KR20080016316A - How to perform network entry in wireless communication system - Google Patents

Abstract

A method for performing a network entry in a wireless communication system is provided to allow an MS(Mobile Station) in a normal operation mode to enter a network quickly at an initial stage compared with an MS in a sleep mode or an idle mode, and allow a BS(Base Station) to distribute initial ranging attempts of MSs suitably. An MS performs an initial network entry procedure by applying random backoff(S401). A BS re-starts for the reason of power failure or maintenance and repair(S402). The BS increases a BS restart count parameter value by 1 and transfers the value to the MS and transfers a backoff window value to the MS(S403). The MS performs a network entry procedure(S404). The MS transmits an initial ranging code by applying a random backoff(S405). The MS checks whether an initial ranging slot has been allocated to a corresponding uplink frame(S406). The MS transmits an initial ranging code on a corresponding initial ranging slot by applying a random backoff value(S407). The MS adjusts an uplink transmission parameter(S408). The BS allocates non-contention-based uplink resources to the BS and the BS transmits a ranging request message including its MAC address by using the allocated uplink resources(S409). The BS transmits a ranging response message(S410). The MS and the BS performs a procedure of basic performance negotiation, authentication and key exchange, registration, and service flow setting(S411).

Description

Method for performing a network entry in mobile communication system

1 is a block diagram illustrating a protocol hierarchy structure of a broadband wireless access system.

2 is a flowchart illustrating an initial network entry procedure of a mobile terminal.

3 is a block diagram illustrating an operation when random backoff is used during initial ranging of a mobile terminal.

4 is an example of a procedure flow diagram illustrating a method for a mobile station to re-enter upon restarting a base station.

5 is a flowchart illustrating a method of differently applying an initial ranging backoff window according to an operation mode.

The present invention relates to network entry of a mobile station due to a base station restart in a broadband wireless access system, and more particularly to network entry with improved entry delay into a network.

Hereinafter, a communication system to which the communication method according to the present invention is applied will be described. The present invention can be applied to a broadband wireless access system. Hereinafter, a communication method in a conventional broadband wireless access system will be described.

1 is a block diagram illustrating a protocol hierarchy structure of 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 convergence sublayer which converts packet data of various upper core networks into a common PDU format according to the MAC standard, and headers of the corresponding packet. It serves to compress it.

2 is a flowchart illustrating an initial network entry procedure of a mobile terminal.

Hereinafter, referring to FIG. 2, a process of performing a network entry procedure when initializing a mobile station in the OFDMA scheme of a conventional broadband wireless access system is shown.

Hereinafter, step S201 will be described.

When the MS is powered on for the first time, the downlink channel is searched and an uplink / downlink map message (UL-MAP / DL-MAP) and an uplink / downlink channel descriptor (UCD: Uplink Channel Descriptor / DCD: Downlink) are detected. Receive a Channel Descriptor message to obtain synchronization with the BS.

Hereinafter, step S202 will be described.

When the mobile station receives an uplink map message (UL-MAP) including allocation information of an initial ranging interval, the mobile station randomly selects one of the initial ranging codes to initialize the uplink. The base station receiving the initial ranging code informs the mobile station of uplink transmission parameter adjustment values, such as time offset, frequency offset, and power offset, through the ranging response message. One mobile station adjusts uplink transmission parameters. The mobile station and the base station can perform the uplink transmission parameter adjustment of the mobile station by repeating the above ranging code and ranging response message (RNG-RSP) exchange procedure, when the uplink transmission parameter adjustment is successfully performed. The success code is transmitted to the mobile station in the ranging response message (RNG-RSP). At this time, the base station allocates a non- contention-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 (RNG-REQ) including its MAC address using the allocated uplink resource, and the base station receives the basic connection identifier (Basic CID: Connection ID) and the corresponding base station. A ranging response message (RNG-RSP) for assigning a primary management connection identifier (Primary CID) is transmitted.

Hereinafter, step S203 will be described.

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, and transmits an SBC-RSP ( Receive SS Basic Capability Response) message.

Hereinafter, step S204 will be described.

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.

Hereinafter, step S205 will be described.

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. Perform the registration procedure to register with.

Hereinafter, step S206 will be described.

The mobile station and the base station, which have completed the registration procedure through REG-REQ and REG-RSP message exchanges, perform a procedure for setting a provisioned service flow in the network. Provisioned Service Flow is performed by the base station transmitting a Dynamic Service Addition Request (DSA-REQ) message containing quality-related parameters, and the mobile station sends a DSA-RSP (Dynamic Service Addition Response) message to the base station in response. do. 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 return to normal operation.

