KR101241887B1 - Method of executing procedure for initial network registration of mobile station in broadband wireless access system - Google Patents

Abstract

In accordance with another aspect of the present invention, there is provided a method of performing a procedure for network entry, comprising: receiving a transmission parameter from a base station and performing uplink to the base station in a method for performing a procedure for network entry of a mobile station in a broadband wireless access system; Performing at least one request for an uplink band for transmitting a management message; and receiving a downlink message for the next procedure from the base station when the uplink band is not allocated until a predetermined time elapses. Characterized in that it comprises a step.

Broadband, Wireless Access, Network Entry, Mobile Terminal

Description

Method of executing procedure for initial network registration of mobile station in broadband wireless access system

1 illustrates a protocol layer structure of a broadband wireless access system according to the prior art.

2 illustrates a process of performing a network entry procedure at the time of initialization of a mobile station in an OFDMA broadband wireless access system in the prior art.

3 is a view for explaining a problem that may occur between the initial ranging process and the basic performance negotiation process in the prior art.

4 is a diagram illustrating a problem that may occur between a base station registration process and a 'provisioned service flow' generation process when the mobile station is initialized in the prior art.

5-11 are flowcharts of procedures of preferred embodiments of the present invention.

The present invention relates to a broadband wireless access system. More specifically, the present invention relates to a method for preventing abnormal operation of a mobile terminal due to an error in the initial network entry procedure of the mobile terminal in a broadband wireless access system.

The broadband wireless access system defines a protocol of a medium access control (MAC) layer and a physical (PHY) layer for point-to-multipoint connection between a base station and a mobile terminal. The protocol layer structure of the broadband wireless access system is shown in FIG. 1, and the uppermost part of the MAC layer is a service specific convergence sublayer, and the packet data of various upper core networks is a common PDU according to the MAC standard. It converts into Protocol Data Unit format and compresses the header of the packet.

2 illustrates a process of performing a network entry procedure at the time of initialization of a mobile terminal in an orthogonal frequency division multiple access (OFDMA) broadband wireless access system.

1. When the mobile station first powers on, it searches for downlink channels and receives uplink / downlink map messages (DL / UL MAP) and uplink / downlink channel descriptor messages (DCD, UCD) to synchronize with the base station. Acquire.

2. When the mobile station receives an uplink map message including the allocation information of the initial ranging interval, the mobile station randomly selects one of the initial ranging codes and transmits it to the base station using the initial ranging interval of the uplink. Upon receiving the initial ranging code, the base station informs the mobile station of uplink transmission parameter adjustment values such as time offset, frequency offset, and power offset through a ranging response message (RNG-RSP). The mobile station adjusts uplink transmission parameters. The mobile station and the base station can perform uplink transmission parameter adjustment of the mobile station by repeating the above ranging code and ranging response message exchange procedure, and if the uplink transmission parameter adjustment is successfully performed, the ranging response message Include success code in the and send it to the mobile station. At this time, the base station allocates a non-competition-based uplink resource to the mobile station through a specific uplink map information element (ie, CDMA Allocation UL-MAP IE) so that the mobile station can transmit a ranging request message. The mobile station transmits a ranging request message including its MAC address by using the allocated uplink resource, and the base station receiving the mobile station has a basic CID and a primary management connection identifier (Primary CID). Sends a ranging response message (RNG-RSP)

