KR20050051225A - Mobile telecommunication system detecting efficiently restart of gateway gprs support node in serving gprs support node and method thereof - Google Patents

Abstract

Disclosed are a mobile communication system and method for efficiently detecting a restart of a GGSN in an SGSN. In the mobile communication system, in the asynchronous wireless mobile communication environment, when the GGSN is restarted and the service can be provided again, an echo request message including an incremented restart counter value is immediately transmitted to the SGSN, thereby prompting its own failure situation. In response, the SGSN, which has determined the restart state of the GGSN, transmits a Create PDP Context Request message to the GGSN using the PDP context information previously set for the corresponding mobile subscriber station. Session information can be immediately reset and restored to the state it was in before the restart. Therefore, regardless of the SGSN echo request message transmission period, the GGSN immediately sends the echo request message, so that it is possible to determine that the GGSN is restarted more quickly than the conventional method, and the SGSN periodically transmits the echo request message. This reduces the amount of traffic between SGSN and GGSN, and saves the restart counter value in non-volatile memory, so that the value is not lost even after restart.

Description

Mobile telecommunication system detecting efficiently restart of gateway GPRS support node in serving GPRS support node and method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to asynchronous wireless mobile communication, and more particularly, in which a Serving GPRS Support Node (SGSN) detects a restart of a Gateway GPRS Support Node (GGSN) when a mobile station uses a packet data service. The present invention relates to a mobile communication system and an improved method.

In order to provide a packet data service compatible with an IP (internet protocol) network, 3GPP defines a general packet radio service (GPRS). GPRS improves the performance of conventional global system for mobile communication (GSM) and simplifies the wireless connection for packet data services.

GSN composed of SGSN and GGSN serves to transfer and route packet data between mobile station and IP network. Here, the SGSN is a GPRS serving node that receives a packet transmitted from the mobile terminal, transmits the packet to the GGSN, and delivers the packet received from the GGSN to the mobile terminal. The GGSN converts the packet received from the SGSN into PDP (packet data protocol) format and transmits the packet to the IP network.

1 is a flowchart illustrating a conventional method of detecting whether a GGSN is restarted in SGSN. Referring to FIG. 1, there is shown a flowchart in which an SGSN detects a restart of a GGSN and recovers a lost session in an asynchronous wireless mobile communication environment. First, when a service is provided again after a failure and restarted in the GGSN, the PDP context information for all subscriber mobile terminals connected to the GGSN becomes invalid, and the GGSN restarts itself. Increment the counter value. Afterwards, when the GGSN receives an Echo Request message from the SGSN (S110), the GGSN transmits an Echo Response message including the increased restart counter value to the SGSN (S120). The SGSN periodically transmits an Echo Request message, and the Echo Response message that the GGSN responds to is transmitted in the form of an information element such as "Private Extension" as shown in [Table 1].

TABLE 1

Information Element Presence Requirement Private extension Optional

Upon receiving the echo response message, the SGSN extracts a restart counter value from the echo response message and compares the restart counter value with the previously stored restart counter value of the GGSN. As a result of the comparison, when the two restart counter values are different from each other, the SGSN determines that the GGSN is restarted (S130). Accordingly, the SGSN switches the state of the subscriber mobile terminal in service through the restarted GGSN to deactivation and requests the subscriber mobile terminal to re-activate PDP context information according to the new restart counter value. (S140).

Thus, in the conventional method in which the SGSN detects the restart of the GGSN, the SGSN periodically sends an echo request message and receives an echo response message from the GGSN, thereby storing the new GGSN restart counter value included in the echo response message and storing it previously. Use the method of comparing the restart counter values that have been set. However, this conventional method of recognizing that the GGSN has been restarted is affected by the period in which the SGSN sends an echo request message to the GGSN. That is, if the period for transmitting the echo request message is long in the SGSN, even if the GGSN has already been restarted, there is a problem in that the restart of the GGSN must be recognized in the next cycle in which the echo request message is transmitted after a long time elapses. In addition, when the period for transmitting the echo request message in the SGSN is short, there is a problem to increase the load on the network (network). In addition, a method of storing PDP context information in service in the GGSN in non-volatile memory may be used, but this causes a problem of high cost and slow response processing.

