KR20110124179A - Apparatus and method for controlling entry of mobile station in broadband wireless communication system - Google Patents

Abstract

PURPOSE: A terminal entry control device and method thereof in a broadband wireless communication system are provided to prevent the performance of a connection procedure in the unnecessary entry. CONSTITUTION: A base station(120) determines weather to prohibit entry attempt of a terminal entry. The base station includes a timer value for inspecting time section to a MAC(Media Access Control) management message(105). The MAC management message is a ranging response message used as the response about the initial ranging request from the terminal.

Description

Terminal access control device and method in broadband wireless communication system {APPARATUS AND METHOD FOR CONTROLLING ENTRY OF MOBILE STATION IN BROADBAND WIRELESS COMMUNICATION SYSTEM}

The present invention relates to a broadband wireless communication system, and more particularly, to an apparatus and method for controlling a base station connection of a terminal in a broadband wireless communication system.

The 4th Generation (hereinafter referred to as '4G') communication system provides users with services of various quality of service (QoS) using a transmission rate of about 100 Mbps. There is active research going on. Particularly, in 4G communication systems, studies are being actively conducted to support high-speed services in a form of guaranteeing mobility and QoS in a broadband wireless access (BWA) communication system such as a wireless local area network system and a wireless urban area network system. Is going on. In addition, the representative communication system is the Institute of Electrical and Electronics Engineers (IEEE) 802.16 system.

The IEEE 802.16 system standard defines various procedures of the media access control (MAC) layer. For example, an initial ranging procedure and a handover procedure initiated by the terminal will be described as follows.

The initial ranging procedure according to the IEEE 802.16 system standard is performed as follows. First, the terminal transmits a ranging code of one of the ranging codes previously promised to the base station, and accordingly, the base station transmits a RNG-RSP (RaNGing ReSPonse) message to the terminal. In this case, the RNG_RSP message includes a ranging status TLV (ranging status Type Length Value). If the base station is in a state in which the ranging of the terminal, that is, the entry (entry) of the terminal is not allowed, the base station sets the ranging state TLV to 'abort', thereby informing the terminal of the ranging unacceptable state. . For this reason, the terminal recognizes that entry is not allowed, and then scans another base station.

The handover procedure according to the IEEE 802.16 system standard is performed as follows. When the terminal starts handover, the terminal scans the neighbor base stations and transmits a MOB_MSHO-REQ (MOBile_Mobile Station HandOver-REQuest) message to the serving base station, which includes information on the scanned neighbor base stations, that is, target base station candidate information. . Accordingly, the serving base station determines whether service support for the terminal is available for the target base station candidates included in the MOB_MSHO-REQ message received from the terminal, and then transmits a MOB_BSHO-RSP (MOBile_Base Station HandOver-ReSPonse) message to the terminal. . In this case, the MOB_BSHO-RSP message includes information of target base station candidates capable of handover. Upon receiving the MOB_BSHO-RSP message, the UE selects a target base station and transmits a MOB_HO-IND (MOBile_HandOver-INDication) message to inform the selected target base station to the serving base station. The base station confirming the target base station selected by the terminal provides information on the terminal to the target base station, the terminal performs the entry procedure to the target base station.

As described above, the base station may limit the entry of the terminal attempting initial ranging. However, the base station cannot prevent the terminal from immediately requesting access again, that is, retrying initial ranging. If the terminal immediately requests to access again, the situation of the base station will not change, so there is a high possibility that it will not be allowed again. Therefore, if the terminal immediately requests to access again, it causes a waste of radio resources. In addition, the terminal that changes the serving base station by performing the handover may attempt to handover to the previous serving base station again. Performing handover repeatedly for two base stations also causes waste of radio resources, and repeatedly attempting handover also wastes radio resources. Thus, there is a need for alternatives to prevent unnecessary entry attempts and performance of entry procedures.

