KR20050025039A - Method and system for controlling sleep mode in broadband wireless access communication system - Google Patents

Abstract

PURPOSE: A system and a method for controlling a sleep mode in a broadband wireless access communication system are provided to control a sleep mode of a subscriber terminal by using a table constructed for managing sleep information of subscriber terminals. CONSTITUTION: A base station(200a) groups subscriber terminals, which have requested for a sleep operation, to each group for sleep mode controlling(S305). The base station(200a) sets a TRF-IND message transmission time of each group(S310). When an SLP-REQ message for transition to a sleep mode is received from a subscriber terminal(100)(S315), the base station(200a) generates and updates a sleep interval scheduling table of each group including subscriber terminals(S320). The base station(200a) transmits an SLP-RES message with respect to the SLP-REQ message to the subscriber terminal(100)(S325). The subscriber terminal(100) is transited to a sleep mode at a sleep mode start time included in the SLP-RSP message(S330). When a sleep interval included in the SLP-RSP message elapses, the subscriber terminal(100) is transited to an awake mode(S335). Meanwhile, the base station(200a) recognizes subscriber terminals waking up at the set TRE-IND message transmission time(S340), adds a BCID of subscriber terminals with packet data to be transmitted to the TRF-IND message(S345) and transmits it at the TRF-IND message transmission time(S350). The subscriber terminal(100) receives the TRF-IND message and checks whether the TRF-IND message is a positive traffic message or a negative traffic message(S355). If the TRF-IND message is a positive traffic message, the subscriber terminal(100) is transited to an active mode(S360).

Description

Sleep mode control system and method thereof of broadband wireless access communication system {METHOD AND SYSTEM FOR CONTROLLING SLEEP MODE IN BROADBAND WIRELESS ACCESS COMMUNICATION SYSTEM}

The present invention relates to a broadband wireless access communication system, and more particularly, to a sleep mode control system and a method of a broadband wireless access communication system.

In conventional cellular networks (eg, code division multiplex access (CDMA) networks, global system for mobile communication (GSM) networks, etc.), a slotted paging scheme is used to implement a sleep mode. It was. That is, terminals operating in a conventional cellular network stay in a sleep mode that consumes less power when not in an active mode, and then wake up once in a while to check whether there is paging on their own. In other words, it only transitions to active mode if it has paging on it, otherwise it enters sleep mode again.

At this time, a paging slot to be checked is determined between the base station and the terminal, and each terminal wakes up only to the paging slot to be promised and checks its own paging message. For example, in the case of CDMA, each terminal has a paging slot, and in the case of GSM, a paging group is defined, the CDMA and GSM terminals need to be woken up once every certain time, and the time is a fixed value determined by the system. It was very easy to implement and manage on the system.

However, it is difficult to control the sleep mode in a broadband wireless access communication system (also known as a 4G generation communication system), which is actively researched and developed to support high speed service. This is because the sleep interval is exponentially increased in the sleep mode proposed by the IEEE 802.16e communication system, which is a system considering mobility of subscriber stations in the IEEE 802.16a communication system. . That is, in the case of the IEEE 802.16e communication system, the sleep interval increases by an exponential power of 2, so that the sleep mode start time, sleep interval, and wake-up time of each of the plurality of subscriber stations are increased. The IEEE 802.16e communication system is difficult to control the sleep mode because it is not easy to manage.

1 is a schematic process diagram of a sleep mode control method proposed in an IEEE 802.16e communication system. Typically, the sleep mode of the IEEE 802.16e communication system is initiated according to the request of the subscriber station or the control of the base station, and FIG. 1 illustrates a method of starting the control of the sleep mode by the request of the subscriber station.

Referring to FIG. 1, the subscriber station 10 to enter a sleep mode sends a sleep request message (SLP-REQ message) to the base station 20 (S31). At this time, the subscriber station may select a minimum size value (eg, a minimum-window) and a maximum size value (eg, a maximum time interval) of a sleep interval desired by the subscriber station. max-window)), and a monitoring interval value, which is a time interval for waking up the terminal and confirming a paging message to be transmitted to the terminal. The unit of these values is frame.

Then, after receiving the SLP-REQ message, the base station 20 performs sleep time scheduling with reference to preset sleep control information (eg, allowable minimum time period, maximum time period, and monitoring period, etc.) (S32). The SLP-RSP message is sent to the subscriber station 10 (S33). At this time, the number of remaining frames (start-time, hereinafter referred to as 'starting time'), the minimum time period (min-window), and the maximum time period (until the time when the subscriber station 10 enters the sleep mode) send max-window and listening interval values. The unit of these values is frame.

Meanwhile, the subscriber station 10 receiving the SLP-RSP message enters a sleep mode at a start time included in the SLP-RSP message (S34). The subscriber station 10 wakes up after a sleep interval and checks whether there is PDU data to be received from the base station 20. That is, when the sleep interval elapses, the subscriber station 10 enters an awake mode (S35) and instructs the traffic broadcasted by the base station 20 during the listening interval. Check the message (TRF-IND message: TRaFfic-INDmessage, aka paging message) (S36). The TRF-IND message is information broadcast by the base station 20 to the subscriber station 10. The TRF-IND message includes basic CIDs of the terminal to which PDU data should be transmitted.

The subscriber station 10 determines whether or not it wakes up by determining whether its basic CID is included in the TRF-IND message. That is, the subscriber station 10 wakes up when it recognizes that there is a PDU to be received if its BCID is included in the received TRF-IND message. That is, if the TRF-IND message received by the subscriber station 10 is a positive traffic indication (S37), the state of the subscriber station 10 is shifted to the active mode (S38).

On the other hand, the subscriber station 10 determines that there is no PDU data to be transmitted to itself if the BCID is not included in the TRF-IND message received by the subscriber station 10 enters the sleep mode again. That is, if the TRF-IND message received by the subscriber station 10 is a negative traffic indication (negative traffic indication), after changing the state of the subscriber station 10 to the sleep mode (S34), the corresponding subscriber station 10 during the sleep interval Wait for) to wake up.

At this time, the subscriber station 10 increases the sleep interval to twice the previous sleep interval (S39) and maintains the sleep mode (S34) during the sleep interval. The subscriber station 10 repeatedly performs the sleep mode and the awake mode until the state of the subscriber station becomes the active mode. In each repetition period, the subscriber station 10 increases the sleep interval twice the previous sleep interval, but the base station 20 determines that the subscriber station ( Increase until the maximum time period allowed by 10) is reached. As described above, in the IEEE 802.16e communication system, the sleep mode is driven while extending the sleep interval by twice the previous sleep interval by a sleep update algorithm. Accordingly, in the IEEE 802.16e communication system, the sleep interval increases exponentially, which makes it difficult for the base station to collectively manage sleep intervals of each of the plurality of subscriber stations.

Meanwhile, in the IEEE 802.16e communication system, there are three messages defined between the subscriber station and the base station in order to enter the sleep mode. That is, the SLP-REQ message (SLeeP REQuest message), the SLP-RSP message (SLeeP ReSPonse message), and the TRF-IND message (TRaFfic INDication message).

2A to 2D are message formats transmitted / received between the base station and the terminal to control the sleep mode. 2A shows the format of the sleep request message 40, FIG. 2B shows the format of the sleep response message 50a when rejecting the sleep, and FIG. 2C shows the format of the sleep response message 50b when the sleep is approved. 2D shows the format of the traffic indication message 60.

2A, SLP-REQ message 40 is SLP-REQ message 40 is MENAGEMENT MESSAGE TYPE (8 bits) 41, MIN-WINDOW (6 bits) 42. , MAX-WINDOW (10bits) 43 and LISTENING INTERVAL (8bits) 44. The SLP-REQ message 40 is a dedicated message transmitted based on a connection ID (CID: Connection ID) of the subscriber station, and is a message requested by the subscriber station to sleep.

At this time, the MANAGEMENT MESSAGE TYPE 41 is information indicating what message is currently being transmitted. If the management message type is '45' (MANAGEMENT MESSAGE TYPE = 45), the corresponding message is SLP-REQ. Indicates a message. The management message type 41 is implemented with 8 bits.

