KR101216736B1 - Apparatus and method for managing sleep mode in wideband wireless access system - Google Patents

Abstract

The present invention relates to an apparatus and method for managing a sleep mode in a broadband wireless access system.

In the sleep mode management method according to the present invention, the wireless channels in the existing subscriber station are separately managed in the available period and the available period in response to the power saving class classified according to the service quality, and the available period, the operation in the sleep mode The transmission of downlink data to the terminal in progress and the end of the sleep mode of the terminal are managed based on the available period of the terminal.

The sleep mode management method according to the present invention can increase the power saving effect of the terminal by preventing the terminal from waking out of the sleep mode unnecessarily.

Broadband Wireless Access System, Sleep Mode, Power Saving Rating, Power Saving, Sleep Cycle, Listen Cycle

Description

Apparatus and method for managing sleep mode in wideband wireless access system

1 is a flowchart illustrating a sleep mode operation performed in a broadband wireless access system according to the prior art.

FIG. 2A is a flowchart illustrating a sleep period and a listening period in a sleep mode of a power saving class belonging to the power saving class type I according to the prior art.

2B is a flowchart illustrating a sleep period and a listening period in a sleep mode of a power saving class belonging to the power saving class type II according to the prior art.

3 is a flowchart illustrating an available interval and an unavailable interval in a sleep mode of a subscriber station according to the prior art.

4 is a signal flowchart illustrating a sleep mode management operation in a broadband wireless access system according to an exemplary embodiment of the present invention.

5 is a flowchart illustrating a sleep mode operation of a terminal when downlink traffic data is generated according to an exemplary embodiment of the present invention.

6 is a flowchart illustrating an operation of a sleep mode on the side of a subscriber station according to an exemplary embodiment of the present invention.

7 is a flowchart illustrating an operation of a sleep mode at a side of a base station according to an exemplary embodiment of the present invention.

8 is a flowchart illustrating an operation of processing a traffic notification in a base station according to an exemplary embodiment of the present invention.

9 is a block diagram illustrating a configuration of an apparatus for managing sleep mode according to an embodiment of the present invention.

10 is a block diagram illustrating a sleep mode manager of a sleep mode manager according to an exemplary embodiment of the present invention.

The present invention relates to a power saving method of a wideband radio access system, and more particularly, to a power saving mode in a broadband wireless access system such as Institute of Electrical and Electronics Engineers (IEEE) 802.16e. mode) or a sleep mode (hereinafter referred to as sleep mode).

The broadband wireless access system refers to a next-generation communication method that further supports mobility to a short-range data communication method using a fixed access point like a conventional wireless LAN.

Various standards for such a broadband wireless access system have been proposed, and international standardization of a broadband wireless access system is actively underway in IEEE 802.16e.

The conventional wireless LAN method such as IEEE 802.11 provides a data communication method capable of wireless communication within a short distance around a fixed access point, but this does not provide mobility of a subscriber station, but only wireless rather than wired. It had a limitation in supporting data communication.

On the other hand, a broadband wireless access system such as IEEE 802.16e ensures mobility even when a subscriber station moves from a cell currently managed by a base station to another cell managed by another base station, thereby providing data communication services that are not interrupted.

Accordingly, in the broadband wireless access system described above, the battery is mainly used as a power supply means of the subscriber station. Therefore, the battery usage time of the subscriber station in the broadband wireless access system described above is a large limiting factor of the service usage time.

Therefore, in the broadband wireless access system, in order to minimize power consumption of the terminal, all devices in the terminal support a sleep mode in which there is no operation to save power when there is no up and down traffic.

Meanwhile, in a broadband wireless access system, the quality of service (hereinafter referred to as "QoS") of a wireless channel set between a terminal and a base station varies according to traffic characteristics of each wireless channel. Accordingly, the IEEE 802.16e standard introduces a power saving class for efficient sleep mode management and separately manages sleep cycles for each power saving class. For example, the radio channel where data is generated every 2 seconds and the radio channel where data is generated every 3 seconds correspond to different power saving classes so that each radio channel has a listening period at different periods during sleep mode to determine whether data is generated. do.

In the IEEE 802.16e standard, power saving classes are classified into three types according to the required QoS, and the method of updating the listening period and the sleep period according to the power saving class type differs from the data reception operation in the listening period.

The power saving class type I is for the best effort traffic (BE), which is the characteristic of existing Internet traffic, or the non-real-time variable rate (nrt-VR), which is a non-real-time traffic with varying transmission rates. Parameters defining power saving class type I include the initial sleep window, the final sleep window base, the final sleep window exponent, and the listening window. ) And the start frame number for sleep window.