Accordingly, an object of the present invention is to provide an apparatus and method for preventing unnecessary entry attempts and access procedures in a broadband wireless communication system.

Another object of the present invention is to provide an apparatus and method for prohibiting entry attempt of a specific terminal to a specific base station in a broadband wireless communication system.

It is still another object of the present invention to provide an apparatus and method for notifying an entry prohibition time of a specific base station of a specific terminal in a broadband wireless communication system.

According to a first aspect of the present invention for achieving the above object, a method of operating a base station in a broadband wireless communication system, a process for determining to prohibit the entry attempt of the terminal, and a MAC value including a timer value indicating prohibition of the entry attempt Generating a management message, and transmitting the MAC management message to the terminal.

According to a second aspect of the present invention for achieving the above object, a method of operating a terminal in a broadband wireless communication system, receiving a MAC management message from the base station and a timer value indicating prohibition of entry attempt included in the message; And confirming and setting an entry attempt prohibition for the base station until the timer expires.

According to a third aspect of the present invention for achieving the above object, the method of the present invention, the process of determining to prohibit the entry attempt of the terminal to the base station in the wireless communication system, the time for which entry to the MAC management message is prohibited And processing to include a timer value indicating a section.

Performing unnecessary entry attempts and entry procedures by limiting re-entry attempts using a parameter indicating that entry attempts are prohibited in initial ranging rejection and handover in a broadband wireless communication system This is avoided.

1 is a diagram illustrating an example of signal exchange during an initial ranging procedure in a broadband wireless communication system according to the present invention;
2 illustrates an example of signal exchange during a handover procedure in a broadband wireless communication system according to the present invention;
3 is a block diagram of a base station in a broadband wireless communication system according to an embodiment of the present invention;
4 is a block diagram of a terminal in a broadband wireless communication system according to an embodiment of the present invention;
5 is a diagram illustrating an operation procedure of a base station in a broadband wireless communication system according to an embodiment of the present invention;
6 is a diagram illustrating an operation procedure of a terminal in a broadband wireless communication system according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, the present invention describes a technique for preventing unnecessary entry attempts and performance of the access procedure in a broadband wireless communication system. Hereinafter, the present invention is referred to as Orthogonal Frequency Division Multiple Access (OFDMA). It will be described taking a wireless communication system of the type), and may be equally applied to other wireless communication systems.

In order to limit the entry attempt of the UE, the present invention defines a TLV (Type Length Value) for exchanging entry restriction timer information as shown in Table 1 below. The TLV defined in the present invention includes various Media Access Control (MAC) management messages, for example, a RNG-RSP (RaNGing-ReSPonse) message, a BSHO-REQ (Base Station HandOver-REQuest) message, and a BSHO-RSP (Base Station). It may be included in a HandOver-ReSPonse) message. However, the above-listed messages are just an example, and the TLV for exchanging the entry limit timer information according to the present invention may be included in another message not mentioned in the present invention.

Type

Length
Value
Scope
xx
One
0-255: In units of 100 milliseconds RNG-RSP
BSHO-REQ
BSHO-RSP

As shown in Table 1, the TLV for limiting the entry of the terminal according to the present invention indicates a timer value. For example, the length of the TLV is 1 byte, the value represents a time in units of 100 milliseconds, and when the value is 0, the entry time limit is infinite. However, the above-described data length and unit are merely examples, and the data length and unit of the TLV for exchanging the entry limit timer information according to the present invention may be set to a size not mentioned in the present invention. For convenience of the following description, the present invention refers to the TLV as shown in Table 1 as the entry limit timer TLV.

In the case of using the entry limit timer TLV according to the present invention, a signal exchange between a base station and a terminal according to an initial ranging procedure is described as follows. 1 illustrates an example of signal exchange during an initial ranging procedure in a broadband wireless communication system according to the present invention.

Referring to FIG. 1, the terminal 110 transmits a ranging request message (eg, a RNG-REQuest (RNG-REQuest) message) to the base station 120 to enter a network (step 101).