The minimum window (MIN-WINDOW) (aka, minimum time interval) 42 represents the requested start value for the SLEEP INTERVAL (measured in frames) and the maximum window (MAX-WINDOW). 43 (also referred to as maximum time interval) 43 indicates a requested stop value for the SLEEP INTERVAL (measured in frames). That is, the sleep interval is updated while increasing the minimum window value by two times from the minimum window 42 value to the maximum window 43 value.

LISTENING INTERVAL 44 indicates the requested LISTENING INTERVAL (measured in frames).

At this time, the minimum window 42, the maximum window 43, and the monitoring section 44 are all set in units of frames.

Referring to FIG. 2B, the SLP-RSP message 50a used when rejecting the sleep request includes a management message type (8 bits) 51a, a sleep permit (SLEEP-APPROVED) (1 bits) 52a, and a reserved area (RESERVED). (7 bits) 53a. The SLP-RSP message 50a is also a dedicated message transmitted based on the connection identifier of the subscriber station. The SLP-RSP message 50a determines the sleep timing of the subscriber station after scheduling the sleep time of the subscriber station at the base station. Message.

In this case, the management message type 51a is information indicating what message is currently being transmitted. When the management message type is 46 (MANAGEMENT MESSAGE TYPE = 46), the management message type 51a indicates the SLP-RSP message.

The sleep permission (SLEEP-APPROVED) 52a is represented by 1 bit, and when the sleep permission 52a is "0", it indicates that the transition to the sleep mode is impossible (SLEEP-MODE REQUEST DENIED).

The reserved area RESERVED 53a is a spare area.

Referring to FIG. 2, when an eNB approves a sleep request, an SLP-RSP message 50b transmitted to a subscriber station is a management message type (8 bits) 51b and a sleep permission (SLEEP-APPROVED) (1 bit). (52b), START-TIME (7bits) (53b), MIN-WINDOW (54b), MAX-WINDOW (55b) and LISTENING INTERVAL (56b) Include.

In this case, the management message type 51b is information indicating what message is currently being transmitted. When the management message type is 46 (MANAGEMENT MESSAGE TYPE = 46), the management message type 51b indicates the sleep response message.

The sleep permission (SLEEP-APPROVED) 52b is represented by 1 bit, and when the sleep permission 52a is "1", it indicates that the transition to the sleep mode is possible (SLEEP-MODE REQUEST APPROVED).

START TIME 53b is a frame value until the subscriber station enters the first SLEEP INTERVAL, and does not include a frame for receiving the sleep response message. That is, the subscriber station transitions to the sleep mode after elapse of frames corresponding to the start time (START TIME) from the next frame after the frame receiving the sleep response message.

The minimum window 54b represents the start value for the SLEEP INTERVAL (measured in frames) and the maximum window 55b represents the stop value for the SLEEP INTERVAL (measured in). frames)). The monitoring section 56b is a value for LISTENING INTERVAL (measured in frames).

Referring to FIG. 2D, the TRF-IND message 60 includes a management message type (8 bits) 61, a number of positive subscribers (NUM-POSITIVE) (8 bits) 62, and connection identifiers (CIDs) of the respective positive subscribers. (16 bits) (63, 64). The TRF-IND message 60 is transmitted in a broadcasting manner unlike the SLP-REQ message and the SLP-RSP message.

First, the management message type 61 is information indicating what message is currently being transmitted, and indicates that the management message type 61 is the TRF-IND message when the management message type 61 is 47 (MANAGEMENT MESSAGE TYPE = 47).

The number of positive subscribers 62 indicates the number of subscriber stations to which packet data is to be transmitted, and the connection identifiers (CIDs) 63 and 64 of each of the positive subscribers indicate the number of connection identifier information corresponding to the number of the positive subscribers. It includes.

3 is a diagram illustrating a sleep interval update algorithm proposed in the IEEE 802.16e communication system. In FIG. 3, "SS" indicates a subscriber station, "BS" indicates a base station, and boxes with "SS" and "BS" indicate a frame.

In FIG. 3, the subscriber station SS requests the sleep mode to the base station BS in the n th frame (S71), and the base station BS designates the sleep mode start time as the n + 3 th frame in the n + 1 th frame. When responding to the sleep mode request (S72), the SS repeats the sleep interval and the monitoring interval. Referring to FIG. 3, the first sleep interval is composed of two frames, but the second sleep interval is composed of four frames that are twice the first sleep interval.

As described above, in the conventional IEEE 802.16e communication system, it is difficult for the base station to manage the sleep interval of the subscriber stations because the subscriber stations request sleep at different times and the sleep intervals of the subscriber stations increase exponentially. There is a disadvantage in that it is difficult to manage by grouping subscriber stations.

Accordingly, a first object of the present invention to compensate for the above disadvantages is to provide a sleep mode control system and method for increasing the efficiency of a broadband wireless access communication system.

It is a second object of the present invention to provide a sleep mode control system and a method of a broadband wireless access communication system for reducing unnecessary paging message transmission by allowing a base station to know in advance a terminal that is awake at the time of paging transmission.

It is a third object of the present invention to provide a sleep mode control system and a method of a broadband wireless access communication system for configuring a table for managing sleep information of subscriber stations and controlling the sleep mode of subscriber stations using the table.

A fourth object of the present invention is to provide a sleep mode control system and a method of a broadband wireless access communication system for increasing efficiency by grouping and managing terminals.

A fifth object of the present invention is to provide a sleep mode control system and a method of a broadband wireless access communication system that enables group-by-group management by different times of group paging message transmission within a unit time period for sleep mode control. have.

The sixth object of the present invention is to notify the terminal in advance if there is no data to be sent to any terminal in the group sleep mode control that allows the terminals belonging to the group immediately enters the sleep mode without having to read and decrypt all the messages A system and method are provided.

The sleep mode control method of the broadband wireless access communication system provided by the present invention to achieve the first to sixth object is a sleep interval and awake interval in a broadband wireless access communication system including a base station and subscriber stations A sleep mode control method comprising an awake interval, comprising: a first process of grouping subscriber stations that have requested a sleep operation to a base station into a predetermined group for sleep mode control, and a unit time for the sleep mode control A second process of differently setting a time for transmitting a paging message for each group within the group; and a sleep interval of each of the subscriber stations in response to a sleep request by the subscriber stations in a sleep mode; Sleep interval scheduling table for managing scheduling information by group It characterized in that it comprises a third step of administration.

In addition, the sleep mode control system of the broadband wireless access communication system provided by the present invention to achieve the first to sixth object includes a sleep interval and awake interval in the broadband wireless access communication system A sleep mode control system comprising: a grouping unit for grouping subscriber stations to be a sleep mode control target into a predetermined group, and a time point for transmitting a paging message for each group within a unit time period for sleep mode control; A paging message transmission section management unit configured and managed by the group, and receives a SLP-REQ message requesting a state transition to a sleep mode by the subscriber stations, and receives a state transition request to the sleep mode. A transmission / reception unit for transmitting a response message (SLP-RSP message) to a corresponding subscriber station; And a sleep interval scheduling table manager for managing the sleep interval scheduling information of each of the subscriber stations in response to a sleep request to the sleep mode. At this time, the sleep mode control system preferably further includes a pre-traffic indicator bit configuration unit for notifying in advance if there is no data to be sent to any terminal in the group.

On the other hand, the sleep mode control method of the broadband wireless access communication system provided by the present invention to achieve the first to the third object is a process of initializing the sleep information table for managing the sleep information of the subscriber station operating in the sleep mode; Registering sleep information of each of the subscriber stations in the sleep information table in response to a sleep request by the subscriber stations in a sleep mode, and registering the sleep information in the sleep information table over time; And updating the sleep information based on the sleep information.

In addition, the sleep mode control system of the broadband wireless access communication system provided by the present invention in order to achieve the first to the third object receives a sleep request message (SLP-REQ message) requesting the sleep of the subscriber station and the sleep request SLP-RS which transmits a response message (SLP-RSP message) to the message, and sleep information table that manages the sleep information of the subscriber station in the sleep state and stores the sleep request message (SLP-) received through the transmitter / receiver a sleep information table manager which registers sleep information of each of the subscriber stations in the sleep information table and updates the sleep information with time, and counts a frame number corresponding to a current time in response to the sleep information. And a frame counter provided to the table manager.