The power saving class type II is for real-time variable rate (rt-VR), which is VoIP or real-time traffic with varying data rates.The parameters defining power saving class type II include initial sleep window, listening window, And the first frame number of the sleep window.

Power-saving class type III delivers a management message or multicast to which UEs in sleep mode should be periodically transmitted, such as Downlink Channel Descriptor / Uplink Channel Descriptor (DCD / UCD) and Mobile Neighbor Base-station Advertisement (MOB_NBR-ADV). For the data that should be intended, the parameters that define the power saving class Type III include the last sleep window basis, the last sleep window index, and the first frame number of the sleep window.

The wireless channels in the subscriber station can be defined as several power saving classes, where all power saving classes must belong to one of the three power saving types described above.

The following describes a sleep mode management method of a subscriber station in the broadband wireless access system according to the prior art, and a sleep cycle management method in power saving class type I and power saving class type II.

The case of power saving class type III is a special case, and thus description of power saving class type III will be omitted below.

1 is a signal flow diagram illustrating a sleep mode management operation in a typical broadband wireless access system.

The subscriber station 10 operating in the awake mode needs to be approved by the base station 20 to enter the sleep mode. The subscriber station 10 to enter the sleep mode transmits a sleep mode request message (SLP-REQ) to the base station 20 and performs a sleep mode request (S10).

If there is a sleep mode request as described above, the base station 20 transmits a sleep mode response message (SLP-RSP) to the subscriber station 10 to approve the sleep mode (S11).

If the sleep mode approval is received from the base station 20, the subscriber station 10 enters the sleep mode that does not receive data from the sleep mode entry time (S12). When the initial sleep period elapses, the subscriber station 10 switches to the listening mode and checks whether there is data waiting to be transmitted during the sleep period from the base station 20 (S13).

Herein, the sleep period refers to a section in which the subscriber station 10 operates in the sleep mode, and the listening period refers to a section in which the subscriber station 10 operates in the listening mode.

At this time, if there is no data waiting to be transmitted during the first sleep period, the base station 20 sets a message indicating the presence of data traffic to 0 and transmits it to the subscriber station 10 (S14).

After confirming that there is no data traffic transmitted during the listening mode, the subscriber station 10 enters the sleep mode again (S15). In this case, the sleep period may be equal to or greater than the initial sleep period according to a setting, and may vary according to the above-described power saving class.

Meanwhile, when there is downlink data waiting to be transmitted to the subscriber station 10 during the second sleep period, the base station 20 may buffer the downlink data (S17). The buffered data is notified of its existence when the subscriber station 10 is operating in the listening mode (S18).

In the listening mode step S16, when the subscriber station 10 determines that there is downlink data to be transmitted to the subscriber station 10, the subscriber station 10 ends the sleep mode, enters the awake mode, and is buffered. The downlink data is received, and then data communication is performed with the base station 20.

As described above, when there is no downlink data to be transmitted to the terminal, the subscriber station maintains the sleep mode to prevent unnecessary power consumption.

Meanwhile, another sleep mode management method in a broadband wireless access system determines whether transmission of the buffered downlink data within the listening period of the terminal is performed when the buffered downlink data is generated while the terminal is operating in the sleep mode. To judge. Accordingly, if it is determined that transmission is possible in the listening period, transmission of the downlink data is terminated in the listening period and the sleep mode of the subscriber station is maintained.

In order to perform the transmission of the downlink data even during the listening mode, a special appointment must be made between the base station and the subscriber station, which is used to trigger traffic of the sleep mode request message (SLP-REQ) and the sleep mode response message (SLP-RSP). This is done by setting the wake flag (traffic_triggered_wakening_flag).

2A and 2B show sleep cycles and listening cycles of power saving class 1 belonging to power saving class type I and power saving class 2 belonging to power saving class type II in one subscriber station operating in the sleep mode; It is.

Referring to FIG. 2A, when the subscriber station maintains the sleep mode, the power saving class 1 continuously increases the sleep period by an exponential power of 2, and determines that data transmission is required in the listening mode or data transmission in the listening period is impossible. If it is ordered to exit the sleep mode immediately. On the other hand, as shown in FIG. 2B, the power saving class 2 is composed of a fixed length listening period and a sleep period regardless of data transmission and reception within the listening period.

3 shows an available period and an unavailable period of a subscriber station operating in a sleep mode.

