KR20060030001A - Method for transmitting message in broadband wireless access system - Google Patents

Abstract

A method for transmitting messages to alter the operating status between a mobile station and a base station in a wireless access system comprises, at the mobile station, transmitting a first message to the base station, setting a first count to a first predetermined value and enabling a first, the first message requesting a alteration in operating status between the mobile station and the base station, whereupon expiration of the first timer before receiving a second message from the base station, the count is decremented and, if the count is above a second predetermined value, the first timer is reset and the first message is retransmitted to the base station. The method also comprises, at a base station, receiving the first message, transmitting a second message to the mobile station and enabling a second timer, whereupon expiration of the second timer, the alteration in operating status is effected.

Description

Message transmission method in broadband wireless access system {METHOD FOR TRANSMITTING MESSAGE IN BROADBAND WIRELESS ACCESS SYSTEM}

1 illustrates the format of a Scan Request (MOB-SCN-REQ) message.

2 illustrates the format of a Scan Response (MOB-SCN-RSP) message.

3 illustrates the format of a sleep request (MOB-SLP-REQ) message.

4 illustrates the format of a Sleep Response (MOB-SLP-RSP) message.

5 shows the format of a Deregistration Request (DREG-REQ) message.

6 is a view showing an operation code included in a deregistration command (DREG-CMD) message.

7 is a signal flow diagram illustrating a case where a conventional scan request and response message are lost.

8 is a signal flow diagram illustrating a case where a conventional sleep request and response message is lost.

9 is a signal flow diagram illustrating a case where a conventional deregistration request and command message are lost.

10 is a flowchart of a scan request and response message using a scan response wait timer according to the present invention;

11 is a flowchart of a sleep request and response message using a sleep response wait timer according to the present invention;

12 is an example of a deregistration request and a command message flow chart using a deregistration command waiting timer according to the present invention (when a deregistration request message transmitted by a mobile terminal is lost on a radio);

Figure 13 is another example of the deregistration request and command message flow chart using the deregistration command wait timer according to the present invention (when the deregistration command message transmitted by the base station is lost over the air).

The present invention relates to a message transmission method between a mobile station and a base station in a broadband wireless access system.

The IEEE802.16e system, which is undergoing international standardization for a broadband wireless access system, consists of only a mobile subscriber station (MSS), a base station (BS), and an authentication service server (ASA). In this case, a common physical layer (PHY) and a connection control layer (MAC) are defined between the base station and the terminal.

1. Scan

The mobile station requests a scanning interval from a currently connected serving BS to measure a signal quality of a neighbor BS and determine a target BS to be newly connected in a handover. do. The request is made through a scan request (MOB-SCN-REQ) message shown in FIG. 1, and in response to the scan request (MOB-SCN), as shown in FIG. 2, the base station includes a scan response including information related to a scan. -RSP) message to the mobile terminal.

2. Sleep Mode

The broadband wireless access system supports the sleep mode to minimize the power consumption of the mobile terminal. The mobile terminal of the sleep mode operates according to a sleep interval that increases at a constant rate, and the sleep interval includes a listening window and a sleep window.

The listening period is fixed by the sleep request / sleep response message. During this period, the mobile station checks whether there is any downlink traffic directed to itself through the MAC management message (MOB-TRF-IND). Or, it is instructed whether to perform ranging for maintaining uplink communication and maintaining proper downlink coding type according to signal quality. The sleep period is a period in which the mobile station receives only a minimum downlink signal from the base station for power saving. During this period, the mobile station maintains scanning and uplink communication of neighbor base stations for handover and maintains an appropriate downlink coding type according to signal quality. Perform ranging and so on.

The sleep mode is initialized by exchanging a sleep request (MOB-SLP-REQ) message and a sleep response (MOB-SLP-RSP) message between the mobile station and the base station. That is, the mobile station transmits a sleep request (MOB-SLP-REQ) message as shown in FIG. 3 to the base station to switch to the sleep mode from the normal operation mode, and the base station sleeps as shown in FIG. 4 with respect to the MOB-SLP-REQ message. Respond to the mobile terminal with a response (MOB-SLP-RSP) message.

