CN1930793B - Method for performing location update by a mobile subscriber station in a broadband wireless access communication system - Google Patents

Abstract

There is provided a method for controlling an operation mode of a medium access control layer by a mobile subscriber station in a broadband wireless access communication system including the mobile subscriber station and a serving base station providing a service to the mobile subscriber station, the method comprising the steps of: mode transition to an idle mode when there is no data transmission between the serving base station and the mobile subscriber station during a predetermined first time interval in an awake mode; detecting that a mobile station in an idle mode moves into another paging area to which a target base station belongs, the paging area being different from a paging area to which a serving base station belongs; and when the movement of the mobile subscriber station is detected, mode-converting to the awake mode and performing location update together with the target base station.

Description

For performing location update by a mobile subscriber station in a broadband wireless access communication system Methods

technical field

The invention relates to a broadband wireless access communication system, in particular to a system and method for controlling the operation mode of a medium access control (MAC) layer.

In a 4th generation (4G) communication system, which is a next-generation communication system, improvements are focused on providing various qualities of service (QoS) at high transmission speeds. The third generation (3G) communication system supports a transmission speed of about 384 kbps under relatively poor channel conditions outdoors, and a maximum transmission speed of about 2 Mbps under relatively good channel conditions indoors.

Wireless Local Area Network (LAN) and Metropolitan Area Network (MAN) communication systems typically support transmission speeds of 20 to 50 Mbps. Since the wireless MAN communication system has wide service coverage and supports high transmission speed, it is suitable for supporting high-speed communication services. However, the Wireless MAN system does not provide mobility of users (ie, Subscriber Stations (SSs)) or handover for high-speed mobility of SSs.

As a result, in the 4G communication system, a new type of communication system is being developed that ensures mobility and QoS of wireless LAN and MAN systems supporting relatively high transmission speeds to support high-speed services in the 4G communication system.

The IEEE (Institute of Electrical and Electronics Engineers) 802.16a communication system adopts an Orthogonal Frequency Division Multiplexing (OFDM) scheme and an Orthogonal Frequency Division Multiple Access (OFDMA) scheme to support a broadband transmission network to physical channels of a wireless MAN system.

IEEE 802.16a communication system only considers single cell structure and fixed SS, so the system does not consider the movement of SS. In contrast, the IEEE 802.16e communication system is defined as a system designed for the mobility of the SS in addition to the IEEE 802.16a communication system, and thus should reflect the mobility of the SS in a multi-cell environment. In order to provide the mobility of the SS in a multi-cell environment as described above, the operation mode changes of the SS and its base station (BS) are considered and adapted. For this reason, research on SS handover in a multi-cell structure is actively conducted to support SS mobility. Here, the mobile SS is called a mobile subscriber station (MSS).

FIG. 1 is a block diagram schematically showing the structure of an IEEE 802.16e communication system.

Referring to FIG. 1 , an IEEE 802.16e communication system has a multi-cell structure including a cell 100 and a cell 150 . In addition, the IEEE 802.16e communication system includes a BS 110 controlling a cell 100 , a BS 140 controlling a cell 150 , and a plurality of MSSs 111 , 113 , 130 , 151 , and 153 . Signal transmission/reception between the BSs 110 and 140 and the MSSs 111, 113, 130, 151, and 153 is accomplished through the OFDM/OFDMA scheme. The MSS 130 is located in a boundary area between the cell 100 and the cell 150 (ie, a handover area). When handover of MSS 130 is possible, MSS 130 can move without loss of traffic.

In the IEEE 802.16e communication system, a specific MSS receives pilot signals transmitted from a plurality of BSs and measures a carrier-to-interference-and-noise ratio (CINR) of the received pilot signals. The MSS selects the BS with the highest CINR as the serving BS, which means the MSS belongs to this BS. The MSS having selected the serving BS receives downlink frames and uplink frames transmitted from the serving BS, and uses them in transmitting and receiving data.

With MSS mobility considered as described above, MMS power consumption plays an important role in system performance. Therefore, sleep mode operation and wake-up mode operation are therefore proposed for BS and MSS to minimize MSS power consumption.

Next, an operation mode of a Medium Access Control (MAC) layer of the IEEE 802.16e communication system will be described with reference to FIG. 2 .

FIG. 2 is a pattern diagram schematically showing the operation mode of the MAC layer of the IEEE 802.16e communication system.

Referring to FIG. 2, the MAC layer of the IEEE 802.16e communication system supports two modes of operation (ie, wake-up mode 210 and sleep mode 220). First, a sleep mode 220 is proposed in order to minimize the power consumption of the MSS during idle time when no packet data is being transmitted. The MSS mode transitions (211) from the wake-up mode 210 to the sleep mode 220, thereby minimizing power consumption of the MSS during idle times when no packet data is being transmitted. Typically, packet data is sent in bursts as it is generated. It would be inefficient to perform the same operation when sending data and when not sending data. To this end, sleep mode operation as described above was developed.

When packet data is generated while the MSS is in the sleep mode, the MSS mode transitions to the wake-up mode, and transmits/receives the packet data. However, since packet data is highly dependent on traffic patterns, dormant mode operations must be performed in an organized manner taking into account the traffic characteristics and transmission scheme characteristics of packet data.

Next, a scheme proposed so far for the IEEE 802.16e communication system to support the operation in the sleep mode 220 will be described.

First, in order to mode transition into the sleep mode 220, the MSS receives a mode transition consent from the BS. The BS allows the MSS to transition into sleep mode 220 while buffering or discarding packet data sent to the MSS. In addition, the BS notifies the MSS of packet data to be transmitted during the listening interval of the MSS. The MSS wakes up from sleep mode 220 and checks if there is any packet data to be sent from the BS to the MSS. The listening interval is described in more detail below. When there is packet data to be transmitted from the BS to the MSS, the MSS mode-transitions from the sleep mode 220 to the wake-up mode 210 and receives packet data from the BS. The MSS stays in sleep mode 220 when there is no packet data to be sent from the BS to the MSS.

Next, parameters supporting operations in the sleep mode and the wake-up mode will be described.

1) Sleep interval

The sleep interval is an interval requested by the MSS and allocated by the BS according to the MSS request. The sleep interval also represents the time it takes to transition from sleep mode 220 to wake mode 210 . In other words, a sleep interval is defined as the interval in which the MSS stays in sleep mode 220 . The MSS may remain in sleep mode 220 even after the sleep interval has ended. In this case, the MSS updates the sleep interval by executing a sleep interval update algorithm using the preset initial sleep window value and final sleep window value. Here, the initial sleep window value corresponds to the minimum sleep window value, and the final sleep window value corresponds to the maximum sleep window value. In addition, both the initial sleep window value and the final sleep window value are allocated by the BS, and are represented by frame numbers. Since the minimum window value and maximum window value will be described in detail below, further description is omitted here.