Upon receiving the ranging request message (eg, the RNG-REQ message), the base station 120 recognizes that the terminal 110 wants to connect to itself and determines whether to allow entry. As a result of the determination of admission, the base station 120 determines that it is not allowed to enter the mobile station (step 103). For example, the base station 120 determines that the terminal 110 cannot be allowed to enter due to lack of resources or service unavailable.

Accordingly, the base station 120 transmits a ranging response message (eg, an RNG-RSP message) including the entry limit timer TLV to the terminal 110 (step 105). That is, the base station 120 determines a ranging status TLV (for example, a ranging status TLV set to 'abort') for informing that the base station 120 rejects the entry to the base station 120 and the entry to the base station 120 for a predetermined time. A ranging response message (eg, an RNS-RSP message) including an entry limit timer TLV for notifying is transmitted. Here, the entry limit timer TLV includes time information for prohibiting entry. In this case, the base station may include a downlink frequency override TLV in the ranging response message (eg, an RNG-RSP message). The downlink frequency override TLV is for inducing an entry request through another frequency allocation (FA) to the terminal and includes information of another FA recommended for the terminal.

Upon receiving the ranging response message (eg, RNG-RSP message) including the entry limit timer TLV, the terminal 110 recognizes that its own entry request has been rejected, and at the same time, checks the entry limit timer TLV for a predetermined time. In step 107, it is recognized that an attempt to enter the base station 120 is prohibited during the time.

Subsequently, the terminal 110 scans other accessible base stations without attempting to enter the base station 120 for a predetermined time (step 109). If the ranging response message (eg, an RNG-RSP message) includes the downlink frequency override TLV, the terminal 110 is assigned to another FA, that is, an FA indicated by the downlink frequency override TLV. Scan for accessible base stations. On the other hand, when the downlink frequency override TLV is not included in the RNG-RSP message, the terminal 110 scans a base station accessible by the same FA.

After the process shown in FIG. 1, the terminal 110 performs a network entry procedure again after scanning in step 109. In this case, even if the base station 120 is determined to be the most appropriate, that is, the base station having the best channel state, the terminal 110 returns to the base station 120 if the predetermined time determined in step 107 has not elapsed. Does not attempt to enter.

In the case of using the entry limit timer TLV according to the present invention, a signal exchange between a base station and a terminal according to a handover procedure will be described as follows. 2 illustrates an example of signal exchange in a handover procedure in a broadband wireless communication system according to the present invention.

Referring to FIG. 2, the terminal 210 transmits a handover request message (eg, a MOB_MSHO-REQ message) to the serving base station 220 to perform a handover to a neighbor base station (step 201). Here, the handover request message (eg MOB_MSHO-REQ message) includes the target base station 230 information.

The serving base station 220 receiving the handover request message (eg MOB_MSHO-REQ message) transmits a handover notification message (eg HO_pre_notification (HandOver_pre_notification) message) to the target base station 230 (step 203). . The handover notification message (eg, HO_pre_notificiaton message) is a message for confirming whether the terminal 210 can accept the entry.

Upon receiving the handover notification message (eg HO_pre_notification message), the target base station 230 determines that it can accept the entry of the terminal 210 and informs of the handover notification response message (eg HO_pre_notification-RSP). (HandOver_pre_notification-ReSPonse) message) (S205).

The serving base station 220 receiving the handover notification response message (eg HO_pre_notification-RSP message) transmits a handover response message (eg MOB_BSHO-RSP message) including an entry restriction timer TLV (step 207). . That is, the serving base station 220 includes the information of the target base station 230 responding that the entry of the terminal 210 is acceptable and the entry limit timer TLV for notifying the entry to the self for a predetermined time. Sends a handover response message (eg MOB_BSHO-RSP message).