Here, the subscriber station includes a power saving class 1 and a power saving class 2, the power saving class 1 has the characteristics of the power saving class type I, and the power saving class 2 has the characteristics of the power saving class Type II.

In addition, the unavailable section refers to a section in which all power saving classes included in the subscriber terminal are in sleep mode, and thus all devices in the subscriber terminal stop operating and enter the power saving mode, and the available section refers to one or more power savings in the terminal. The class stays in the listening mode, and thus, the terminal does not enter the power saving mode and means a period in which all devices in the terminal perform normal operation.

As shown in FIG. 3, the power saving classes in the subscriber station update the sleep period according to the power saving class type to which each power saving class corresponds.

In addition, in the existing sleep mode management method, when downlink data to be transmitted to the terminal is generated, it is determined whether the downlink data is transmitted within the listening period and whether the terminal is in the sleep mode based on the listening period of the corresponding power saving class.

That is, when downlink data serviced by the power saving class 1 occurs, the base station determines whether the downlink data can be transmitted to the terminal only as a listening period of the power saving class 1, and the listening period of the power saving class 2 is This is not a consideration for transmitting downlink data.

When managing the sleep mode as described above, even if it is possible to calculate the optimal sleep cycle for each power saving class, the terminal may inefficiently wake up from the sleep mode.

For example, when the first listening period of the power saving class 1 is reached, the base station determines whether data stored for transmission on the wireless channel corresponding to the power saving class 1 can be transmitted within the listening period. If it is determined that transmission is impossible within a given listening period, the base station will send a traffic notification message (TRF-IND) to wake up the subscriber station in sleep mode.

However, even when the listening cycle is completed in the power saving class 1, if the wireless channel corresponding to the strategy saving class 2 enters the listening mode, the subscriber station does not actually enter the sleep mode, and thus transmits data through the uplink and downlink. This is possible. Therefore, it is unnecessary to wake up the subscriber station in the sleep mode. As such, the conventional scheme manages the sleep period and the listening period separately for each power saving class, and manages the sleep mode of the terminal based on the sleep period and the listening period, thereby causing a problem of waking up the subscriber station in the sleep mode unnecessarily.

An object of the present invention is to provide an efficient sleep mode management method and apparatus for improving power saving effect of a terminal by maintaining a sleep mode of the terminal without additional power consumption in a broadband wireless access system, particularly an IEEE 802.16e system. .

A method for managing a sleep mode by a base station in a broadband wireless access system supporting sleep mode for power saving of a terminal according to an aspect of the present invention for achieving the above object,

a) checking whether there is downlink data to be transmitted to the terminal operating in the sleep mode; And b) if there is downlink data scheduled to be transmitted in step a), the available interval of the terminal, wherein the available interval means a period in which one or more strategic savings classes among the strategic savings classes in the terminal enter the listening period. Transmitting the downlink data to the terminal.

In addition, a sleep mode management apparatus for managing a sleep mode in a broadband wireless access system supporting a sleep mode for power saving of the terminal according to an aspect of the present invention for achieving the above object,

A memory for storing sleep mode definition parameters classified by power saving classes in the terminal; The sleep mode that calculates and outputs an available section of the terminal corresponding to a sleep mode definition parameter stored in the memory, wherein the available section represents a section in which one or more strategic savings classes of the terminal enter a listening period. Management; And a traffic transmission manager for transmitting downlink data to the terminal in response to the available interval received from the sleep mode manager.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Now, in the broadband wireless access system according to an embodiment of the present invention, a sleep mode management method will be described in detail with reference to the accompanying drawings.

In the following description, an operation of waking up from the subscriber station in the sleep mode due to generation of uplink data to be transmitted to the base station while the subscriber station operates in the sleep mode will be omitted. Since the sleep mode operation method in such a case is already well known, a detailed description thereof will be readily understood by those skilled in the art even if the detailed description thereof is omitted.

In addition, the following describes a sleep mode management method performed in a state where the base station and the terminal recognizes that downlink data can be transmitted and received within an available period when the subscriber station operates in the sleep mode by prior agreement. However, this can be modified so that the base station recognizes that the downlink data transmission is possible within the available interval by setting the indicator of the MAC message (eg, SLP-REQ message) when the subscriber station requests the sleep mode.

4 is a signal flowchart illustrating a sleep mode management operation in a broadband wireless access system according to an exemplary embodiment of the present invention.