2) Listening interval

The listening interval is an interval requested by the MSS and allocated by the BS according to the MSS request. In addition, the listening interval represents the time it takes for the MSS to wake up from the sleep mode 220 and synchronize with the downlink signal of the BS enough to decode a downlink message such as a Traffic Indication (TRF_IND) message. Here, the TRF_IND message is a message indicating the existence of a service (ie, packet data) to be transmitted to the MSS. Since the TRF_IND message will be described in detail below, further description is omitted here. The MSS determines whether to stay in the wake-up mode or switch back to the sleep mode according to the value of the TRF_IND message.

3) Sleep interval update algorithm

When the MSS enters the sleep mode 220, it determines the sleep interval while taking the preset minimum window value as the minimum sleep mode interval. After the sleep interval has elapsed, the MSS wakes up from the sleep mode 220 in the listening interval, and checks whether there is packet data to be transmitted from the BS. If there is no packet data to send, the MSS resets the sleep interval to twice as long as the previous sleep interval and continues to stay in sleep mode 220. For example, when the minimum window value is "2", the MSS sets the sleep interval to 2 frames, and stays in sleep mode for 2 frames. After 2 frames have elapsed, the MSS wakes up from the sleep mode, and determines whether a TRF_IND message is received. When no TRF_IND message is received (i.e. when there is no packet data sent from BS to MSS), MSS sets sleep interval to 4 frames (twice as long as 2 frames), and stays in sleep during these 4 frames Mode 220. In this way, the sleep interval increases from the initial sleep window value to the final sleep window value. The algorithm described above for updating the sleep interval is the sleep interval update algorithm.

Next, network re-entry processing of the MSS will be described with reference to FIG. 3 .

FIG. 3 is a signal flow diagram schematically showing network re-entry processing of an MSS of a conventional IEEE 802.16e communication system.

First, in step 311, according to handover, the MSS receives a preamble of a downlink frame transmitted from a handover-to BS (ie, a new serving BS) and acquires system synchronization with the new serving BS. The MSS then obtains downlink synchronization from the BS information contained in the messages broadcast by the BS, including Downlink Channel Descriptor (DCD) messages, Uplink Channel Descriptor (UCD) messages, Downlink Mapping (DL_MAP) messages , Uplink Mapping (UL_MAP) message, Mobile Neighbor Advertisement (MOB_NBR-ADV) message.

Then, in step 313, the MSS transmits a ranging request (RNG_REQ) message to the BS, receives a ranging response (RNG_RSP) message from the BS in response to the RNG_REG message, and obtains uplink synchronization with the BS from the RNG_RSP message. Then, in step 315, the MSS adjusts its frequency and power.

Then, in step 317, the MSS negotiates the basic capabilities of the MSS with the BS. In step 319, the MSS obtains an Authentication Key (AK) and a Traffic Encryption Key (TEK) by performing an authentication operation with the BS. In step 321, the MSS requests the BS to register the MSS, and the BS completes the registration of the MSS. In step 323, the MSS performs an Internet Protocol (IP) connection with the BS. In step 325, the MSS downloads the operation information through the IP associated with the BS. In step 327, the MSS performs traffic connection with the BS. Here, the service flow refers to a flow in which a MAC_SDU (Service Data Unit) is transmitted and received through a connection with a certain predetermined threshold QoS. Then, in step 329, the MSS uses the service provided from the BS. Then, the processing ends.

Next, handover processing in the IEEE 802.16e communication system will be described with reference to FIG. 4 .

FIG. 4 is a signal flow diagram schematically showing handover processing of a conventional IEEE 802.16e communication system.

Referring to FIG. 4, the MSS scans CINRs of pilot signals from neighboring BSs in the above process (step 411). When the MSS 400 determines that it should change the serving BS (step 413), the MSS 400 sends a Mobile Handover Request (MOB_HO_REQ) message to the current serving BS 410 (step 415). FIG. 4 is based on the assumption that MSS 400 has two neighbor BSs including first BS 420 and second BS 430 . Here, the MOB_HO_REQ message includes the result of the MSS 400 scan.

When the serving BS 410 receives the MOB_HO_REQ message, the serving BS 410 detects information on a list of neighbor BSs to which the MSS 400 can handover from among information contained in the received MOB_HO_REQ message (step 417). Here, for convenience of description, the list of neighbor BSs to which the MSS 400 can handover is referred to as “handover available neighbor BS list”, and this example assumes that the handover available neighbor BS list includes the first BS 420 and the second BS 430 . The serving BS 410 transmits a handover notification (HO_NOTIFICATION) message to neighbor BSs (ie, the first BS 420 and the second BS 430 ) included in the handover-available neighbor BS list (steps 419 and 421 ).

After receiving the HO_NOTIFICATION message from the serving BS 410, each of the first BS 420 and the second BS 430 sends a handover notification response (HO_NOTIFICATION_RESPONSE) message to the serving BS 410 (steps 423 and 425), which is a response to the HO_NOTIFICATION message Answer message. The HO_NOTIFICATION_RESPONSE message contains a number of information elements (IEs), including the MSS ID of the MSS 400, an acknowledgment (ACK/NACK) as to whether the neighbor BS can perform handover in response to the request of the MSS 400, and each neighbor BS handover to each The bandwidth and service level information that can be provided by each BS.

When the serving BS 410 receives the HO_NOTIFICATION_RESPONSE messages sent from the first neighbor BS 420 and the second neighbor BS 430, the serving BS 410 selects a neighbor BS that can optimally provide the bandwidth and service level requested by the MSS 400 when the MSS 400 is handed over, As the target BS that MSS400 will actually handover to.

For example, if the service level required by the MSS 400 is higher than the service level that the first neighbor BS 420 can provide and is equal to the service level that the second neighbor BS 430 can provide, then the serving BS 410 will select the second neighbor BS 430 as the service level. Target BS. Then, the serving BS 410 sends a handover notification confirmation (HO_NOTIFICATION_CONFIRM) message to the second neighbor BS 430 as a response to the HO_NOTIFICATION_RESPONSE message (step 427).

The serving BS 410 sends a mobile handover response (MOB_HO_RSP) message to the MSS 400 as a response to the MOB_HO_REQ message (step 429). The MOB_HO_RSP message contains information on a target BS to which the MSS 400 is to be handed over.

Then, upon receiving the MOB_HO_RSP message, the MSS 400 analyzes information contained in the MOB_HO_RSP message, and selects a target BS. After selecting the target BS, the MSS 400 sends a Mobile Handover Indication (MOB_HO_IND) message to the serving BS 410 as a reply to the MOB_HO_RSP message (step 431).

After receiving the MOB_HO_IND message, the serving BS 410 recognizes that the MSS 400 will handover to the target BS contained in the MOB_HO_IND message (ie, the second neighbor BS 430), and then releases the link currently established with the MSS 400 (step 433). Then, the MSS 400 performs an initial adjustment process with the second neighbor BS 430 (step 435), and when the initial adjustment process is successful, performs a network re-entry process with the second neighbor BS 430 (step 437).