3. Idle Mode

The idle mode prevents power consumption by receiving only the downlink traffic message (MOB-PAG-ADV) that is periodically transmitted when the mobile station moves to an area covered by several base stations without registering with a specific base station. In the idle mode, there is no signaling requirement of the mobile terminal for handover and by limiting the operation related to scanning, the mobile terminal can save resources such as power and connection ID.

The mobile terminal transmits a deregistration request (DREG-REQ) message as shown in FIG. 5 to the base station for idle mode initialization, and the base station transmits a deregistration command (i.e., a deregistration command including the idle mode permission and related information of the mobile station). Reply with DREG-CMD) message. After the base station transmits the DREG-CMD message to the mobile station, the base connection, primary connection, and standard-based message (DHCP) for transmitting and receiving a MAC management message with the mobile station. , TFTP, etc.), and releases administrative resources such as Secondary Connection.

6 is an operation code included in the DREG-CMD message, and the mobile terminal performs an operation according to an indication indicated by the operation code. For example, if the code is 0X05, the mobile station performs a de-registration procedure at the base station and initializes the idle mode. In addition, even if the mobile station does not request a DREG-REQ message, the base station may transmit a DREG-CMD (Unsolicited DREG-CMD) message with operation code 0X05, thereby allowing the mobile station to enter idle mode.

As described above, the mobile station transmits one of a scan request (MOB-SCN-REQ) message, a sleep request (MOB-SLP-REQ) message, and a deregistration request (DREG-REQ) message to the base station, and responds to the base station. Wait for one of a scan response (MOB-SCN-RSP) message, a sleep response (MOB-SLP-RSP) message, and a deregistration command (DREG-CMD) message from the base station.

In this case, as shown in FIGS. 7 to 9 due to limited resources of the radio link and environmental factors on the radio, the MOB-SCN-REQ message, the MOB-SLP-REQ message, and the DREG-REQ transmitted by the mobile station to the base station. The message may not be transmitted normally, or the MOB-SCN-RSP message, the MOB-SLP-RSP message, and the DREG-CMD message responded to the mobile station may not be normally transmitted.

However, in the current wideband wireless access system, since the processing procedure for the next operation of the mobile terminal is not defined in the above case, there is a great possibility that the mobile terminal or the base station performs wrong operation.

In the idle mode, the mobile station does not receive the DREG-CMD message because the base station releases the established connections (basic connection, first connection, and second connection) at the same time as transmitting the DREG-CMD message to the mobile station. If you resend the DREG-REQ, there will be no connection available (the default connection). In addition, even if the mobile station does not request the idle mode initialization through the DREG-REQ message, when the DREG-CMD (Unsolicited DREG-CMD) message transmitted by the base station to switch the mobile station to the idle mode is lost on the radio, The mobile station continues to operate in the normal operation mode, and after determining that the mobile station has switched to the idle mode, the base station releases the administrators for the mobile terminal. Therefore, the mobile station can no longer transmit a message to the base station.

Accordingly, an object of the present invention is to provide a message transmission method between a mobile station and a base station in a broadband wireless access system.

Another object of the present invention is to provide a message transmission method effective when a message is lost due to limited resources of a radio link and environmental factors on the radio.

In order to achieve the above object, in the broadband wireless access system for transmitting a specific request message to the base station to measure the channel quality of the neighboring base station for handover or to switch from the normal mode to the sleep mode or idle mode, Sending the request message and driving a wait timer; Checking whether a response message has been received from the base station before the waiting timer expires; Resending the request message to the base station according to the number of request retries when the response message is not received.

Preferably, the request message is one of a scan request message, a sleep request message, and a deregistration request message.

Preferably, the response message is one of a scan response message, a sleep response message, and a deregistration command message.

Preferably, the mobile terminal retransmits the request message to the base station after resetting the waiting timer only when the number of retry requests remains.

In addition, the present invention includes the step of setting a management resource holding timer for maintaining a connection with the mobile station for a certain period after the base station transmits the DREG-CMD to the mobile station in the idle mode. .

In another aspect of the present invention, there is provided a message transmission method, comprising: a first step of transmitting a deregistration request message to a mobile station for switching to an idle mode in a broadband wireless access system; Receiving a deregistration response message for the deregistration request message transmitted from the mobile terminal; And a third step of releasing a manager member for the mobile terminal.

 The present invention is implemented in a broadband wireless access system. However, the present invention can also be applied to a wireless communication system operating according to other standards.

