KR20050071329A - Method to evade collision between access terminals by double allocating uati - Google Patents

Abstract

The present invention provides a mobile communication system having an access network (AN) and at least one access terminal (AT), wherein a first access terminal is assigned an access terminal identifier and a first time identifier from the access network. Initializing a connection terminal identifier database of the access network, requesting a data service from the access network using the access terminal identifier and the second time identifier, and accessing the access network; Broadcasting a session release message including the access terminal identifier and the second time identifier to the at least one access terminal, and the first access terminal releasing the session and initializing the access terminal identifier and the first time identifier. Concerning the collision avoidance method between access terminals comprising a, the same There is an effect that can prevent collision between access terminals due to one UATI allocation.

Description

Method for avoiding collision between access terminals due to duplicate assignment of unicast access terminal identifiers {Method to Evade Collision between Access Terminals by Double Allocating UATI}

The present invention relates to a collision avoidance method between access terminals (AT) due to unicast access terminal identifier (UATI) duplication allocation, and more particularly, to an access network. When the (Access Network; hereinafter 'AN') is restarted, the present invention relates to a method for preventing collisions between ATs that may occur due to duplicate allocation of UATI.

The AN of the mobile communication system allocates UATI for each AT to distinguish each authenticated AT. At this time, when a part of allocating and managing the UATI in the AN is restarted while the first AT assigned the UATI releases the service, all the UATI information of the AN is initialized. And, the same UATI as the UATI allocated to the first AT before restarting may be allocated to the second AT. If the first AT attempts to use the same UATI while the second AT is receiving data service using its assigned UATI, the AN may collide with the UATI of the first AT and the second AT. The first AT and request the service release.

However, at this point, since a traffic channel has not been allocated yet, a service release message including the same UATI is transmitted to both the first AT and the second AT through the control channel. Therefore, neither the first AT nor the second AT can receive the service using the UATI for a predetermined time.

In addition, if a separate hard disk drive (HDD) is added to each base station controller (BSC) of the AN, the cost of the system increases, and the processor and HDD responsible for assigning and managing the UATI of the AN There is a problem in that an additional interface needs to be established, and additional processing time is required for allocating a UATI to a separate HDD and storing and managing a result value at the request of each AT.

1 is a flowchart illustrating an UATI allocation method according to the prior art. As shown in FIG. 1, according to the prior art, the first AT transmits to the AN including a first Random Access Terminal Identifer (RATI) in a UATI request message for a data service request ( S111).

Then, the AN allocates the UATI to the first AT in response to the UATI request message of the first AT (S112), and the first AT stores the allocated UATI in its memory area (S113).

The first AN assigned the UATI receives data service from the AT (S114). After the data service ends, if the AN restart occurs (S115), the UATI database is initialized. After the UATI database of the AN is initialized, the second AT transmits a UATI request message including the second RATI to the AN in order to request data service (S116). Then, the AN allocates the UATI to the second AT in response to the UATI request message of the second AT (S117), and the second AT stores the UATI received from the AN in its memory area (S118). . The second AT receives data service from the AN using the allocated UATI (S119).

In this case, the UATI assigned to the second AT may be the same as the UATI assigned to the first AT prior to restarting the AN. Then, the following problem occurs. That is, before the AN is restarted, the first AT, which has been assigned the UATI from the AN, transmits the UATI including the allocated UATI in the connection request message (S120). At this time, since the UATI assigned by the first AT is the same as the UATI assigned by the second AT, a collision occurs between the UATIs in the AN.

When the AN detecting the collision transmits a session close message including a UATI through a control channel (S121), all sessions of the first AT and the second AT are released. On the other hand, since the UATI values of the first AT and the second AT are the same, there is a problem that a continuous collision occurs even after the session is released.

The present invention has been proposed to solve the above problems, and when a collision occurs between ATs using the same UATI, the AT releases a session release message including the UATI and a time identifier to the ATs. The goal is to provide a way to prevent collisions.