The operation related to handover described with reference to FIG. 4 is an operation performed by the MSS in the wake-up mode. However, when the MSS detects that it has reached the cell boundary area while being in the sleep mode, the MSS switches to the wake-up mode and performs the handover-related operations of FIG. 4 . In other words, when the MSS moves from the first cell to the second cell in the sleep mode, the MSS cannot resume connection with the first cell BS and perform network re-entry processing with the second cell BS. When performing a network reentry process in the current IEEE 802.16e communication system, the MSS transmits a BS identifier (BS ID) of a previous BS to which the MSS belongs so that a new BS can recognize that the MSS is handing over. Then, the new BS can obtain information of the MSS from the previous BS, and perform handover together with the MSS.

The above description gives the method for reducing the power consumption of MSS and the method for MSS handover. However, when the method for reducing power consumption is applied to an MSS in sleep mode, the method becomes inefficient because while the MSS is in sleep mode, whenever it moves between cells, it has to perform Handover as described above, especially, even if the MSS has no traffic to transmit or receive at all, handover must be performed every time it moves between cells. During handover operation, the effect of MSS power consumption reduction is reduced and message overhead is generated. In addition, all MSSs in sleep and wake-up modes perform periodic adjustments. This also results in unnecessary power consumption and creates message overhead.

In addition, the current IEEE 802.16e communication system continuously allocates various types of basic radio resources to MSSs that have no traffic to transmit or receive. The following are basic radio resources that are always allocated regardless of actual need.

(1) Basic Connection Identifier (CID) (Basic CID)

The basic CID is a connection identifier used when sending messages that are relatively short and must be sent urgently (ie, emergency control messages).

(2) Main management CID

The primary management CID is a connection identifier used when sending relatively long messages with relatively low urgency.

(3) Auxiliary management CID

The secondary management CID is a connection identifier used when sending messages with relatively low urgency and involving at least three layers of standard protocols.

Furthermore, in the IEEE 802.16e communication system, each MSS is assigned an Internet Protocol version 4 (IPv4) address, which is also a limited radio resource. As described above, in the IEEE 802.16e communication system, the above-mentioned wireless resources, such as connection identifiers and IPv4 addresses, may be allocated to MSSs that have no data to transmit or receive, thereby reducing the utilization efficiency of wireless resources. Therefore, there is a need for a MAC layer-specific operation scheme supporting operations between BSs and MSSs, which can maximize the utilization efficiency of radio resources while minimizing the power consumption of MSSs moving at high speed.

Contents of the invention

Therefore, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a system and method for controlling a MAC layer operation mode of a broadband wireless access communication system.

Another object of the present invention is to provide a system and method for minimizing power consumption of an MSS by controlling a MAC layer operation mode of a broadband wireless access communication system.

Another object of the present invention is to provide a system and method for paging an MSS in an idle mode of a MAC layer in a broadband wireless access communication system.

Another object of the present invention is to provide a location update system and method according to movement of an MSS in an idle mode of a MAC layer in a broadband wireless access communication system.

In order to achieve this object, there is provided a method for controlling the mode of operation of a medium access control layer by a mobile subscriber station in a broadband wireless access communication system comprising a mobile subscriber station and providing services to the mobile subscriber station serving base station. The method comprises the steps of: when the mobile subscriber station is in an inactive state, the mode transitions into an idle mode to save power and operating resources; detecting that the mobile station in the idle mode moves to another paging area to which the target base station belongs, The paging area is different from the paging area to which the serving base station belongs; and when the movement of the mobile subscriber station is detected, the mode is switched to the wake-up mode, and a location update is performed with the target base station.

According to another aspect of the present invention, there is provided a method for controlling the operation mode of the medium access control layer by a mobile subscriber station in a broadband wireless access communication system, the broadband wireless access communication system includes a mobile subscriber station and a The serving base station that provides the service. The method comprises the steps of: when there is no data transmission between the serving base station and the mobile subscriber station during a predetermined first time interval in the wake-up mode, the mode transitions to an idle mode; and at each predetermined interval in the idle mode, the mode Transition to wake-up mode and perform the mobile subscriber station's own location update.

According to another aspect of the present invention, there is provided a method in which a paging controller determines when some mobile subscriber stations among a plurality of mobile subscriber stations switch from a wake-up mode with traffic transmission to no traffic transmission in a broadband wireless access communication system A method for paging time points of multiple mobile subscriber stations in idle mode, the broadband wireless access communication system includes a base station, multiple mobile subscriber stations in a cell controlled by the base station, and a paging control station connected to the base station device. The method includes the steps of: determining a paging cycle; determining an offset value to differently set a time point at which the mobile subscriber station wakes up; and determining a time point at which the mobile subscriber station wakes up based on the paging cycle and the offset value.

According to another aspect of the present invention, there is provided a system for controlling the operation mode of the media access control layer by a mobile subscriber station in a broadband wireless access communication system, the broadband wireless access communication system includes a mobile subscriber station and a The serving base station that provides the service. The system includes: a mobile subscriber station, when in the wake-up mode, there is no data transmission between the serving base station and the mobile subscriber station during a predetermined first time interval, the mode transitions to the idle mode, when a mobile mobile station in the idle mode is detected When the station moves into another paging area to which the target base station belongs, which is different from the paging area to which the serving base station belongs, the mode transitions to the wake-up mode, and sends a location update request to the target base station, and according to the response to the location update request, The location update response from the target base station performs location update; the target base station, together with the paging controller, executes the paging area, and when detecting the location update request from the mobile subscriber station, executes the location update of the mobile subscriber station, and sends to the mobile The subscriber station transmits a location update response; and a paging controller for updating the location of the mobile subscriber station corresponding to the location update operations of the target base station and the mobile subscriber station.

According to another aspect of the present invention, a system for controlling an operation mode of a medium access control layer in a broadband wireless access communication system is provided. The system includes a mobile subscriber station mode transitioning to an idle mode when, in the wake-up mode, there is no data transmission between the base station and the mobile subscriber station during a predetermined first time interval, and in the idle mode at each predetermined interval, The mode transitions to the wake-up mode and sends a location update request to the base station, and performs location update according to the location update reply from the target base station in response to the location update request; the base station, together with the paging controller, performs paging area, when detected When a location update request is received from the mobile subscriber station, performing location update of the mobile subscriber station and sending a location update response to the mobile subscriber station; and a paging controller for updating the mobile The location of the user station.

According to another aspect of the present invention, there is provided a method in which a paging controller determines when some mobile subscriber stations among a plurality of mobile subscriber stations switch from a wake-up mode with traffic transmission to no traffic transmission in a broadband wireless access communication system A method for paging time points of multiple mobile subscriber stations in idle mode, the broadband wireless access communication system includes a base station, multiple mobile subscriber stations in a cell controlled by the base station, and a paging control station connected to the base station device. The method includes the steps of: determining a paging cycle; determining an offset value to differently set a time point at which the mobile subscriber station wakes up; and determining a time point at which the mobile subscriber station wakes up based on the paging cycle and the offset value.