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

4 is a diagram illustrating a processing procedure between a base station and a subscriber station for controlling a sleep mode according to a first embodiment of the present invention. That is, FIG. 4 includes a sleep interval and an awake interval in a broadband wireless access communication system including a base station 200a (more specifically, a 'sleep mode control system') and subscriber stations 100. FIG. 1 illustrates a processing procedure for a sleep mode control method.

Referring to FIG. 4, in order to control the sleep mode according to the first embodiment of the present invention, the base station 200a first groups the subscriber stations that request the sleep operation into the predetermined group for the sleep mode control (S305). . In this case, the method of grouping the subscriber stations can be applied to a variety of methods.

First, the subscriber stations are grouped so that a predetermined number of subscriber stations are included for each group according to the order in which the subscriber station requests the sleep operation from the base station. It is possible to apply a method of increasing the dynamics. For example, if four subscriber stations are configured to be included in each group, the first terminal to the fourth terminal requesting the sleep operation from the base station are included in the first group, and then the fifth terminal requesting the sleep operation from the fifth terminal to eight. Up to the first terminal is included in the second group. When two of the terminals belonging to the first group end the sleep operation and become active, the first group removes the two terminals, and when there is a terminal requesting a new sleep operation, the terminal is called the group. Dynamically assigns to For example, if there are three subscriber stations performing sleep operation among the subscriber stations included in the base station, only one group exists in the base station, and the subscriber stations performing sleep operation among the subscriber stations included in the base station exist. If there are five, then there are two groups in the base station. In this case, as the number of subscriber stations in sleep operation increases, the number of groups increases. As described above, the method of dynamically generating and removing the number of groups and the terminals included in the group may manage the terminals that effectively perform the sleep operation with the minimum group.

On the other hand, unlike the above method, it is possible to assign a fixed terminal to each group with a fixed number of groups. That is, it is possible to apply a method of grouping subscriber stations on the basis of a modulo operation of a subscriber station identification number (BCID) assigned by the base station to each subscriber station with a preset number of groups. Do. For example, if four groups are configured in the corresponding base station, each of the terminals requesting the sleep operation to the base station divides the BCID by '4' and the remaining value is '0' (group 0), and the BCID is '4'. Groups with a remainder of '1' divided by (1), groups with a BCID divided by '4' (group 2), a group with BCID divided by '4', '3' Will be grouped into (Group 3).

When the subscriber stations connected to the base station 200a are grouped as described above (S305), the base station 200a sets a time point for transmitting a TRF-IND message (aka paging message) for each group (S310). That is, the TRF-IND message transmission time is set differently for each group within the unit time period (eg, the minimum time period allowable by the base station) for sleep mode control. As such, an example of a TRF-IND message transmission time set differently within a predetermined time period (for example, a unit time period) is illustrated in FIG. 6. Referring to FIG. 6, one frame (A) section is divided into four equal sections (B), and the starting point of the section is a time point at which the TRF-IND message is transmitted for each of the four groups G0, G1, G2, and G3. An example of the case where is set as is shown.

When the base station 200a performs the preparation process for the sleep mode control through the processes S305 and S310, the base station 200a performs a sleep request message from the subscriber station 100 (hereinafter, 'SLP-REQ message'). Is called).

On the other hand, the subscriber station 100 transmits an SLP-REQ message that specifies the size of the minimum time interval (min-window), the maximum time interval (max-window), and the watch interval (listen interval), which are desired sleep interval scheduling information. (S315).

When the SLP-REQ message for the state transition from the subscriber station 100 to the sleep mode is received (S315), the base station 200a generates a sleep interval scheduling table for each group including the subscriber stations. And update (S320). That is, the sleep interval of each of the subscriber stations using the sleep interval scheduling information (min-window, max-window, and watch interval) included in the sleep request message. The sleep interval scheduling table managing scheduling information is managed for each group.

To this end, the base station 200a may refer to preset sleep control information (eg, allowable minimum time period, maximum time period, and monitoring interval, etc.) and sleep interval scheduling information specified in the SLP-REQ message to determine the subscriber station 100. The minimum time section, the maximum time section, and the monitoring section are determined, and the state information for each unit time section of the corresponding subscriber station is determined based on the minimum time section, the maximum time section, and the monitoring section. Then, the sleep interval scheduling information including the minimum time section, the maximum time section, the monitoring section, and the state information for each unit time section of the subscriber station 100 is registered in the sleep interval scheduling table together with the identification information of the corresponding subscriber station.

An example of the sleep interval scheduling table generated at this time is illustrated in FIG. 7. Referring to FIG. 7, the sleep interval scheduling table includes a subscriber station identification information (ID), a min-window, a max-window, a watch interval, and a unit time interval of a subscriber station. Contains status information per (frame). The sleep interval scheduling table manages sleep interval scheduling information of each of subscriber stations by a predetermined unit time frame, and moves a pointer indicating one unit time period at any one time point as time passes. . In the example of FIG. 7, sleep interval scheduling information of each of subscriber stations is managed by 24 unit time periods, and an example of a case where a pointer indicates a frame '3' is illustrated. If the pointer indicates the last unit time period (eg, frame index 24), the base station updates the sleep interval scheduling information of all subscriber stations registered in the sleep interval scheduling table and sets the unit time period to which the pointer points next. Change to a time period (eg frame index 1).

Meanwhile, in the example of FIG. 7, state information for each unit time period of the subscriber station is indicated as '0' or '1'. That is, the sleep interval of the subscriber station is indicated by '0' and the monitoring interval of the subscriber station is indicated by '1'. That is, the subscriber station is awake at the time when the status information value is '1'. In the example of FIG. 7, the subscriber station SS # 1 wakes up at a time when unit time intervals are '2', '5', and '10' and transmits a TRF-IND message transmitted to the subscriber station SS # 1 during the monitoring interval. The subscriber station SS # 2 wakes up at the time when the frames are '3' and '8' and checks the TRF-IND message transmitted to the subscriber station SS # 2. At this time, it checks its BCID in the TRF-IND message during the monitoring interval, and if its BCID is not included, it is not in awake mode until the next unit time interval starts, but immediately goes to sleep mode after the monitoring interval ends. Transition

If there is a subscriber station transitioning from the sleep mode to the active mode, the base station deletes the identification information of the subscriber station corresponding to the sleep interval scheduling information of the subscriber station from the sleep interval scheduling table. In the example of FIG. 7, if the subscriber station SS # 2 transitions to the active mode at the time when the frame index is '3', the base station identifies the identification information of the subscriber station SS # 2 at the time when the frame index is '4'. And delete sleep interval scheduling information (eg, a subscriber station (SS # 2) field) from the sleep interval scheduling table.

Meanwhile, after generating and updating the sleep interval scheduling table in step S320, the base station 200a transmits an SLP-RSP message for the SLP-REQ message to the subscriber station 100 (S325). At this time, the remaining number of frames (start-time, hereinafter referred to as a 'start time'), the minimum time period (min-window), and the maximum time period (until the time when the subscriber station 100 enters the sleep mode) send max-window and listening interval values.

Then, the subscriber station 100 receiving the SLP-RSP message transitions to the sleep mode at a sleep mode start time included in the SLP-RSP message (S330), and is included in the SLP-RSP message. After the sleep interval has elapsed, the state transitions to the awake mode (S335) and the TRF-IND message from the base station 200a is transmitted during the listening interval included in the SLP-RSP message. Wait

On the other hand, the base station 200a is based on the sleep interval scheduling table for each group managed in the step (S320), the subscriber stations included in the group corresponding to the time of each TRF-IND message transmission set in the step (S310) The subscriber stations waking up at that point of time are identified (S340), and the subscriber station identification number (BCID) of the subscriber stations with packet data (PDU data) to be transmitted among the identified subscriber stations is transmitted corresponding TRF-IND message. In addition to the TRF-IND message to be transmitted at the time point (S345), the TRF-IND message is transmitted (S350).