3. A mobile station assigned a basic connection identifier and a primary connection identifier through a ranging response message transmits an SBC-REQ (SS Basic Capability Request) message for basic capability negotiation with the base station. Receive an SS Basic Capability Response (RSP) message. However, in order to transmit the SBC-REQ message, the mobile station must be allocated an uplink band from the base station. For this purpose, the mobile station receives the band request allocation interval information through the uplink map from the base station, and optionally selects a band request in the corresponding uplink period. Send the code. The base station receiving the bandwidth request code from the mobile station allocates a non-competition-based uplink resource to the mobile station through a specific uplink map information element (CDMA Allocation UL-MAP IE), and the mobile station receiving the mobile station receives the uplink resource. A band request header for requesting an uplink band required for transmitting an SBC-REQ message is transmitted using a link resource. The base station receiving the band request header allocates an uplink resource to the corresponding terminal through an uplink map information element (UL-MAP IE). The mobile station transmits its basic performance information to the base station by transmitting the SBC-REQ message using the allocated uplink resources. The base station receiving the SBC-REQ message transfers the SBC-RSP message to the mobile station, thereby completing the basic performance negotiation procedure between the mobile station and the base station. However, after the mobile station transmits the bandwidth request code to the base station and then receives an uplink resource capable of transmitting the SBC-REQ, the mobile station can directly transmit the SBC-REQ message to the base station without transmitting the bandwidth request header.

4. The mobile station receiving the SBC-RSP message exchanges a PKM-REQ (Privacy Key Management Request) and a PKM-RSP (Privacy Key Management Response) message for the authentication and key exchange procedure with the base station. However, at this time, the mobile station can perform the bandwidth request code transmission process of step 3 for the uplink resource allocation request for the PKM-REQ message transmission.

5. When the PKM-REQ and PKM-RSP messages are exchanged and the authentication and key exchange procedures of the mobile station and the base station are completed, the mobile station exchanges REG-REQ (Registration Request) and REG-RSP (Registration Response) messages with the base station. As a result, a registration procedure for registering with the base station is performed. However, in this case, as in processes 3 and 4, the mobile station may transmit a band request code to the base station for the uplink band request for transmitting the REG-REQ message.

6. The mobile station and the base station that have completed the registration procedure through REG-REQ and REG-RSP message exchange perform a procedure for setting a provisioned service flow in the network. 'Provisioned Service Flow' transmits a Dynamic Service Addition Request (DSA-REQ) message that includes parameters related to quality of service, and the mobile station transmits a Dynamic Service Addition Response (DSA-RSP) message to the base station in response. Is performed. As soon as the settings of the predefined 'Provisioned Service Flow' connections are completed, the mobile station and the base station complete the initial network registration procedure and switch to normal operation.

In the prior art, the mobile terminal defines various timers and the number of retransmissions so that the mobile station can normally exchange management messages with the base station upon initial network entry. For example, a mobile station that has sent a ranging request message has a timer T3 defined for waiting for receiving a ranging response message from a base station, and is previously received when the ranging response message is not received until the timer expires. Retransmit the ranging request message by the defined number of retransmissions. If the mobile station does not receive the ranging response message from the base station to exceed the number of retransmission of the ranging request message, the mobile station determines that the mobile station is in an abnormal state and attempts to access another base station or performs an initialization procedure for access to the base station. Start over from the beginning.

Parameters related to the timer and the number of retransmissions required for the initialization process of the mobile terminal defined in the prior art include those shown in Table 1 below.

System Name Time reference Minimum value Default value Maximum value BS Initial Ranging Interval Time between Initial Ranging regions assigned by the BS 2 s SS Contention Ranging Retries Number of retries on contention Ranging Requests 16 SS, BS Invited Ranging Retries Number of retries on inviting Ranging Requests 16 SS Request Retries Number of retries on bandwidth allocation requests 16 SS Registration Request Retries Number of retries on registration requests 3 BS Tproc Time provided between arrival of the last bit of a UL-MAP at an SS and effectiveness of that map SC: 200 ㎲ OFDM: 1 ms OFDMA: 10 OFDMA symbols BS SS Ranging Response Processing Time Time allowed for an SS following receipt of a ranging response before it is expected to reply to an invited ranging request 10 ms SS, BS DSx Request Retries Number of Timeout Retries on DSA / DSC / DSD Requests 3 SS, BS DSx Response Retries Number of Timeout Retries on DSA / DSC / DSD Responses 3 SS T1 Wait for DCD timeout 5 * DCD interval maximum value SS T2 Wait for broadcast ranging timeout 5 * ranging interval SS T3 Ranging Response reception timeout following the transmission of a Ranging Request 200 ms 200 ms SS T4 Wait for unicast ranging opportunity. If the pending-until-complete field was used earlier by this SS, then the value of that field shall be added to this interval. 30 s 35 s BS T5 Wait for Uplink Channel Change response 2 s SS T6 Wait for registration response 3 s SS, BS T7 Wait for DSA / DSC / DSD Response timeout 1 s SS, BS T8 Wait for DSA / DSC Acknowledge timeout 300 ms BS T9 Registration Timeout, the time allowed between the BS sending a RNG-RSP (success) to an SS, and receiving a SBC-REQ from that same SS 300 ms 300 ms SS, BS T10 Wait for Transaction End timeout 3 s SS T12 Wait for UCD descriptor 5 * UCD Interval maximum value SS T14 Wait for DSX-RVD Timeout 200 ms SS T18 Wait for SBC-RSP timeout 50 ms << T9