According to another aspect of the present invention, a broadband wireless access communication system is provided, including: a base station; a plurality of mobile subscriber stations in a cell controlled by the base station; and a paging controller, configured to determine when a plurality of mobile subscriber stations When some of the mobile subscriber stations switch from the wake-up mode with traffic transmission to the idle mode without traffic transmission, for the paging time point of a plurality of mobile subscriber stations, determining the offset value so as to differently set the time point of the mobile subscriber station wake-up, And determining the time point when the mobile subscriber station wakes up based on the paging cycle and the offset value.

Description of drawings

The above and other objects, features and advantages of the present invention will become clear from the following detailed description in conjunction with the accompanying drawings, wherein:

FIG. 1 is a block diagram schematically showing the structure of a typical IEEE 802.16e communication system;

FIG. 2 is a pattern diagram schematically showing an operation mode supported by a MAC layer of a typical IEEE 802.16e communication system;

FIG. 3 is a signal flow diagram schematically showing a process in which an MSS enters a network of a typical IEEE 802.16e communication system;

4 is a signal flow diagram schematically showing handover processing in a typical IEEE 802.16e communication system;

FIG. 5 is a diagram schematically showing the operation modes supported by the MAC layer of the broadband wireless access communication system according to an embodiment of the present invention;

6 is a diagram schematically illustrating a mode transition of an MSS from a wake-up mode to an idle mode according to an embodiment of the present invention;

7 is a signal flow diagram of a process of paging an MSS in idle mode according to an embodiment of the present invention;

8 is a signal flow diagram of handover processing of an MSS in an idle mode that does not require location update according to an embodiment of the present invention;

9 is a signal flow diagram of handover processing of an MSS in an idle mode requiring location update according to an embodiment of the present invention; and

10 is a signal flow diagram of periodic location update processing for an MSS in idle mode according to an embodiment of the present invention.

detailed description

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, when a detailed description of known functions and configurations incorporated herein may make the subject matter of the present invention unclear, the description will be omitted.

FIG. 5 is a diagram schematically illustrating operation modes supported by a Medium Access Control (MAC) layer of a Broadband Wireless Access (BWA) communication system according to an embodiment of the present invention.

In the following description of the embodiments of the present invention, the Institute of Electrical and Electronics Engineers (IEEE) 802.16e communication system is used as an example of the BWA communication system of the present invention. The IEEE 802.16e communication system adopts the Orthogonal Frequency Division Multiplexing (OFDM) scheme and Orthogonal Frequency Division Multiple Access (OFDMA) scheme for communication. Referring to FIG. 5, the MAC layer of the IEEE 802.16e communication system supports three operation modes (ie, wake-up mode 510, sleep mode 520, and idle mode 530). The wake-up mode 510 and the sleep mode 520 are the same as the wake-up mode 210 and the sleep mode 220, so a detailed description thereof will be omitted here.

The idle mode 530 is a new mode included in the embodiment of the present invention. A mobile subscriber station (MSS) in idle mode 530 is not sending or receiving traffic. It measures the strength of downlink preambles, especially pilot signals, transmitted from neighboring base stations (BSs), and only receives system information and paging messages broadcast from neighboring BSs, thereby maximizing the effect of power consumption reduction. That is, the MSS in the idle mode 530 is in an inactive state, so the MSS changes the current mode to the idle mode 530 in order to conserve power and operating resources in the inactive state.

In this case, when the carrier-to-interference-to-noise ratio (CINR) from a specific neighbor BS (i.e., the target BS) is higher than the current BS, the MSS determines that the MSS is moving from the serving BS to the target BS while in the idle state 530 .

The MSS analyzes system information (SI) broadcast from the target BS, and compares the paging zone identifier (PZID) with the PZID of the previous BS or the serving BS. When the PZID of the previous BS is different from the PZID of the target BS, the MSS performs location registration. When the PZID of the previous BS is the same as that of the target BS, the MSS remains dormant for a predetermined time interval again. After a predetermined time interval has elapsed, the MSS performs location registration even when there is no change in location, thereby updating location information.

Next, the paging area will be described.

A paging area is an area in which a plurality of BSs are gathered to form one paging unit. That is, a plurality of BSs are aggregated to generate one paging area as a paging unit, and location information of an MSS is managed for each paging area. Each paging zone is identified using a paging zone identifier (PZID). Each BS broadcasts the BS's PZID along with other system information every frame. If the MSS leaves the current paging area and enters a new paging area, the MSS receives a new PZID from the new paging area BS. The difference between the new PZID and the previously received PZID enables the MSS to recognize the entry into the new paging zone from the previous paging zone. Here, the PZID value may be contained in a downlink map (DL_MAP) message or the like.

When the MSS changes the paging area, it requests a change of location to the corresponding BS of the new paging area so that the network paging can be answered with the new location. In a preferred embodiment of the invention, a plurality of cells are grouped to form a paging area. However, it is not outside the scope of the present invention that the paging area includes a single cell. In addition, a paging area including a single cell can be applied to an inter-cell handover operation. When the concept of a paging area is the same as that of a single cell described above, the concept of a paging area can be applied to handover between cells in the same manner. In addition, when the concept of the paging area is the same as that of the above-mentioned single cell, the MSS can recognize the movement from the previous cell to the new cell through the BS ID contained in the DL_MAP message.

It is preferable not to allocate basic resources, such as basic connection identifiers (CIDs), primary management CIDs, and secondary management CIDs, which should be basically continuously allocated in the IEEE 802.16e communication system, to the MSS in the idle mode 530, thereby maximizing the utilization of wireless resources. usage efficiency.

First, the process of transition of the MSS from the awake mode 510 to the idle mode 530 will be described below.

The mode transition of the MSS from the awake mode 510 to the idle mode 530 is usually forced by the BS or at the request of the MSS. When no data transmission/reception is expected during a predetermined time interval preset by the BS or the MSS, the MSS in the wake-up mode 510 transmits a Mobile Idle Mode Transition Request (MOB_IDL_REQ) message and receives a Mobile Idle Mode Transition Response (MOB_IDL_RSP) message, the mode Transition to idle mode 530 . The mode transition of the MSS from the awake mode 510 to the idle mode 530 will be described in detail later.

Meanwhile, when the MSS receives a mobile paging request (MOB_PAG_REQ) from the BS, when the MSS has data to send, when the MSS leaves the current paging area, when a location update is performed at the expiration of a predetermined time interval, or when the MSS When the new BS moved to does not support the idle mode 530, a mode transition of the MSS from the idle mode 530 to the wake-up mode 510 as shown by arrow 541 may be performed. The mode transition of the MSS from the idle mode 530 to the wake-up mode 510 will be described in detail later, so its detailed description is omitted here.

