KR100871254B1 - Method for rab reestablishment in mobile communication system - Google Patents

Abstract

The present invention relates to a method for establishing a RAB in a mobile communication system, and more particularly, to a method for reconfiguring a RAB according to the cause of failure when the RAB setup from the SGSN to the base station fails. To this end, the present invention analyzes if the failure of RAB configuration from the SGSN to the base station, the cause of the failure is due to the QoS parameters. As a result of this analysis, if the failure is caused by the QoS parameter, the bit value corresponding to the failure cause is changed in the bit string stored in the table. The SGSN re-requests RAB establishment from the base station with a value of QoS re-adjusted downlink according to the changed bit value.

RAB reassignment (setup), PDP, QoS, downlink, uplink

Description

How to reset radio access bearer in mobile communication system {METHOD FOR RAB REESTABLISHMENT IN MOBILE COMMUNICATION SYSTEM}             

1 is a diagram illustrating a network configuration of a typical code division multiple access mobile communication system serving packet data.

2 is a diagram illustrating an active PDP connection process of a typical code division multiple access mobile communication system serving packet data.

3 is a view illustrating in detail the RAB setup process of FIG.

4 is a diagram illustrating a process of newly allocating a QoS to which the present invention is applied.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and more particularly, to a method for resetting a wireless carrier when a wireless access carrier setup fails.

In general, a mobile communication system refers to a system that services voice or data through a wireless network. Such mobile communication systems can be distinguished by a multiplexing scheme. A representative example thereof is a code division multiple access (CDMA) mobile communication system, and the code division multiple access mobile communication system performs a mobile communication service using a wireless communication service using a code division multiple access method. Say the system. The CDMA mobile communication system has been developed in the IS-95 standard which focuses on the transmission / reception of voice signals, and has been discussed in the IMT-2000 standard capable of transmitting high speed data as well as voice. The IMT-2000 standard aims to provide services such as high quality voice, moving picture, and Internet search.

As described above, in the mobile communication system, various methods for servicing information such as voice and data are implemented, and representative examples thereof may be classified into a circuit switched network and a packet switched network. The circuit switching network is a switching network that processes circuit data including voice, and the packet switching network refers to a switching network that processes packet data. Meanwhile, the network configuration of the mobile communication system requires a network configuration capable of efficiently transmitting voice, data, and the like. This demand is more urgently required in the mobile communication system (IMT-2000) in which the amount of data to be transmitted is expected to increase as various services are made. In response to this demand, a general packet radio service (hereinafter referred to as GPRS) developed in an existing circuit-switched global system for mobile communication (GSM) network has been developed. The primary purpose of the user in packet data services such as GPRS is to utilize conventional Internet-based applications such as file transfer of wireless PCs, submission and receipt of e-mail, and Internet browsing through the World Wide Web (WWW). will be.

In general, the GPRS is divided into a terminal part, an access part, and a core network part. In addition, the access portion includes a base station and a wireless network controller, and the core network portion is referred to as a serving GPRS support node (hereinafter referred to as SGSN) and a gateway GPRS support node (hereinafter referred to as GGSN). .)

1 is a diagram showing a network configuration of a typical GPRS for serving packet data.

The mobile station (MS) 100 of FIG. 1 is connected to a base station (UTRAN) 102, and the base station 102 is composed of SGSNs 112a and 112b and GGSNs 118a and 118b. Connected to the core network. The core network is also connected to an external data network (Internet). Accordingly, in order to transmit and receive packet data, the mobile terminal 100 must establish a packet date protocol (hereinafter referred to as PDP) connection between the GGSNs 118a and 118b. . Active PDP connection, packet call setup, have the same meaning.

2 is a diagram illustrating a signal processing flow for performing a packet data service in the code division multiple access mobile communication system. Hereinafter, a signal processing flow for performing the packet data service will be described in detail with reference to FIG. 2.

In step 200, the mobile terminal 100 sends an Activate PDP Context Request message to the SGSNs 112a and 112b. In this case, the mobile terminal 100 designates a desired service level (QoS) and sends it to the active PDP connection request message.

