CN1332534C - Method of supporting node monitoring mobile user state by service universal packet wireless service - Google Patents

Abstract

The invention discloses a method for SGSN to monitor the status of mobile users. The method utilizes a timer to trigger a cyclic scanning task to scan the MM contexts of all mobile users stored in the SGSN. If a user is in the STANDBY state or IDLE state, the SGSN The current time of the device is compared with the state transition time recorded in the user's MM context. If the time difference is greater than or equal to the timing parameter configured by the SGSN device, the implicit separation process and the user deletion process are respectively started. This method does not need to set a large number of timers for monitoring the status of mobile users in the SGSN, which improves the stability and integration of the SGSN equipment; and can reduce the overhead of this task by changing the parameters of the cycle scanning task, and it is easy to realize the overall flow control ; At the same time, because the data change of the SGSN equipment can take effect immediately, it is convenient for the system maintenance personnel to carry out centralized management on the mobile users controlled by the SGSN.

Description

Method for monitoring mobile user state by serving general packet radio service support node

technical field

The present invention relates to a general packet radio service (General Packet Radio Service, GPRS) technology, in particular to a method for a Serving GPRS Support Node (Serving GPRS Support Node, SGSN) to monitor the state of a mobile user.

Background technique

At present, the GPRS network and Wide Code Divided Multiple Address (WCDMA) network applied to high-speed Internet access are just in the ascendant, especially the GPRS network, which has already been commercialized on a large scale by China Mobile.

GPRS is a mobile packet data service developed on the basis of the existing GSM mobile communication system. GPRS completes data transmission in packet mode by introducing the functional entity of packet switching in the GSM digital mobile communication network. The GPRS system can be regarded as a service expansion based on the original GSM circuit switching system to support the needs of mobile users to use packet data mobile terminals to access the Internet or other packet data networks.

The wireless protocol system itself is very complicated, and needs to complete all functions from user wireless access to wired switching. In order to reduce the complexity of the equipment, the 3rd Generation Partnership Project (The ^3rd Generation Partnership Project, 3GPP) protocol divides the interface Layer processing, using multiple different types of equipment such as MS/UTRAN/SGSN/GGSN to complete the entire wireless communication system.

Fig. 1 is the schematic diagram of GPRS network architecture, as can be seen from Fig. 1, GPRS system comprises GPRS core network and GSM system, and GPRS core network comprises nodes such as SGSN and gateway GPRS support node (Gateway GPRS Support Node, GGSN). One of the main functions of the SGSN is to provide mobility management functions for MSs in the service area of the SGSN.

Although layered processing reduces the complexity of each device, it introduces another problem, which is to ensure the consistency of user status/device resources between different devices, especially the consistency of the state between the core switching device SGSN and the mobile user MS .

The state of the mobile user is stored in the Mobile Management (MM) context. In the GPRS system, the mobile user has three states: idle (IDLE), standby (STANDBY) and ready (READY). IDLE means that the mobile user is not attached to the GPRS mobile management; STANDBY means that the mobile user is attached to the GPRS mobile management, but there is no data transmission state; READY means that the mobile user is attached to the GPRS mobile management and has the state of data transmission.

In order to keep the user state in the SGSN consistent with the actual MS state, the 3GPP protocol introduces two user monitoring timers: mobile reachable timer and PURGE timer.

The mobile reachable timer monitors whether the user state in the SGSN is consistent with the actual MS state. If the MS does not notify the network in time to perform the normal separation process due to abnormal shutdown, power exhaustion or other reasons, the SGSN is required to trigger the MS to hide. separation process.

When the user enters the READY state, the mobile reachable timer stops. When the MS state returns to STANDBY, the mobile reachable timer is restarted and started. If the mobile reachable timer expires, the SGSN starts the implicit detach procedure.

The implicit separation process is to convert the user state in the user's MM context in the SGSN to IDLE. The SGSN can delete the user's MM context immediately, or temporarily retain the user's MM context for a period of time.

The PURGE timer ensures that the user data of the SGSN is consistent with the location attribution register (HomeLocation Register, HLR).