3 is a view for explaining a problem that may occur between the initial ranging process and the basic performance negotiation process in the prior art.

As shown in FIG. 3, after the mobile station receives a basic connection identifier (Basic CID) and a primary connection identifier (Primary CID) from the base station through an initial ranging process, the mobile station transmits an SBC-REQ message to the base station. Basic performance negotiation should be initiated. In addition, the base station transmits a ranging response message to the mobile station, and then allocates a basic connection identifier and a primary connection identifier, and then operates a timer T9 to wait for reception of the SBC-REQ message from the mobile station. If the base station does not receive the SBC-REQ message until the timer expires, the base station releases the primary connection identifier and the primary connection identifier assigned to the mobile station, and assigns the same connection identifiers to other mobile stations.

However, the mobile station needs to allocate uplink resources from the base station in order to transmit the SBC-REQ message to the base station. In this process, uplink bandwidth requests from other mobile stations may collide with each other, or channel quality may deteriorate. If the base station does not receive the uplink band request from the mobile station, the uplink band request retry may be performed. That is, if the mobile station fails to allocate uplink resources and the timer running in the base station expires and the mobile station does not transmit the SBC-REQ message, the base station releases the management connection identifiers assigned to the mobile station and releases the mobile station. May not be aware that the managed connection identifier has been released. If the base station allocates a corresponding management connection identifier to another mobile terminal, a problem may occur in which the same identifier is assigned to two different mobile terminals.

4 is a diagram illustrating a problem that may occur between a base station registration process and a 'provisioned service flow' generation process when the mobile station is initialized in the prior art.

After the registration process is completed, the mobile station and the base station complete the preset service flow generation process to complete the network entry procedure of the mobile station. However, as shown in FIG. 4, when the mobile station does not receive the service flow generation request message for a predetermined time after receiving the registration response message from the base station, the mobile station does not switch to normal operation and falls into an error situation. In addition, if the base station that has transmitted the service generation request message to the mobile station does not receive the service generation response message from the mobile station for a predetermined time, it retransmits the service generation request message. If the service generation response message is not received from the terminal, an abnormal state occurs. In the prior art, there is a problem in that the operation of the terminal and the base station is not described for such an error situation.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention is to provide a method for the mobile terminal to efficiently proceed to the initial network entry process in a broadband wireless access system.

Another object of the present invention is to provide a method for preventing abnormal operation of a mobile terminal due to an error in the initial network entry of the mobile terminal in a broadband wireless access system.

In the present invention, when the base station does not receive an uplink transmission message (SBC-REQ, PKM-REQ, REG-REQ, etc.) within a predetermined time from the mobile terminal during the initial network entry procedure of the mobile terminal, through the following method Prevent error situations.

Releases a management resource such as a management connection identifier assigned to the mobile station and transmits a reset command message (RES-CMD) so that the mobile station performs a new network entry procedure. Upon receiving this, the mobile station stops attempting to request a bandwidth for transmitting an uplink management message such as SBC-REQ and starts a network entry procedure including a ranging procedure from the beginning.

The base station determines that the mobile station's request for bandwidth through the contention-based uplink bandwidth request interval has repeatedly failed, and assigns a non-contention based uplink band to the mobile station to thereby uplink. Allows you to send management messages.