In the prior art, when the mobile station performs initial ranging for initial access to the network, a random backoff scheme is used during initial ranging code transmission to prevent collision due to simultaneous access of the mobile terminals. The base station transmits an initial ranging backoff start parameter (Initial_ranging_backoff_start) and an initial ranging backoff end parameter (Initial_ranging_backoff_end) to the mobile station through the uplink channel descriptor message, when the mobile station performs initial ranging. Allows you to select the backoff value that should be applied. The mobile station randomly selects the backoff value within the initial ranging backoff start value to transmit the initial initial ranging code, and if it does not receive the ranging response, the mobile station exponentially increases the backoff window value to range Attempt to resend the code. The mobile station attempts to retransmit the ranging code by repeating this process until the initial ranging backoff end value is reached.

Table 1 below shows an example of an initial ranging backoff window start parameter and an initial ranging backoff end parameter included in an uplink channel descriptor message. The minimum and maximum values of the backoff window during initial ranging of the mobile station are shown. Used.

Name Type (1 byte) Length Value Initial_ranging_backoff_start 198 One Initial backoff window size for initial ranging contention, expressed as a power of 2. Values of n range 0-15 (the highest order bits shall be unused and set to 0) This TLV shall be used in NBR-ADV message only to represent corresponding values that appear in UCD message fields. Initial_ranging_backoff_end 199 One Final backoff window size for initial ranging contention, expressed as a power of 2. Values of n range 0-15 (the highest order bits shall be unused and set to 0) This TLV shall be used in NBR-ADV message only to represent corresponding values that appear in UCD message fields.

3 is a block diagram illustrating an operation when random backoff is used during initial ranging of a mobile terminal.

Hereinafter, referring to FIG. 3, when an initial ranging backoff value is set to 13 in an initial ranging process of an MS, the MS transmits an initial ranging code. (However, since the mobile station randomly selects a backoff value within the initial backoff window, the size of the initial backoff window in Table 1 should be set to be larger than 13.)

When the mobile station selects 13 as the initial ranging backoff value as shown in FIG. 3, the mobile station transmits a ranging code to the 14th uplink ranging slot. As described above, the mobile station arbitrarily selects a ranging slot for transmitting the ranging code in the ranging backoff window to minimize collisions caused by multiple mobile stations simultaneously transmitting the ranging code.

In addition, in the prior art, when the base station is restarted during normal operation, the mobile station recognizes this and defines the initial network entry process to the base station. To this end, the base station transmits the number of base station restarts to the mobile station through a downlink channel identifier (DCD), and the mobile station that receives the base station determines whether to restart the base station to determine whether to perform an initial network entry procedure.

Table 2 below is an example of a base station restart count parameter included in a downlink channel descriptor (DCD) message.

Name Type (1 byte) Length Value (variable length) PHY  scope BS Restart Count 154 One The value is incremented by one whenever BS restarts (see 6.3.9.11). The value rolls over from 0 to 255. All

Each time the base station restarts, the base station restart count parameter setting value shown in Table 2 is increased by 1, and the mobile station receives the downlink channel descriptor message and then compares the previous base station restart count value with the current value. If the base station is restarted (that is, the base station restart count value is increased compared to the previous time), it is re-registered with the base station by performing the initial network entry procedure.

Hereinafter, an initial network entry procedure according to the prior art will be described.

In the prior art, the initial network entry procedure of the mobile station is performed by the mobile station voluntarily for initial access to a network or access to a base station having a good channel environment, and the normal registration of the mobile station with the base station. There is an initial network entry procedure performed due to the restart of the base station in the operating state.

In the case of voluntary network entry procedure performed by the mobile station, the number of mobile terminals and the time point of performing the network entry procedure are randomly configured. However, the number and execution time of the mobile terminal due to the restart of the base station are different. It is predictable and has a feature that can be concentrated in a moment.

In addition, the mobile station performs random backoff to prevent collision with other mobile stations during initial ranging for performing an initial network entry procedure, and the base station sets a backoff window value for the uplink channel descriptor (UCD) message. It passes to the mobile terminal through.

The present invention has been proposed to improve the above-described prior art, and an object of the present invention is to provide a network entry method of improved performance.

It is still another object of the present invention to provide a control information transmission method for a network entry method for preventing a deterioration of service quality.

Summary of the Invention

According to an aspect of the present invention, there is provided a method of performing a network entry, the method comprising: receiving first network entry control information regarding a network entry time of at least one mobile terminal set to a specific first value; Performing network entry according to the received first network entry control information; Receiving second network entry control information regarding a network entry time of the at least one mobile terminal, set to a specific second value; And performing network entry according to the received second network entry control information.