As mentioned above, after the implicit separation, the SGSN can immediately delete the user's MM context, or keep the user's MM context for a period of time. If the SGSN wants to delete the user's MM context immediately, it starts the PURGE timer, and temporarily reserves the separated user's MM context before the PURGE timer expires. When the PURGE timer expires, the SGSN starts the user deletion process.

The process of user deletion is that SGSN notifies HLR, and after HLR responds, deletes the MM context of this user and cleans up related resources.

Fig. 2 is the method flow chart of prior art SGSN monitoring subscriber status, as can be seen from Fig. 2, this method comprises the following steps:

Step 201: SGSN detects the status of each user.

Step 202: Judging whether the user status has shifted to STANDBY, if yes, go to step 203; otherwise, end.

Step 203: Start a mobile reachable timer for the user.

Step 204: Judging whether the user status has shifted to READY, if yes, go to step 205; otherwise, go to step 206.

Step 206: The SGSN stops the mobile reachable timer of the user, and then ends.

Step 206: Determine whether the mobile reachable timer has expired, if yes, go to step 207; otherwise, go back to step 204.

Step 207: The SGSN stops the mobile reachable timer, starts an implicit detach procedure, and transfers the user state to IDLE.

Step 208: Determine whether the user's MS or SGSN supports the SUPER CHARGE feature, if yes, go to step 209; otherwise go to step 210.

Step 209: The SGSN temporarily reserves the MM context, and then ends.

Step 210: SGSN starts a PURGE timer for the user.

Step 211: Judging whether the user status has shifted to READY, if yes, go to step 214; otherwise, go to step 212.

Step 212: Determine whether the PURGE timer has expired, if yes, go to step 213; otherwise, go back to step 211.

Step 213: The SGSN notifies the HLR, and after receiving the HLR response, deletes the user's MM and PDP context, cleans up related resources, and ends.

Step 214: The SGSN stops the PURGE timer, and then ends.

It can be seen from the technical solutions of the prior art that the SGSN needs to start a timer for each MS in the non-READY state. However, this method starts a very large number of timers in a state where the SGSN is heavily loaded. According to a typical statistical estimation data in the business model formulated by China's third-generation mobile communication technology expert group, for an SGSN with a user capacity of 50,000, the number of MSs in the non-READY state controlled by the SGSN equipment is about 48,600, then, SGSN needs to start about 48600 timers at the same time to realize its monitoring of mobile users in non-READY state.

In actual application, there are many defects in the prior art:

First of all, the timer consumes a lot of system resources and hinders the further improvement of the integration of SGSN equipment. In SGSN equipment, if a large number of timers are started at the same time, it will bring huge and unpredictable risks to the stability of the system. Moreover, setting a large number of timers will inevitably make it impossible to further reduce the size of the SGSN equipment, so it is not conducive to further improving the SGSN The degree of integration of the device.

Second, using a large number of timers is not conducive to centralized management. Since the timer has already been started when the user state transitions, when the SGSN maintenance personnel need to dynamically adjust the timeout period of the timer, the timer that has been started cannot take effect immediately for this adjustment, which will cause the timer to time out when the equipment personnel change the SGSN device After the timeout period, the timeout period of the timer in the SGSN device is inconsistent.

Third, the use of a large number of timers is not conducive to the flow control of the SGSN as a whole. Since the monitoring tasks for users are low-priority tasks, when the load of SGSN equipment suddenly increases, the resources occupied by the monitoring tasks need to be allocated to tasks with high priority, such as flow control tasks, but if the timer has been started, it cannot Reclaim the resources occupied by monitoring tasks and allocate them to high-priority tasks such as flow control tasks, so it is impossible to control the flow of this part of the monitoring process.

Contents of the invention

The main purpose of the present invention is to provide a method for SGSN to monitor the status of mobile users, which reduces the system resources occupied by the task of monitoring the status of mobile users.

