sleep window and the listening period. As described in the first embodiment, the listening period is variable, that is, the data. The operation of maintaining the listening period may be performed while transmission and reception occur. Here, the two operations will be described as 'new sleep mode' operations.

The following parameters are newly defined for controlling sleep mode operation between the BS and the MS. The parameter is added to the REG-REQ (REGistration-REQuest) message and the REG-RSP (REGistration-RSPonse) message transmitted and received by the MS when entering the network with the BS in the form of TLV Encoding. The TLV Encoding may be represented as shown in Table 5.

When the TLV Encoding is omitted from the REG-REQ message and the REG-RSP message and is transmitted and received, it is regarded as '0' which is a default value. In addition, when the variable listening interval indicator (hereinafter, referred to as 'VLII') is set to '0' and transmitted, it indicates that a new sleep mode operation cannot be performed. Since the variable listening interval indicator will be described in detail below, the detailed description thereof will be omitted.

In more detail, in the case of the BS that can support the new sleep mode operation, it is determined whether the MS can perform the new sleep mode operation. If the MS cannot perform the new sleep mode operation, the BS transmits the REG-RSP message without including the TLV Encoding, or sets the VLII parameter to '0' in the future MOB_SLP-REQ message transmission. Set it.

On the contrary, in case of the MS capable of performing the new sleep mode operation, it is determined whether the BS can support the new sleep mode operation. If the BS cannot support the new sleep mode operation, the MS sends an RNG-REQ message without including the TLV Encoding, or sets the VLII parameter to '0' when sending a MOB_SLP-RSP message in the future. .

The TLV Encoding may be transmitted and received using another message besides the REG-REQ message or the REG-RSP message, for example, a Subscriber Station Basic Capability REQuest (SBC-REQ) message or a Subscriber Station Basic Capability RSPonse (SBC-RSP) message. Of course you can.

Meanwhile, in order for the power saving class type 1 having TTWF = 0 to operate a new sleep mode, that is, a sleep mode having a fixed listening period and a sleep mode having a variable listening period, the following message needs to be modified.

(1) MOB_SLP-REQ message

The MOB_SLP-REQ message is a message transmitted to the BS when the MS is in an awake state and wants to transition to a sleep state. The format of the MOB_SLP-REQ message is shown in Table 6 below.

As shown in Table 6, the MOB_SLP-REQ message includes VLII parameters unlike Table 1 above. The VLII parameter applies only when the TTWF is set to '0'. That is, if the MS does not perform a new sleep mode, it is always set to '0', and if the MS may perform the new sleep mode, even if the BS does not support the new sleep mode, '0'. Set to '.

The VLII parameter has two meanings as follows.

* VLII = 0: means that the MS operates in a basic sleep mode. That is, the MS and the BS perform data transmission and reception during the fixed listening period. When the listening section ends, the MS must transition to the sleep state and operate in the next listening section.

* VLII = 1: means that the MS operates according to the first embodiment. That is, the MS and the BS perform data transmission and reception during a variable listening period. That is, when the MS and the BS transmit and receive data in the listening section, when there is data to be continuously transmitted and received, the listening section is extended and another data transmission and reception is performed for a predetermined time after the data transmission and reception is completed. If it does not, it goes back to sleep and operates in the next listening section.

(2) MOB_SLP-RSP message

The MOB_SLP-RSP message is transmitted to the MS or indicates an unsolicited instruction, including whether the BS allows a mode transition to the sleep mode in consideration of the situation of the BS itself and the MS. This message is sent to the MS. The MOB_SLP-RSP message includes parameters necessary for the MS to operate in a sleep mode, that is, IEs, and the MOB_SLP-RSP message format is shown in Table 7 below.

As shown in Table 7, the MOB_SLP-RSP message includes VLII parameters as in Table 6. The VLII parameter applies only when the TTWF is set to '0'.

The VLII parameter is used according to whether the BS can support the new sleep mode. If the BS cannot support the new sleep mode, it is always set to '0' and transmitted.