Upon receiving the handover response message (eg, the MOB_BSHO-RSP message), the terminal 210 recognizes that the target base station 230 can accept its entry, and at the same time, checks the entry limit timer TLV. As a result, it is recognized that an attempt to enter the serving base station 220 is prohibited for a predetermined time (step 209).

Subsequently, the terminal 210 that determines the handover to the target base station 230 transmits a handover indication message (eg, a MOB_HO-IND message) to inform the target base station 230 that handover is to be performed. (Step 211).

The serving base station 220 receiving the handover indication message (eg, a MOB_HO-IND message) provides the target base station 230 with information of the terminal 210 (step 213). For example, the information of the terminal 210 is meant to include service information being used, capability information of the terminal 210, and the like.

Thereafter, the terminal 210 and the target base station 230 exchange initial messages for the access procedure and perform initial access (step 215).

After the process shown in FIG. 2, even if the terminal 210 determines the handover to the serving base station 220, if the predetermined time determined in step 209 has not elapsed, the terminal 210 returns to the serving base station 220. Handover, i.e., does not attempt to enter. In other words, if the predetermined time has not elapsed, the terminal 210 stops handover to the serving base station 220.

In FIG. 2, only one target base station is shown as a target base station candidate, but this is for convenience of description, and there may be a plurality of target base station candidates.

Hereinafter, the present invention will be described in detail with reference to the drawings the configuration and operation of the base station and the terminal for limiting the entry as described above.

3 is a block diagram of a base station in a broadband wireless communication system according to an exemplary embodiment of the present invention.

As shown in FIG. 3, the base station includes a radio frequency (RF) receiver 302, an OFDM demodulator 304, a subcarrier demapper 306, a symbol demodulator 308, a decoder 310, and ranging. Code detector 312, message interpreter 314, MAC controller 316, message generator 318, encoder 320, symbol modulator 322, subcarrier mapper 324, OFDM modulator 326, RF transmitter And 328.

The RF receiver 302 downconverts an RF band signal received through an antenna to a baseband signal. The OFDM demodulator 304 divides the signal provided from the RF receiver 302 in OFDM symbol units, removes a CP, and restores complex symbols mapped to a frequency domain through a fast fourier transform (FFT) operation. . The subcarrier dimapper 306 extracts complex symbols mapped to a frequency domain in a processing unit. For example, the subcarrier dimapper 306 extracts signals mapped to a ranging subcarrier and provides the ranging code detector 312 to the ranging code detector 312. The symbol demodulator 308 demodulates the complex symbols into a bit string. The decoder 310 restores the information bit stream by channel decoding the bit stream.

The ranging code detector 312 detects the ranging code transmitted by the terminal. That is, the ranging code detector 312 correlates the signals mapped to the ranging subcarriers with predetermined ranging codes to detect which ranging code is transmitted.

The message interpreter 312 interprets the MAC management message received from the terminal. For example, the message interpreter 312 identifies the terminal to enter the network by interpreting a ranging request message (eg, RNG-REQ message) for the network entry of the terminal. Also, the message interpreter 312 checks candidate target base stations by interpreting a handover request message (eg, a MOB_MSHO-REQ message) for a handover request of the terminal, and handovers including target base station information determined by the terminal. The target base station to which the information of the terminal should be provided is identified by interpreting an indication message (eg, a MOB_HO-IND message).

The MAC controller 316 controls the overall function of the MAC layer of the base station. For example, upon initial ranging attempt of the terminal, the MAC controller 316 determines whether the terminal is allowed to enter based on radio resource margin and service availability. In addition, when requesting a handover of the terminal, the MAC controller 316 controls to determine whether the terminal can accept the handover.

In particular, according to the present invention, the MAC controller 316 determines that the entry attempt of the terminal is to be prohibited. Here, the entry means access of a base station by initial ranging or handover. That is, when denying entry to itself through initial ranging of the terminal, the MAC controller 316 prohibits entry attempt to the terminal for a predetermined time from the entry denied entry. In addition, when the terminal performs the handover to the neighboring base station, the MAC controller 316 prohibits the terminal performing the handover to enter the terminal for a predetermined time, that is, the handover attempt to the terminal.