Referring to FIG. 5 above, a description is given of the operation modes supported by the MAC layer of the broadband wireless access communication system according to the embodiment of the present invention. Next, the operation of the MSS from the wake-up mode to the idle mode will be described with reference to FIG. 6 .

First, in a state where the MSS 610 is in an awake mode, when there is no data transmission or reception between the MSS and the BS 620, the MSS 610 sends a MOB_IDL_REQ message to the BS 620 (step 611). The MOB_IDL_REQ message may contain a preferred idle interval (PREF_IDLE_INTERVAL), ie, an idle interval (or paging cycle) for which the MSS 610 stays in idle mode. The nomenclature such as paging cycle or preferred paging cycle is derived from the fact that the MSS comes out of idle mode and monitors for pages from the base station during this cycle. In the following description, the term "paging cycle" will be mainly used instead of "idle interval".

The MOB_IDL_REQ message has the structure shown in Table 1.

Table 1 syntax size illustrate MOB_IDL-REQ_Message_Format(){ Management Message Type = ? ? 8 bits PREF_IDLE_INTERVAL_INDEX 8 bits reserve 4 bit }

In Table 1, "Management Message Type" contains information on the type of message currently being transmitted. Currently, the 'Management Message Type' of the MOB_IDL_REQ message has not been determined and is therefore marked as '? ? '. Also, 'PREF_IDLE_INTERVAL_INDEX' represents an MSS preferred idle interval (ie, paging cycle).

After receiving the MOB_IDL_REQ message from the MSS 610, the BS 620 transmits an idle mode request (IDLE_MODE_REQUEST) message to the paging controller (PC) 630 in step 613 . After receiving the IDLE_MODE_REQUEST message from the BS 620 , the paging controller 630 determines the paging cycle of the MSS 610 by referring to the preferred paging cycle of the MSS 610 and the MAC address of the MSS 610 . Here, the paging cycle determined by the paging controller 630 is referred to as a 'selected paging cycle'. In addition, the paging controller 630 determines a paging time point for paging the MSS 610 according to the selected paging cycle (step 615). The paging controller 630 transmits an idle mode response (IDLE_MODE_RESPONSE) message including the selected paging cycle and paging time point to the BS 620 (step 617).

After receiving the IDLE_MODE_RESPONSE message, BS 620 sends a MOB_IDL_RSP message containing information about the selected paging cycle (step 619). The MOB_IDL_RSP message has the structure shown in Table 2 below.

Table 2 syntax size illustrate MOB_IDL_RSP_Message_Format(){ Management Message Type = ? ? 8 bits free license 1 person 0: idle transition denied 1: idle transition permitted if (idle_permission == 0){ After-REQ-action 1 person 0: MSS can retransmit MOB_IDL_REQ by BS after the duration (REQ-duration) given in this message 1: MSS should not retransmit this MOB_IDL-REQ, but should wait for MOB_IDL_RSP from BS REQ-duration 4 bit Duration when the value of After-REQ-action is 0 reserve 2 digits }else{ SEL_IDLE_INTERVAL_INDEX 4 bit TB_REGI_REQUIRED 1 person Timer-based registration required 0: not required 1: required if (TB_REGI_REQUIRED != 0) TB_REGI_INDEX 8 bits 0: reserved 1~255

} reserved 2 digits }

In Table 2, 'Management Message Type' contains information on the type of message currently being sent. Currently, the 'Management Message Type' of the MOB_IDL_RSP message has not been determined and is therefore marked as '? ? '. Also, 'Idle approved' indicates whether mode transition to idle mode is approved. When 'Idle Grant' has a value of '0', it indicates that a mode transition to idle mode is not permitted. When 'Idle Grant' has a value of '1', it indicates that a mode transition to idle mode is permitted. 'After-REQ-action' indicates whether the MSS should retransmit the MOB_IDL_REQ message; '0' indicates that it should retransmit, and '1' indicates that it should not.

'REQ_duration' indicates the time the MSS waits before retransmitting the MOB_IDL_REQ message. 'SEL_IDLE_INTERVAL_INDEX' represents the selected paging cycle determined by the paging controller 630. 'TB_REGI_REQUIRED' indicates whether timer-based registration is required, '0' indicates that registration is not required, and '1' indicates that registration is required. 'TB_REGI-INDEX' indicates the count value of the timer when timer-based registration is required.

MSS 610 transitions from awake mode to idle mode by referring to the selected paging cycle contained in the MOB_IDL_RSP message from BS 620, and monitors whether there is a paging message to MSS 610 itself in each paging cycle (step 621 ).

Next, operations of the paging controller 630 for determining a paging cycle and a paging time point will be described.

First, the paging controller 630 calculates the first paging time point F ₀ by using a hash function with the MAC address of the MSS 610 as an input parameter. The paging controller 630 obtains a set of paging time points by using the selected paging cycle D. Here, the selected paging cycle D can be expressed by the following formula (1):

D＝( ²ⁱ ×δ)＜Y ..........(1)

In Equation (1), D represents the paging cycle, Y represents the maximum value of the frame number, i represents the index of the paging cycle, δ is equal to 2 ^j , and j typically has a value of 0. Of course, j can have other values than 0.

When the set of paging time points is expressed as {Fi} (i=0, 1, ..., Y/D), the (n+1)th paging time point F _n+1 and the nth paging time point The relationship between time points F _n can be expressed by the following formula (2):

_Fn+1 ＝( _Fn +D)modY ..........(2)

As shown in formula (2), the (n+1)th paging time point _Fn+1 is set to be different from the nth paging time point _Fn , and considering the nth paging time point _Fn and The paging cycle produces as much deviation. Here, the interval between _Fn+1 and _Fn is a paging cycle.

Information on the paging cycle and the paging time point determined by the paging controller 630 is shared by all BSs in the paging area to which the MSS 610 belongs.

Referring to FIG. 6 above, a description is given of the operation of the MSS from the wake-up mode to the idle mode according to the embodiment of the present invention. Next, an operation of paging an MSS in an idle mode will be described with reference to FIG. 7 .

FIG. 7 is a signal flow diagram of a process of paging an MSS in idle mode according to an embodiment of the present invention.

First, when the paging controller 780 detects paging or traffic of the MSS 710, the paging controller 780 sends a PAGING_REQUEST message to all BSs in the paging area to which the MSS 710 currently belongs (steps 711, 713, and 715). In FIG. 7 , the paging area to which the MSS 710 currently belongs includes three BSs, a first BS 720 , a second BS 740 and a third BS 760 . The PAGING_REQUEST message is sent to all BSs in the same paging area because each BS lacks sufficient information to determine which paging area it is in. The first BS 720, the second BS 740, and the third BS 760 receive the PAGING_REQUEST message from the paging controller 780, and transmit a MOB_PAG_REQ message targeting the MSS 710 to the MSS 710 (steps 717, 719, and 721).