In addition, the BS may support the new sleep mode, but when the TTWF is set to '1', the TTWF should be changed to '0'. In addition, if it is determined that the MS cannot perform the new sleep mode when the network enters, it should be set to '0' and when the MS enters the network, a new sleep mode is supported by the support of new sleep mode with variable listening Interval TLV encoding. Even if it is recognized that the mode is not supported, it is set to '0' so that the MS operates in the existing sleep mode.

Next, the timer proposed by the MS to transition to the awake state in the listening interval will be described.

The MS and the BS confirm that VLII = 1 by transmitting and receiving the MOB_SLP-REQ message and the MOB_SLP-RSP message, and assume that both the BS and the MS can operate in a new sleep mode. . At this time, the MS and the BS drive the timer as described below to recognize the end of the variable listening period proposed in the new sleep mode and the transition time to the sleep state.

(1) Timer of MS for new sleep mode (Timer_in_MS-for_NEW_SLM): The timer is a timer managed by the MS. The timer starts from the next frame after the listening interval obtained by the MOB_SLP-REQ message and the MOB_SLP-RSP message exchanged between the MS and the BS, and is reset every time data is received from the BS in the corresponding frame. At this time, if there is no data to be transmitted or received during the listening period, the terminal transitions to the sleep state without operating the timer. If the MOB_TRF-IND message is received, it is confirmed that the MOB_TRF-IND message does not include the identifier of the MS and transitions to the sleep state. If the timer expires and there is no data for the MS to transmit to the BS, the MS transitions to the sleep state in the listening period and maintains the sleep state until the next listening period starts. Of course, when the next listening section arrives, the timer is again driven.

(2) Timer of BS for New Sleep Mode (Timer_in_BS_for_New_SLM): The timer is a timer managed by the BS. The timer is used every frame and is reset every time data is received from the MS in that frame. If the timer expires and there is no data to be transmitted to the MS by the BS, the BS recognizes that the MS has transitioned to the sleep state, and the MS is in the next listening interval even if data occurs. The generated data must not be sent until awake, but must be buffered. Of course, when the BS reaches the next listening interval, the BS restarts the timer.

In this case, the unit of the timer may be a time or the number of frames. If the unit of the timer is the number of frames and the maximum expiration time is 5 frames, there is no data to be transmitted to the MS by the BS or data to be transmitted to the BS by the MS during the 5 frame period. Otherwise the timer expires.

On the other hand, when TTWF = 0 and VLII = 1, in order for the power saving class to be terminated, that is, for the MS to exit the sleep mode, transmission and reception of MOB_SLP-REQ and MOB-SLP-RSP messages, bandwidth and uplink sleep are performed. Disable control header, downlink sleep control extension subheader.

That is, the MS may leave the power saving class, that is, the sleep mode, by a management message.

In addition, when the timer expires or there is no data to transmit or receive, the MS transitions to the sleep state. However, if the MS wants to transition to sleep state before the timer expires, or if the BS wants to transition the MS to sleep state, the MS uses a management message to send the MOB_SLP-REQ message and the MOB_SLP-RSP. A message can be sent and received and transitioned to a sleep state.

The BS may also cause the MS to go to sleep using the management message. In this case, the BS refers to a case in which the management message is set as an unsolicited indication and transmitted.

The third embodiment to be described below is the same form as the second embodiment. However, it is proposed that the VLII is included in the MOB_SLP-REQ message and the MOB_SLP-RSP message in the form of TLV Encoding rather than the parameter type included in the MOB_SLP-REQ message and the MOB_SLP-RSP message.

That is, in the third embodiment, the MOB_SLP-REQ message format and the MOB_SLP-RSP message format are transmitted in the form of Tables 1 and 2. Here, the TLV encoding may be represented in the form of Table 8 in the TLV encoded information IE in the MOB_SLP-REQ message and the MOB_SLP-RSP message.

As shown in Table 8, the TLV includes a power saving class ID, and indicates whether VLII is applied to the power saving class identifier. The TLV Encoding may be performed by the MS and the BS to perform or support the new sleep mode, and in a power saving class in which the TTWF is set to 0 in the MOB-SLP-REQ and MOB_SLP-RSP messages of Tables 1 and 2, respectively. Include only for.

Next, a fourth embodiment will be described. In the fourth embodiment to be described below, the BS and the MS perform the same operations as the second embodiment. However, the operation of the timer proposed in the second embodiment is different.