If the uplink management message is not received from the mobile station due to a bad channel condition between the mobile station and the base station or the exceeding number of accommodating terminals of the base station, a management message for instructing the mobile station to register with another base station (eg For example, by transmitting the deregistration command message (DREG-CMD) or ranging response message (RNG-RSP) to the mobile terminal, the mobile terminal can perform a network entry procedure to another base station.

In addition, the base station is a channel identifier (Downlink Channel Descriptor, DCD) or downlink management message (for example, RNG-RSP, SBC-RSP, PKM-RSP message, etc.) transmitted in the form of a broadcast during the initial network entry of the mobile station By notifying the setting value of the uplink management message waiting timer and the start time of the timer operated by the base station through the base station, if the mobile station fails to transmit the uplink management message until the corresponding timer expires, the initial network entry procedure is repeated. Make it work. The timer setting value and the timer operation start time are transmitted to the mobile terminal in a TLV (Type, Length, Value) type parameter as shown in Table 2 or Table 3, thereby obtaining timer synchronization between the mobile terminal and the base station.

Name Type Length Value Scope Registration validity time TBD 2 Registration Timeout, For example, the time allowed between the BS sending a RNG-RSP (success) to an SS, and receiving a SBC-REQ from that same SS. The unit is ms. DCD, RNG-RSP, SBC-RSP, PKM-RSP Start time TBD One Start time of the timer upon MS receiving this parameter. The unit is ms (or a frame).

Name Type Length Value Scope Registration validity time TBD 3 Bits # 0-15: Registration Timeout, For example, the time allowed between the BS sending a RNG-RSP (success) to an SS, and receiving a SBC-REQ from that same SS. The unit is ms.
Bits # 16-23: Start time of the timer upon MS receiving this parameter. The unit is ms. DCD, RNG-RSP, SBC-RSP, PKM-RSP

Through the above method, an error situation that may occur when the base station does not receive the uplink management message from the mobile station within a predetermined time when performing the network entry procedure of the mobile station can be prevented.

After receiving the registration response message, if the mobile station does not receive the preset service flow generation request message from the base station within a predetermined time, an error situation can be prevented through the following method.

The mobile station transmits an uplink management message (eg, a service response message having an error code indicating that the wait for receiving a service request message has expired, or a management message or header that performs the same function) to the base station. Notify that the reception has not been received, and causes the base station to transmit a service generation request message. Preferably, the number of retransmission attempts for transmitting the uplink management message and a wait timer for receiving a service generation request message may be defined together. The mobile station can release the registration with the base station by transmitting a DREG-REQ message to the base station, and can perform a network entry procedure to another base station.

If the base station fails to receive the service generation response message of the mobile station for the service generation request transmitted by the base station during the initial network entry of the mobile station, and the generation of the preset service flow fails, the base station sends a reset command message (RES-CMD). ) May be transmitted to the mobile station to re-initiate the initialization of the mobile station or the DREG-CMD message or the RNG-RSP message may be transmitted to allow the mobile station to perform a network entry procedure to another base station.

In one aspect of the present invention, there is provided a method for performing a procedure for network entry according to the present invention, the method for performing a procedure for network entry of a mobile station in a broadband wireless access system, the method comprising: assigning transmission parameters from a base station; And performing at least one request for an uplink band for transmitting an uplink management message to the base station, and if the uplink band is not allocated until a predetermined time elapses, proceed with the following procedure from the base station. Receiving a downlink message for characterized in that it is configured.

The construction, operation, and other features of the present invention will be readily understood by the preferred embodiments of the present invention described below with reference to the accompanying drawings.

The description of the operation of the present invention will be divided into two parts as in the configuration of the present invention. One shows the operation description of the mobile station and the base station when the base station does not receive the uplink management message that should be received from the mobile station within a predetermined time when the mobile station enters the network. An operation description of the case where the mobile station and the base station fail to generate the service flow normally is shown.