The message generator 318 generates a MAC management message transmitted to the terminal. For example, the message generator 318 may include a ranging response message (eg, RNG-RSP message) in response to a ranging attempt of the terminal, and a handover response message (eg, MOB_BSHO) in response to a handover request of the terminal. -RSP message), and generates a handover request message (eg MOB-BSHO-REQ message) for requesting a handover to the terminal. In particular, in accordance with the present invention, the message generator 318 generates a MAC management message that includes a parameter indicating prohibition of an attempt to enter itself for a predetermined time, i.e., the entry limit timer TLV. Here, the entry means entry through initial ranging or handover. For example, the entry limit timer TLV may include the ranging response message (eg, RNG-RSP message), the handover response message (eg, MOB_BSHO-RSP message), and the handover request message (eg, MOB_BSHO-REQ message). ) And the like, and are configured as shown in Table 1 above. When the MAC management message is a ranging response message (eg, RNG-RSP message), the ranging response message (eg, RNG-RSP message) may include the entry limit timer TLV, a parameter indicating entry rejection, and another entry recommending entry. It includes at least one of the parameters for informing the FA. Further, when the MAC management message is the handover response message (eg MOB_BSHO-RSP message) or the handover request message (eg MOB_BSHO-REQ message), the handover response message (eg MOB_BSHO-RSP message) Alternatively, the handover request message (eg, a MOB_BSHO-REQ message) includes at least one of the entry limit timer TLV and information of a target base station candidate that can accommodate the handover.

The encoder 320 performs channel coding on the information bit stream. The symbol modulator 322 demodulates the channel-coded bit string and converts the result into complex symbols. The subcarrier mapper 324 maps the complex symbols to the frequency domain. The OFDM modulator 326 converts complex symbols mapped to the frequency domain into a time domain signal through an inverse fast fourier transform (IFFT) operation, and configures an OFDM symbol by inserting a CP. The RF transmitter 328 up-converts the baseband signal into an RF band signal and transmits it through an antenna.

4 is a block diagram of a terminal in a broadband wireless communication system according to an exemplary embodiment of the present invention.

As shown in FIG. 4, the terminal includes an RF receiver 402, an OFDM demodulator 404, a subcarrier demapper 406, a symbol demodulator 408, a decoder 410, and a signal strength meter 412. Message interpreter 414, MAC controller 416, message generator 418, encoder 420, symbol modulator 422, subcarrier mapper 424, OFDM modulator 426, RF transmitter 428 It is configured by.

The RF receiver 402 down-converts an RF band signal received through an antenna to a baseband signal. The OFDM demodulator 404 divides the signal provided from the RF receiver 402 in OFDM symbol units, removes a CP, and restores complex symbols mapped to a frequency domain through an FFT operation. The subcarrier dimapper 406 extracts complex symbols mapped to a frequency domain in a processing unit. For example, when scanning a base station for network entry or handover, the subcarrier demapper 406 extracts a signal for scanning, for example, a preamble signal, and provides the signal to the signal strength meter 412. The symbol demodulator 408 demodulates the complex symbols into a bit string. The decoder 410 restores the information bit stream by channel decoding the bit stream.

The signal strength meter 412 measures the received signal strength from the base station. For example, the received signal strength may be represented by Received Signal Strength Indication (RSSI), Signal to Noise Ratio (SNR), Signal to Interference and Noise Ratio (SINR), Carrier to Interference and Noise Ratio (CINR), and the like. .