The SGSN 112a and 112b sends a Create PDP Context Request message to the GGSN 118a and 118b in step 202. The generated PDP connection request message carries parameters related to the quality of service that the SGSN 112a and 112b can support to the GGSN 118a and 118b. That is, in step 202, the SGSNs 112a and 112b request the PDP connection requested by the mobile terminal 100 to the GGSNs 118a and 118b connected to the external data network. In this case, the SGSNs 112a and 112b obtain an Internet protocol of the GGSNs 118a and 118b connected to the external data network by using an APN to a Domain Name System (DNS) server. . The DNS server stores a record of the external data network to be serviced and a record of the GGSNs 118a and 118b connected thereto. Therefore, when the DNS server inquires the APN about the Internet protocol of the GGSN 118a and 118b connected to the external data network from the SGSN 112a and 112b, the DNS server uses the stored information. Find the Internet protocols of the GGSNs 118a and 118b that are connected to the data network. After this process, the DNS server notifies the SGSNs 112a and 112b of the information inquired by the SGSNs 112a and 112b. The SGSNs 112a and 112b notified of the information of the GGSNs 118a and 118b request a PDP connection with one of the notified GGSNs 118a and 118b.                         

In step 204, the GGSNs 118a and 118b send a Create PDP Context Response message to the SGSN 112a and 112b in response to the creation PDP connection request message. The generated PDP connection response message carries parameters related to the quality of service that the GGSNs 118a and 118b can support to the SGSNs 112a and 112b.

The parameters related to QoS include: maximum bit rate for downlink, guaranteed bit rate for downlink, maximum bit rate for uplink, uplink Guaranteed bit rate for uplink, and the like.

The SGSNs 112a and 112b and the mobile terminal 100 set up a radio access bearer (hereinafter referred to as RAB) in step 206. This will be described in detail with reference to FIG. 3. In FIG. 2, the RAB setting process is shown in two sections, a section between the mobile terminal 100 and the base station 102 and a section between the base station 102 and the SGSNs 112a and 112b. However, FIG. 3 illustrates the RAB establishment process between the SGSNs 112a and 112b and the base station 102 related to the present invention.

3, the SGSN 112a and 112b sends a RAB assignment request message to the base station 102 in step 300. The RAB assignment request message carries a QoS value negotiated between the SGSNs 112a and 112b and the GGSNs 118a and 118b. In step 302, the base station 102 sends a RAB assignment response message, which is a response to the RAB assignment request message, to the SGSNs 112a and 112b.

The SGSNs 112a and 112b analyze the contents sent by the base station 102 in step 302, and if the contents allow the RAB allocation request, the SGSNs 112a and 112b become active as the mobile terminal 100. Send an PDP Context Accept message.

When the setting procedure is completed by the above-described operation, the SGSN 112a and 112b may route a PDP protocol data unit between the mobile terminal 100 and the GGSN 118a and 118b. As it is possible to communicate between the mobile terminal 100 and the GGSN (118a, 118b).

The SGSNs 112a and 112b analyze the contents sent by the base station 102 in step 302 to analyze whether the sent contents have failed the RAB allocation request and whether the failed cause is the QoS parameter. As a result of the analysis, it is analyzed whether the cause of the failure is a case where the failure is caused by the QoS parameter. As a result of the analysis, if the cause of failure is due to the QoS parameter, the SGSNs 112a and 112b adjust the value of the QoS parameter to a down grade. The control proceeds to step 206 again with the readjusted downgrade.

After performing steps 300 and 302 of FIG. 3 according to step 206 based on the readjusted value, the base station 102 analyzes the contents notified again. The SGSNs 112a and 112b analyze the content sent from the base station 102 in step 302 and go to step 208 if the content sent allows the RAB allocation request. The SGSNs 112a and 112b send an Update PDP Context Request message to the GGSNs 118a and 118b in step 208 with the QoS parameters set by the readjustment. In step 210, the GGSNs 118a and 118b send an Update PDP Context Response message to the SGSN 112a and 112b, which is a response to the update PDP connection request message.

The SGSN 112a and 112b sends an Activate PDP Context Accept message to the mobile terminal 100 when a response in step 210 is received in step 212. By the above operation, communication between the mobile terminal 100 and the GGSNs 118a and 118b is enabled as described above.