FIG. 5 is a flowchart illustrating a procedure of a preferred embodiment of the present invention, in which a base station does not receive an uplink management message from a mobile station within a predetermined time when the mobile station enters an initial network.

The base station exchanges the ranging request message (RNG-REQ) and the ranging response message (RNG-RSP) with the mobile station [S51, 52], thereby providing a basic connection identifier (Basic CID) and a primary management connection identifier ( Primary CID), and the base station operates a timer T9 after transmitting the corresponding ranging response message [S53] and waits for receiving a basic performance request message (SBC-REQ) from the mobile station. When the mobile station receives the ranging response message including the basic connection identifier and the primary management connection identifier, the mobile station requests an uplink band for transmitting the SBC-REQ message using a band request code and a band request header [S54, S55]. If the mobile station is not allocated an uplink band from the base station [S56], the mobile station repeatedly performs a band request by performing a backoff [S57].

If the base station does not receive the SBC-REQ message from the mobile terminal until the timer T9 expires [S58], the base station sends a reset command message RES-CMD to instruct the mobile terminal to re-initialize the initialization process. S59]. At the same time, the primary connection identifier and the primary management connection identifier assigned to the mobile station are released [S60]. When the mobile station receives the RES-CMD from the base station [S59], the mobile station stops the uplink band request process for SBC-REQ message transmission and performs the initialization process including the ranging process [S61]. However, like the base station, the mobile station also releases the default connection identifier and the primary management connection identifier that have been allocated. The mobile station performs an initial ranging process by transmitting an initial ranging code [S63].

FIG. 6 is a flowchart illustrating another exemplary embodiment of the present invention, in which the base station does not receive an uplink management message from the mobile terminal within a predetermined time when the mobile station enters an initial network.

The base station allocates a basic connection identifier and a primary management connection identifier to the mobile station by exchanging a ranging request message (RNG-REQ) and a ranging response message (RNG-RSP) with the mobile station [S61, 62]. After transmitting the ranging response message to the mobile station, the timer T9 is operated to wait for reception of the basic performance request message SBC-REQ from the mobile station [S63]. When the mobile station receives a ranging response message including a basic connection identifier and a primary management connection identifier, the mobile station requests an uplink band for transmitting an SBC-REQ message using a band request code and a band request header [S65]. . If the mobile station does not receive an uplink band from the base station [S66], the mobile station repeatedly performs a band request by performing a backoff [S67].

If the base station does not receive the SBC-REQ message from the mobile station until the timer (T9) expires [S68], the base station is up to the non-contention based (non-contention based) to transmit the SBC-REQ message Allocates a link radio resource [S69]. The mobile station, which is allocated contention-based uplink resources from the base station, transmits an SBC-REQ message to the base station [S70]. However, if the base station does not receive the SBC-REQ message from the mobile terminal even though the base station allocates the non-competitive uplink radio resource, the base station repeatedly allocates the non-competition based uplink radio resource a predetermined number of times, and thereafter, SBC-REQ. If the message is not received, the mobile station is considered to be in an abnormal state and the primary connection identifier and the primary management connection identifier assigned to the mobile station are released, and then the RES-CMD message is transmitted to perform the initialization procedure again. It can transmit to the mobile terminal.

7 is a flowchart illustrating a procedure according to another preferred embodiment of the present invention, when a base station does not receive an uplink management message from a mobile station within a predetermined time when the mobile station enters an initial network.

The base station allocates a basic connection identifier and a primary management connection identifier to the mobile station by exchanging a ranging request message and a ranging response message with the mobile station [S71, S72]. After the base station transmits the corresponding ranging response message, The timer T9 is operated to wait for reception of the basic performance request message (SBC-REQ) from the mobile station [S73]. When the mobile station receives the ranging response message including the basic connection identifier and the primary management connection identifier, the mobile station requests an uplink band for transmitting the SBC-REQ message using a band request code and a band request header [S75]. . If the mobile station does not receive an uplink band from the base station [S76], it performs a backoff and repeatedly attempts a band request [S77].