Therefore, the present invention was devised to solve the above problems, and the technical problem to be achieved by the present invention is that, in the asynchronous wireless mobile communication environment, when the GGSN is restarted to be able to provide service again, one increased restart Immediately send the echo request message including the counter value to the SGSN to quickly inform the user of the failure condition. Accordingly, the SGSN that has determined the restart status of the GGSN uses the PDP context information previously set for the subscriber mobile terminal. The present invention provides a mobile communication system and method capable of restoring a session information of a lost GGSN by restarting by sending a "Create PDP Context Request" message to the GGSN. .

According to an aspect of the present invention, there is provided a mobile communication system comprising: a GGSN for generating and transmitting an echo request message when a service can be provided again after a failure occurs and restarted; And SGSN for transmitting the PDP context setup request message to the GGSN using the previously set PDP context information when it is determined that the GGSN is restarted after receiving the echo request message. The echo request message may include information on a restart counter value increased by one. The restart counter value may be updated and stored in the nonvolatile memory. The SGSN extracts a restart counter value from the echo request message and determines that the GGSN is restarted if the restart counter value is different from a previous restart counter value. The PDP context establishment request message may immediately reactivate and reestablish session information of the GGSN lost by restart.

According to another aspect of the present invention, there is provided a mobile communication method, comprising: transmitting an echo request message when a service is restarted after a failure occurs in a GGSN; And at the SGSN, receiving the echo request message; Determining, at the SGSN, whether to restart the GGSN; And transmitting, at the SGSN, a PDP context setting request message to the GGSN by using previously set PDP context information.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

2 is a block diagram schematically illustrating a mobile communication system for detecting whether a GGSN is restarted in an SGSN according to an embodiment of the present invention. 2, a mobile communication system according to an embodiment of the present invention includes a Serving GPRS Support Node (SGSN) 100, a Gateway GPRS Support Node (GGSN) 200, and a non volatile memory ( 300). The mobile communication system according to an embodiment of the present invention operates in an asynchronous wireless mobile communication environment.

The SGSN 100 receives a packet transmitted from a mobile station of a subscriber and transmits the packet to the GGSN 200 and transfers the packet received from the GGSN 200 to the mobile terminal. radio service) serving node. In particular, when the SGSN 100 according to an embodiment of the present invention receives an echo request message (ERQ) from the GGSN 200 and determines that the GGSN 200 is restarted, the existing PDP context is set. A PDP context request message (CPCR) is transmitted to the GGSN 200 using the information. After extracting a restart counter value from the echo request message ERQ, the SGSN 100 determines that the GGSN 200 is restarted if the restart counter value is different from a previous restart counter value. The "Create PDP Context Request" message (CPCR) immediately resets and reactivates session information of the GGSN 200 lost due to restart. The session information of the GGSN 200 is used for call connection between subscriber stations.

The GGSN 200 converts the packet received from the SGSN 100 into a packet data protocol (PDP) format and transmits the packet to an IP (internet protocol) network. In particular, the GGSN 200 according to an embodiment of the present invention generates and transmits the echo request message ERQ when the service is restarted and restarted after a failure occurs. The echo request message ERQ includes information about a restart counter value increased by one. If the GGSN 200 is restarted after the failure is provided, the PDP context information for all subscriber mobile terminals connected to the GGSN 200 is invalid. It becomes a state.

The restart counter value is updated and stored in a nonvolatile memory 300 such as a flash random access memory (FRAM), and increases one previous restart counter value stored in the nonvolatile memory 300 even when a next restart occurs. Save it with the updated value.

Hereinafter, the operation of the mobile communication system according to an embodiment of the present invention will be described in more detail.

3 is a flowchart for describing an operation of the mobile communication system of FIG. 2. Referring to FIG. 3, there is shown a flowchart in which an SGSN 100 detects a restart of the GGSN 200 and recovers a lost session in an asynchronous wireless mobile communication environment. First, when a service is provided again after a failure occurs and restarted in the GGSN 200 (S310), the GGSN 200 increases the restart counter value stored in the nonvolatile memory 300 (S320). At this time, the GGSN 200 does not wait for the periodic echo request message from the SGSN 100 as in the prior art and immediately sends the echo request message ERQ including information on the increased restart counter value. Configure and transmit to the SGSN (100) (S330). The GGSN 200 configures an echo request message (ERQ) by including a "Recovery" information element in addition to "Private Extension" as shown in [Table 2]. A restart counter value of the GGSN 200 is set in the "Recovery" information element, and an echo request message (ERQ) including the same is sent to the SGSN 100.