As described above, when the RAB setting request between the SGSN 112a and 112b and the base station 102 fails due to an inappropriately set QoS value among the RAB parameters, the SGSN 112a and 112b sets the RAB using the newly set QoS value. Will be required. In this case, the newly rescheduled QoS value is down-grade than the existing value. However, in the related art, although it is mentioned that the QoS value is reset when the RAB setting fails, the resetting method is not described in detail. Therefore, there is a need for a method of setting a QoS value that is reset to a lower level when a RAB configuration request is made again.

Accordingly, an object of the present invention to solve the above problems is to provide a method for retrying the RAB configuration by the QoS value which is preset and stored when the RAB configuration fails.

Another object of the present invention is to provide a method of resetting the QoS value by analyzing only elements corresponding to the cause of failure when resetting the QoS value.

It is still another object of the present invention to provide a method of reducing an active PDP connection time by resetting a QoS value based on a pre-stored value.

The present invention for achieving the above object indicates the value of the QoS to retry the RAB configuration according to the bit string having a certain number of bits. The cause of QoS failure corresponds to the bit position of the bit string having the predetermined number of bits. In this way, the cause of failure due to QoS is analyzed and the value of the bit position associated with the cause of failure is converted. In the above process, the bit string has a new bit value. New attempts are made to RAB with QoS values corresponding to new bit strings with new bit values.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that the detailed description of the related known technology or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. 2 and 4 will be described in detail with respect to the QoS adjustment process for resetting the RAB when the RAB configuration fails to apply the present invention. In the present invention, the active PDP connection process goes from step 200 to step 206 as described above with reference to FIG. 2.

After the step 206, the SGSN 112a and 112b determines whether RAB establishment between the base station 102 and the SGSN 112a and 112b is successful. As a result of the determination, it is determined again whether the RAB setting has failed and the cause of the failure is due to the QoS. As a result of the determination, if the cause of the failure of the RAB configuration is due to the QoS, a downgrade value is found and sent from a table preconfigured with QoS values in the RAB allocation request message.

The SGSNs 112a and 112b analyze the QoS that is the cause of the failure when the RAB setup fails. In the present invention, the causes of failure are classified as follows.

A; The maximum bit rate requested for the uplink is not valid.

B: The maximum bit rate requested for downlink is not valid.

C: The guaranteed bit rate requested for the uplink is not valid.

D: The guaranteed bit rate requested for downlink is not valid.

E: The requested maximum bit rate is invalid. That is, if the maximum bit rate requested for uplink and downlink is not valid at the same time.

F: The requested guaranteed bit rate is invalid. That is, if the guaranteed bit rates requested for the uplink and downlink are not valid at the same time.

On the other hand, there is a case in which the same cause of failure may occur two times in succession, although not posted in the cause of failure.                     

The value of the QoS is found in a predetermined table according to the value of the bit string while changing the value of the bit string consisting of 5 digits according to the cause of the failure. Table 1 shows the QoS parameters according to the value of the bit string of 5 bits.

Bit heat Maximum Bit Rate for Uplink (kbps) Maximum Bit Rate for Downlink (kbps) Guaranteed Bit Rate (kbps) for Uplink Guaranteed Bit Rate (kbps) for Downlink 00000 128 128 64 64 00001 128 128 64 32 00010 128 128 32 64 00011 128 128 32 32 00100 64 64 64 64 00101 64 64 64 32 00110 64 64 32 64 00111 64 64 32 32 01000 64 128 64 64 01001 64 128 64 32 01010 64 128 32 64 01011 64 128 32 32 01100 32 32 32 32 01101 32 32 32 16 01110 32 32 16 32 01111 32 32 16 16 10000 64 64 32 32 10001 64 64 32 16 10010 64 64 16 32 10011 64 64 16 16 10100 32 32 32 32 10101 32 32 32 16 10110 32 32 16 32 10111 32 32 16 16 11000 32 64 32 32 11001 32 64 32 16 11010 32 64 16 32 11011 32 64 16 16 11100 16 16 16 16 11101 16 16 16 8 11110 16 16 8 16 11111 16 16 8 8