If the base station does not receive the SBC-REQ message from the mobile station until the timer T9 expires [S78], the base station and the primary management connection identifier assigned to the mobile station is released [S79] and registered. It sends a release command message (DREG-CMD) or a ranging response message (RNG-RSP) to perform a network entry procedure to another base station [S80]. The mobile station receiving the DREG-CMD or RNG-RSP message from the base station releases the primary connection identifier and the primary management connection connection identifier allocated from the base station [S81], and scans another base station channel to determine the appropriate other. A network entry procedure is performed to the base station [S82].

8 is a preferred embodiment of the present invention, a mobile station performing a network entry procedure does not transmit an uplink management message (SBC-REQ) until the base station timer T9 expires, and is transmitted from a base station. An embodiment of the present invention for preventing abnormal operation that may occur when the network entry procedure re-execution command is not received.

When the mobile station first powers on, the UE searches for the downlink channel and receives uplink / downlink map message (DL / UL MAP) and uplink / downlink channel descriptor message (DCD, UCD) to obtain synchronization with the base station. [S83]. The mobile station can receive the uplink management message reception wait timer setting value and the timer start time parameter shown in Table 2 from the DCD message.

When the mobile station receives an uplink map message including the allocation information of the initial ranging interval [S84], one of the initial ranging codes is randomly selected and transmitted to the base station using the initial ranging interval of the uplink. [S85]. Upon receiving the initial ranging code, the base station informs the mobile station of uplink transmission parameter adjustment values such as time offset, frequency offset, and power offset through a ranging response message (RNG-RSP) [S86]. ], The mobile station receiving this adjusts an uplink transmission parameter. The mobile station and the base station may perform uplink transmission parameter adjustment of the mobile station by repeating the above ranging code and ranging response message exchange procedure, and if the uplink transmission parameter adjustment is successfully performed, the lane A success status is included in the message response message and transmitted to the mobile station [S86]. In this case, the base station allocates a non-competition-based uplink resource to the mobile station through a specific uplink map information element (ie, CDMA Allocation UL-MAP IE) so that the mobile station can transmit a ranging request message [S87]. ]. The mobile station transmits a ranging request message including its MAC address by using the allocated uplink resource [S88], and the base station receiving the MS transmits a basic connection identifier (Basic CID) and a primary management connection to the mobile station. A ranging response message (RNG-RSP) for allocating an identifier (Primary CID) is transmitted [S89]. In this case, when the timer setting values and timer start time parameters as shown in Table 2 are not transmitted through the DCD message, the base station sets the uplink management message reception wait timer setting values and timer start time parameters as shown in Table 2 in the ranging response message. It can be included and delivered to the mobile terminal.

After transmitting the corresponding ranging response message, the base station operates a timer T9 and waits for receiving the basic performance request message (SBC-REQ) from the mobile station [S90]. When the mobile station receives the ranging response message from the base station, the mobile station operates an uplink management message reception wait timer (Timer X) as shown in Table 2 or Table 3 according to a timer start time [S91]. When the mobile station receives the ranging response message including the basic connection identifier and the primary management connection identifier, the mobile station requests an uplink band for transmitting the SBC-REQ message using a band request code and a band request header [S93]. . If the mobile station does not receive an uplink band from the base station [S94], the mobile station performs a backoff request repeatedly [S95].

If the base station does not receive the SBC-REQ message from the mobile station until the timer T9 expires [S96, S97], the base station and the primary management connection identifier assigned to the mobile station are released [S98]. In addition, by transmitting a deregistration command message (DREG-CMD) or a ranging response message (RNG-RSP) to command to perform the network entry procedure to the appropriate base station again [S99].

The MS does not transmit the SBC-REQ message to the base station until the timer setting value received in the DCD message or the ranging response message such as Table 2 or Table 3 expires, or performs the network entry procedure from the base station again. When receiving the deregistration command message (DREG-CMD) or ranging response message (RNG-RSP) of the command, the mobile station releases the primary connection identifier and the primary management connection identifier assigned from the base station [S100], The network entry procedure is performed again by scanning the base station channel [S101]. The timer shown in Table 2 or Table 3 operated by the mobile terminal includes up / down management messages between the mobile terminal and the base station (SBC-REQ / SBC-RSP, PKM-REQ / PKM-RSP, REG-REQ / REG). -RSP) exchange is performed successfully or is released when the timer expires.