TABLE 2

Information Element Presence Requirement Recovery Mandatory Private extension Optional

Accordingly, the SGSN 100 receives an echo request message ERQ, extracts a restart counter value from the echo request message ERQ, and compares the restart counter value with a previous restart counter value, in the comparison. If the compared values are different from each other, it is determined that the GGSN 200 is restarted (S340). In this case, the SGSN 100 updates its restart counter value and transmits an echo response message (ERS) to the GGSN 200 to deactivate the state of the subscriber mobile terminal in service through the restarted GGSN 200. Switch to the (deactivation) state (S350). Accordingly, when a service is provided again after a failure occurs and restarted by the GGSN 200, the PDP context information of all subscriber mobile terminals connected to the GGSN 200 becomes invalid. In addition, the SGSN 100 transmits a PDP context setup request (“Create PDP Context Request”) message (CPCR) to the GGSN 200 by using previously set PDP context information, thereby losing the GGSN. The session information of 200 is immediately reset and reactivated (S360).

As described above, in the mobile communication system according to an embodiment of the present invention, when the GGSN 200 is able to provide service again after a failure occurs, when the GGSN 200 restarts, it generates and transmits an echo request message (ERQ) The SGSN 100 determines that the GGSN 200 is restarted from the restart counter value included in the echo request message ERQ, and accordingly, the GGSN 200 uses the previously set PDP context information. The PDP context setup request (“Create PDP Context Request”) message (CPCR) is transmitted to reactivate the session of the GGSN 200.

The functions used in the systems and methods disclosed herein can be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet). do. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

As described above, optimal embodiments have been disclosed in the drawings and the specification. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not intended to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

In the mobile communication system according to the present invention, in the asynchronous wireless mobile communication environment, when the GGSN is restarted and the service can be provided again, an echo request message including an incremented restart counter value is immediately transmitted to the SGSN for its own failure. Informs the situation promptly, and accordingly, SGSN, which determines the restart state of the GGSN, transmits a PDP context setup request ("Create PDP Context Request") message to the GGSN using the PDP context information previously set for the subscriber mobile terminal. The session information of the GGSN lost by the restart can be immediately reset and restored to the previous restart state. Therefore, regardless of the SGSN echo request message transmission period, the GGSN immediately sends the echo request message, so that it is possible to determine that the GGSN is restarted more quickly than the conventional method, and the SGSN periodically transmits the echo request message. This reduces the amount of traffic between SGSN and GGSN, and saves the restart counter value in non-volatile memory, so that the value is not lost even after restart.

1 is a flowchart illustrating a conventional method of detecting whether a GGSN is restarted in SGSN.

2 is a block diagram schematically illustrating a mobile communication system for detecting whether a GGSN is restarted in an SGSN according to an embodiment of the present invention.

3 is a flowchart for describing an operation of the mobile communication system of FIG. 2.

<Description of Major Symbols in Drawing>

100: SGSN 200: GGSN

300: nonvolatile memory

Claims (10)

GGSN which generates and transmits an echo request message when the service is restarted and restarted after a failure occurs; And And receiving the echo request message and determining that the GGSN has been restarted, the SGSN transmitting a PDP context setup request message to the GGSN using previously set PDP context information. The method of claim 1, wherein the echo request message, And a restart counter value incremented by one. The method of claim 2, wherein the restart counter value, The mobile communication system, characterized in that the update is stored in the nonvolatile memory. The method of claim 1, wherein the SGSN, Extracting a restart counter value from the echo request message, and determining that the GGSN is restarted if the restart counter value is different from a previous restart counter value. The method of claim 1, wherein the PDP context setting request message, And reactivating the session information of the GGSN lost by restart immediately. Transmitting, at the GGSN, an echo request message when the service is restarted after the failure occurs and the service is restarted; And Receiving, at an SGSN, the echo request message; Determining, at the SGSN, whether to restart the GGSN; And And transmitting, at the SGSN, a PDP context setting request message to the GGSN by using the previously set PDP context information. The method of claim 6, wherein the transmitting of the echo request message comprises: Incrementing the restart counter value by one; Constructing the echo request message that includes information about the incremented restart counter value; And And immediately sending the echo request message to the SGSN. The method of claim 7, wherein the restart counter value, The mobile communication method, characterized in that the update is stored in the nonvolatile memory. The method of claim 6, wherein the determining whether to restart the GGSN, Extracting a restart counter value from the echo request message; Comparing the restart counter value with a previous restart counter value; And And determining that the GGSN is restarted if the compared values differ from each other in the comparison. The method of claim 6, wherein the PDP context setting request message, And reactivating the session information of the GGSN lost by restart immediately.