Then, the subscriber station 100, which has woken up in step S335 and waits for a TRF-IND message, receives the TRF-IND message transmitted in step S350 and determines whether the TRF-IND message is a positive traffic message or a negative traffic message. Check (S355). That is, it is checked whether or not the BCID of the subscriber station 100 is included in the received TRF-IND message. In the case of a positive traffic message (that is, when the received TRF-IND message includes the BCID of the subscriber station 100), the state transition to the active mode is performed (S360). Otherwise, the state transition is made to the sleep mode again (S330). ).

At this time, the subscriber station 100 increases the sleep interval to twice the previous sleep interval (S365) and maintains the sleep mode (S330) for the time excluding the monitoring interval from the sleep interval, and then wakes up during the monitoring interval. Operate in wake mode. The subscriber station 100 repeatedly performs the sleep mode and the awake mode until the state of the subscriber station becomes the active mode. In each repetition period, the subscriber station 100 increases the sleep interval to twice the previous sleep interval, but the base station 200a determines that the subscriber station (the subscriber station (the subscriber station) has the subscriber station (the subscriber station). Increase until the maximum time period allowed by 100) is reached. At this time, the sleep interval of the subscriber station updated in the step S365 is the same as the information managed in the sleep interval scheduling table managed by the base station 200a. This is because the subscriber station 100 and the base station 200a schedule the sleep interval of the subscriber station 100 by the same sleep interval scheduling information.

At this time, the base station 200a preferably informs the terminal in advance when there is no data to be sent to any of the terminals waking up at the time of transmission of the TRF-IND message, so that the terminals can enter the sleep mode more quickly.

For example, when there is no data to be transmitted to any of the terminals waking up at the time of transmitting the TRF-IND message, the base station 200a may transmit a pre-traffic indicator bit of the frame control header. ) Is set to '0' and the TRF-IND message is not sent. On the other hand, if there is data to be sent to either terminal, the base station 200a includes the identification number (BCID) of the terminal in the TRF-IND message and transmits the pre-traffic indication of the frame control header. Transmit by setting bit (Pre-Traffic Indicator bit) to '1'.

In this case, the frame control header is data that comes in the same frame as the TRF-IND message, but the data comes first in the frame and is not modulated or channel coded so that the data can be checked immediately. There is a characteristic.

Then, the subscriber station waking up at the time of transmitting the TRF-IND message and waiting for the TRF-IND message first checks the pre-traffic indicator bit of the frame control header. If the bit value is '0', it is determined that there is no data to be sent. If the bit value is '1', it immediately transitions to the sleep mode. If the bit value is '1', the TRF-IND message is received. The process of determining whether or not its own identification number (BCID) is included (S355) is performed.

5 is a flowchart illustrating a process of a base station for controlling a sleep mode according to a first embodiment of the present invention. Referring to FIG. 5, in order to control the sleep mode, the base station first groups the terminals registered with the base station (S410). As the grouping method, it is possible to apply the method illustrated in step S305 of FIG. 5. The TRF-IND message transmission time for each group is set differently within a predetermined unit time period (eg, a frame) (S420). When receiving the sleep request message from the subscriber station, a sleep interval scheduling table for each group is generated based on the information included in the sleep request message (S430). In addition, the terminal wakes up in the TRF-IND message transmission interval based on the sleep interval scheduling table for each group (S440). In addition, the BSIDs of the UEs having the PDU data to be transmitted among the identified UEs are added to the TRF-IND message (S450), and the TRF-IND message is transmitted at the time when the TRF-IND message of the corresponding group is transmitted during the TRF-IND message transmission period. It transmits (S460). When performing the process (S460), the base station determines whether there is a terminal to send data among the terminals waking up at the time of transmission of the TRF-IND message of the group, and transmits the TRF-IND message according to the result It is preferable to set the pre-traffic indicator bit of the frame control header set at the very front of the N-axis. For example, if there is no terminal to send data among the terminals waking up at the time of transmission of the TRF-IND message, the bit is set to '0' and if there is any terminal waking up at the transmission time, the bit is set to '1'. It is preferable to transmit with setting.

Each of the processes illustrated in FIG. 5 corresponds to those in the base station 200a among the processes illustrated in FIG. 4. That is, the process S410 of FIG. 5 corresponds to the process S305 of FIG. 4, the process S420 of FIG. 5 corresponds to the process S310 of FIG. 4, the process S430 of FIG. 5 corresponds to the process S320 of FIG. 4, and the process of FIG. 5. The process S440 corresponds to the process S340 of FIG. 4, the process S450 of FIG. 5 corresponds to the process S345 of FIG. 4, and the process S460 of FIG. 5 corresponds to the process S350 of FIG. 4. Therefore, the description of each process of FIG. 5 is replaced with the description of the corresponding process of FIG. 4.

8 is a diagram illustrating an example of a sleep operation by a sleep interval scheduling table for each group according to a first embodiment of the present invention. That is, FIG. 8 is a diagram illustrating how the UE actually operates during the unit time period according to the bit '0' and '1' values in the sleep interval scheduling table for each group. If the unit time period is indicated by the bit '0', the terminal operates in the sleep mode throughout the unit time period. On the contrary, when the unit time period is indicated by the bit '1', the terminal operates in the awake mode during the monitoring period from the start frame of the unit time period and the remaining time operates in the sleep mode.

9A and 9B are schematic block diagrams of a sleep mode control system 200a according to a first embodiment of the present invention. Referring to FIG. 9A, the sleep mode control system 200a of the present invention includes a grouping unit 210a, a TRF-IND transmission interval managing unit 220a for each group, a transmitter / receiver 230a, and a sleep interval scheduling table management for each group ( 240a), a TRF-IND generator 250a, and a TRF-IND transmitter 260a. In this case, the sleep mode control system 200a may be implemented in a base station of the IEEE 802.16e communication system or in a system separate from the base station. FIG. 9A illustrates an example in which the sleep mode control system 200a is implemented in the same system as the base station.

The grouping unit 210a groups the subscriber stations that are the sleep mode control targets into a predetermined group. As a method of grouping subscriber stations in the grouping unit 210a, various methods may be applied.

First, the grouping unit 210a groups the subscriber stations so that a predetermined number of subscriber stations are included for each group based on the order in which the subscriber stations request a sleep operation from the base station. It is possible to apply the method of increasing the number. In addition, the grouping unit 210a has a method of grouping subscriber stations on the basis of a result obtained by modulating a subscriber station identification number (BCID) assigned by the base station to each subscriber station with a preset number of groups. It is possible to apply. Specific examples for each case are the same as those mentioned in the description with reference to FIG. 5 and thus will be omitted.

The TRF-IND transmission period managing unit 220a for each group sets and manages TRF-IND transmission time differently for each group within a unit time period for sleep mode control.

The transmitting / receiving unit 230a receives a sleep request message (SLP-REQ message) requesting a state transition to the sleep mode by the subscriber stations, and responds to the state transition request to the sleep mode (SLP-RSP). Message) to the corresponding subscriber station.

The sleep interval scheduling table manager 240a for each group manages a sleep interval scheduling table for each group including subscriber stations in response to the SLP-REQ message. For example, the sleep interval scheduling table manager 240a for each group may include a minimum time period, a maximum time period, and a watchdog interval of a subscriber station corresponding to a response to a sleep request to the sleep mode. Determine the state information for each unit time period of the corresponding subscriber station based on the minimum time period, the maximum time period, and the watch interval (listen interval), and determine the minimum time period, the maximum time period, and the monitoring period of the subscriber station. And sleep interval scheduling information including state information for each unit time period, together with identification information of a corresponding subscriber station, in the sleep interval scheduling table. In addition, the sleep interval scheduling table manager 240a for each group deletes, from the sleep interval scheduling table, identification information corresponding to the sleep interval scheduling information of the subscriber station which has transitioned from the sleep mode to the active mode.

On the other hand, the sleep interval scheduling table manager 240a for each group manages the sleep interval scheduling information of each of the subscriber stations by a predetermined unit time period, and assigns a pointer to one unit time period at any one point in time. When the pointer indicates the last unit time period, the sleep interval scheduling information of all subscriber stations registered in the sleep interval scheduling table is updated, and the unit time period to which the pointer points next is changed to the first unit time period. .