Preferably, the first network access control information is a ranging backoff value for spontaneous access, and the second network access control information is a backoff value according to restart of a base station. Preferably, the backoff value for restart is greater than the ranging backoff value for spontaneous access.

In accordance with another aspect of the present invention, there is provided a network entry method comprising: receiving first network entry control information including information regarding a network entry time point of mobile terminals; Performing network entry according to the received first network entry control information; Receiving second network entry control information regarding network entry times of mobile terminals that are determined differently according to an operation mode of the mobile terminal; And performing network entry according to the received second network entry control information.

Preferably, the operation mode of the terminal is classified according to the connection state of the terminal and the network or a power control method of the terminal. Preferably, the operation mode is divided into a normal mode, an idle mode, a sleep mode, and the like. Preferably, the first network access control information is a ranging backoff value for spontaneous access, and the second network access control information is a backoff value according to restart of a base station. Preferably, the backoff value for restart is greater than the ranging backoff value for spontaneous access.

According to another aspect of the present invention, there is provided a network entry method comprising: setting first network entry control information regarding a network entry time of at least one mobile terminal to a specific first value and transmitting the same to a specific first mobile terminal; Performing a registration procedure for the first mobile terminal attempting to enter a network based on the first network entry control information; When re-registration of the first mobile terminal is required, setting second network entry control information regarding a network entry time of the at least one mobile terminal to a specific second value and transmitting the same to the first mobile terminal; And performing a re-registration procedure for the first mobile terminal attempting to enter a network based on the second network entry control information.

In addition, the network entry method according to another aspect of the present invention, transmitting the first network entry control information about the network entry time of at least one mobile terminal to a specific first mobile terminal; Performing a registration procedure for the first mobile terminal attempting to enter a network based on the first network entry control information; When re-registration of the first mobile terminal is required, the second mobile entry control information regarding the network entry time of the at least one mobile terminal determined differently according to an operation mode of the at least one mobile terminal is moved. Transmitting to the terminal; And performing a re-registration procedure for the first mobile terminal attempting to enter a network based on the second network entry control information.

One embodiment of the invention

The present invention relates to a network entry method of improved performance and a control information transmission and reception method therefor. The operation, construction and effects of the present invention will be further embodied by one embodiment of the present invention described below.

As described above, the initial network entry procedure may be divided into two types. In this case, conventionally, the values of various control information regarding the random back off window for the above two network entry procedures are equally applied. Therefore, it is possible to increase the probability of collision at the initial network entry of the mobile terminals performing the network entry procedure at the base station restart. This results in degradation of system performance and deterioration of service quality of the mobile terminal through delay of network entry of mobile terminals.

In order to solve this problem, an embodiment of the present invention provides a backoff window value for initial ranging performance of a mobile station upon restarting a base station and a backoff window value for initial ranging performance applied when a mobile station voluntarily enters a network. By differently defining, minimizes network entry collision between mobile terminals that may occur when the base station restarts.

In addition, another embodiment of the present invention, the operating mode (eg, normal mode, sleep mode, idle mode) of the mobile terminal during the initial ranging backoff due to the base station restart set the initial ranging backoff parameter to a different value. In this way, the mobile station in the normal operation mode (normal mode) according to the initial ranging backoff parameter setting value to make the initial network entry faster than the sleep mode (idle mode) terminal, and the base station Proposes a method for properly distributing initial ranging attempts of mobile terminals.

Hereinafter, various parameters proposed by an embodiment of the present invention will be described. The parameters described below are examples of parameters related to the back off window among control information for initial ranging of the mobile terminal.

Table 3a below is an example of back off parameters for initial ranging due to base station restart.

Name Type (1 byte) Length Value BS restart ranging backoff TBD One A parameter for initial ranging performed due to restart of the base station. More specifically, it is a parameter that expresses the size of an initial backoff window for initial ranging as a power of two. (Initial backoff window size for initial ranging contention due to BS restart, expressed as a power of 2.)

Table 3b below shows an example of a back off parameter for initial ranging due to a base station restart, in which a back off parameter is controlled according to an operation mode of a mobile terminal.

Name Type (1 byte) Length Value BS restart ranging backoff TBD 3 A parameter for initial ranging performed due to restart of the base station. More specifically, it is a parameter that expresses the size of an initial backoff window for initial ranging as a power of two. (Initial backoff window size for initial ranging contention due to BS restart, expressed as a power of 2) In addition, each bit of the parameter may be configured as follows according to the operation mode of the mobile terminal. Bit # 0 ~ Bit # 7: Backoff window size for normal mode Bit # 8 ~ Bit # 15: Backoff window for sleep mode Backoff window size for sleep mode Bit # 16 ~ Bit # 23: Backoff window size for idle mode

Table 3c below is another example of a back off parameter for initial ranging due to a base station restart.