In the four embodiments described with reference to FIGS. 5 to 8, the mobile station has not described the case in which the SBC-REQ message is not transmitted to the base station within a predetermined time during the network entry process. After the basic performance negotiation is completed by sending and receiving SBC-RSP messages, the base station receives the PKM-REQ message transmitted by the mobile station for authentication and key exchange with the base station and the REG-REQ message sent for registration within a predetermined time. If not, the same process can be performed. In this process, the uplink management message reception wait timer setting value and the timer start time parameter of Table 2 may be included in the SBC-RSP message and the PKM-RSP message and transmitted to the mobile station.

FIG. 9 is a flowchart illustrating still another preferred embodiment of the present invention, in which a mobile station that has completed registration by receiving a REG-RSP message from a base station when the mobile station enters an initial network fails to receive a preset service flow generation request message from the base station. The first embodiment for the case.

The mobile station and the base station perform a base station registration procedure of the mobile station by exchanging REG-REQ messages and REG-RSP messages [S102, S103]. When the base station completes the registration procedure by transmitting a REG-RSP message to the mobile station, a dynamic service addition request message (DSA-REQ) is transmitted to generate a preset service flow [S105], and a dynamic service addition response message ( A timer T7 for waiting to receive the DSA-RSP is operated [S106]. On the other hand, the mobile station receiving the REG-RSP message from the base station operates a timer waiting for the reception of the DSA-REQ message [S104]. If the base station does not receive the DSA-RSP message from the mobile station until the timer T7 of the base station expires after transmitting the DSA-REQ message, the base station repeats the transmission of the DSA-REQ message for a predetermined number of times, Wait for reception of a DSA-RSP message [S107, S108, S109, S110].

When the mobile station does not receive the DSA-RSP message for a predetermined time, the mobile station transmits an uplink management message (for example, a DSA-RSP message with an error code) or an uplink header to transmit a DSA-RSP message. Notify the base station that it did not receive [S111]. The base station receiving this transmits a DSA-REQ message to the mobile station by applying a coding and modulation scheme suitable for the mobile station [S112]. After receiving the DSA-REQ message from the base station, the mobile station delivers a DSA-RSP message to the base station to perform a preset service flow generation procedure [S113]. The base station receiving the DSA-RSP message transmits a DSA-ACK message to the mobile station to complete the service flow procedure. The mobile station and the base station complete a network entry procedure by exchanging DSA messages to generate a predetermined number of predetermined service flows [S114].

FIG. 10 is a flowchart illustrating still another preferred embodiment of the present invention, in which a mobile station that has completed registration by receiving a REG-RSP message from a base station when the mobile station enters an initial network fails to receive a preset service flow generation request message from the base station. The second embodiment is for.

The mobile station and the base station perform a base station registration procedure of the mobile station by exchanging REG-REQ messages and REG-RSP messages [S115, S116]. When the base station completes the registration procedure by transmitting a REG-RSP message, the base station transmits a DSA-REQ message to generate a preset service flow [S118], and operates a timer T7 waiting to receive the DSA-RSP message [ S119]. On the other hand, the mobile station receiving the REG-RSP message from the base station operates a timer waiting for the reception of the DSA-REQ message [S117].

If the DSA-RSP message is not received from the mobile station until the timer T7 of the base station expires after transmitting the DSA-REQ message, the base station repeats the transmission of the DSA-REQ message a predetermined number of times, Wait for reception of a DSA-RSP message [S120, S121, S122, S123]. If the base station does not receive the DSA-RSP message from the mobile terminal even though the base station retransmits the DSA-REQ message a predetermined number of retransmissions, the mobile station performs a reset command message (RES-CMD). ) Or transmits a deregistration command message (DREG-CMD) [S124]. When the mobile station waiting for the reception of the DSA-REQ message transmitted from the base station receives the RES-CMD message from the base station, the mobile station performs the initial network entry procedure including the initial ranging procedure again and moves upon receiving the DREG-CMD message. The terminal releases the network entry procedure with the base station, performs a network entry procedure to another appropriate base station by scanning another base station channel [S125].