A detailed description of the operation of the sleep interval scheduling table manager 240a for each group is as described in reference to FIG. 7.

Based on the sleep interval scheduling table for each group, the TRF-IND generation unit 250a includes subscribers included in a corresponding group for each TRF-IND message transmission time managed by the group TRF-IND transmission section managing unit 220a. Among the terminals, subscribers waking up at that point are identified, and subscriber terminal identification numbers (BCIDs) of the subscriber stations with packet data to be transmitted among the identified subscriber stations are transmitted at the time of transmission of the corresponding TRF-IND message. Append to the IND message.

The TRF-IND transmitter 260a receives TRF-IND message transmission time information for each group from the TRF-IND message transmission section managing unit 220a for each group, and generates a TRF generated by the TRF-IND message generator based on the information. Send an IND message.

FIG. 9B further includes a pre-traffic indicator bit configuration unit 270a and a pre-traffic indication bit transmission unit 280a in the sleep mode control system 200a illustrated in FIG. 9A. An example is shown. The pre-traffic indicator bit configuration unit 270a generates a pre-traffic indicator bit that informs in advance if there is no data to be sent to any terminal in the group, and pre-traffic indicator bit. The traffic indication bit transmission unit 280a receives the pre-traffic indication bit from the pre-traffic indication bit configuration unit 270a and transmits the received signal. That is, the pre-traffic indication bit configuration unit 270a receives information from the TRF-IND generation unit 250a about whether there is a subscriber station to transmit data among the subscriber stations waking up at the time of TRF-IND transmission. According to the pre-traffic indicator bit (Pre-Traffic Indicator bit) is set, and transmits the pre-traffic indicator bit to the pre-traffic indicator bit transmission unit (280a). For example, the pre-traffic indication bit configuration unit 270a sets the bit to '0' and wakes up at the time of transmission when there is no terminal to send data among the terminals waking up at the time of transmission of the TRF-IND message. If there is at least one terminal, the bit is set to '1' and transmitted to the pre-traffic indication bit transmitter 280a.

10 is a diagram illustrating a processing procedure between a base station and a terminal for controlling a sleep mode according to a second embodiment of the present invention. That is, FIG. 10 includes a sleep interval and an awake interval in a broadband wireless access communication system including a base station 200b (more specifically, a 'sleep mode control system') and subscriber stations 100. A diagram illustrating a processing procedure for a sleep mode control method.

Referring to FIG. 10, in order to control the sleep mode according to the second embodiment of the present invention, the base station 200b first initializes a sleep information table for managing sleep information of subscriber stations operating in the sleep mode (S505). 11A illustrates an example of a sleep information table initialized in step S505. Referring to FIG. 11A, the sleep information table includes a 16-bit BCID region, an 11-bit sleep start frame number region, a 10-bit sleep interval region, and a 10-bit maximum time period. (max-window) region and an 11-bit awake interval start frame number region. The BCID area stores the subscriber station identification number, and the sleep start frame number area stores the frame number at the time when the subscriber station next transitions to the sleep mode, and sleep interval area Stores an operation interval (i.e., sleep interval) of the next sleep mode, the max-window region stores the maximum sleep interval allowed for the corresponding subscriber station, and awake interval start frame number frame number) region stores a frame number of the time at which the UE wakes up. At this time, the subscriber station identification number, the frame number at which the subscriber station first transitions to the sleep mode, the initial sleep interval (i.e., min-window), and the maximum time allowed for the subscriber station The interval is information obtained from the sleep request message transmitted by the subscriber station. However, the frame number at the time when the terminal wakes up should be calculated by the base station 200b using the information. In addition, the frame number and the sleep interval at the time when the subscriber station transitions to the sleep mode may be obtained from the sleep request message with an initial value, but the base station 200b should calculate the information using the above information except for the first time. At this time, the method of registering the sleep information of the subscriber station in the sleep information table and updating the sleep information with time will be described in detail with reference to FIGS. 11B to 11D.

The base station 200b which initialized the sleep information table in step S505 waits for a sleep request message (hereinafter, referred to as an SLP-REQ message) from the subscriber station 100.

On the other hand, the subscriber station 100 has a minimum time interval (min-window), the maximum time interval (max-window) and the watch interval (listen interval) of the desired sleep interval scheduling information (hereinafter referred to as 'sleep information') SLP-REQ message is specified (usually three frames) (S510).

Upon receiving the SLP-REQ message for the state transition from the subscriber station 100 to the sleep mode, the base station 200b may include preset sleep control information (eg, the minimum allowable time period, the maximum time period, and the monitoring period). The minimum time section, the maximum time section and the monitoring section of the subscriber station 100 are determined with reference to sleep information specified in the SLP-REQ message, and the result is transmitted to the user (S515). That is, a response message (SLP-RSP message) to the SLP-REQ message is transmitted to the subscriber station 100 (S515).

Then, the sleep information transmitted to the subscriber station 100 is registered in the sleep information table (S520). The registration process will be described in more detail with reference to FIG. 11B. 11B shows an example in which four subscriber stations are registered in the sleep information table.

As such, when the sleep information of the subscriber stations operating in the sleep mode is registered in the sleep information table in step S520, the base station 200b updates the sleep information of the subscriber stations based on the sleep information as time passes ( S525). That is, by using the next sleep mode start frame number and the sleep interval of the subscriber station operating in the sleep mode, the time to wake up in the next sleep mode is calculated and stored in the sleep information table. The process S525 will be described in more detail with reference to FIGS. 11B to 11D.

In addition, the base station 200b identifies terminals waking up in the TRF-IND message transmission interval based on the sleep information table (S530), and among the subscriber stations having packet data (PDU data) to be transmitted among the identified subscriber stations. The terminal identification number (BCID) is added to the TRF-IND message to be transmitted at the time of transmission of the corresponding TRF-IND message (S535) and the TRF-IND message is transmitted (S540). For example, if the base station 200b wants to transmit a TRF-IND message when the frame number is '278', it checks the waking subscriber station at the frame number and TRFs the BCID of the subscriber station having data to be transmitted among the terminals. Send in addition to the -IND message. Referring to FIG. 11B, since the second and fourth subscriber stations SS # 2 and SS # 4 are awakened at the frame number '278', the base station 200b uses the second and fourth subscriber stations SS # 2 and SS # 4. ) Is transmitted by adding the BCID of the UE having the data to be transmitted to the TRF-IND message.

Meanwhile, the subscriber station 100 receiving the SLP-RSP message from the base station 200b in step S515 transitions to the sleep mode at the start time of the sleep mode included in the SLP-RSP message (S545). ), After a sleep interval included in the SLP-RSP message has elapsed, the state transitions to an awake mode (S550), and the base station is included during the monitoring interval included in the SLP-RSP message. Wait for a TRF-IND message from 200b. When receiving the TRF-IND message transmitted in step S540, it is checked whether the TRF-IND message is a positive traffic message or a negative traffic indication (S555). That is, it is checked whether or not the BCID of the subscriber station 100 is included in the received TRF-IND message. And if it is a positive traffic message (i.e., if the received TRF-IND message includes the BCID of the subscriber station 100), then transition to the active mode (S560); otherwise, increase the sleep interval to twice the previous sleep interval. After the operation (S565), the state transitions to the sleep mode again (S545).

11A through 11D are diagrams illustrating a sleep information table generated in a process of controlling a sleep mode according to a second embodiment of the present invention. Referring to FIGS. 11A through 11D, sleep according to the second embodiment of the present invention is described with reference to FIGS. The management method of the information table is as follows.

11A is a diagram illustrating an initialization state of a sleep information table. The description of FIG. 11A is the same as the process of FIG. 10 (S505). Therefore, description of FIG. 11A is omitted.

FIG. 11B is a diagram illustrating a result of performing process S520 of FIG. 10. In FIG. 11B, four subscriber stations SS # 1, SS # 2, SS # 3, and SS # 4 are registered in a sleep information table. To illustrate. That is, in FIG. 11B, a subscriber terminal having a BCID of '0x0001' (first subscriber terminal (SS # 1)), a subscriber terminal having a BCID of '0x0010' (second subscriber station (SS # 2)), and a BCID of '0x012F' Sleep information of the subscriber station (the third subscriber station SS # 3) and the subscriber station (the fourth subscriber station SS # 4) whose BCID is '0x00A0' is registered.