According to an aspect of the present invention, there is provided a collision avoidance method between an access network (AN) and an access terminal applied to a mobile communication system having at least one access terminal (AT). Receiving, by the access network, a service connection request message including an access terminal identifier and a time identifier from the access terminal, comparing time information of the received time identifier with a reset time of the access network; and As a result of the comparison, when the time information is earlier than the restart time, the method may include broadcasting a message including the access terminal identifier and the time identifier to the at least one access terminal.

The present invention also provides a collision avoidance method between an access network (AN) and an access terminal applied to a mobile communication system having at least one access terminal (AT), wherein the access network is a first access terminal. Receiving a service connection request message including an access terminal identifier and a first time identifier from the terminal, and checking whether there is a second access terminal using the same access terminal identifier as the received access terminal identifier; Comparing the time information of the first time identifier with the reset time of the access network when the second access terminal exists, and when the time information is earlier than the restart time as a result of the comparison, At least one message including an access terminal identifier and the first time identifier of the first access terminal It comprises the step of broadcasting (broadcasting) for the access terminal.

In addition, the present invention provides a collision avoidance method between an access network (AN) and an access terminal applied to a mobile communication system having at least one access terminal (AT), wherein the access network is connected from the access terminal. Receiving a service connection request message including an access terminal identifier and a time identifier, comparing time information of the received time identifier with a current system time of the access network, and as a result of the comparison, the time information Comparing the time information with a reset time of the access network when it is earlier than the system time of the access network, and when the time information is earlier than the restart time as a result of the comparison, the access terminal identifier and the Recall a Session Close Message containing a time identifier. At least one broadcast terminal (broadcating) is performed comprising the steps.

The present invention also provides a collision avoidance method between an access network (AN) and an access terminal applied to a mobile communication system having at least one access terminal (AT), wherein the access network is a first access terminal. Receiving a service connection request message including an access terminal identifier and a first time identifier from the server, comparing time information of the received time identifier with a current system time of the access network, and as a result of the comparison, If the information is earlier than the system time of the access network, checking whether there is a second access terminal using the same access terminal identifier as the received access terminal identifier, and if the second access terminal is present In this case, the time information of the first time identifier and the reset time of the access network are determined. At least one session close message including an access terminal identifier of the first access terminal and the first time identifier when the time information is earlier than the restart time. Broadcasting to the access terminals (broadcasting) is made.

The present invention provides a collision avoidance method between an access terminal applied to a mobile communication system having an access network (AN) and at least one access terminal (AT), wherein the access terminal is connected to the access network. Receiving a session release message including an access terminal identifier and a time identifier, comparing the received access terminal identifier with an access terminal identifier of the access terminal, and if the comparison result is the same, the received time identifier Comparing with the time identifier of the access terminal and if the comparison result is the same, initializing the access terminal identifier and time identifier of the access terminal.

Meanwhile, the present invention provides a collision avoidance method between an access terminal applied to a mobile communication system having an access network (AN) and at least one access terminal (AT), wherein the first access terminal is the access network. Assigning an access terminal identifier and a first time identifier from the terminal; initializing an access terminal identifier database of the access network; and a second access terminal using the access terminal identifier and the second time identifier. Requesting a data service to the server; broadcasting, by the access network, a session release message including the access terminal identifier and the second time identifier to the at least one access terminal; and the first access terminal releases the session; And initializing the access terminal identifier and the first time identifier. .

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a flowchart illustrating a method for allocating a unicast access terminal identifier (hereinafter, referred to as 'UATI') according to the present invention.

As shown in FIG. 2, the first AT transmits a UATI request message to the AN for a service request (S211). Meanwhile, the AN allocates the UATI and the time identifier in response to the UATI request message of the first AT and transmits the UATI and the time identifier to the first AT (S212). The time identifier includes information on the time when the UATI is allocated, and may include time information up to days, hours, minutes, and seconds.