The present invention provides a scan request (MOB-SCN-REQ) and scan response (MOB-SCN-RSP) message for measuring the channel quality of a neighboring base station for handover by a mobile terminal in a broadband wireless access system, Sleep Request (MOB-SLP-REQ) and Sleep Response (MOB-SLP-RSP) messages sent and received with the base station to initiate the Sleep mode, and registrations that the mobile station sends and receives with the base station to initiate Idle mode. We propose a method to optimize the release request (DREG-REQ) and deregistration command (DREG-CMD) messages. In particular, the present invention proposes a message transmission procedure effective between a mobile terminal and a base station when a message is lost due to limited resources of a radio link and environmental factors in a wireless band wireless access system.

To this end, the present invention operates a response waiting timer for the scan request, sleep request and deregistration request message, and sets the number of request retries of the messages to perform retransmission of the request messages.

First, the present invention sets a scan response wait timer and a scan request retry count when performing a scan operation, and retransmits a scan request (MOB-SCN-REQ) message.

The mobile station transmits a MOB-SCN-REQ message to the base station and simultaneously sets a scan response waiting timer. If the MOB-SCN-RSP message is not received from the base station before the timer expires, the mobile station considers that the MOB-SCN-REQ message or the MOB-SCN-RSP message is lost on the radio link and retries the scan request. If is remaining, retransmit the MOB-SCN-REQ message to the base station.

Table 1 is an exemplary diagram of the driving time of the scan response wait timer and the number of scan request retries according to the present invention.

system name action value Mobile terminal Scan Response Wait Timer The amount of time to wait for receiving a scan response message after sending a scan request message. 1 sec Scan request retries Number of times that scan request messages can be resent 3rd time

When the initialization of the sleep mode is performed, the present invention sets a sleep response wait timer and a sleep request retry count, and retransmits a sleep request (MOB-SLP-REQ) message.

 The mobile station transmits a sleep request (MOB-SLP-REQ) message to the base station and sets a sleep response wait timer. If a sleep response message is not received from the base station within a specific timer time, the mobile station considers that the MOB-SLP-REQ message or the MOB-SLP-RSP message is lost on the radio link, and if there are remaining sleep requests, the base station Resend the MOB-SLP-REQ message.

Table 2 is an exemplary view of the driving time and the sleep request retry count of the sleep response wait timer according to the present invention.

system name action value Mobile terminal Sleep Response Wait Timer Waiting time for receiving sleep response message after sending sleep request message 1 sec Number of sleep request retries Number of times you can resend a sleep request message 3rd time

In addition, the present invention sets a deregistration command waiting timer and a deregistration request retry count when initializing an idle mode, and retransmits a deregistration request (DREG-REQ) message.

The mobile terminal transmits a deregistration request (DREG-REQ) message to the base station and simultaneously sets a deregistration command waiting timer. If a non-registration command message is not received from the base station within a specific timer time, the mobile terminal considers that the DREG-REQ message or the DREG-CMD message is lost on the radio link, and if there is a remaining number of non-registration requests, the DREG is sent to the base station. -REQ Resend the message.

Table 3 is an exemplary diagram of the driving time of the deregistration command waiting timer and the number of deregistration request retries according to the present invention.

system name action value Mobile terminal Deregistration Waiting Timer The amount of time to wait after receiving the Unregister Request message after sending the Unregister Request message. 1 sec Number of requests for deregistration The number of possible retransmissions of the deregistration request message 3rd time

In this case, the base station sets a Management Resource Holding Timer at the same time as transmitting the DREG-CMD message to the mobile station and maintains the connections for a certain period of time. Thereafter, when the manager member maintenance timer expires, the manager members are released.

Table 4 is an exemplary view of a manager maintenance timer according to the present invention.

system name action value Base station Manager maintenance timer Timer to maintain the administrators for a certain period after sending the deregistration command message to the mobile terminal 1 sec                                             

Table 5 is an exemplary diagram of the driving time of the deregistration wait timer according to the present invention and the number of deregistration command retries.

system name action value Base station Unregister Response Wait Timer Waiting time for response message after sending deregistration notice 1 sec Number of attempts to unregister The number of possible retransmissions of the deregistration notice 3 sec

Table 6 shows a deregistration request code for responding with a DREG-REQ message when a mobile station receives an Unsolicited DREG-CMD message from a base station according to the present invention.