The message interpreter 412 interprets the MAC management message received from the base station. For example, the message interpreter 412 checks whether the initial ranging is allowed by interpreting a ranging message (eg, an RNG-RSP message) that is a response to the initial ranging attempt, and the response to the handover request. A handover request message (eg, a MOB-BSHO-REQ message) for identifying a target base station capable of accepting a handover by interpreting a handover response message (eg, a MOB_BSHO-RSP message) and requesting handover to the terminal. Identify the target base station acceptable for handover by interpreting In particular, according to the present invention, the message interpreter 412 checks a parameter indicating prohibition of an attempt to enter the base station for a predetermined time, that is, the entry limit timer TLV. Here, the entry means access of a base station by initial ranging or handover. For example, the entry limit timer TLV may include the ranging response message (eg, RNG-RSP message), the handover response message (eg, MOB_BSHO-RSP message), and the handover request message (eg, MOB_BSHO-REQ message). ) And the like, and are configured as shown in Table 1 above.

The MAC controller 416 controls the overall function of the MAC layer of the terminal. For example, upon initial ranging attempt of the terminal, the MAC controller 416 controls to generate and transmit a ranging request message (eg, an RNG-REQ message). In addition, upon handover request, the MAC controller 416 controls to generate and transmit a handover request message (eg, a MOB_MSHO-REQ message) including information on the collected target base station candidates. The MAC controller 416 controls the operation of the terminal according to ranging permission information included in a ranging response message (eg, an RNG-RSP message) that is a response to the initial ranging attempt. For example, if entry into the base station through the initial ranging is denied, the MAC controller 416 controls to scan another base station for network entry. In addition, the MAC controller 416 controls the operation of the terminal according to the target base station candidate information that can accommodate the handover included in the handover response message (eg, MOB_BSHO-RSP message) that is a response to the handover request. That is, the MAC controller 416 selects one target base station among target base station candidates that can accept the handover, and controls to transmit a handover indication message (eg, a MOB_HO-IND message) for informing it.

Particularly, according to the present invention, when the entry limit timer TLV included in the received MAC management message is confirmed, the MAC controller 416 may perform a predetermined time indicated by the entry prohibition timer TLV, that is, an expiration time of the timer. Until the access to the base station transmitting the MAC management message is prohibited. For example, when the ranging response message (eg, RNG-RSP message) includes an entry limit timer TLV, the MAC controller 416 performs the ranging response message (eg, RNG-RSP message) for a predetermined time. Attempt to enter the base station that transmits the signal, that is, the initial ranging attempt is prohibited. That is, when the base station that has transmitted the ranging response message is selected again as a result of scanning the base stations for network entry, the MAC controller 416 determines that the base station has transmitted the ranging response message if the predetermined time has not elapsed. The other base stations are controlled to attempt initial ranging to one base station. In addition, when the handover response message (eg MOB_BSHO-RSP message) or a handover request message (eg MOB_BSHO-REQ message) includes an entry limit timer TLV, the MAC controller 416 performs the hand for a predetermined time. Attempt to enter the base station that transmitted the over response message (eg MOB_BSHO-RSP), that is, handover attempt is prohibited.

The message generator 418 generates a MAC management message sent to the base station. For example, the message generator 418 may include a handover request message (eg, a MOB_MSHO-REQ message) for a handover request, a handover indication message (eg, a MOB_HO-IND message) including the determined target base station information, and an initial message. Generate a ranging request message (eg, RNG-REQ message) for ranging.

The encoder 420 channel-codes the information bit stream. The symbol modulator 422 demodulates the channel-coded bit string and converts the result into complex symbols. The subcarrier mapper 424 maps the complex symbols to the frequency domain. The OFDM modulator 426 converts complex symbols mapped to the frequency domain into a time domain signal through an IFFT operation, and configures an OFDM symbol by inserting a CP. The RF transmitter 428 up-converts the baseband signal into an RF band signal and transmits it through an antenna.