Referring to FIG. 11B, the first subscriber station SS # 1 transitions to the sleep mode for the first time when the frame number is '30', and the sleep interval (minimum time interval) of the first sleep mode is '256 frames'. The maximum time interval is '1024 frames'. Accordingly, the sleep interval of the first subscriber station SS # 1 is doubled from '256' to '1024' (eg, 256, 512, 1024, etc.). When the frame number is '30', the first subscriber station SS # 1 transitioning to the sleep mode wakes up when the frame number is '286'. This is a point calculated by the base station 200b using the two values since the sleep mode transition time point of the subscriber station is a frame number '30' and the sleep interval at that time is '256 frames'. That is, the value obtained by adding the two values.

In the same manner, the frame numbers of the second to fourth subscriber stations SS # 2, SS # 3, and SS # 4 transition to the first sleep mode, the sleep interval of the first sleep mode, and the maximum time period are shown in FIG. 11B. same. In particular, awake interval start frame numbers of the second to fourth subscriber stations SS # 2, SS # 3, and SS # 4 in the first sleep mode are 278, 285, and 278, respectively. This is a value obtained by adding a sleep start frame number and a sleep interval of each subscriber station in the base station 200b as in the case of the first subscriber station SS # 1.

11C and 11D are diagrams illustrating a result of performing process S520 of FIG. 10, and FIG. 11C is a diagram for describing a method of updating sleep information when the frame number is '278'. 11d is a diagram for explaining a sleep information updating method when the frame number is '285'.

First, referring to FIG. 11B, among the four subscriber stations registered in the sleep information table, the first waking up subscriber stations are the second and fourth subscriber stations SS # 2 and SS # 4, and the terminals SS # 2 and The frame number at which SS # 4 wakes up is '278'. Therefore, the base station 200b maintains the sleep information table until the frame number becomes '278'. When the frame number becomes '278', sleep information of the second and fourth subscriber stations SS # 2 and SS # 4 is updated. That is, the second and fourth subscriber stations SS # 2 and SS # 4 waking up to the frame number '278' calculate the frame number (ie, the sleep start frame number) to be transitioned to the sleep mode next time, and then the sleep start frame number. The contents stored in the area are updated, the value of the sleep interval is doubled to update the contents stored in the sleep interval area, and the second and fourth subscriber stations SS # 2 and SS # 4 are respectively in the corresponding sleep mode by using the values. Calculate the frame number to wake up and update the contents stored in the wake interval start frame area. Referring to FIG. 11C, the base station 200b firstly uses the second and fourth values as a frame number '278' in which each subscriber station is added to a watch interval ('3') plus a watch interval ('3'). The sleep start frame number areas of the subscriber stations SS # 2 and SS # 4 are updated. The sleep intervals of the subscriber stations SS # 2 and SS # 4 are updated. In this case, referring to FIG. 11B, since the initial sleep intervals (minimum time intervals) of the second and fourth subscriber stations SS # 2 and SS # 4 are '128' and '45', the values are doubled. The sleep interval of each of the second and fourth subscriber stations SS # 2 and SS # 4 is updated ('256' and '90'). Finally, the base station 200b calculates an awake interval start frame number in which each of the second and fourth subscriber stations SS # 2 and SS # 4 wakes up in the corresponding sleep mode by adding the updated values. Thereafter, the awake interval start frame numbers of the second and fourth subscriber stations SS # 2 and SS # 4 are updated. The update result is as illustrated in FIG. 11C.

Meanwhile, referring to FIG. 11C, after the sleep information of the subscriber stations is updated as described above, the third subscriber wakes up when the frame number reaches '285' and maintains the sleep information table until the frame number becomes '285'. The sleep information of the terminal SS # 3 is updated. That is, the third subscriber station SS # 3 waking up to the frame number '285' calculates the frame number (ie, the sleep start frame number) to be transitioned to the sleep mode (ie, sleep start frame number) (288 = 285 + 3). After updating the contents stored in the sleep interval area by updating the contents stored in the sleep interval and calculating twice the sleep interval (30 = 15 * 2), the third subscriber station SS # 3 uses the values to determine the sleep mode. The frame number waking up is calculated (318 = 288 + 30) to update the content stored in the awake interval start frame region. The update result is as illustrated in Fig. 11D.

12A and 12B are schematic block diagrams of a sleep mode control system according to a second embodiment of the present invention. Referring to FIG. 12A, the sleep mode control system 200b according to the second embodiment of the present invention may include a transmitter / receiver 230b, a sleep information table manager 240b, a TRF-IND message generator 250b, and a TRF-IND. A transmitter 260b and a frame counter 290b . In this case, the sleep mode control system 200b may be implemented in a base station of the IEEE 802.16e communication system or in a system separate from the base station. FIG. 12A illustrates an example in which the sleep mode control system 200b is implemented in the same system as the base station.

The transmitting / receiving unit 230b receives a sleep request message (SLP-REQ message) requesting a state transition to the sleep mode by subscriber stations, and responds to the state transition request to the sleep mode (SLP-RSP message). ) Is transmitted to the corresponding subscriber station.

The sleep information table manager 240b stores / manages a sleep information table for managing sleep information of subscriber stations in a sleep state. For example, the sleep information table manager 240b may respond to the sleep request of the subscriber station (eg, BCID, sleep start frame number, sleep interval, max-window, awake interval start frame) of the corresponding subscriber station. number) and update its sleep information (e.g., sleep start frame number, sleep interval, awake interval start frame number) over time. That is, the sleep information table manager 240b registers and updates the sleep information of the subscriber station as described in the description with reference to FIGS. 11A through 11D. The specific method is as mentioned in the description with reference to FIGS. 11A-11D.

The frame counter 290b transmits the frame number corresponding to the current time to the sleep information table manager 240b.

The TRF-IND generation unit 250b identifies the subscriber stations waking up at the time of transmitting the TRF-IND message based on the sleep information table managed by the sleep information table manager 240b, and packet data to be transmitted among the identified subscriber stations. Adds the subscriber station identification number (BCID) of the subscriber station with the TRF-IND message to be transmitted at the time of transmission of the corresponding TRF-IND message.

The TRF-IND transmitter 260b transmits the paging message generated by the TRF-IND generator 250b.

FIG. 12B further includes a pre-traffic indicator bit configuration unit 270b and a pre-traffic indicator bit transmission unit 280b in the sleep mode control system 200b illustrated in FIG. 12A. An example is shown. The pre-traffic indicator bit configuration unit 270b receives information on whether there is a subscriber station to transmit data among the subscriber stations waking up from the TRF-IND generation unit 250b at the time of TRF-IND transmission. Receive and set a pre-traffic indicator bit according to the result. The pre-traffic indication bit is transmitted to the pre-traffic indication bit transmission unit 280b. The pre-traffic indication bit transmitter 280b then transmits the pre-traffic indication bit to the outside. For example, the pre-traffic indication bit configuration unit 270b sets the bit to '0' and wakes up at the time of transmission when there is no terminal to transmit data among the terminals waking up at the time of transmission of the TRF-IND message. If there is at least one terminal, the bit is set to '1' and transmitted to the pre-traffic indication bit transmitter 280b.

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.

In the broadband wireless access communication system as described above, a table for managing sleep information of subscriber stations is configured and the sleep mode of subscriber stations is controlled by the table so that the base station can know in advance the terminal awake at the time of transmitting the paging message. There is an advantage in reducing unnecessary paging message transmission, thereby increasing the efficiency of a broadband wireless access communication system. In addition, the terminals operating in the sleep mode may be grouped and managed by the sleep information management table, and the management of the subscriber terminals by the group may be performed by different times of transmission of paging messages for each group within a unit time period for sleep mode control. There is an advantage to this. In addition, the present invention, if there is a small number of terminals waking up at the time of transmission of any TRF-IND message and there is no data to send to any of the terminals, it is not necessary to configure the TRF-IND message in advance in the frame control header (frame control header) By setting Pre-Traffic Indicator bit to inform the presence or absence of TRF-IND message in advance, UEs read only the frame control header value and pre-traffic indicator bit If '0', enter sleep mode without waiting for TRF-IND message. This has the effect of reducing the power consumption of the subscriber station.