The first AT stores the UATI and the time identifier transmitted from the AN as a pair in its memory (S213). In this case, the memory may be stored in a non-volatile memory, electrically programmable read only memory (EEPROM), so that information is not lost even when the AT is turned off.

On the other hand, when the first AT terminates one service and later requests the service again, the assigned UATI and time identifier pair are used. When the first AT receives the service from the AN using the allocated UATI and time identifier pair (S214), and the AN restarts after the service is terminated (S215), the UATI database of the AN is initialized.

After the AN is restarted, the second AT transmits to the AN including the second RATI in the UATI request message for the service request (S216). Meanwhile, the AN allocates a UATI and a time identifier in response to the UATI request message of the second AT and transmits the UATI and the time identifier to the second AT (S217). The time identifier includes information on the time when the UATI is allocated, and may include time information up to days, hours, minutes, and seconds. The second AT stores the UATI and the time identifier transmitted from the AN as a pair in its memory (S218). The second AT receives a service from the AN using the UATI and the time identifier pair allocated thereto (S219).

In order to receive the service from the AN, the first AT previously assigned the UATI from the AN transmits a connection request message including a UATI and a time identifier pair to the AT (S220).

In this case, the UATI assigned to the second AT may be the same as that assigned to the first AT. That is, since the UATI assigned to the second AT is newly allocated after the AN's UATI database is initialized, the AN does not know that the same UATI has already been assigned to the first AT, and thus duplicates the allocation to the second AT. Can be. Therefore, when the first AT requests a service using the UATI allocated before the database initialization of the AN, the first AT causes a collision with the UATI of the second AT.

As described above, when two or more ATs having the same UATI collide with each other, the AT may be identified using the time identifier. Meanwhile, the initialization of the UATI and the time identifier may be requested for broadcasts other than one of the ATs having the same UATI through broadcast control through a control channel.

As shown in FIG. 2, the AN transmits a session close message including a UATI and a time identifier to each AT (S221). The first AT then compares the UATI transmitted from the AN with the UATI stored in its memory. As a result of the comparison, in the same case, the time identifier stored in its memory is compared with the time identifier transmitted from the AN. If the time identifier is also the same, the UATI and the time identifier stored in the memory are initialized.

3 is a flow diagram of a first embodiment illustrating the operation of AN to avoid collisions between ATs, in accordance with the present invention.

Referring to FIG. 3, the AN receives a connection request message transmitted from the AT (S311). The connection request message sent from the AT includes the UATI and time identifier assigned to the AT.

The AN checks whether the same UATI as the UATI included in the connection request message is currently being used by another AT (S312). As a result of the check, if not in use, the data service is performed to the AT which transmitted the connection request message by using the UATI (S313). However, if the same UATI is already in use as a result of the check, the time identifier included in the connection request message is compared with the restart time of the AN (S314).

As a result of the comparison, when the time identifier is earlier than the restart time, it may be determined that the UATI has been assigned before restarting. Thus, if another AT is using the allocated UATI after restarting, the UATI of the AT can no longer be regarded as a valid UATI. Therefore, the AN transmits a session release message including a UATI and a time identifier of the AT to a broadcast via a control channel (S315).

On the other hand, as a result of comparing the time identifier of the AT with the restart time of the AN (S314), if the time identifier is later than the restart time, it may be determined that the UATI is assigned after the restart. That is, the UATI of the AT is assigned after restarting and can be regarded as a valid UATI.

Therefore, since the UATI of another AT which already uses the same UATI can be regarded as invalid, the AN transmits a session release message including the UATI and time identifier of the other AT to broadcastcating through the control channel. (S316). Then, a data service is performed on the AT.