Name Type (1 byte) Length Value BS restart ranging backoff start TBD One A parameter for initial ranging performed due to restart of the base station. More specifically, it is a parameter that expresses the size of an initial backoff window for initial ranging as a power of two. (Initial backoff window size for initial ranging contention due to BS restart, expressed as a power of 2.) BS restart ranging backoff end TBD One A parameter for initial ranging performed due to restart of the base station. More specifically, the size of the final backoff window for initial ranging (final backoff window) is a parameter expressed in the power of two. Final backoff window size for initial ranging contention due to BS restart, expressed as a power of 2.

Table 3d below shows an example of a back off parameter for initial ranging due to a base station restart, in which a back off parameter is controlled according to an operation mode of a mobile terminal.

Name Type (1 byte) Length Value BS restart ranging backoff start TBD 3 A parameter for initial ranging performed due to restart of the base station. More specifically, it is a parameter that expresses the size of an initial backoff window for initial ranging as a power of two. (Initial backoff window size for initial ranging contention due to BS restart, expressed as a power of 2.) In addition, each bit of the parameter may be configured as follows according to the operation mode of the mobile terminal. Bit # 0 ~ Bit # 7: Backoff window size for normal mode Bit # 8 ~ Bit # 15: Backoff window for sleep mode Backoff window size for sleep mode Bit # 16 ~ Bit # 23: Backoff window size for idle mode BS restart ranging backoff end TBD 3 A parameter for initial ranging performed due to restart of the base station. More specifically, the size of the final backoff window for initial ranging (final backoff window) is a parameter expressed in the power of two. (Final backoff window size for initial ranging contention due to BS restart, expressed as a power of 2.) In addition, each bit of the parameter may be configured as follows according to the operation mode of the mobile terminal. Bit # 0 ~ Bit # 7: Backoff window size for normal mode Bit # 8 ~ Bit # 15: Backoff window for sleep mode Backoff window size for sleep mode Bit # 16 ~ Bit # 23: Backoff window size for idle mode

Table 3a describes an example of a parameter for performing random backoff using the same backoff window regardless of an operation mode of the mobile station when the mobile station performs initial ranging upon restart of the base station. . In addition, Table 3b describes an example of a parameter for performing random backoff by differently applying a backoff window value according to an operation mode of a mobile terminal.

The base station sets the initial ranging backoff window size differently according to the operation mode of the mobile terminal in performing network entry through initial ranging of the mobile terminal after restarting the base station using the parameters as shown in Table 3b. Give priority to reentry. Through this, the mobile terminal in the normal operation state that exchanges service data with the base station can reconnect to the network faster than the mobile terminal in the sleep mode or the idle mode. In Table 3b, the size of the backoff window for the initial ranging is set differently according to the operation mode of the mobile terminal, but the backoff for the initial ranging according to the activated service type of the mobile terminal and the priority class of the mobile terminal. You can also set the window size differently.

One example of the parameter relates to giving a constant backoff window size when the terminal is operating in normal mode. However, the mobile terminal is provided with a service having various Quality of Service (QoS) before the base station performs restart. That is, the mobile terminal may be provided with a service requiring real time transmission or a service in which real time transmission is not important. If the mobile terminal was provided with a service requiring real time transmission before restarting the base station, it is necessary to enter the network more quickly after the restart of the base station.

That is, the size of the backoff window according to the restart of the base station may be set not only according to the operation mode of the mobile terminal, but also according to the type or property of the service received by the mobile terminal before restarting the base station.

Tables 3c and 3d show the initial backoff window size and final backoff window size for the backoff window sizes for the initial ranging in Tables 3a and 3b. An example is shown.

The mobile terminal receiving the parameters of Table 3a and Table 3b from the base station performs a random backoff by applying only the initial backoff window for initial ranging to the corresponding parameters. If the reception of the ranging response message fails, the exponentially increasing backoff window may be increased based on the backoff window parameters for initial ranging as shown in Table 1 above. That is, the mobile terminal uses the parameters shown in Tables 3a and 3b only at the initial initial ranging attempt, and then applies the backoff parameter values for the initial ranging as shown in Table 1, and then initially ranging random back. OFF can be performed.

When the mobile terminal receives the table 3c and the table 3d from the base station, even if the initial initial ranging random backoff value as well as exponentially increasing the backoff window based on the parameters of the table 3c and the table 3d Random backoff can be applied.