1 is a schematic procedure diagram of a sleep mode control method proposed in an IEEE 802.16e communication system;

2A to 2D illustrate a message format transmitted / received between a base station and a terminal to control a sleep mode in an IEEE 802.16e communication system;

3 is a view for explaining a sleep interval update algorithm proposed in the IEEE 802.16e communication system,

4 is a diagram illustrating a processing procedure between a base station and a terminal for controlling a sleep mode according to a first embodiment of the present invention;

5 is a flowchart illustrating a process of a base station for controlling a sleep mode according to a first embodiment of the present invention;

6 is a diagram illustrating a time point at which a TRF-IND message is set differently for each group within a predetermined time period according to the first embodiment of the present invention;

FIG. 7 illustrates a sleep interval scheduling table for each group generated in a process of controlling a sleep mode according to a first embodiment of the present invention; FIG.

8 illustrates an example of a sleep operation by a sleep interval scheduling table for each group according to the first embodiment of the present invention;

9A and 9B are schematic block diagrams of a sleep mode control system according to a first embodiment of the present invention;

10 is a diagram illustrating a processing procedure between a base station and a terminal for controlling a sleep mode according to a second embodiment of the present invention;

11A to 11D illustrate a sleep information table generated in a process of controlling a sleep mode according to a second embodiment of the present invention;

12A and 12B are schematic block diagrams of a sleep mode control system according to a second embodiment of the present invention.

Claims (42)