5 is a flowchart illustrating an operation procedure of a base station in a broadband wireless communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 5, in step 501, the base station determines whether the terminal performs handover to an adjacent base station or whether the terminal is denied initial network entry. Specifically, during handover of the terminal, the base station determines whether at least one target base station candidate among target base station candidates can accept the handover of the terminal. Alternatively, when an entry request of a terminal through initial ranging occurs, the base station determines whether entry is denied due to lack of resources or service unavailable.

If the terminal performs a handover to the neighboring base station or if the terminal is denied initial entry, the base station determines to prohibit entry into the terminal for a predetermined time in step 503. Here, the entry means access of a base station by initial ranging or handover. In this case, the length of the predetermined time depends on the specific embodiment. For example, the predetermined time length may be used as a predetermined length.

After determining that the terminal tries to prohibit an entry attempt, the base station proceeds to step 505 and generates a MAC management message including a parameter indicating that the entry attempt is prohibited, that is, an entry limit timer TLV. For example, the entry limit timer TLV may be included in a ranging response message (eg RNG-RSP message), a handover response message (eg MOB_BSHO-RSP message), a handover request message (eg MOB_BSHO-REQ message), and the like. It can be, and is configured as shown in Table 1 above. If the MAC management message is a ranging response message (eg, RNG-RSP message), the ranging response message (eg, RNG-RSP message) is a parameter (eg, entry limit timer TLV) indicating entry prohibition time, entry. And at least one of a parameter indicating rejection (for example, ranging state TLV) and a parameter for informing other FAs (for example, downlink frequency override TLV). In addition, when the MAC management message is the handover response message (eg MOB_BSHO-RSP message) or the MOB_BSHO-REQ message, the handover response message (eg MOB_BSHO-RSP message) or the handover request message (eg The MOB_BSHO-REQ message includes at least one of a parameter (eg, entry limit timer TLV) indicating the entry prohibition time and information of a target base station candidate capable of accommodating handover.

In step 507, the base station transmits the MAC management message generated in step 505 to the terminal.

6 is a flowchart illustrating an operation procedure of a terminal in a broadband wireless communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 6, the terminal determines whether a MAC management message is received from the base station in step 601.

When the MAC management message is received, the terminal proceeds to step 603 and interprets the MAC management message to determine whether a parameter indicating to prohibit an entry attempt, that is, an entry restriction timer TLV is included. Here, the entry means access of a base station by initial ranging or handover. For example, the entry limit timer TLV may be included in a ranging response message (eg RNG-RSP message), a handover response message (eg MOB_BSHO-RSP message), a handover request message (eg MOB_BSHO-REQ message), and the like. It can be, and is configured as shown in Table 1 above. That is, the terminal interprets the ranging response message (eg RNG-RSP message), the handover response message (eg MOB_BSHO-RSP message) or the handover request message (eg MOB_BSHO-REQ message), Check the entry limit timer TLV. If the entry limit timer TLV is not included, the terminal proceeds to step 607.

On the other hand, if the entry limit timer TLV is included, the terminal proceeds to step 605 to the base station transmitting the MAC management message for a predetermined time indicated by the entry limit timer TLV, that is, until the timer expires. Set to prohibit entry attempt of. For this reason, the terminal, even if the base station is selected as the optimal base station as a result of scanning for network entry, or the base station is selected as the optimal base station as a result of scanning for handover, if the predetermined time has not elapsed, the mobile station returns to the base station. Shall not attempt entry.