The parameters of Tables 3A to 3D are merely examples of the present invention, and specific numerical values used for the respective parameters are merely for explaining the present invention. Therefore, the present invention is not limited to the specific numerical values of the above-described parameters, and the specific numerical values described above may be freely converted. The type of operation mode described above may also be variously adjusted according to the intention of the service provider, and thus the present invention is not limited to the type of operation mode described above.

Examples of Tables 3b and 3d described above are examples in which specific backoff window values are assigned to mobile terminals operating in the sleep mode. However, since the sleep mode has various classes according to the characteristics of the sleep mode operation, it is preferable that parameters are determined in consideration of this point. That is, it is more preferable to set the back off window value differently depending on which class of sleep mode among sleep modes.

In addition, as described above, the size of the backoff window may be determined by considering only a specific mode, for example, a normal mode and a sleep mode.

Tables 4a to 4b below are examples of modifications of conventional parameters in accordance with the spirit of the present invention.

Name Type (1 byte) Length Value Initial_ranging_backoff_start 198 One A parameter for initial ranging performed due to restart of the base station. More specifically, it is a parameter that expresses the size of an initial backoff window for initial ranging as a power of two. (Initial backoff window size for initial ranging contention, expressed as a power of 2.) The displayed TLV (Type, Length and Value) is used to indicate the corresponding value displayed in the UCD message field in a NBR-ADV (Neighbor Advertisement Message) message. Used. If the base station performs the restart, the value should be changed to accommodate the mobile terminal that is already registered before the restart. (This TLV shall be used in NBR-ADV message only to represent corresponding values that appear in UCD message fields.In case of BS restart, this value should be changed to accommodate MSs which have been registered before.) Initial_ranging_backoff_end 199 One A parameter for initial ranging performed due to restart of the base station. More specifically, the size of the final backoff window for initial ranging (final backoff window) is a parameter expressed in the power of two. (Final backoff window size for initial ranging contention, expressed as a power of 2.) The displayed TLV (Type, Length and Value) is used to indicate the corresponding value displayed in the UCD message field in a NBR-ADV (Neighbor Advertisement Message) message. Used. If the base station performs the restart, the value should be changed to accommodate the mobile terminal that is already registered before the restart. (This TLV shall be used in NBR-ADV message only to represent corresponding values that appear in UCD message fields.In case of BS restart, this value should be changed to accommodate MSs which have been registered before.)

Name Type (1 byte) Length Value Initial_ranging_backoff_start 198 One A parameter for initial ranging performed due to restart of the base station. More specifically, it is a parameter that expresses the size of an initial backoff window for initial ranging as a power of two. (Initial backoff window size for initial ranging contention, expressed as a power of 2.) The indicated TLV (Type, Length and Value) is used to indicate the corresponding value indicated in the UCD message field in the NBR-ADV message. If the base station performs the restart, the parameter may consist of three parts as follows. (This TLV shall be used in NBR-ADV message only to represent corresponding values that appear in UCD message fields.In case of BS restart, this parameter consists of the following three parts.) Bit # 0 ~ Bit # 3: Normal mode Backoff window for normal mode Bit # 4 ~ Bit # 5: Backoff window for sleep mode, calculated as the square of the backoff window value for normal mode (Backoff window for sleep mode, which is calculated as a power of the value from bit # 0 to bit # 3.) Bit # 6 ~ Bit # 7: Back off window for non-work mode, but calculated as the square of the back off window value for normal mode ( Backoff window for idle mode, which is calculated as a power of the value from bit # 0 to bit # 3.) Initial_ranging_backoff_end 199 One A parameter for initial ranging performed due to restart of the base station. More specifically, the size of the final backoff window for initial ranging (final backoff window) is a parameter expressed in the power of two. (Final backoff window size for initial ranging contention, expressed as a power of 2.) The indicated TLV (Type, Length and Value) is used to indicate the corresponding value indicated in the UCD message field in the NBR-ADV message. If the base station performs the restart, the parameter may consist of three parts as follows. (This TLV shall be used in NBR-ADV message only to represent corresponding values that appear in UCD message fields.In case of BS restart, this parameter consists of the following three parts.) Bit # 0 ~ Bit # 3: Normal mode Backoff window for normal mode Bit # 4 ~ Bit # 5: Backoff window for sleep mode, calculated as the square of the backoff window value for normal mode (Backoff window for sleep mode, which is calculated as a power of the value from bit # 0 to bit # 3.) Bit # 6 ~ Bit # 7: Back off window for non-work mode, but calculated as the square of the back off window value for normal mode ( Backoff window for idle mode, which is calculated as a power of the value from bit # 0 to bit # 3.)