A sleep mode control method comprising a sleep interval and awake interval in a broadband wireless access communication system including a base station and subscriber stations, the method comprising: A first step of grouping subscriber stations requesting a sleep operation to a base station into a predetermined group for sleep mode control; A second process of differently setting a paging message transmission time for each group within a unit time period for controlling the sleep mode; A third process of managing a sleep interval scheduling table for managing the sleep interval scheduling information of each of the subscriber stations in response to a sleep request by the subscriber stations in a sleep mode; Sleep mode control method of a broadband wireless access communication system comprising a. The method of claim 1, A fourth process of identifying subscriber stations waking up at that time among subscriber stations included in a group corresponding to each time of group paging message transmission set in the second process, based on the sleep interval scheduling table for each group; A fifth step of transmitting a paging message by adding a subscriber station identification number (BCID) of subscriber stations having packet data to be transmitted among the identified subscriber stations to a paging message to be transmitted at a corresponding paging message transmission point; And a sixth step of releasing a sleep mode by a subscriber station that wakes up at the time of transmitting the paging message and receives a corresponding paging message. The method of claim 2, wherein the fifth process Among the identified subscriber stations, a flag indicating whether or not there is a subscriber station with packet data to be transmitted is included in a frame control header of a paging message to be transmitted at a corresponding paging message transmission time. A sleep mode control method of a broadband wireless access communication system. The method of claim 3, wherein the fifth process is If there is a subscriber station with packet data to be transmitted among the identified subscriber stations, the flag is set to '1', otherwise the flag is set to '0'. How to control sleep mode. The method of claim 3 or 4, wherein the flag is And a pre-traffic indicator bit of the frame control header. The method of claim 1 or 2, wherein the first process is performed. According to the order in which the subscriber station requests a sleep operation from the base station, the subscriber stations are grouped so that a predetermined number of subscriber stations are included in each group, and the number of groups is increased whenever the number of subscriber stations increases. A sleep mode control method of a broadband wireless access communication system. The method of claim 1 or 2, wherein the first process is performed. According to the broadband wireless access communication system, the subscriber stations are grouped based on a result of modularly calculating the subscriber station identification number (BCID) assigned by the base station to each subscriber station with a preset number of groups. How to control sleep mode. The method of claim 1 or 2, wherein the third process Determine a minimum time period, a maximum time period, and a watch interval (listen interval) of a corresponding subscriber station in response to a sleep request to the sleep mode; Determine the state information for each unit time period of the corresponding subscriber station based on the minimum time period, the maximum time period, and the watch interval; And registering sleep interval scheduling information including state information for each of a minimum time period, a maximum time period, a monitoring period, and a unit time period of the subscriber station together with identification information of the corresponding subscriber station in the sleep interval scheduling table. Sleep mode control method of a wireless access communication system. The method of claim 8, wherein the third process is And deleting identification information of the subscriber station corresponding to the sleep interval scheduling information of the subscriber station which has transitioned from the sleep mode to the active mode to the sleep interval scheduling table. The method of claim 8, wherein the third process is The sleep interval scheduling information of each of the subscriber stations is managed by a predetermined unit time period, and a pointer indicating one unit time period is moved at any one time point as time passes. If the pointer points to the last unit time period Updating sleep interval scheduling information of all subscriber stations registered in the sleep interval scheduling table and changing a unit time period to which the pointer points next to an initial unit time period; . A sleep mode control system comprising a sleep interval and awake interval in a broadband wireless access communication system, A grouping unit for grouping subscriber stations to be a sleep mode control object into a predetermined group; A paging message transmission section management unit for each group, which sets and manages a paging message transmission time for each group within a unit time period for sleep mode control; A subscriber station receiving a SLP-REQ message requesting a state transition to a sleep mode by the subscriber stations and receiving an SLP-RSP message for a state transition request to the sleep mode. A sending / receiving unit for sending to And a sleep interval scheduling table manager for managing sleep interval scheduling information of each of subscriber stations in response to a sleep request to the sleep mode. system. The method of claim 11, Based on the sleep interval scheduling table for each group, each of the subscriber stations included in the corresponding group for each time of group paging message transmission managed by the group paging message transmission interval management unit is identified and A paging message generation unit for adding a subscriber station identification number (BCID) of subscriber stations with packet data to be transmitted among the identified subscriber stations to a paging message to be transmitted at a corresponding paging message transmission point; And a paging message transmitter for receiving paging message transmission time information for each group from the paging message transmission section management unit for each group and transmitting a paging message generated by the paging message generator based on the information. Sleep mode control system of connected communication system. The method of claim 12, Further comprising a pre-traffic indication bit configuration for notifying there is no data to be sent to any terminal in the group The pre-traffic indication bit configuration unit receives information on the presence / absence of the subscriber station to transmit data among the subscriber stations waking up at the time of paging message transmission from the paging message generator and receives the pre-traffic indication bit according to the result. And setting the signal to transmit the pre-traffic indication bit to the paging message generator. 14. The apparatus of claim 13, wherein the pre-traffic indication bit component is If there is a subscriber station to transmit data among the subscriber stations waking up at the time of transmitting the paging message, the pre-traffic indication bit is set to '1', otherwise the pre-traffic indication bit is set to '0'. Sleep mode control system of a broadband wireless access communication system, characterized in that. 15. The method of claim 14, wherein the paging message generating unit And generating a paging message frame including the pre-traffic indication bit, and transmitting only a frame control header when the pre-traffic indication bit is '0'. Sleep mode control system. The method of claim 11, wherein the grouping unit The subscriber stations are grouped so that the predetermined number of subscriber stations are included in each group according to the order in which the subscriber stations request a sleep operation from the base station, and the number of groups is increased whenever the number of subscriber stations increases. Sleep mode control system of a broadband wireless access communication system. The method of claim 11, wherein the grouping unit According to the broadband wireless access communication system, the subscriber stations are grouped based on a result of modularly calculating the subscriber station identification number (BCID) assigned by the base station to each subscriber station with a preset number of groups. Sleep mode control system. 12. The method of claim 11, wherein the sleep interval scheduling table management unit for each group The minimum time period, the maximum time period and the watch interval of the corresponding subscriber station are determined in response to the sleep request to the sleep mode, and the minimum time period, the maximum time period, and the monitoring period are determined. determine the state information for each unit time period of the corresponding subscriber station based on the (listen interval), and correspond to the sleep interval scheduling information including the state information for the minimum time period, the maximum time period, the monitoring period, and the unit time period of the subscriber station. The sleep mode control system of the broadband wireless access communication system, characterized in that registered in the sleep interval scheduling table together with the identification information of the subscriber station. 19. The method of claim 18, wherein the sleep interval scheduling table management unit for each group And deleting identification information of the subscriber station corresponding to the sleep interval scheduling information of the subscriber station which has transitioned from the sleep mode to the active mode to the sleep interval scheduling table. 19. The method of claim 18, wherein the sleep interval scheduling table management unit for each group The sleep interval scheduling information of each of the subscriber stations is managed by a predetermined unit time period, and a pointer indicating one unit time period is moved over time at any one time point, and the pointer indicates the last unit time period. If the sleep interval scheduling information of all the subscriber stations registered in the sleep interval scheduling table is updated, the sleep mode control of the broadband wireless access communication system, characterized in that for changing the unit time period to point next to the first unit time period; system. A sleep mode control method comprising a sleep interval and awake interval in a broadband wireless access communication system including a base station and subscriber stations, the method comprising: Initializing a sleep information table for managing sleep information of subscriber stations operating in a sleep mode; Registering sleep information of each of the subscriber stations in the sleep information table in response to a sleep request by the subscriber stations in a sleep mode; And updating the sleep information based on sleep information registered in the sleep information table as time passes. The method of claim 21, Identifying subscriber stations waking up at the time of transmitting a paging message based on the sleep information table; Transmitting a paging message by adding a subscriber station identification number (BCID) of subscriber stations having packet data to be transmitted among the identified subscriber stations to a paging message to be transmitted at a corresponding paging message transmission time point; And releasing a sleep mode by a subscriber station that wakes up at the time of transmitting the paging message and receives a corresponding paging message. The method of claim 22, wherein the transmission process Among the identified subscriber stations, a flag indicating whether or not there is a subscriber station with packet data to be transmitted is included in a frame control header of a paging message to be transmitted at a corresponding paging message transmission time. A sleep mode control method of a broadband wireless access communication system. The method of claim 23, wherein the transmission process If there is a subscriber station with packet data to be transmitted among the identified subscriber stations, the flag is set to '1', otherwise the flag is set to '0'. How to control sleep mode. The method of claim 23 or 24 wherein the flag is And a pre-traffic indicator bit of the frame control header. 23. The method of claim 21 or 22, wherein the sleep information table is An identification area for storing the subscriber station identification number; A start frame area for storing a frame number at the time when the subscriber station enters the sleep mode; A sleep interval region for storing a sleep interval of the sleep mode; A maximum time interval area for storing the maximum sleep interval information allowed for the subscriber station; And an awake frame area for storing a frame number of a time point at which the subscriber station wakes up from the sleep mode. The method of claim 26, wherein the registration process Storing the identification number of the corresponding subscriber station in the identification area, storing the sleep start frame number approved in the subscriber station in the start frame area, storing the minimum time period approved in the subscriber station in the sleep interval area, The maximum time period approved by the subscriber station is stored in the maximum time period area, and the frame number of the time at which the subscriber station wakes up using the frame number stored in the start frame area and the minimum time period stored in the sleep interval area. And calculating and storing the frame number in an awake frame region. The method of claim 27, wherein the registration process And calculating a frame number at the time of waking up of the subscriber station by adding the frame number stored in the start frame region and the minimum time interval stored in the sleep interval region. The method of claim 26, wherein the updating process When at least one of the subscriber stations operating in the sleep mode comes to wake up, a frame number of the wake-up time, a monitoring interval approved by the subscriber station, and a sleep interval of the sleep mode are used. Calculating a start frame number, a sleep interval of a next sleep mode, a wake-up time of a next sleep mode, and updating information in the sleep information table using the result of the calculation; . The method of claim 29, wherein the updating process The start frame number of the next sleep mode is calculated by adding the frame number at the time of waking up of the subscriber station and the monitoring interval, and doubles the current sleep interval to calculate a sleep interval of the next sleep mode, and the next sleep mode. And calculating a frame number at the time of waking from the next sleep mode by adding a start frame number of the first sleep mode and a sleep interval of the next sleep mode. The method of claim 30, wherein the updating process And setting the current sleep interval as a sleep interval of a next sleep mode if the current sleep interval is equal to the maximum time period approved by the subscriber station. A sleep mode control system including a sleep interval and awake interval in a broadband wireless access communication system, A transmitter / receiver which receives an SLP-REQ message requesting sleep of subscriber stations and transmits an SLP-RSP message to the sleep request message; Stores sleep information table for managing sleep information of subscriber stations in a sleep state and registers sleep information of each subscriber station in the sleep information table in response to a sleep request message (SLP-message) received through the transmitter / receiver. A sleep information table manager for updating the sleep information with time; And a frame counter that counts a frame number corresponding to a current time and provides the sleep information table manager to the sleep information table manager. 33. The method of claim 32, Identify the subscriber stations waking up at the time of transmitting the paging message based on the sleep information table, and the subscriber terminal identification number of the subscriber stations having the packet data to be transmitted among the identified subscriber stations is transmitted to the corresponding paging message transmission time Paging message generating unit to add to the message, And a paging message transmitter for transmitting a paging message generated by the paging message generator. The method of claim 33, wherein Further comprising a pre-traffic indication bit configuration for notifying there is no data to be sent to any terminal in the group The pre-traffic indication bit configuration unit receives information on the presence / absence of the subscriber station to transmit data among the subscriber stations waking up at the time of paging message transmission from the paging message generator and receives the pre-traffic indication bit according to the result. And setting the signal to transmit the pre-traffic indication bit to the paging message generator. 35. The apparatus of claim 34, wherein the pre-traffic indication bit component is If there is a subscriber station to transmit data among the subscriber stations waking up at the time of transmitting the paging message, the pre-traffic indication bit is set to '1', otherwise the pre-traffic indication bit is set to '0'. Sleep mode control system of a broadband wireless access communication system, characterized in that. 36. The apparatus of claim 35, wherein the paging message generator And generating a paging message frame including the pre-traffic indication bit, and transmitting only a frame control header when the pre-traffic indication bit is '0'. Sleep mode control system. 33. The system of claim 32, wherein the sleep information table is An identification area for storing the subscriber station identification number; A start frame area for storing a frame number at the time when the subscriber station enters the sleep mode; A sleep interval region for storing a sleep interval of the sleep mode; A maximum time interval area for storing the maximum sleep interval information allowed for the subscriber station; And a wake-up frame area for storing a frame number of a time point at which the subscriber station wakes up from the sleep mode. 38. The apparatus of claim 37, wherein the sleep information table management unit Storing the identification number of the corresponding subscriber station in the identification area, storing the sleep start frame number approved in the subscriber station in the start frame area, storing the minimum time period approved in the subscriber station in the sleep interval area, The maximum time period approved by the subscriber station is stored in the maximum time period area, and the frame number of the time at which the subscriber station wakes up using the frame number stored in the start frame area and the minimum time period stored in the sleep interval area. And calculating and storing the frame number in an awake frame region. 39. The apparatus of claim 38, wherein the sleep information table manager is used. And calculating a frame number at the time of waking up of the subscriber station by adding the frame number stored in the start frame region and the minimum time interval stored in the sleep interval region. 38. The apparatus of claim 37, wherein the sleep information table management unit When at least one of the subscriber stations operating in the sleep mode comes to wake up, a frame number of the wake-up time, a monitoring interval approved by the subscriber station, and a sleep interval of the sleep mode are used. A sleep mode control system of a broadband wireless access communication system, comprising: calculating a start frame number, a sleep interval of a next sleep mode, a time of waking from a next sleep mode, and updating the information of the sleep information table using the calculation result . 41. The apparatus of claim 40, wherein the sleep information table management unit The start frame number of the next sleep mode is calculated by adding the frame number at the time of waking up of the subscriber station and the monitoring interval, and doubles the current sleep interval to calculate a sleep interval of the next sleep mode, and the next sleep mode. And calculating a frame number at the time of waking from the next sleep mode by adding a start frame number of the first sleep mode and a sleep interval of the next sleep mode. 42. The system of claim 41, wherein the sleep information table management unit And setting the current sleep interval as a sleep interval of a next sleep mode if the current sleep interval is equal to the maximum time period approved by the corresponding subscriber station.