In step 607, the terminal performs an operation of the MAC layer according to the received MAC management message. For example, when the MAC management message is a ranging response message (eg, an RNG-RSP message) and the ranging state TLV is set to 'abort', the terminal scans a base station for network entry. Alternatively, when the MAC management message is a handover response message (eg MOB_BSHO-RSP message) or a handover request message (eg MOB_BSHO-REQ message), the terminal selects a target base station to handover to a serving base station. The information of the selected target base station is transmitted.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

Claims (24)

Determining that the entry attempt of the terminal to the base station is prohibited in the wireless communication system;
And processing a timer value indicating a time interval for which entry is prohibited in a media access control (MAC) management message. The method of claim 1,
The entry is one of initial ranging and handover. The method of claim 2,
The MAC management message is a ranging response message used as a response to the initial ranging request from the terminal. The method of claim 3,
And the ranging response message includes a ranging state indicating acceptance or rejection of the initial ranging request. The method of claim 3,
The ranging response message includes a frequency allocation indicating a different frequency band to which entry is recommended. The method of claim 2,
The MAC management message is a handover response message used as a response to the scanning of at least one target base station for handover of the terminal. The method of claim 6,
The handover response message includes information on at least one target base station candidate capable of accepting handover of the terminal. The method of claim 2,
The MAC management message is a handover request message for instructing the terminal to perform a handover to a target base station. The method of claim 1,
The process of processing the MAC management message,
And the terminal receiving the MAC management message from the base station. 10. The method of claim 9,
And stopping the attempt of initial ranging to the base station after the time interval expires after the initial ranging to the base station is rejected. 10. The method of claim 9,
And stopping the handover attempt to the base station until the time interval expires. The method of claim 1,
The process of processing the MAC management message,
And transmitting, by the base station, the MAC management message to the terminal. The method of claim 12,
The process of processing the MAC management message,
After the initial entry is rejected by the base station, transmitting the timer value to the terminal to inhibit the initial ranging attempt of the terminal until the time interval indicated by the timer value expires. Characterized in that. The method of claim 12,
The process of processing the MAC management message,
After the start of the handover, transmitting the timer value to the terminal to prohibit a handover attempt of the terminal to the base station until the time interval indicated by the timer value expires. . A method of operating a base station in a broadband wireless communication system,
Determining that the entry attempt of the terminal is to be prohibited;
Generating a media access control (MAC) management message including a timer value indicating prohibition of entry attempt;
Transmitting the MAC management message to the terminal. 16. The method of claim 15,
The timer may indicate a time duration for prohibiting the terminal from attempting to enter the network. The method of claim 16,
The process of determining to prohibit the entry attempt of the terminal,
If the entry through the initial ranging (initial ranging) of the terminal is denied, determining that the entry attempt of the terminal is prohibited;
The MAC management message is a ranging response message including at least one of the timer value, a parameter for notifying the entry rejection and a parameter for notifying other frequency allocation (FA) for the entry. The method of claim 16,
The process of determining to prohibit the entry attempt of the terminal,
If the terminal is to perform a handover (handover) to the neighbor base station, determining that the entry attempt of the terminal is prohibited,
And the MAC management message is a handover response message including at least one of the timer value and information of a target base station candidate capable of accepting handover. The method of claim 16,
The process of determining to prohibit the entry attempt of the terminal,
When requesting a handover (handover) to the neighboring base station to the terminal, comprising the step of determining to prohibit the entry attempt of the terminal,
The MAC management message is a handover request message comprising the timer value. In the method of operating a terminal in a broadband wireless communication system,
Receiving a media access control (MAC) management message from a base station;
Checking a timer value indicating prohibition of entry attempt included in the message;
And setting an entry attempt prohibition for the base station until the timer expires. The method of claim 20,
The timer may indicate a time duration for prohibiting the terminal from attempting to enter the network. The method of claim 21,
The MAC management message is a ranging response message received as a response to a ranging code transmission for initial ranging.
If the base station which has transmitted the ranging response message is selected as a result of scanning the base stations for network entry, if the timer has not expired, stopping the entry to the base station. The method of claim 21,
The MAC management message is a handover response message received as a response to a handover request.
If the handover to the base station is determined, if the timer has not expired, stopping the handover to the base station. The method of claim 21,
The MAC management message is a handover request message indicating a handover request by a base station.
If the handover to the base station is determined, if the timer has not expired, stopping the handover to the base station.

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