Here, the available section and the unavailable section of the subscriber station 10 are derived according to the relationship between the listening period and the sleep period, which are classified and managed by power saving class according to the QoS characteristics of each radio channel. The available section refers to a section in which one or more power saving classes in the subscriber station 10 enter a listening period instead of a sleep period, in which all devices in the subscriber station 10 perform normal operations. On the other hand, the unavailable section means the remaining sections except for the available section, and all devices in the subscriber station 10 during the unavailable section stop operation and operate in the power saving mode.

The subscriber station 10 needs the approval of the base station 20 to enter the sleep mode. The subscriber station 10 to enter the sleep mode transmits a sleep mode request message (SLP-REQ) to the base station 20 and performs a sleep mode request (S20).

If there is a sleep mode request as described above, the base station 20 transmits a sleep mode response message (SLP-RSP) to the subscriber station 10 to approve the sleep mode (S21).

If the sleep mode is approved, the subscriber station 10 enters a sleep mode state in which data is not received from the sleep mode entry time (S22).

When the downlink traffic occurs in the unavailable section S23 when the subscriber station 10 is operating in the sleep mode, the base station 20 buffers the traffic (S24) and transmits the corresponding downlink data in the available section S25 of the terminal. Determine if the transfer can be completed.

At this time, if it is determined that the transmission of the downlink data can be completed within the available period S25 of the subscriber station 10, the base station 20, when the subscriber station 10 enters the available period S25, the corresponding downlink. The data is transmitted to the subscriber station 10 (S26).

Then, if another downlink data is received in the next unavailable section (S27), the base station 20 buffers the downlink data as described above (S28) and stores the downlink data in an available section of the subscriber station 10 (S28). In S29), it is determined whether transmission can be completed.

If it is determined that it is impossible to complete the transmission in the available section (S29), the base station 20 transmits data during the available section (S29) of the subscriber station 10 (S30), immediately before the end of the available section (S30) A traffic notification message (TRF-IND) for waking 10) from the sleep mode is transmitted to the subscriber station 10 (S31).

Upon receiving the traffic notification message TRF-IND, the terminal 10 wakes up from the sleep mode and enters the wake mode (S32).

Recognizing that the subscriber station 10 has entered the wake-up mode, the base station 20 completes the transmission of the downlink data transmitted in the sleep mode (S33).

As described above, according to an embodiment of the present invention, when downlink data to be transmitted to the terminal is generated when the subscriber station 10 is operating in the sleep mode, the base station 20 downlinks within an available period of the terminal 10. It is determined whether data transmission can be completed, and thus management of transmission of downlink data and termination of sleep mode are managed accordingly.

That is, the sleep mode management method according to an embodiment of the present invention is based on the available period and the unavailable period of the subscriber station derived from the relationship between the sleep period and the listening period of the wireless channels managed for each power saving class according to QoS. It is to determine the end of downlink data transmission or sleep mode.

The sleep mode management method as described above can maximize the power saving effect of the terminal by maintaining the sleep mode of the subscriber station without additional power consumption.

5 is a flowchart illustrating a sleep cycle update method and a sleep mode termination management operation of a terminal when downlink data is generated according to an embodiment of the present invention.

Here, power saving class 1 corresponds to power saving class type I and power saving class 2 corresponds to power saving class type II. In addition, the dotted arrow indicates downlink data scheduled to be transmitted on the wireless channel belonging to the power saving class 1, and the thick arrow indicates downlink data scheduled to be transmitted on the wireless channel belonging to the power saving class 2.

As shown in FIG. 5, regardless of the characteristics of the data traffic, that is, whether the data traffic corresponds to the power saving class 1 or the power saving class 2, the data is transmitted in response to the available interval of the terminal. . In addition, when it is determined that transmission of downlink data cannot be completed within an available period, a traffic notification message (TRF-IND) is transmitted to the corresponding terminal to wake up the terminal in sleep mode and transmit downlink data that cannot be transmitted within the available period. To complete.

The sleep mode management method may transmit downlink data when any of the power saving class 1 and the power saving class 2 in the subscriber station are operating in a listening period, and thus wakes up the subscriber station in the sleep mode. The incidence is reduced, resulting in efficient sleep mode management.

For example, even if the downlink data transmission is not completed within the listening period of the power saving class 1, when the power saving class 2 is operating in the listening period, the terminal is in an available period in which all devices in the terminal are normally operated, so that the terminal sleep mode. There is no need to terminate the downlink data only within the available interval. Therefore, the subscriber station can maximize the power saving effect by maintaining the sleep mode without additional power consumption.