Syntax Size (bits) Notes DREG-REQ message format () {  Management message type = 49 8  De-registration Request Code 8 0x00: MSS de-regstration request from BS and network 0x01: request for MSS de-regstration from Serving BS and initiation of MSS Idle mode 0x02: Acknowledgement for unsolicited DREG-CMD 0x03-0xFF: Reserved  TLV encoded parameters variables }

Table 7 shows a message format for responding with a DREG-ACK message when the mobile station receives an Unsolicited DERG-CMD message from the base station according to the present invention.

Syntax Size (bits) Notes DREG-ACK message format () {   Management message type = xx 8    Action code 8 This indicates Action code from the BS    HMAC tuple variables }

10 is a flowchart illustrating a scan request and response message using a scan response wait timer proposed in the present invention.

The mobile terminal transmits a scan request (MOB-SCN-REQ) message to the base station and drives a scan response wait timer. If the scan response (MOB-SCN-RSP) message is not received from the base station until the scan response wait timer expires, the mobile station determines whether the number of possible scan requests remains. If the number of scan requests remains as a result of the check, the timer is reset, and the MOB-SCN-REQ message is retransmitted to the base station. After receiving the scan response (MOB-SCN-RSP) message from the base station within the scan response wait timer time, the mobile station performs a scanning operation according to the information contained in the response message.

11 is a flowchart illustrating a sleep request and response message using a sleep response wait timer proposed in the present invention.

Referring to FIG. 11, the mobile terminal transmits a sleep request (MOB-SLP-REQ) message to the base station and simultaneously drives a sleep response waiting timer. If the sleep response (MOB-SLP-RSP) message is not received from the base station until the sleep response waiting timer expires, the mobile station checks whether the number of sleep request available times remains. If the number of sleep requests remains as a result of the check, the mobile station resets the timer and then retransmits the MOB-SLP-REQ message to the base station. After receiving the sleep response (MOB-SLP-RSP) message from the base station within the sleep response wait timer time, the mobile station performs a sleep mode operation according to the information included in the response message.

12 and 13 are flowcharts of a deregistration request and command message using a deregistration wait command timer proposed in the present invention.

FIG. 12 illustrates a case in which a deregistration request message (DREG-REQ) transmitted by a mobile terminal is lost over the air. The mobile terminal sends a deregistration request (DREG-REQ) message to the base station and simultaneously starts a deregulation command wait timer. If the deregistration command (DREG-CMD) message is not received from the base station until the deregistration command waiting timer expires, the mobile station checks whether the current deregistration request retry count remains. If the number of re-registration request retry attempts remains, the mobile station resets the timer and retransmits the DREG-REQ message to the base station. Then, if the DREG-CMD message is received from the base station within the deregistration command waiting timer time, the mobile station performs the idle mode operation according to the information included in the response message.

FIG. 13 shows a case in which a deregistration command (DREG-CMD) message transmitted from a base station to a mobile station is lost over the air. The base station transmits a DREG-CMD message to the mobile station and simultaneously drives a management resource holding timer. If the DREG-CMD message is lost over the air, the mobile terminal retransmits the DREG-REQ through the basic connection maintained by the administrator maintenance timer after the deregistration command wait timer expires. In response to this, the base station transmits the DREG-CMD to the mobile terminal and resets the maintenance staff maintenance timer. If the administrator-owned timer is terminated after the DREG-CMD is normally transmitted to the mobile station, the base station determines that the mobile station has switched to the idle mode and releases the managers.

14 and 15 show a flowchart of another preferred embodiment of the present invention. In the examples shown in Figs. 14 and 15, the technical feature according to the present invention is that the base station sends an unsolicited deregistration command sent to the mobile terminal even if the mobile terminal does not request initialization of an idle mode through a DREG-REQ message. (Unsolicited DREG-CMD) indicates that the message was applied when lost on the radio.