In Table 4a, when the base station is restarted, it is more preferable to set the initial ranging backoff window value for network reentry of previously registered mobile terminals to be larger than the normal value. Through these, collisions may be prevented during initial ranging of mobile terminals. Table 4b shows an example in which the initial ranging backoff parameter can be set to a different value according to an operation mode of mobile stations during initial ranging backoff due to a base station restart.

As described above, the parameters of Tables 4A to 4B are merely examples of the present invention, and specific numerical values used for the respective parameters are merely for explaining the present invention. Therefore, the present invention is not limited to the specific numerical values of the above-described parameters, and the specific numerical values described above may be freely converted.

Hereinafter, a method in which the mobile terminal reenters the network using the above-described parameters will be described.

4 is an example of a procedure flow diagram illustrating a method for a mobile station to re-enter upon restarting a base station. Hereinafter, a method of performing reentry into a network according to the above-described parameters will be described with reference to FIG. 4.

Hereinafter, step S401 will be described.

As described in the prior art, the mobile station (MS) performs an initial network entry procedure by applying a random backoff during initial ranging through an initial ranging backoff parameter of an uplink channel descriptor (UCD) message upon initial network entry. do. 4 shows an example in which the initial ranging backoff parameter is determined to be 8. After registering with the base station, by receiving the BS restart count (BS restart count) parameter of the downlink channel descriptor message, it is determined whether to perform the network entry procedure again.

Step S402 indicates that the base station is restarted due to power outage or maintenance.

Hereinafter, step S403 will be described.

The base station increases the base station restart count parameter value (BS restart count) of the downlink channel descriptor (DCD) message by 1 to the mobile station. In addition, when performing an initial network entry procedure of the mobile station, the mobile station transmits a backoff window value (set to 32 in FIG. 4) for initial ranging code transmission to the mobile station through an uplink message (UCD).

Hereinafter, step S404 will be described.

The mobile station receiving the downlink channel descriptor message parameter indicating that the base station restart count has been increased from the base station performs a network entry procedure. In this case, a random backoff value (10 in the example of FIG. 4) for initial ranging code transmission is determined based on the backoff window parameter value (32 in the example of FIG. 4) of the uplink channel descriptor message received from the base station. .

Hereinafter, step S405 will be described.

The mobile station receives uplink slot assignment information for initial ranging code transmission from an uplink map (UL-MAP) message from a base station and transmits an initial ranging code by applying a random backoff. For example, when the random backoff value is determined as 10, if six initial ranging slots are allocated to an uplink frame, the mobile station does not transmit the initial ranging code to the frame.

Hereinafter, step S406 will be described.

The mobile station receives the uplink map message from the base station and checks whether an initial ranging slot is allocated to the corresponding uplink frame.

Hereinafter, step S407 will be described.

The mobile station transmits an initial ranging code to a corresponding initial ranging slot by applying a random backoff value.

Hereinafter, step S408 will be described.

The base station receiving the initial ranging code from the mobile 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), and receives the mobile station. Adjusts an uplink transmission parameter. The mobile station and the base station may perform the 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 ( RNG-RSP) delivers the success code to the mobile station.

Hereinafter, step S409 will be described.

The base station provides a mobile station with a contention-free uplink resource through a specific uplink map information element (eg, CDMA Allocation UL-MAP IE) so that the mobile station can transmit a ranging request (RNG-REQ) message. The mobile station transmits a ranging request message including its MAC address using the allocated uplink resource.

Hereinafter, step S410 will be described.

Upon receiving the ranging request message from the mobile station, the base station transmits a ranging response message for allocating a basic connection identifier (CID) and a primary management connection identifier (CID) to the corresponding terminal.

Hereinafter, step S411 will be described.

After completing the ranging procedure, the mobile station and the base station perform procedures such as basic performance negotiation, authentication and key exchange, registration, and service flow setting as shown in S203 to S206 of FIG. 2.

Step S412 is as follows. The mobile station and the base station complete the network entry procedure and operate in the normal operation mode.

In the above process, when the base station maintains the information of the mobile terminals when the base station is restarted, it is possible to switch to the normal operation state by exchanging the information required in step S411 using the ranging message of step S409 and step S410. In this case, the message exchange procedure required in step S411 may be omitted.

In the above, an example of distinguishing the back off window value applied when the spontaneous network entry and the back off window value applied when the base station is restarted has been described.

Hereinafter, an embodiment of an operation for differently applying an initial ranging backoff window value according to an operation mode of a mobile terminal upon restart of a base station.