Hereinafter, the sleep mode operation on the subscriber station side and the sleep mode operation operation on the base station side will be described in detail with reference to the accompanying drawings.

6 is a flowchart illustrating an operation of a sleep mode on a terminal side according to an exemplary embodiment of the present invention, and illustrates an example of a sleep mode operation flowchart on a terminal side.

Referring to FIG. 6, only a normal sleep mode entry procedure is shown as an example except for an exceptional case such as an entry rejection when a sleep mode entry request is made.

First, the terminal is in the awake state (S100).

If the subscriber station in the current wake-up mode recognizes that no uplink data exists for all of the services it receives, for up to a certain time (Tset) (S110), the subscriber station is characterized by the characteristics of the service it receives. In consideration of this, a sleep mode request message (SLP-REQ) having a parameter value set is transmitted to the base station (S120), and then the state is waiting for reception of the sleep mode response message (SLP-RSP) (S130).

Thereafter, when the terminal receives the corresponding message in the standby mode for receiving the sleep mode response message (SLP-RSP) (S140), the terminal operates the sleep mode in response to a parameter value specified in the sleep mode response message (SLP-RSP). Set a parameter value for (S150), after which the subscriber station enters the sleep mode (S160).

Table 1 shows an example of a sleep mode request message (SLP-REQ) according to an embodiment of the present invention. In this case, parts unnecessary for describing the embodiment of the present invention are omitted from the sleep mode request message (SLP-REQ) shown in Table 1.

[Table 1]

Syntax Size Notes MOB_SLP-REQ_Message_format () { Management message type = 50 8 bits Number of Classes 8 bits Number of power saving classes For (i = 0; i <Number of Classes; i ++) {    Power_Saving_Class_ID 6 bits    Power_Saving_Class_Type 2 bits    Initial-sleep window 8 bits    Listening window 8 bits    Final-sleep window base 10 bits    Final-sleep window exponent 3 bits    For (j = 0; j <Number_of_CIDs; j ++) {       CID 16 bits       }    }    TLV encoded information variable }

As shown in Table 1, the sleep mode request message (SLP-REQ) includes information on how many power saving classes the subscriber station includes (Number of Classes), the power saving class type (Power_Saving_Class_Type) included in the terminal, and each power saving. Sleep mode definition parameters corresponding to the classes and radio channel identifiers (CIDs) belonging to the respective power saving classes.

The sleep mode definition parameters may vary according to the power saving class. For the power saving class type I, the sleep mode definition parameters include an initial sleep window, a final sleep window base, It includes a final sleep window exponent, a listening window, and a start frame number for sleep window. In the case of the power saving class type II, the sleep mode defining parameter has an initial sleep window and a listening window, and the above-described parameters are used as parameters for setting the sleep period and the listening period for each power saving class.

7 is a flowchart illustrating an operation of a sleep mode on the side of a base station according to an exemplary embodiment of the present invention.

In this case, only the case of entering the normal sleep mode is considered, and the exception is omitted.

Referring to FIG. 7, the base station is in a state in which it is initially recognized that a specific terminal is operating in a wake-up mode (BS-SS awake mode) (S200).

Subsequently, when receiving a sleep mode request message (SLP-REQ) from a specific terminal in this state (S210), the base station defines a sleep mode corresponding to the parameters included in the sleep mode request message (SLP-REQ) for the terminal. The parameter is determined (S220).

In operation S230, a sleep mode start frame of the terminal is determined, and a sleep mode response (SLP-RSP) message including the sleep mode definition parameter and information on the sleep mode start frame is transmitted to the corresponding terminal (S240). .

Thereafter, the base station enters a state (BS-SS sleep mode) that the terminal is in the sleep mode (S250).

Here, the parameter of the sleep mode response message (SLP-RSP) includes an initial sleep period, a last sleep period, or a start frame corresponding to one or more power saving classes of the corresponding terminal, which is the sleep mode request message (SLP-REQ). May be the same as

Table 2 shows an example of a sleep mode response message (SLP-RSP) according to an embodiment of the present invention.

In the sleep mode response message (SLP-RSP) shown in Table 2, parts unnecessary for describing the embodiment of the present invention are omitted.