The MOB_PAG_REQ message has the structure shown in Table 3 below.

table 3 syntax size illustrate MOB_PAG-REQ_Message_Format(){ Management Message Type = ? ? 8 bits Number of terminals paged 8 bits For (j=0; j<number of terminals paged; j++){ MAC_ADDRESS 48 bits 48-bit MSS unique MAC address PAG_PURPOSE 8 bits

LENGTH 8 bits Payload length, in bytes PAYLOAD 8x LENGTH bits paging information } }

In Table 3, 'Management Message Type' contains information on the type of message currently being sent. Currently, the 'Management Message Type' of the MOB_IDL_RSP message has not been determined and is therefore marked as '? ? '. 'Number of paged terminals' indicates the number of MSSs currently paged by the network among MSSs in idle mode. 'MAC_ADDRESS' represents a MAC address (ie, a specific identifier) of each paged MSS. Here, the paging message can be obtained by modifying an existing message currently used in the IEEE802.16e communication system, or by generating a new message. Furthermore, 'PAG_PURPOSE' indicates the object to which the MOB_IDL_REQ message is to be sent, 'LENGTH' (length) indicates the length of 'PAYLOAD' (payload), and 'PAYLOAD' indicates the actual content corresponding to the value marked in 'PAG_PURPOSE'.

The values marked in 'PAG_PURPOSE' are shown in Table 4 below.

Table 4 value describe 00000000 reserve 00000001 Perform network re-entry and initialization 00000010 No confirmation required (no MOB PAG-RSP) 00000011 Acknowledgment required (no MOB_PAG-RSP) 00000100 change idle interval 00000101 request location update 00000110~0xff reserve

In Table 4, '00000000' is a reserved value for future use, '00000001' indicates that MSS receiving MOB_PAG_REQ performs network re-entry and initialization, '00000010' indicates that MSS receiving MOB_PAG_REQ does not need to send MOB_PAG_RSP in response to MOB_PAG_REQ, '00000011 ' indicates that the MSS receiving MOB_PAG_REQ should send MOB_PAG_RSP in response to MOB_PAG_REQ, '00000100' indicates that it is necessary to change the paging cycle, '00000101' indicates that location update should be performed, and '00000110' to '0xff' are reserved values for future use.

Record the contents of tables 5 to 9 in 'PAYLOAD' according to the value marked in 'PAG_PURPOSE'.

table 5 syntax size illustrate PAG_PURPOSE_1_Format(){ reason 8 bits Value 0: cache DL user data 1~0xff: reserved

The content in Table 5 indicates the content recorded in 'PAYLOAD' when '00000001' is marked on 'PAG_PURPOSE'. When '00000001' is marked on 'PAG_PURPOSE', it indicates that the message is a MOB_PAG_REQ message containing downlink data targeted at the MSS.

Table 6 syntax size illustrate PAG_PURPOSE_2_Format(){ information variable Messages such as SMS, MMS, etc. do not require a response.

The contents in Table 6 indicate the contents recorded in 'PAYLOAD' when '00000010' is marked on 'PAG_PURPOSE'. When '00000010' is marked on 'PAG_PURPOSE', it indicates that the message is a MOB_PAG_REQ message that does not require sending a MOB_PAG_RSP message in response to a MOB_PAG_REQ message.

Table 7 syntax size illustrate PAG_PURPOSE_3_Format(){ information variable SMS, MMS, etc. messages require a response.

The contents in Table 7 indicate the contents recorded in 'PAYLOAD' when '00000011' is marked on 'PAG_PURPOSE'. When '00000011' is marked on 'PAG_PURPOSE', it indicates that the message is a MOB_PAG_REQ message requesting that a MOB_PAG_RSP message be sent in response to a MOB_PAG_REQ message.

Table 8 syntax size illustrate PAG_PURPOSE_4_Format(){ free interval index 4 bit reserve 4 bit

The content in Table 8 indicates the content recorded in 'PAYLOAD' when '00000100' is marked on 'PAG_PURPOSE'. When '00000100' is marked on 'PAG_PURPOSE', it indicates that the message is a MOB_PAG_REQ message requesting to change the paging cycle.

Table 9 syntax size illustrate PAG_PURPOSE_5_Format(){ reserve 8 bits

The content in Table 9 indicates the content recorded in 'PAYLOAD' when '00000101' is marked on 'PAG_PURPOSE'. When '00000101' is marked on 'PAG_PURPOSE', it indicates that the message is a MOB_PAG_REQ message requesting a location update.

The example of FIG. 7 assumes that the 'PAG_PURPOSE' flag of the MOB_PAG_REQ message is '00000011', which indicates that the MOB_PAG_RSP message is sent in response to the MOB_PAG_REQ message. Table 10 shows the structure of this MOB_PAG_REQ message.

Table 10 syntax size illustrate MOB_PAG- RSP_Message_Format(){ Management Message Type = ? ? 8 bits reason 2 digits 00&11: reserved 01: MOB_PAG_REQ accepted 10: MOB_PAG_REQ rejected

PL_TYPE 6 digits 0: Acknowledgment only 1: Reply messages for SMS, MSS, etc. 2-63: Reserved LENGTH 8 bits If PL_TYPE==0, this field is also set to 0 PAYLOAD 8xLENGTH bits }

In Table 10, 'Management Message Type' contains information on the type of message currently being transmitted. Currently, the 'Management Message Type' of the MOB_PAG_REQ message has not been determined and is therefore marked as '? ? '. 'Cause' indicates the reason for sending the MOB_PAG_RSP message. When '01' is marked on 'Cause', it indicates that the MOB_PAG_REQ message has been granted. '10' indicates that the MOB_PAG_REQ message has been rejected. Also, 'PL_TYPE' indicates the type of 'PAYLOAD' of the MOB_PAG_RSP message; '01' indicates confirmation only, and '10' indicates a reply message. 'LENGTH' indicates the length of 'PAYLOAD'.

After receiving the MOB_PAG_REQ message, the MSS 710 recognizes from '00000011' marked on 'PAG_PURPOSE' that the MSS 710 transmits the MOB_PAG_RSP message to the corresponding BS in response to the MOB_PAG_REQ message. Here, if the MSS 710 moves within the paging area to another BS other than the BS to which the MSS 710 belongs before the mode shifts to the idle mode, the MSS 710 performs initial adjustment again (step 723). The MSS 710 performs an initial adjustment because the MSS 710 needs allocated uplink bandwidth, etc., in order to send the MOB_PAG_RSP message. FIG. 7 assumes that the MSS 710 determines from the initial adjustment that the first BS 720 is the serving BS to which the MSS 710 currently belongs.

Then, the MSS 710 sends a MOB_PAG_RSP message to the first BS 720 (step 725). After receiving the MOB_PAG_RSP message, the first BS 720 transmits a 'PAGING_RESPONSE' message in response to the 'PAGING_REQUEST' message to the paging controller 780 (step 727). In addition, the first BS 720 transmits a MOB_IDL_RSP message to the MSS 710, thereby controlling the MSS 710 to transition to an idle mode (step 729).