FIG. 11 is a flowchart illustrating still another preferred embodiment of the present invention, in which a mobile station that has completed registration by receiving a REG-RSP message from a base station when the mobile station enters an initial network fails to receive a preset service flow generation request message from the base station. The third embodiment is for.

The mobile station and the base station perform a base station registration procedure of the mobile station by exchanging REG-REQ and REG-RSP messages [S125, S126]. When the base station completes the registration procedure by transmitting a REG-RSP message, the base station transmits a DSA-REQ message to generate a preset service flow [S128], and operates a timer T7 waiting to receive the DSA-RSP message [ S129]. On the other hand, the mobile station receiving the REG-RSP message from the base station operates a timer waiting for the reception of the DSA-REQ message (S130). If the DSA-RSP message is not received from the mobile station until the timer T7 of the base station expires after transmitting the DSA-REQ message, the base station repeats the transmission of the DSA-REQ message a predetermined number of times, Wait for reception of a DSA-RSP message [S131, S132, S133].

If the mobile station does not receive the DSA-RSP message for a predetermined time, it sends a deregistration request message (DREG-REQ) to the base station and requests deregistration [S134]. Receiving the deregistration request message from the mobile station, the base station releases the basic connection identifier, the primary management connection identifier and the management resource of the mobile station, and sends a deregistration command message (DREG-CMD) to the mobile station to deregister. To complete [S135]. The mobile station receiving the DREG-CMD message from the base station releases the connection identifier and management resources allocated from the base station and performs the initial network entry procedure to the base station again or performs a network entry procedure to another base station. [S136]. However, if the mobile station does not receive the DREG-CMD message for a certain time after transmitting the DREG-REQ message, the mobile station releases the management connection identifier and management resources allocated from the base station and enters the initial network into the base station. Perform the procedure again or perform the network entry procedure to another base station.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

According to the present invention, by defining a clear operation for a case in which a management message required for a network entry procedure is not exchanged within an appropriate time in the process of performing a network entry procedure of the mobile station, a normal state operation can be performed between the mobile station and the base station. It can be effective.

Claims (14)

A method for performing a procedure for network entry of a mobile terminal in a broadband wireless access system, Receiving a transmission parameter from a base station; Performing at least one request for an uplink band for transmitting an uplink management message to the base station; And Receiving a downlink message from the base station when the uplink band is not allocated until a predetermined time elapses, And the downlink message is for allocating a contention-free uplink radio resource. The method of claim 1, And wherein said transmission parameter comprises a primary connection identifier and a primary management connection identifier. The method of claim 1, The uplink management message is one of a basic performance request message (SBC-REQ), a private key management request message (PKM-REQ), and a registration request message (REG-REQ). delete 4. The method according to any one of claims 1 to 3, Releasing said transmission parameter. delete 4. The method according to any one of claims 1 to 3, And transmitting the uplink management message through the non-competition based uplink radio resource. A method for performing a procedure for network entry of a mobile terminal in a broadband wireless access system, Receiving a transmission parameter from a base station; Performing at least one request for an uplink band for transmitting an uplink management message to the base station; And Receiving a downlink message from the base station when the uplink band is not allocated until a predetermined time elapses, The downlink message is a message instructing to perform a network entry procedure to another base station. 9. The method of claim 8, Releasing said transmission parameter. A method for performing a procedure for network entry of a mobile terminal in a broadband wireless access system, Assigning a transmission parameter to the mobile terminal; Checking whether there is a request for an uplink band for transmitting an uplink management message from the mobile station for a predetermined time; And And transmitting a downlink message to the mobile station when there is no request for allocation of the uplink band after the predetermined time elapses. And the downlink message is for allocating a contention-free uplink radio resource. delete delete delete delete

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