[Table 2]

Syntax Size Notes MOB_SLP-RSP_Message_format () Management message type = 51 8 bits Number of Classes 8 bits Number of power saving classes For (i = 0; i <Number of Classes; i ++) {    Sleep Approved 1 bit    Power_Saving_Class_ID 6 bits    if (Sleep Approved == 1) {       Start_frame_number 6 bits       Power_Saving_Class_Type 2 bits       Initial-sleep window 8 bits       Listening window 8 bits       Final-sleep window base 10 bits       Final-sleep window exponent 3 bits       SLPID 10 bits       For (j = 0; j <Number_of_CIDs; j ++) {          CID 16 bits          }       } else In case Sleep Approved == 0          REQ-duration 8 bits    }    TLV encoded information variable }

As shown in Table 2, the sleep mode response message SLP-RSP includes sleep mode definition parameters for each power saving class corresponding to the sleep mode request message SLP-REQ, and sleep mode start frame information.

Hereinafter, a process of transmitting data to a subscriber station in a sleep mode and processing a traffic notification according to an embodiment of the present invention will be described in detail.

8 is a flowchart illustrating a process of processing a traffic notification in a base station according to an embodiment of the present invention.

Referring to FIG. 8, if there is no downlink data stored or received for terminals entering the sleep mode (S300), the base station updates the sleep period corresponding to the terminal and indicates that the terminal is in the sleep mode. Return to the recognized state (S310).

If there is downlink data scheduled to be transmitted to the corresponding terminal, the base station checks whether the transmission of the data can be completed within the available interval of the corresponding terminal (S320), and if the transmission is possible, subscribes the downlink data to the subscriber. Sends to the terminal and returns to the state that the terminal is in sleep mode.

On the other hand, if it is determined that transmission cannot be completed within the available interval, the base station transmits downlink data to the terminal within the available interval and sets an indicator for notifying traffic to the corresponding terminal (S330). Here, the indicator setting may be a bitmap method or a method including an identifier of each terminal.

Thereafter, the base station transmits a traffic notification message (TRF-IND) for waking the terminal from the sleep mode before the unavailable period starts (S340), the subscriber station receiving the traffic notification message (TRF-IND) Enter the wake-up mode (S350).

As described above, in the sleep mode management according to the embodiment of the present invention, when downlink traffic occurs to the subscriber station while the subscriber station is operating in the sleep mode, transmission of downlink data and transmission of the downlink data based on the available period of the terminal Manage sleep mode exit. That is, the aforementioned sleep mode management method wakes up the UE in the sleep mode only when it is unable to complete the transmission of the downlink data in the available period of the UE, thereby performing data transmission, thereby reducing the occurrence of unnecessary wake up of the UE in the sleep mode. The power saving of the terminal can be maximized.

Hereinafter, the sleep mode management apparatus 200 according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

9 is a block diagram showing the configuration of the sleep mode management apparatus 200 according to an embodiment of the present invention.

The sleep mode management apparatus 200 may be implemented in a base station managing subscriber stations, and may utilize a component for operating a sleep mode of an existing broadband wireless access system.

The sleep mode management apparatus 200 may include a sleep mode message receiver 210, a message analyzer 220, a subscriber station identifier 230, a sleep mode manager 240, a traffic receiver 250, a memory 260, and traffic. And a transmission manager 270 and a sleep mode message transmitter 280.

The sleep mode message receiver 210 receives a sleep mode request message (SLP-REQ) from the subscriber station. The sleep mode request message (SLP-REQ) includes a subscriber station identifier and sleep mode definition parameters for setting a sleep period of the terminal.

The message analyzer 220 analyzes the sleep request message (SLP-REQ) received from the sleep mode message receiver 210, extracts the subscriber station identifier and the sleep mode definition parameter, and sleep mode manager 240 and the subscriber station identifier. Transmit to 230.

The subscriber station identification unit 230 analyzes the received subscriber station identifier and transmits identification information corresponding to the subscriber station to the sleep mode manager 240.

The sleep mode manager 240 receives the subscriber station identifier and sleep mode definition parameters from the message analyzer 220, sets a sleep mode entry time of the corresponding terminal, and transmits the sleep mode message transmission unit to the sleep mode message transmitter 280.

That is, when the subscriber station enters the sleep mode by the sleep mode manager 240, the sleep mode manager 240 notifies the sleep mode message transmitter 280, and the sleep mode message transmitter 280 enters the sleep mode. Control to transmit a sleep mode response message to the subscriber station. Accordingly, the sleep mode message transmitter 280 responds to the sleep mode request by transmitting a MAC message (eg, an SLP-RSP message) including a sleep mode definition parameter and a sleep mode entry time point to the subscriber station.