4 is a flow diagram of a second embodiment illustrating the operation of AN to avoid collisions between ATs, in accordance with the present invention. Referring to FIG. 4, the AN receives a connection request message transmitted from the AT (S411). The connection request message sent from the AT includes the UATI and time identifier assigned to the AT. The AN compares the time identifier included in the connection request message with the restart time of the AN (S412). As a result of the comparison, when the time identifier is earlier than the restart time, it may be determined that the UATI has been assigned before restarting. Therefore, the AN may determine that the UATI allocated before restarting is invalid, and transmits a session release message including the UATI and the time identifier of the AT to the broadcasting through a control channel (S413).

On the other hand, as a result of comparing the time identifier of the AT with the restart time of the AN (S42), if the time identifier is later than the restart time, it may be determined that the UATI is assigned after the restart. That is, the UATI of the AT is assigned after restarting and can be regarded as a valid UATI. In this case, the data service is performed to the AT (S414).

5 is a flowchart of a third embodiment illustrating the operation of AN to avoid collisions between ATs, in accordance with the present invention. Referring to FIG. 5, the AN receives the connection request message transmitted from the AT (S511). The connection request message sent from the AT includes the UATI and time identifier assigned to the AT. The AN compares the time identifier included in the connection request message with the current time of the AN (S512).

The time identifier contains information about the day, hour, minute, and second at the time of UATI allocation, so that the information about the day, hour, minute, and second of the time identifier sent from the AT precedes the AT's current time. Means that 1 month or more has elapsed since the time of assigning the UATI. Therefore, in this case, it may be determined that the received UATI is not valid. When the invalid UATI is received, the AN transmits a session release message including the UATI and the time identifier to broadcast (S513).

If the information about the day, hour, minute, and second of the time identifier transmitted from the AT indicates before the current time of the AT, it is determined as a valid UATI. Then, the AN compares the time identifier included in the connection request message with the restart time of the AN (S514). As a result of the comparison, when the time identifier is earlier than the restart time, it may be determined that the UATI has been assigned before restarting. Therefore, the AN may determine that the UATI allocated before restarting is invalid, and transmits a session release message including the UATI and the time identifier of the AT to the broadcast via a control channel (S513).

On the other hand, as a result of comparing the time identifier of the AT with the restart time of the AN (S514), if the time identifier is later than the restart time, it may be determined that the UATI is assigned after the restart. That is, the UATI of the AT is assigned after restarting and can be regarded as a valid UATI. In this case, the data service is performed to the AT (S515).

6 is a flowchart of a fourth embodiment illustrating the operation of AN to avoid collisions between ATs, in accordance with the present invention. Referring to FIG. 6, the AN receives a connection request message transmitted from the AT (S611). The connection request message sent from the AT includes the UATI and time identifier assigned to the AT.

The AN compares the time identifier included in the connection request message with the current time of the AN (S612).

The time identifier contains information about the day, hour, minute, and second at the time of UATI allocation, so that the information about the day, hour, minute, and second of the time identifier sent from the AT precedes the AT's current time. Means that 1 month or more has elapsed since the time of assigning the UATI. Therefore, in this case, it may be determined that the received UATI is not valid. When the invalid UATI is received, the AN transmits a session release message including the UATI and the time identifier to broadcast (S613).

If the information about the day, hour, minute, and second of the time identifier transmitted from the AT indicates before the current time of the AT, it is determined as a valid UATI. The AN checks whether the same UATI as the UATI included in the connection request message is currently being used by another AT (S614). As a result of the check, if not in use, the data service is performed to the AT which transmitted the connection request message using the UATI (S615). However, if the same UATI is already in use as a result of the check, the time identifier included in the connection request message is compared with the restart time of the AN (S616).

As a result of the comparison, when the time identifier is earlier than the restart time, it may be determined that the UATI has been assigned before restarting. Thus, if another AT is using the allocated UATI after restarting, the UATI of the AT can no longer be regarded as a valid UATI. Therefore, the AN transmits a session release message including a UATI and a time identifier of the AT to a broadcast via a control channel (S613).