Referring to FIG. 7 above, a description is given of the operation of paging an MSS in idle mode according to an embodiment of the present invention. Next, handover of an MSS in idle mode that does not require location update according to an embodiment of the present invention will be described with reference to FIG. 8 .

FIG. 8 is a signal flow diagram of a handover process for an MSS in idle mode that does not require location update according to an embodiment of the present invention.

FIG. 8 is based on the case where the MSS 810 in idle mode moves (ie, performs handover) in the same paging zone (ie, in a paging zone using the same PZID). Referring to FIG. 8, the serving BS 830 transmits a MOB_IDL_RSP message to the MSS 810 (step 811). The serving BS 830 may transmit the MOB_IDL_RSP message in response to the MOB_IDL_REQ message or based on an unsolicited scheme. Here, the transmission of the MOB_IDL_RSP message of the serving BS 830 is based on an unsolicited scheme, and may be intended to adjust the load of the serving BS 830 . After receiving the MOB_IDL_RSP message from the serving BS 830, the MSS 810 transitions from the awake mode to the idle mode.

While the MSS 810 is in idle mode, it moves from the service area controlled by the serving BS 830 to another service area controlled by the target BS 850 (step 813). For this example, assume that the serving BS 830 and the target BS 850 are located in the same paging area.

When the MSS 810 moves, even if the MSS 810 performs network monitoring after waking up at the paging time point, communication between the serving BS 830 and the MSS 810 is disconnected, so that the MSS 810 cannot receive the MOB_PAG_REQ message. Therefore, when the MSS 810 moves to a new BS (i.e., the target BS 850), the MSS broadcasts an Uplink Channel Descriptor (UCD) message, a Downlink Channel Descriptor (DCD) message, and DL_MAP and UL_MAP messages from the target BS 850 The information of the target BS 850 is received in (step 815). As described above, the PZID of the target BS 850 may be included in the DL_MAP message.

By receiving the BS information broadcast by the target BS 850, the MSS 810 detects the PZID of the target BS 850, thereby recognizing that the serving BS 830 and the target BS 850 are located in the same paging area (step 817). Then, MSS 810 checks the frame number, thereby realizing its own paging time point. Then, MSS 810 checks whether it reaches the paging time point (step 819). If it has not reached the paging time point, the MSS 810 scans for neighbor BSs (step 821). Here, scanning the neighbor BSs includes scanning the carrier-to-interference-and-noise ratio (CINR) of pilot signals transmitted from the neighbor BSs to detect the movement of the MSS in the idle mode.

When it reaches the paging time point, the MSS wakes up from the idle mode, and receives the MOB_PAG_REQ message from the target BS 850 (step 823). Here, it is assumed that the MOB_PAG_REQ message transmitted from the target BS 850 does not contain the MAC address of the MSS 810, and thus the MSS 810 is still in idle mode.

Referring to FIG. 8 above, a description is given of handover of an MSS in idle mode that does not require location update according to an embodiment of the present invention. Now, handover of an MSS in an idle mode using location update according to an embodiment of the present invention will be described with reference to FIG. 9 .

9 is a signal flow diagram of a handover process of an MSS in idle mode using location updating according to an embodiment of the present invention.

FIG. 9 is based on the case where the MSS 810 in idle mode moves (ie, performs handover) in different paging areas (ie, in paging areas using different PZIDs). Referring to FIG. 9, the serving BS 930 transmits a MOB_IDL_RSP message to the MSS 910 (step 911). The serving BS 930 may transmit the MOB_IDL_RSP message in response to the MOB_IDL_REQ message or based on an unsolicited scheme. Here, the MOB_IDL_RSP message is transmitted based on an unsolicited scheme, and may be intended to adjust the load of the serving BS 930 . After receiving the MOB_IDL_RSP message from the serving BS 930, the MSS 910 transitions from the awake mode to the idle mode.

In this example, while the MSS 910 is in idle mode, it moves from the service area controlled by the serving BS 930 to another service area controlled by the target BS 950 (step 913). Here, it is assumed that the serving BS 930 and the target BS 950 are located in different paging areas. When the MSS 910 moves, even if the MSS 910 performs network monitoring after waking up at the paging time point, the communication between the serving BS 930 and the MSS 910 is disconnected, so that the MSS 910 cannot receive the MOB_PAG_REQ message. Therefore, when the MSS 910 moves to a new BS (ie, the target BS 950), the MSS receives the information of the target BS 950 from the UCD message, the DCD message, and the DL_MAP and UL_MAP messages broadcast by the target BS 950 (step 915). As described above, the PZID of the target BS 950 may be included in the DL_MAP message.

By receiving the BS information broadcast by the target BS 950, the MSS 910 detects the PZID of the target BS 950, thereby recognizing that the serving BS 930 and the target BS 950 are located in different paging areas (step 917). Then, MSS 910 performs initial adjustment (step 919) to obtain the basic CID and the primary management CID. Then, the MSS 910 transmits a Mobile Location Update Request (MOB_LU_REQ) message to the target BS 950 (step 921). The MOB_LU_REQ message has the structure shown in Table 11.

Table 11 syntax size illustrate MOB_LU-REQ_Message_Format(){ Management Message Type = ? ? 8 bits PREF_IDLE_INTERVAL_INDEX 4 bit PREV_PZONE_ID }

In Table 11, 'Management Message Type' contains information on the type of message currently being transmitted. Currently, the 'Management Message Type' of the MOB_LU_REQ message has not been determined and is therefore marked as '? ? '. Also, 'PREF_IDLE_INTERVAL_INDEX' represents an idle interval (ie, paging cycle) preferred by the MSS, and 'PREF_PZONE_ID' represents the PZID of the serving BS 930 to which the MSS 910 belongs before handover.

After receiving the MOB_LU_REQ message from the MSS 910, the target BS 950 transmits a location update request (LOCATION_UPDATE_REQUEST) message to the paging controller 970 (step 923). Here, the LOCATION_UPDATE_REQUEST message transmitted from the target BS 950 contains the MAC address of the MSS 910 requiring location update, and the PZID of the serving BS 930 to which the MSS 910 belongs before handover. After receiving the LOCATION_UPDATE_REQUEST message, the paging controller 970 updates the location of the MSS 910 based on the PZID and MAC address included in the LOCATION_UPDATE_REQUEST message, and then sends a location update response (LOCATION_UPDATE_RESPONSE) message to the target BS 950 in response to the LOCATION_UPDATE_REQUEST message (step 925 ). After receiving the LOCATION_UPDATE_RESPONSE message from the paging controller 970, the target BS 950 sends a Mobile Location Update Reply (MOB_LU_RSP) message to the MSS 910 (step 927). The MOB_LU_RSP message has the structure shown in Table 12 below.