In addition, the sleep mode manager 240 classifies the sleep mode definition parameters for each power saving class in the terminal and stores them in the memory 260 to manage them. Subsequently, when downlink data to be transmitted to the terminal is generated while the terminal operates in the sleep mode, the sleep mode manager 240 reads the sleep mode definition parameters of the subscriber terminal from the memory and calculates the available period and the unavailable period. do.

The available interval thus calculated is used by the traffic transmission management unit 270 to transmit downlink data. That is, outputting the available section information to the traffic transmission management unit 270 so that the downlink data is transmitted to the subscriber station within the available section, and if the transmission of the downlink data to the corresponding terminal in the available section is not completed, it is notified to the subscriber station The terminal manages to wake up from sleep mode.

Meanwhile, the traffic receiver 250 receives downlink data through a network, identifies a subscriber station to which data is to be transmitted, and transmits downlink data and terminal identification information to the traffic transmission manager 270.

The traffic transmission manager 270 requests the sleep mode manager 240 for available interval information corresponding to the received terminal identification information, and transmits downlink data to the terminal in the available interval. That is, the traffic transmission management unit 270 temporarily stores the downlink data in the buffer when the terminal enters the unavailable section, and transmits the stored downlink data to the corresponding terminal when entering the available section or in the weather mode. do.

10 is a block diagram illustrating a sleep mode manager 240 according to an exemplary embodiment of the present invention.

The sleep mode manager 240 includes a sleep mode entry manager 241, a power saving class manager 242, an available interval calculator 243, and a traffic message manager 244.

The sleep mode entry manager 241 receives subscriber station identification information and sleep mode definition parameters from the message analyzer 220 and the subscriber station identification unit 230, sets a sleep mode entry time of the corresponding subscriber station, and sets the sleep mode. Definition parameters are transmitted to the power saving class management unit 242.

The power saving class manager 242 classifies the sleep mode definition parameter for each power saving class in the corresponding terminal and stores the sleep mode definition parameter in the memory 260. Meanwhile, when downlink data to be transmitted to the subscriber station in the sleep mode is generated, the sleep mode definition parameter of the corresponding terminal is read from the memory 260 and transmitted to the available interval calculating unit 243.

When the available section calculation unit 243 is notified of the occurrence of the downlink data, the available section calculation unit reads the sleep mode definition parameters of the subscriber station to transmit the data from the memory 260 to calculate the available section.

Thereafter, the available section calculating unit 243 transmits the information on the available section to the traffic transmission management unit 270, and if it is determined that the traffic transmission management unit 270 cannot complete the transmission of the downlink data in the available section, Informs the traffic message manager 244,

The traffic message management unit 244 sets an indicator for a traffic notification message (TRF-IND) to be transmitted to the subscriber station according to the information received from the available interval calculation unit 243, and a typical traffic transmitter (not shown) in the system. Through the traffic notification message (TRF-IND) is transmitted to the subscriber station.

Hereinafter, the operation of the sleep mode management apparatus 200 in the broadband wireless access system according to an embodiment of the present invention will be described in detail.

The sleep mode message receiver 210 receiving the sleep mode request message SLP-REQ from a specific subscriber station transmits the sleep mode request message SLP-REQ to the message analyzer 220.

The message analyzer 220 extracts the terminal identifier and the sleep mode definition parameter from the received sleep mode request message (SLP-REQ) and transmits the terminal identifier and the sleep mode definition parameter to the subscriber station identifier 230 and the sleep mode manager 240.

The subscriber station identification unit 230 analyzes the information on the terminal corresponding to the terminal identifier and notifies the sleep mode manager 240.

The sleep mode manager 240 receives sleep mode definition parameters and information on the terminal from the message analyzer 220 and the subscriber station identification unit 230, sets a sleep mode entry time of the corresponding terminal, 280).

The sleep mode message transmitter 280 transmits a sleep mode response message (SLP-RSP) including information on the sleep mode entry time point and the sleep mode definition parameter to the corresponding terminal.

Meanwhile, the sleep mode manager 240 classifies the sleep mode definition parameter according to the terminal and the power saving class in the terminal and stores the sleep mode definition parameter in the memory 260.

In the future, when the traffic transmission management unit 270 is notified that the downlink data traffic for the corresponding terminal is generated from the network, the sleep mode manager 240 reads the sleep mode definition parameter from the memory and makes available and unavailable intervals of the corresponding terminal. To calculate. The available interval thus calculated serves as a criterion for determining the transmission of the downlink data traffic and the end of the sleep mode.