On the other hand, as a result of comparing the time identifier of the AT with the restart time of the AN (S616), if the time identifier is later than the restart time, it may be determined that the UATI is assigned after the restart. That is, the UATI of the AT is assigned after restarting and can be regarded as a valid UATI.

Therefore, since the UATI of another AT which already uses the same UATI can be regarded as invalid, the AN transmits a session release message including the UATI and time identifier of the other AT to broadcastcating through the control channel. (S617). Then, a data service is performed on the AT.

7 is a flowchart illustrating an operation of an AT according to the present invention. Referring to FIG. 7, the AT transmits a message for requesting allocation of a UATI to the AN in order to receive a service (S711). When the UATI and the time identifier are received from the AN, the UATI and the time identifier are stored as a pair in the memory (S712).

Operation at AT after UATI assignment is as follows. That is, after the UATI assignment, the AT transmits a connection request including a pair of the UATI and the time identifier assigned thereto to the AN (S713).

When the session release message is received from the AN (S714), the UATI included in the session release message is compared with its UATI (S715). As a result of the comparison, if the UATIs are not the same, the session release message is ignored (S716). However, if the UATI is the same, the time identifier included in the session release message is compared with its own time identifier (S717). As a result of the comparison, if the time identifiers are not the same, the session release message is ignored (S716). However, if the time identifier is also the same, the session is released and its own UATI and time identifier are initialized (S718).

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, the present invention provides an access terminal due to the same UATI assignment without adding a separate hard disk drive (HDD) to each base station controller (BSC) of an access network (AN). There is an effect that can prevent the collision between AT (Access Terminal).

1 is a flowchart illustrating a method for allocating a unicast access terminal identifier (hereinafter referred to as 'UATI') according to the prior art.

Figure 2 is an embodiment flow diagram illustrating a UATI allocation method according to the present invention.

3 is a flowchart of a first embodiment showing the operation of an access network (AN) hereinafter to avoid collisions between access terminals (AT) in accordance with the present invention.

4 is a flowchart of a second embodiment showing the operation of AN to avoid collisions between ATs, in accordance with the present invention;

5 is a flowchart of a third embodiment illustrating the operation of AN to avoid collisions between ATs, in accordance with the present invention;

6 is a flowchart of a fourth embodiment illustrating the operation of AN to avoid collisions between ATs, in accordance with the present invention;

7 is an exemplary flowchart illustrating a session release operation of an access terminal according to the present invention.

Claims (22)