If the MS proposes the TLV encoding shown in Table 9 together with the Support of new sleep mode with variable listening Interval TLV encoding proposed in the second embodiment, the MS may include the REG-REQ message.

If the REG-REQ message includes only the Support of new sleep mode with variable listening Interval TLV encoding and does not include the TLV encoding as shown in Table 9, it is considered to request a default value.

Accordingly, the BS checks the REG-REQ message transmitted by the MS, supports the new sleep mode with variable listening Interval TLV encoding in the REG-RSP message corresponding to the REG-REQ message and the TLV as shown in Table 10 below. Transmit with encoding.

As shown in Table 10, the Timer_in_MS-for_NEW_SLM value may include a value requested by the MS in the MOB_SLP-REQ message, and may be different from a value requested by the MS within an allowance supported by the BS. Can be included. At this time, the value of the Timer_in_MS-for_NEW_SLM is set to a value larger than the value of the Timer_in_BS-for_NEW_SLM managed by the BS and transmitted.

Meanwhile, when the BS transmits the REG-RSP message to the MS, only the Support of new sleep mode with variable listening Interval TLV encoding may be included and transmitted, and the Timer_in_MS-for_NEW_SLM encoding may not be included. At this time, the MS decodes the REG-RSP message, recognizes that Timer_in_MS-for_NEW_SLM encoding is not included, and considers that the timer value is driven to a preset value.

In addition, the timer proposed in the fourth embodiment may be set differently for each power saving class. That is, of course, different timer values may be set for each data pattern, that is, a connection belonging to the power saving class. The proposed TLV encoding may be represented as shown in Table 11 below.

As shown in Table 11, in the TLV encoding, the MS and BS may perform or support the new sleep mode. In the MOB_SLP-REQ and MOB_SLP-RSP messages of Tables 1 and 2, TTWF is '0'. Only included for power saving classes set to. At this time, the MS may request Timer_in_MS-for_NEW_SLM.

In addition, in the second embodiment, the VLII may be included in the MOB_SLP-REQ message and the MOB_LSP-RSP message in a parameter type different from that of the TLV encoding. In this case, the timer may be defined and transmitted in a TLV form as shown in Table 12 below. That is, when the VLII is transmitted in the form of a parameter, the timer transmits in the form of a TLV as follows.

At this time, the TTWF is set to '0' and the VLII may inform the value of the timer managed by the MS by including the TLV as shown in Table 12 for the power saving class set to '1'. .

1 is a diagram illustrating a process of performing an operation for a sleep mode of a communication system;

2 is a diagram illustrating an operation for a BS to transmit data in a communication system according to an exemplary embodiment of the present invention.

3 is a diagram illustrating an operation for transmitting data by an MS in a communication system according to an exemplary embodiment of the present invention.

4 is a diagram illustrating an operation of an MS in a communication system according to an exemplary embodiment of the present invention.

5 is a diagram illustrating the operation of a BS according to an embodiment of the present invention.

Claims (23)