 5 is a flowchart illustrating a method of differently applying an initial ranging backoff window according to an operation mode. Hereinafter, a method of differently applying an initial ranging backoff window according to an operation mode will be described with reference to FIG. 5.

Hereinafter, step S501 will be described.

The mobile station performs an initial network entry procedure by applying random backoff during initial ranging through an initial ranging backoff parameter of an uplink channel descriptor (UCD) message upon initial network entry. After registering with the base station, by receiving the base station restart count parameter of the downlink channel descriptor (DCD) message, it is determined whether to perform the network entry procedure again. In the example of FIG. 5, the back off value is set to eight.

The base station is restarted due to a power failure or maintenance (S502).

Hereinafter, step S503 will be described.

The base station increases the BS restart count parameter value of the downlink channel descriptor (DCU) message by one to the mobile station. In addition, when performing an initial network entry procedure of the mobile station, the mobile station transmits a backoff window value for initial ranging code transmission to the mobile station through an uplink message. However, at this time, the base station may allow different backoff window parameter values to be applied according to the operation mode of the mobile station. In the example of FIG. 5, the backoff window value of the normal mode terminal is set to 12 and the backoff window value of the sleep mode terminal is set to 24.

Hereinafter, step S504 will be described.

The mobile station receiving the downlink channel descriptor message parameter indicating that the base station restart count has been increased from the base station performs a network entry procedure. At this time, a random backoff value for initial ranging code transmission is determined based on the backoff window parameter values of Tables 3a to 3d or Tables 4a to 4b of the uplink channel descriptor message received from the base station. If the backoff window value is given differently according to the operation mode, a random backoff value is set accordingly. If the backoff window parameter value for the mobile terminal in the normal operation mode is given as 12, the mobile terminal in the normal operation randomly determines the backoff value within 12 windows (decides to 5 in this embodiment), and moves to the sleep mode. When the backoff window parameter value for the terminal is 24, the mobile terminal in the sleep mode randomly determines the backoff value within the 24 windows (14 in this embodiment).

When eight initial ranging slots are allocated from the uplink map message (S505), the mobile station in the normal operation mode receiving the initial ranging slot is applied with a random backoff value of 5 to the sixth initial ranging slot of the corresponding uplink frame. The randomly selected initial ranging code is transmitted, and the sleep mode mobile terminal waits until the next initial ranging slot allocation is made (S506).

When eight initial ranging slots are allocated from an uplink map message (S507), the sleep mode mobile station applies a random backoff value of 14 to a randomly selected initial lane in the seventh initial ranging slot of the corresponding uplink frame. The gong code is transmitted (S508).

Hereinafter, step S509 will be described.

The mobile station in the normal operation mode that transmits the initial ranging code receives the ranging response message and, after adjusting the ranging parameter, receives the ranging response message after receiving the ranging request message to complete the initial ranging process.

Hereinafter, step S510 will be described.

The sleep mode mobile terminal which transmits the initial ranging code receives the ranging response message and, after adjusting the ranging parameter, receives the ranging response message after receiving the ranging request message to complete the initial ranging process.

Hereinafter, step S511 will be described.

After completing the ranging procedure, the mobile station and the base station in the normal operation mode perform procedures such as basic performance negotiation, authentication and key exchange, registration, and service flow setting as shown in S203 to S206 of FIG. 2.

Hereinafter, step S512 will be described.

The mobile station and the base station in the normal operation mode that has completed the ranging procedure perform procedures such as basic performance negotiation, authentication and key exchange, registration, and service flow setting as shown in S203 to S206 of FIG. 2.

Hereinafter, step S513 will be described.

Normal mode mobile station and base station complete network reentry procedure and operate in normal operation mode.

Hereinafter, step S514 will be described.

The sleep mode mobile station and the base station complete the network reentry procedure and operate in the normal operation mode. The mobile station can request the base station to switch to the sleep mode using a sleep request message or a sleep control header.

In the above process, when the base station maintains the information of the mobile stations when the base station is restarted, by switching the information required in step S511 or S512 using the ranging message of step S509 or S510, it can be switched to the normal operation state. . In this case, the message exchange procedure required in step S511 or S512 can be omitted.

Hereinafter, a method of providing a plurality of modes through separate signaling and controlling the backoff window value according to the modes will be described.

4 and 5 described above differently define a backoff window value for initial ranging performance of the mobile station when the base station restarts and a backoff window value for initial ranging performance applied when the mobile station voluntarily enters the network. It is about how to. That is, the examples of FIGS. 4 and 5 determine a backoff window value and provide it to the mobile terminal according to a specific situation in the network, and the mobile terminal operates according to the provided backoff window value.