The base station transmits an Unsolicited DREG-CMD message to the mobile station and simultaneously drives a management resource holding timer and a deregistration command response waiting timer to check whether a predetermined time elapses. If the deregistration response (DREG-REQ in FIG. 14 or DREG-ACK in FIG. 15) is not received from the mobile terminal as an acknowledgment response to the Unsolicited DREG-CMD until the deregistration wait timer expires, The mobile station checks whether a preset number of deregistration commands available remains. If the number of deregistration commands remains as a result of the check, the base station resets the administrator member maintenance timer, retransmits the Unsolicited DREG-CMD message to the mobile station, and resets the administrator member maintenance timer. Then, if a deregistration response (DREG-REQ or DREG-ACK) message is received from the mobile station within the deregistration response waiting timer time, the base station is a manager for the mobile terminal that has been maintained after the administrator maintenance timer expires. The circles are released.

FIG. 14 illustrates a case in which the mobile station transmits a deregistration response message to the base station and transmits the deregistration response message by modifying an existing deregistration request message as shown in the example of Table 6. FIG. FIG. 7 illustrates a case where the deregistration response message is transmitted through a DREG-ACK message.

As described above, the present invention provides an effective processing procedure when a message is lost due to limited resources of a radio link and environmental factors in a wireless broadband system, thereby preventing malfunctions occurring in a conventional mobile terminal or a base station. It can be effective. That is, the present invention transmits a scan request, sleep request and deregistration request message, and operates a response wait timer for this, even if the response message of each request message or its request messages is lost on the radio link, and if the timer expires. Resend the request message.

Claims (18)

In a broadband wireless access system, a mobile station transmits a request message to a base station to measure channel quality of a neighboring base station for handover or to switch from a normal mode to a sleep mode or an idle mode. Sending the request message and driving a wait timer; Checking whether a response message has been received from the base station before the waiting timer expires; And resending the request message to a base station according to the number of request retries when the response message is not received. The method of claim 1, wherein the request message is And one of a scan request message, a sleep request message, and a deregistration request message. The method of claim 1, wherein the response message And a scan response message, a sleep response message, or a deregistration command message. The method of claim 1, wherein the mobile terminal And re-transmitting the request message to the base station after resetting the waiting timer only when the number of request retries remains. The method of claim 1, further comprising performing a scan operation or switching to a sleep mode or an idle mode by receiving a response message from the base station. In a broadband wireless access system, Transmitting, by the mobile terminal, a scan request message to a base station and setting a scan response waiting timer; If the scan request message or the scan response message is lost on the wireless link, retransmitting the scan request message to the base station when the scan response waiting timer expires. The method of claim 6, wherein the mobile terminal And retransmitting the scan request message to the base station after resetting the scan response waiting timer only when the number of scan request retries remains. In a broadband wireless access system, The mobile terminal transmitting a sleep request message to the base station and setting a sleep response waiting timer; And resending the sleep request message to a base station when the sleep response waiting timer expires when the sleep request message or the sleep response message is lost on the wireless link. The method of claim 8, wherein the mobile terminal And retransmitting the sleep request message to the base station after resetting the sleep response waiting timer only when the number of sleep request retries remains. In a broadband wireless access system, The mobile terminal transmitting a deregistration request message to the base station and setting a deregistration command waiting timer; And if the deregistration request message or deregistration command message is lost on the wireless link, re-transmitting the deregistration request message to the base station when the deregistration command waiting timer expires. The method of claim 10, wherein the mobile terminal And re-transmitting the deregistration request message to the base station after resetting the deregistration command waiting timer only when the deregistration request retry count remains. The method of claim 10, wherein the base station And transmitting a DREG-CMD message and maintaining a manager member with a mobile terminal for a predetermined period of time by driving a manager member maintenance timer. The method of claim 12, wherein the base station Even if the deregistration command message is lost over the air, the mobile terminal retransmits the deregistration request message using the basic connection, and when the administrator maintenance timer expires, the mobile terminal determines that the mobile terminal has entered the idle mode and releases the administrators. Message transmission method characterized in that. In a broadband wireless access system, A first step of transmitting a deregistration request message to a mobile terminal for switching to an idle mode; Receiving a deregistration response message for the deregistration request message transmitted from the mobile terminal; And a third step of releasing a manager member for the mobile terminal. The method of claim 14, Retransmitting the deregistration request message if the deregistration response message is not received for a preset time after the deregistration request message is transmitted. The method according to claim 14 or 15, The deregistration request message is 'Unsolicited DREG-CMD'. The method according to claim 14 or 15, The deregistration response message is transmitted in a deregistration request (DREG-CMD) message. The method according to claim 14 or 15, The deregistration response message is transmitted in a DREG-ACK message.

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