In the sleep mode operation control method of a mobile terminal in a communication system, Transitioning the mobile terminal to an awake state in a listening section of a sleep mode; Performing, by the mobile terminal, any one of a first operation, a second operation, and a third operation in the awake state, and after completing any one operation, data to be transmitted to the base station and the Transitioning to a sleep state when detecting that there is no data to be received from the base station; If there is no data to be transmitted to the base station and data to be received from the base station, counting a timer before transitioning to the sleep state, The first operation is a process of receiving data from the base station, the second operation is a process of transmitting data to the base station, and the third operation is receiving data from the base station and transmitting data to the base station. Sleep mode operation control method characterized in that the process. The method of claim 1, And after at least one of the data to be transmitted to the base station and the data to be received from the base station after the execution of any one operation is completed, maintaining the awake state. delete The method of claim 2, And resetting the timer if at least one of data to be transmitted to the base station and data to be received from the base station exists. A method for controlling sleep mode operation of a base station in a communication system, Recognizing that the mobile terminal has awakened in the sleep mode; After the mobile terminal recognizes the awake state, the base station performs one of a first operation, a second operation, and a third operation; After the completion of any one operation, if it is detected that there is no data to be transmitted to the mobile terminal and data to be received from the mobile terminal, the base station recognizes that the mobile terminal has transitioned to a sleep state; If there is no data to be transmitted to the mobile terminal and data to be received from the mobile terminal, counting a timer; The first operation is a process of transmitting data to the mobile terminal, the second operation is a process of receiving data from the mobile terminal, and the third operation is transmitting data to the mobile terminal, and from the mobile terminal. Sleep mode operation control method characterized in that the process of receiving data. The method of claim 5, After the completion of any one operation, if there is at least one of data to be transmitted to the mobile terminal and data to be received from the mobile terminal, recognizing that the mobile terminal maintains the awake state. How to control sleep mode operation. delete The method of claim 6, And resetting the timer when at least one of data to be transmitted to the mobile terminal and data to be received from the mobile terminal is present. In the sleep mode operation control method of a mobile terminal in a communication system, Transmitting, by the mobile terminal, a first message including a variable listening interval indicator to a base station to transition from an awake state to a sleep state; Maintaining the sleep state and reaching a listening section to transition to the awake state; Performing one of a first operation, a second operation, and a third operation corresponding to the variable listening period indicator in the awake state; The first operation is a process of receiving data from the base station, the second operation is a process of transmitting data to the base station, and the third operation is receiving data from the base station and transmitting data to the base station. Sleep mode operation control method characterized in that the process. 10. The method of claim 9, If the variable listening interval indicator is set to 0, Transitioning to the sleep state if it is detected that there is no data to be transmitted to the base station and data to be received from the base station after the execution of one of the operations is completed. 10. The method of claim 9, If the variable listening interval indicator is set to 1, After the completion of one of the operations, if it is detected that there is no data to be transmitted to the base station and data to be received from the base station, a sleep mode operation including driving a timer before transitioning to the sleep state. Control method. The method of claim 11, And resetting the timer if at least one of data to be transmitted to the base station and data to be received from the base station exists. 10. The method of claim 9, And the variable listening interval indicator is included in the first message and transmitted in one of a parameter type and a type legth value (TLV) type. The method of claim 11, And including a request for a value of a timer to be managed by the mobile terminal in the first message transmitted by the mobile terminal to transition from an awake state to a sleep state. The method of claim 14, And requesting a value of the timer is configured differently for each data traffic connection. A method for controlling sleep mode operation of a base station in a communication system, Receiving a first message including a variable listening interval indicator from a mobile terminal, Transmitting a second message to the mobile terminal, the second message including the variable listening interval indicator corresponding to the received first message; After the mobile terminal maintains a sleep state and recognizes that it has reached the listening interval and has reached the awake state, the mobile terminal performs one of the first operation, the second operation, and the third operation corresponding to the variable listening period indicator. Includes the process of performing, The first operation is a process of transmitting data to the mobile terminal, the second operation is a process of receiving data from the mobile terminal, and the third operation is transmitting data to the mobile terminal, and from the mobile terminal. Sleep mode operation control method characterized in that the process of receiving data. The method of claim 16 After the completion of any one operation, if there is at least one of data to be transmitted to the mobile terminal and data to be received from the mobile terminal, recognizing that the mobile terminal maintains the awake state. How to control sleep mode operation. The method of claim 16, If the variable listening interval indicator is set to 0, After the completion of any one operation, detecting that there is no data to be transmitted to the mobile terminal and data to be received from the mobile terminal, recognizing that the mobile terminal transitions to the sleep state. How to control sleep mode operation. The method of claim 16, If the variable listening interval indicator is set to 1, And after the completion of one of the operations, detecting that there is no data to be transmitted to the mobile terminal and data to be received from the mobile terminal, driving a timer. The method of claim 19 And resetting the timer when at least one of data to be transmitted to the mobile terminal and data to be received from the mobile terminal is present. The method of claim 16 And the variable listening interval indicator is included in the second message and transmitted in one of a parameter type and a type legth value (TLV) type. The method of claim 19, And including a value of a timer to be managed by the mobile terminal in the second message and transmitting the same. The method of claim 22, The value of the timer is a sleep mode operation control method characterized in that it is set to one of the value requested by the mobile terminal and the value set by the base station.

Images