In Table 1, the first bit on the right side of the bit string is mapped to the guaranteed bit rate requested for downlink, and the second bit on the right side of the bit string is the guaranteed bit requested for uplink. Mapped to the rate. The third bit on the right side of the bit string is mapped to the maximum bit rate requested for downlink, and the fourth bit on the right side of the bit string is mapped to the maximum bit rate requested for uplink. . That is, when the RAB setup fails, it is possible to indicate whether or not it is valid by changing the value of the bit corresponding to the cause of the failure. The leftmost bit (the fifth bit from the right) of the bit string is also mapped when the requested maximum bit rate is invalid and when the requested guaranteed bit rate is invalid.

In step 206 of FIG. 2, when the SGSN 112a and 112b requests the RAB configuration from the base station 102 for the first time, the SGSN 112a and 112b sends one of the QoS values shown in Table 1 to the RAB allocation request message. The corresponding bit of the bit string corresponding to the QoS value sent to the base station 102 is stored in the SGSN 112a and 112b. The first QoS value to be sent is divided according to the grade of the quality of packet data service selected by the subscriber of the mobile terminal 100 upon subscription. That is, the subscriber who desires high quality of service supports the service of higher level and the subscriber who desires low quality of service supports the service of low level. When the RAB setting between the SGSN 112a and 112b and the base station 102 fails due to the set QoS parameter, as described above, the SGSN 112a and 112b analyzes whether the cause of the failure is due to the QoS parameter. .

If the cause of the failure as a result of the analysis is due to the QoS parameter, the bit of the bit string associated with the QoS parameter is newly set. This will be described in detail with reference to FIG. 4.

The SGSNs 112a and 112b analyzes the RAB assignment response message sent from the base station 102 in step 400 and recognizes that the RAB establishment with the base station 102 has failed. The SGSNs 112a and 112b count the number of times the RAB is set in step 402. In step 402, N denotes the designated number of RAB setting attempts, and n denotes the number of RAB setting attempts. If the counted value is greater than the specified number of attempts to set the RAB, the flow proceeds to step 418. If the counted value is less than or equal to the specified number of attempts to set the RAB, step 406 is reached.

The SGSNs 112a and 112b analyze the cause of the RAB establishment failure in step 406. In the present invention, as described above, only the case where the cause of the RAB configuration failure is determined by the QoS parameter is shown. If the guaranteed bit rate requested for downlink is invalid (D), if the guaranteed bit rate requested for uplink is not valid (C); If the maximum bit rate requested for the downlink is invalid (B) or if the maximum bit rate requested for the uplink is invalid (A), go to step 408. . If the cause of the RAB establishment failure is related to the case where the requested maximum bit rate is not valid (E) and the requested guaranteed bit rate is not valid (F), the flow proceeds to step 412.

SGSNs 112a and 112b check bits associated with the cause of failure in step 408. That is, if the first bit on the right side of the bit string is the guaranteed bit rate requested for downlink, the second bit on the right side of the bit string is the guaranteed bit requested for uplink. If the rate is not valid, the third bit from the right of the bit string is for the downlink. If the maximum bit rate requested for the downlink is not valid, the fourth bit from the right of the bit string is for the uplink. These bits are associated with the case where the requested maximum bit rate is invalid. Therefore, the above procedure does not check all bits, but only the QoS parameters related to the cause of the RAB configuration failure. Obviously, in this case, the RAB setting by two or more QoS parameters may fail.

SGSNs 112a and 112b check corresponding bits of the QoS parameters related to the RAB establishment failure in step 410. In step 410, the m value has a value of 1 to 4. If the value of the bit is 0 as a result of checking the corresponding bit, the operation proceeds to step 414. If the value of the bit is 1, the operation proceeds to step 412.

SGSN (112a, 112b) is the cause of the RAB setting failure in step 412 and the requested maximum bit rate is invalid and the requested guaranteed bit rate is invalid and the RAB setup failure moved in step 410 Examine the case where the corresponding bit value of the associated QoS parameter is 1. In step 412, the value of the leftmost bit of the bit string is examined. If the bit value is 0, go to step 414; if the bit value is 1, go to step 418.