Table 12 syntax size illustrate MOB_LD_RSP_Message_Format(){ Management Message Type = ? ? 8 bits LU License 1 person 0: location update failed 1: location update successful if (lu permission == 0) { After-REQ-action 1 person 0: MSS can retransmit MOB_LU_REQ after the duration (REQ-duration) given by BS in this message 1: MSS should not retransmit MOB_IDL-REQ, but should wait for MOB_LU_RSP from BS

REQ-duration 4 bit The duration when the value of After-REQ-action is 0 reserve 2 digits }else{ SEL_IDLE_INTERVAL_INDEX 4 bit TB_REGI_REQUIRED 1 person Timer-based registration required 0: not required 1: required If(TB_REGI_REQUIRED!=0) TB_REGI_INDEX 8 bits 0: reserved 1~255 } reserve 2 digits }

In Table 12, 'Management Message Type' contains information on the type of message currently being transmitted. Currently, the 'Management Message Type' of the MOB_LU_RSP message has not been determined and is therefore marked as '? ? '. Also, 'LU Permission' indicates whether the location update has failed; a value of '0' indicates failure, and a value of '1' indicates success. 'After-REQ-action' indicates whether the MSS should retransmit the MOB_LU_REQ message when the location update fails, '0' indicates retransmission after waiting for a predetermined time, and '1' indicates no retransmission is required. 'REQ_duration' indicates the duration that the MSS waits for retransmission of the MOB_LU_REQ message. 'SEL_IDLE_INTERVAL_INDEX' indicates a paging cycle newly determined when implementing location update. 'TB_REGI_REQUIRED' indicates whether the new BS (target BS) requires timer-based registration. 'TB_REGI-INDEX' indicates the count value of the timer when timer-based registration is required.

After receiving the MOB_LU_RSP message from the target BS 950, the MSS 910 switches or mode transitions to an idle mode corresponding to the selected paging cycle etc. included in the MOB_LU_RSP message.

Referring to FIG. 9 above, a description is given of handover of an MSS in idle mode using location update according to an embodiment of the present invention. Now, periodic location update of an MSS in an idle mode according to an embodiment of the present invention will be described with reference to FIG. 10 .

10 is a signal flow diagram of periodic location update processing for an MSS in idle mode according to an embodiment of the present invention.

First, the MSS 1010 in an awake mode sends a MOB_IDL_REQ message to the BS 1030 (step 1011). After receiving the MOB_IDL_REQ message from the MSS 1010, the BS 1030 sends an IDLE_MODE_REQUEST message to the paging controller 1050 (step 1013). After receiving the IDLE_MODE_REQUEST message from the BS 1030, the paging controller 1050 transmits an IDLE_MODE_RESPONSE message in response to the IDLE_MODE_REQUEST message to the BS 1030 (step 1050). After receiving the IDLE_MODE_RESPONSE message, the BS 1030 transmits a MOB_IDL_RSP message in response to the MOB_IDL_REQ message to the MSS 1010 (step 1017). Here, the MOB_IDL_RSP message contains a request for the selected paging cycle and paging time point determined by the MSS 1010, and timer-based registration. That is, it is assumed that 'TB_REGI-REQUIRED' of the MOB_IDL_REQ message is marked as 1.

After receiving the MOB_IDL_RSP message from BS 1030, the MSS switches or mode transitions from awake mode to idle mode. The MSS 1010 starts counting of a predetermined time interval 'TB_REGI_INTERVAL' to request timer-based registration in idle mode, and when it reaches 'TB_REGI_INTERVAL' (step 1019), performs initial adjustment for location update (step 1021). By performing an initial adjustment, the MSS 1010 obtains a base CID and a primary management CID. Then, MSS 1010 sends a MOB_LU_REQ message to BS 1030 (step 1023). Steps 1023 to 1029 in FIG. 10 are similar to steps 921 to 927 between the MSS 910, the target BS 950, and the paging controller 970 in FIG. 9, so detailed descriptions thereof will not be repeated here.

Next, the steps for the MSS 910 to determine 'TB_REGI_INTERVAL' are described.

First, the MSS 910 obtains 'TB_REGI_INTERVAL' by using 'TB_REGI_INDEX' and 'SEL_IDLE_INTERVAL_INDEX' in the MOB_IDL_RSP message. Here, 'TB_REGI_INTERVAL' can be represented by the following equation (3).

TB_REGI_INTERVAL = 2 ⁱ T ...................(3)

In formula (3), i represents 'SEL_IDLE_INTERVAL_INDEX', and T represents 'TB_REGI_INDEX'. That is, 'TB_REGI_INTERVAL' can be expressed as an integer multiple of the paging cycle.

The location update of the MSS is performed periodically to increase the convenience of the location update and the reliability of the location update of the MSS. Of course, as described above with reference to FIG. 10 , location update can be performed even when the area where the MSS is located has not actually changed. However, when the paging controller performs paging under the condition that the paging area is enlarged from the cell whose MSS has been updated recently, the load increase due to the periodic location update can be replaced by the load reduction due to the paging area reduction. to compensate.

As described above, the present invention provides a new MAC layer operation mode suitable for a broadband wireless access communication system, thereby minimizing power consumption while supporting MSS mobility and high-speed data transmission. In addition, the present invention prevents unnecessary occupation of radio resources by discarding network entry processing in the same paging area. Therefore, the present invention can maximize resource utilization efficiency and eliminate message overhead due to network entry.

Although the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the claims. Change.

Claims (3)

1. the method being performed location updating by mobile subscriber station in broadband wireless access communication system using multi, this broadband wireless connects Entering communication system include mobile subscriber station and provide the serving BS of service to this mobile subscriber station, the method comprising the steps of:

If in the wake mode, there is no data between predetermined interim very first time serving BS and mobile subscriber station Transmission, then patten transformation is in the idle pulley being different from park mode；

If in the wake mode, there is no data between serving BS and mobile subscriber station during the second predetermined time interval During transmission, patten transformation is to park mode；

When in idle mode, at the time determined based on paging cycle and deviant, patten transformation is to awakening mode, institute State the time point that deviant is determined to be arranged differently than mobile subscriber station from idle pulley patten transformation to awakening mode；

The paging information of broadcast is monitored in paging cycle；

When mobile subscriber station moves in same paging domain, maintain this idle pulley and be performed without initially adjusting；

When detecting paging domain and changing to another paging domain belonging to target BS, this another paging domain and serving BS Affiliated paging domain is different, from idle pulley patten transformation to awakening mode；

When at awakening mode, send position updating request to target BS；And

When at awakening mode, update response from target BS receiving position,

Wherein this paging information comprises the MAC address of mobile subscriber station,

Reduce the distribution of basic Radio Resource the most in idle mode.

2. the method for claim 1, further comprises the steps of:

If paging information comprises the MAC Address of mobile subscriber station self, it is understood that the existence of paging；And

Recognize that according to mobile subscriber station the existence of this paging performs mode change operation.

3. the method for claim 1, wherein awakening mode be perform wherein mobile subscriber station and serving BS it Between the pattern of grouped data send/receive operation.

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