That is, if transmission of the downlink data can be completed within the available interval, the sleep mode manager 240 notifies the traffic transmission manager 270 to transmit the corresponding data to the terminal, otherwise the sleep mode manager ( 240 transmits the traffic notification message (TRF-IND) to the terminal to wake up the terminal in the sleep mode.

As described above, the sleep mode management apparatus 200 according to the embodiment of the present invention, instead of managing the transmission of the downlink data and whether the end of the sleep mode of the terminal for each power saving level in the subscriber station, all of the power saving class By managing based on the available period and the unavailable period of the terminal calculated from the sleep period, it is possible to reduce unnecessary sleep mode termination and to transmit downlink data even in the sleep mode, thereby achieving high power saving effect.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

According to an embodiment of the present invention, a sleep mode management method of a broadband wireless access system for performing downlink data transmission during operation in a sleep mode and determination for waking a terminal from a sleep mode based on an available period and an unavailable period of the terminal; The device may maximize the power saving effect of the terminal by maintaining the sleep mode of the terminal without additional power consumption.

Claims (10)

In a method for managing a sleep mode by a base station in a broadband wireless access system supporting a sleep mode for power saving of the terminal, a) checking whether there is downlink data to be transmitted to the terminal operating in the sleep mode; And b) if there is downlink data scheduled to be transmitted in step a), the available section of the terminal, wherein the available section means a section in which one or more strategic savings classes among the strategic savings classes in the terminal enter the listening period. Transmitting downlink data to the terminal Sleep mode management method comprising a. The method of claim 1, After step b), c) terminating the sleep mode of the terminal by determining whether the terminal is in the sleep mode within the available interval; Sleep mode management method further comprising. 3. The method of claim 2, C), Determining whether to terminate the sleep mode of the terminal by determining whether transmission of the downlink data to the terminal can be completed within the available period; And Waking the terminal from the sleep mode when it is necessary to end the sleep mode of the terminal Sleep mode management method comprising a. The method of claim 3, Sleep mode management method characterized in that to send a traffic notification message including a sleep mode end indicator to the terminal to terminate the sleep mode of the terminal. A sleep mode management apparatus for managing a sleep mode in a broadband wireless access system supporting a sleep mode for power saving of a terminal, A memory for storing sleep mode definition parameters classified by power saving classes in the terminal; The sleep mode that calculates and outputs an available section of the terminal corresponding to a sleep mode definition parameter stored in the memory, wherein the available section represents a section in which one or more strategic savings classes of the terminal enter a listening period. Management; And Traffic transmission management unit for transmitting the downlink data to the terminal in response to the available interval received from the sleep mode management unit Sleep mode management device comprising a. 6. The method of claim 5, The sleep mode manager determines a sleep mode termination of the terminal in response to the available period. The method according to claim 5 or 6, A sleep mode message receiver configured to receive and output the sleep mode request message from the terminal; A sleep mode message transmitter configured to transmit a sleep mode response message including a sleep mode entry time point to the terminal; A message analyzer configured to output a terminal identifier and the sleep mode definition parameter corresponding to the sleep mode request message received from the sleep mode message receiver; A subscriber station identifier for outputting terminal identification information by analyzing the terminal identifier received from the message analyzer; And A traffic receiver for receiving downlink data to be transmitted from the network to the terminal and outputting the downlink data and the terminal information. More, The sleep mode management unit, And receiving and managing the sleep mode definition parameter and the terminal identification information from the subscriber station identification unit and the message analyzer, and outputting a sleep mode entry time point of the terminal to the sleep mode message transmitter. 8. The method of claim 7, The sleep mode management unit, A sleep mode entry manager configured to set the sleep mode entry time point corresponding to the sleep mode definition parameter received from the message analyzer and transmit the sleep mode entry time point to the sleep mode message transmitter; A power saving class manager configured to classify the sleep mode definition parameter received through the sleep mode entry manager by power saving class and store and manage the power saving class in the memory; An available interval calculator configured to calculate and output the available interval in response to the terminal information received through the traffic transmission manager, and to output whether the downlink data can be transmitted within the available interval; And Traffic message control unit for transmitting a traffic notification message corresponding to the transmission completion received from the available interval calculation unit to the terminal Sleep mode management apparatus comprising a. 6. The method of claim 5, The power saving rating is, Sleep mode management apparatus characterized in that the sleep mode management class is classified according to the quality of service required corresponding to the traffic characteristics of each radio channel. 6. The method of claim 5, The sleep mode definition parameter is, And at least one of an initial sleep window, a last window basis, a last window index, a listening window, and an initial frame number of the sleep window.

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