The SGSNs 112a and 112b change the corresponding bit value of the QoS parameter related to the cause of the RAB setting failure from 0 to 1 when it is moved in step 410 in step 414, and the leftmost part of the bit string when it is moved in step 412. Change the bit value from 0 to 1. In step 414, l has a value of 1 to 5.

As described above, when the RAB setting failure associated with the fourth bit from the first bit of the right bit of the bit string is performed, the corresponding bit is first checked. If the bit value is 0 as a result of checking the bit, if the bit value is 1, the leftmost bit value is again examined. Therefore, changing the corresponding bit value from 0 to 1 means that the QoS value is adjusted downward.

In addition, the SGSN 112a and 112b searches for the QoS value corresponding to the bit string having the newly changed bit value in Table 1 in step 414. Table 1 may be stored inside the SGSN (112a, 112b), it may be stored in the outside of the SGSN (112a, 112b) is apparent. The SGSNs 112a and 112b request RAB establishment from the base station 102 in the RAB allocation request message in the new QoS values found in Table 1 above. Hereinafter, an example of a method of resetting the QoS values will be described.

1. First embodiment (when the value of the QoS parameter in the RAB of the RAB allocation request message is set to 01000 bit string)

Maximum bit rate requested for uplink: 64 kbps

Maximum bit rate requested for downlink: 128 kbps

Guaranteed bit rate requested for uplink: 64 kbps

Guaranteed bit rate requested for downlink: Request RAB with QoS with value of 64 kbps. If the RAB setting fails due to a case where the maximum bit rate requested for downlink is not valid, the SGSN 112a, 112b checks the third bit from the right. The bit value is changed to 1 since the value of the third bit is 0 as a result of the checking. This change causes the new bit string to have a value of 01100. Therefore, the value of 01100 is found in Table 1, the QoS value corresponding to the value is reset, and the RAB configuration is attempted again. The reset QoS value is as follows.

 Maximum bit rate requested for uplink: 32 kbps

Maximum bit rate requested for downlink: 32 kbps

Guaranteed bit rate requested for uplink: 32 kbps

Guaranteed bit rate requested for downlink: 32 kbps

2. Second embodiment (when the value of QoS parameter in RAB of RAB allocation request message is set to 00111 bit string)

Maximum bit rate requested for uplink: 64 kbps

Maximum bit rate requested for downlink: 64 kbps

Guaranteed bit rate requested for uplink: 32 kbps

Guaranteed bit rate requested for downlink: Request RAB with QoS with a value of 32 kbps. If the RAB configuration fails because the guaranteed bit rate requested for downlink is invalid, the SGSN 112a, 112b checks the first bit on the right. Since the first bit value is 1, the leftmost bit is checked again. Since the leftmost bit value is 0, the bit value is changed to 1. This change causes the new bit string to have a value of 10111. Therefore, the value of 10111 is found in Table 1, the QoS value corresponding to the value is reset, and the RAB configuration is attempted again. The reset QoS value is as follows.

 Maximum bit rate requested for uplink: 32 kbps

Maximum bit rate requested for downlink: 32 kbps

Guaranteed bit rate requested for uplink: 16 kbps

Guaranteed bit rate requested for downlink: 16 kbps

The SGSNs 112a and 112b try again the RAB by the newly set QoS values in step 416. The process is described in detail in FIG. The SGSNs 112a and 112b move to step 420 if the RAB setting succeeds, and moves to step 404 if the RAB setting fails. The SGSNs 112a and 112b increase the number of RAB setting attempts by 1 in step 404 and then move back to step 402.

SGSNs 112a and 112b terminate in step 418 after rejecting the active PDP connection. Due to the rejection, the SGSN 112a and 112b attempts to connect an active PDP by another path or retry after a predetermined time interval. SGSNs 112a and 112b allow for an active PDP connection in step 420. In this case, step 420 is performed after performing steps 208 and 210 of FIG. 2. That is, the SGSN 112a and 112b sends an Update PDP Context Request message to the GGSNs 118a and 118b in step 208. In step 210, the GGSNs 118a and 118b send an Update PDP Context Response message to the SGSN 112a and 112b, which is a response to the update PDP connection request message.                     