However, the example described below provides information about a particular control mode through separate signaling. For example, when performing the initial ranging of the mobile station when the base station is restarted, the control mode is determined to be “1” and transmitted to the mobile station. In addition, when the initial ranging performance applied when the mobile terminal voluntarily enters the network is problematic, the control mode is determined to be “0” and transmitted to the mobile terminal.

The mobile terminal may determine the backoff window value by itself through the control mode. That is, when the control mode is determined to be "1" and is transmitted, it is possible to perform entry into the network by setting a relatively large backoff window value, and when the control mode is determined to be "0" and transmitted. In, the entry into the network can be performed by setting the backoff window value relatively small.

Through this operation, it is possible to reduce overhead between the network and the mobile terminal and to minimize network entry collisions between mobile terminals that may occur when the base station is restarted.

An example of applying the above-described control mode may be applied to an operation mode (eg, a normal mode, a sleep mode, or a sleep mode) of the mobile terminal. For example, different control modes are assigned according to the operation mode. That is, the mobile terminal operating in the normal mode informs the backoff window value to be set through the control mode value, the mobile terminal operating in the idle mode informs the backoff window value through the control mode value, The mobile terminal operating in the sleep mode may inform the backoff window value to be set through the control mode value.

In addition, the type of service provided by the mobile terminal may also be controlled by the control mode. For example, QoS information provided by a specific mobile terminal may be informed through the control mode value. That is, a specific first control mode value may be assigned to a terminal requiring a real time service, and a specific second control mode value may be assigned to a terminal that does not require a real time service. The mobile terminal may set a backoff window value suitable for itself through an assigned control mode value and attempt to re-enter the network.

The above-described operation mode may be variously selected, and each operation mode may be classified into various classes according to the characteristics of the operation mode.

Those skilled in the art through the above description can be seen that various changes and modifications can be made without departing from the spirit of the present invention. Therefore, the technical scope of the present invention is not limited to the contents described in the detailed description of the specification but by the claims.

The effects of the present invention are as follows.

Network entry between mobile terminals that may occur when the base station is restarted by differently defining the backoff window value for initial ranging of the mobile station when the base station restarts and the initial ranging backoff window value applied when the mobile station voluntarily enters the network. It has the effect of minimizing collision. In addition, when the initial ranging backoff due to the base station restart, the initial ranging backoff parameter may be set to a different value according to the operation modes of the mobile stations, thereby moving the normal operation mode according to the initial ranging backoff parameter setting value. The terminal makes the initial network entry faster than the sleep mode or idle mode terminal, and the base station has the effect of properly distributing the initial ranging attempts of the mobile terminals.

Claims (10)

A method for performing network entry in a wireless communication system, Receiving network reentry control information about a network entry time of the at least one mobile terminal, which is set to a specific value for reentry due to a restart of a base station; And Performing reentry into the network according to the received network reentry control information; Method of performing network entry in a wireless communication system comprising a. The method of claim 1, The network reentry control information is different from the network entry control information set for spontaneous network entry of the mobile terminal. Method of performing network entry in a wireless communication system, characterized in that. The method of claim 1, The network reentry control information is control information relating to a backoff window for initial ranging. The method of claim 1, The network entry time period included in the network reentry control information is later than the network entry control information set for spontaneous network entry of the mobile terminal. Method of performing network entry in a wireless communication system, characterized in that. The method of claim 1, The network re-entry control information is configured to accommodate at least one mobile terminal registered in the network before restarting the base station. Method of performing network entry in a wireless communication system, characterized in that. The method of claim 1, The section of the network entry point included in the network reentry control information is determined differently according to the operation mode of the mobile terminal. Method of performing network entry in a wireless communication system, characterized in that. The method of claim 6, The operation mode, Comprising at least one of normal mode, sleep mode, and idle mode Method of performing network entry in a wireless communication system, characterized in that. The method of claim 7, wherein The sleep mode is divided into a plurality of classes Characterized in that the network entry in the wireless communication system. The method of claim 6, The section of the network entry point included in the network reentry control information is determined differently according to the characteristics of the service provided by the mobile terminal. Characterized in that the network entry in the wireless communication system. A method for performing network entry in a wireless communication system, When re-registration of a specific first mobile terminal is required due to restart of a base station, Setting network re-entry control information about network entry time of at least one mobile terminal to a specific first value determined for re-registration due to the restart and transmitting it to the first mobile terminal; And Performing a re-registration procedure for the first mobile terminal attempting to enter a network based on the network re-entry control information; Method of performing network entry in a wireless communication system comprising a.

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