A collision avoidance method between an access network (AN) and an access terminal applied to a mobile communication system having at least one access terminal (AT), Receiving, by the access network, a service connection request message including an access terminal identifier and a time identifier from the access terminal; Comparing time information of the received time identifier with a reset time of the access network; And As a result of the comparison, when the time information is earlier than the restart time, broadcasting a message including the access terminal identifier and the time identifier to the at least one access terminal. Collision avoidance method between the access terminal comprising a. The method of claim 1, If the time information is later than the restart time, as a result of the comparison, further comprising performing a data service to the access terminal. The method of claim 1, And the time identifier includes system time information to which the access terminal is assigned the access terminal identifier from the access network. The method of claim 1, And the access terminal identifier is a unicast access terminal identifier (UATI). The method of claim 1, And a message including the access terminal identifier and the time identifier is transmitted through a control channel. A collision avoidance method between an access network (AN) and an access terminal applied to a mobile communication system having at least one access terminal (AT), Receiving, by the access network, a service connection request message including an access terminal identifier and a first time identifier from a first access terminal; Checking whether there is a second access terminal using the same access terminal identifier as the received access terminal identifier; Comparing the time information of the first time identifier with a reset time of the access network when the second access terminal exists; And As a result of the comparison, if the time information is earlier than the restart time, broadcasting a message including the access terminal identifier of the first access terminal and the first time identifier to at least one access terminal; Collision avoidance method between the access terminal comprising a. The method of claim 6, And if there is no second access terminal using the same access terminal identifier as the received access terminal identifier, performing a data service on the first access terminal. The method of claim 6, As a result of the comparison, when the time information is later than the restart time, a message including the access terminal identifier of the second access terminal and the second time identifier of the second access terminal is broadcasted to the at least one terminal. The collision avoidance method between the access terminal further comprising. The method of claim 6, And a message including the access terminal identifier and the time identifier is a session close message. A collision avoidance method between an access network (AN) and an access terminal applied to a mobile communication system having at least one access terminal (AT), Receiving, by the access network, a service connection request message including an access terminal identifier and a time identifier from the access terminal; Comparing the time information of the received time identifier with the current system time of the access network; Comparing the time information with a reset time of the access network when the time information is earlier than a system time of the access network; And As a result of the comparison, when the time information is earlier than the restart time, broadcasting a session close message including the access terminal identifier and the time identifier to the at least one access terminal. Collision avoidance method between the access terminal comprising a. The method of claim 10, If the time information is later than a system time of the access network, broadcasting a session close message including the access terminal identifier and a time identifier to the at least one access terminal. A collision avoidance method between access terminals comprising a. The method of claim 10, If the time information is later than the restart time, performing a data service for the access terminal. The method of claim 10, And the access terminal identifier is a unicast access terminal identifier (UATI). In a collision avoidance method between an access network (AN) and an access terminal applied to a mobile communication system having at least one access terminal (AT), Receiving, by the access network, a service connection request message including an access terminal identifier and a first time identifier from a first access terminal; Comparing the time information of the received time identifier with the current system time of the access network; As a result of the comparison, when the time information is earlier than the system time of the access network, checking whether a second access terminal using the same access terminal identifier as the received access terminal identifier exists; Comparing the time information of the first time identifier with a reset time of the access network when the second access terminal exists; And As a result of the comparison, when the time information is earlier than the restart time, a session close message including an access terminal identifier of the first access terminal and the first time identifier is transmitted to at least one access terminal. Broadcasting step Collision avoidance method between the access terminal comprising a. The method of claim 14, If the time information is later than the system time of the access network, broadcasting a session close message including the first access terminal identifier and the first time identifier to the at least one access terminal. The collision avoidance method between the access terminal further comprising. The method of claim 14, And if there is no second access terminal using the same access terminal identifier as the received access terminal identifier, performing a data service on the first access terminal. The method of claim 14, As a result of the comparison, when the time information is later than the restart time, a message including the access terminal identifier of the second access terminal and the second time identifier of the second access terminal is broadcast to the at least one terminal ( The collision avoidance method between the access terminal further comprising the step of broadcating. In a collision avoidance method between an access network (AN) and an access terminal applied to a mobile communication system having at least one access terminal (AT), Receiving, by the access terminal, a session release message including an access terminal identifier and a time identifier from the access network; Comparing the received access terminal identifier with an access terminal identifier of the access terminal; If the comparison result is the same, comparing the received time identifier with the time identifier of the access terminal; And If the comparison result is the same, initializing an access terminal identifier and a time identifier of the access terminal; Collision avoidance method between the access terminal comprising a. The method of claim 18, And comparing the received access terminal identifier with the access terminal identifier of the access terminal, and disabling the session release message if it is not the same. The method of claim 18, And comparing the received time identifier with the time identifier of the access terminal, if not identical, disregarding the session release message. The method of claim 18, And a message including the access terminal identifier and the time identifier is received through a control channel. In a collision avoidance method between an access network (AN) and an access terminal applied to a mobile communication system having at least one access terminal (AT), Receiving, by a first access terminal, an access terminal identifier and a first time identifier from the access network; Initializing an access terminal identifier database of the access network; Requesting, by a second access terminal, a data service from the access network using the access terminal identifier and a second time identifier; The access network broadcasting a session release message to the at least one access terminal, the session release message comprising the access terminal identifier and a second time identifier; And The first access terminal releasing the session and initializing the access terminal identifier and the first time identifier A collision avoidance method between access terminals comprising a.