When the SGSN 112a and 112b receives the normal response in step 210, the SGSN 112a and 112b sends the Activate PDP Context Accept message to the mobile terminal 100 and terminates. By the above operation, communication between the mobile terminal 100 and the GGSNs 118a and 118b is enabled as described above.

As described above, when the RAB configuration fails, the present invention searches for a serviceable QoS value in a pre-stored table and attempts to set the RAB by the newly set QoS value, so that the RAB configuration failure does not check values corresponding to all failure causes. Only the bits corresponding to the cause of the failure are checked. In this way, the optimal QoS value can be selected when retrying the RAB configuration. In addition, the time loss can be reduced by selecting the QoS value based on the pre-stored table.

Claims (15)

The QoS in the SGSN when a radio access bearer (RAB) setting between a service GPRS support node (SGSN) and a base station fails by an inappropriately set Quality of Service (QoS) parameter among RAB parameters In the radio access bearer reconfiguration method for re-adjusting the quality of service according to the parameter, Changing a value of a bit corresponding to a particular QoS parameter associated with the failure of the RAB establishment among the QoS parameters in a binary bit string consisting of bits corresponding to each of the QoS parameters; And re-adjusting the quality of service according to the QoS parameters by a new binary bit string having the changed bit value. 2. The radio access bearer of claim 1, wherein the QoS parameters comprise a guaranteed bit rate for the downlink, a guaranteed bit rate for the uplink, a maximum bit rate for the downlink, and a maximum bit rate for the uplink. How to reset. The method of claim 1, wherein the number of QoS parameters is set to an arbitrary number. 4. The method of claim 3, wherein the number of QoS parameters is five. The method of claim 1, wherein changing the value of the bit changes to 1 when the value of each bit is 0. 6. The method of claim 5, wherein when the value of the bit is changed from 0 to 1, the quality of service is adjusted downward. 6. The method of claim 5, wherein the leftmost bit value of the bits constituting the binary bit string is adjusted by a change value of the remaining bits. 8. The method of claim 7, wherein the checking of the leftmost bit value among the bits constituting the binary bit string is performed when the value of the remaining bits is one. The method of claim 8, wherein the leftmost bit value of the bits constituting the binary bit string is changed to 1 when the bit value of the leftmost bit is 0. 10. The method of claim 8, wherein the RAB setup is stopped when the leftmost bit value of the bits constituting the binary bit string is 1. The method of claim 1, wherein the quality of service according to QoS parameters corresponding to each of the bits constituting the binary bit string and the binary bit string are stored differently. The QoS in the SGSN when a radio access bearer (RAB) configuration between a service GPRS support node (SGSN) and a base station fails by an inappropriately set Quality of Service (QoS) parameter among RAB parameters In the radio access bearer reconfiguration method for adjusting the quality of service according to the parameter, Setting and storing quality of service of bit strings having a certain number of bits and QoS parameters corresponding to each of the bit strings; Selecting a bit string corresponding to desired quality of service among the stored bit strings, and attempting to set the RAB by transmitting the selected bit string to the base station; When the RAB setting fails, selecting a bit string corresponding to different quality of service among the stored bit strings, and retrying the RAB setting by transmitting the selected bit string to the base station. How to reset radio access bearer. 13. The radio access bearer of claim 12, wherein the QoS parameters comprise a guaranteed bit rate for the downlink, a guaranteed bit rate for the uplink, a maximum bit rate for the downlink, and a maximum bit rate for the uplink. How to reset. The method of claim 13, wherein the bits constituting each of the bit strings include: The quality of service of each of the corresponding QoS parameters, The same quality of service occurs consecutively as a cause of RAB establishment failure, or when the guaranteed bit rate for the downlink and the guaranteed bit rate for the uplink occur simultaneously as a cause of the RAB establishment failure, or for the downlink And the maximum bit rate and the maximum bit rate for the uplink are mapped when the RAB establishment failure occurs at the same time. The service quality of claim 12, wherein, when the RAB configuration fails, only the quality of service corresponding to the failure cause of the quality of services of each of the QoS parameters used in the RAB configuration is changed, and the quality of service including the changed quality of service. And selecting a bit string corresponding to the radio access bearer resetting method.

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