The purpose of the present invention is achieved through the following technical solutions:

A method for serving a general packet radio service support node (SGSN) to monitor a mobile subscriber state, comprising the steps:

A. Pre-set the timer used to periodically trigger the SGSN to scan the user status information including the user status and the user status switching time, the mobile reachable timing parameter for judging whether the SGSN starts the implicit separation process, and the timing parameter for starting the user deletion process Clear the timing parameters and the location pointer used to point to the storage location of the user state information in the SGSN;

B. Judging whether the timer has reached the timing time, if yes, then go to step C; otherwise, return to step B;

C, SGSN scans the user status information pointed to by the location pointer, if the user status is standby, then perform step D; if the user status is idle, then perform step E; if the user status is ready, then the location pointer points to the next user status information, Then return to step C;

D. Judging whether the time difference between the current moment and the user state switching moment is greater than or equal to the preset mobile reachable timing parameter, if yes, the SGSN starts the implicit separation process, the location pointer points to the next user state information, and then returns to step C; Otherwise, the location pointer points to the next user state information, and then returns to step C;

E. Judging whether the time difference between the current moment and the user state switching moment is greater than or equal to the preset clearing timing parameter, if yes, the SGSN starts the user deletion process, the location pointer points to the next user state information, and then returns to step C; otherwise, the location The pointer points to the next user state information, and then returns to step C.

Step A further includes: pre-setting the scanning step size for limiting the number of user status information scanned by the SGSN;

Between step B and step C, further include: judging whether the SGSN has scanned the number of user state information limited by the scan step size, if yes, storing the location pointer in memory, and returning to step B; otherwise, go to step C.

The user state information is the user's mobility management context.

The method of the present invention utilizes a timer to trigger a cycle scanning task, scans the MM contexts of all mobile users stored in the SGSN, if a certain user is in the STANDBY state or IDLE state, the current moment of the SGSN device and the MM context of the user are recorded Compared with the state transition time, if the time difference exceeds the timeout period of the timer configured by the SGSN device, the implicit separation process and the user deletion process are respectively started. And the method of prior art is to each state enters the mobile user of STANDBY or IDLE to distribute a dedicated timer, so, need to start a large amount of timers simultaneously in SGSN equipment, not only brings very big risk to the stability of the system, It is also unfavorable for the SGSN equipment to further improve the integration level. It can be seen from the above comparison that the method of the present invention can not only improve the stability of the system, but also help to improve the integration degree of the SGSN equipment.

The method of the present invention adopts the timing parameter currently configured by the SGSN device every time the cycle scanning task is executed, so the modification of the timing parameter by the device maintenance personnel can take effect immediately. However, in the method of the prior art, as long as the timer has been started, the parameters of this part of the timer cannot be changed. Therefore, when the equipment maintenance personnel change the timer parameters, they cannot make overall changes. It can be seen from the above comparison that the method of the present invention improves the real-time performance of SGSN monitoring user status.

The method of the present invention can reduce the overhead brought by this task by modifying the scanning parameters of the cyclic scanning task and the duration of the timing trigger, thereby supporting the SGSN equipment to implement flow control. However, in the prior art method, if the timer has already been started, the SGSN cannot perform flow control on this part of the process, and it is not conducive to the SGSN to implement flow control when the SGSN load increases. It can be seen from the above comparison that the method of the present invention is beneficial for the SGSN to implement overall flow control when necessary.

In addition, in the method of the present invention, the state switching time of the mobile user is stored in the MM context, so that the state switching time of the user can be backed up by backing up the MM context, and when the SGSN equipment fails, it can be retrieved from the backed up MM context Restores the user's state transition moment. And in the method of prior art, if SGSN equipment breaks down, the information of the timer that has started is all lost, can't recover, although can avoid this problem by restarting timer in batches, but restarting in batches produces batch timeout problem again . It can be seen from the above comparison that the method of the present invention is beneficial to ensure the security and integrity of monitoring data.

Description of drawings

Figure 1 is a schematic diagram of the GPRS system architecture.

Fig. 2 is a flowchart of a method for SGSN to monitor the state of a mobile user by using a mobile reachable timer and a PURGE timer.

Fig. 3 is a flowchart of a method for monitoring the state of a mobile user by the SGSN using a timer-triggered cycle scanning task according to the present invention.

Fig. 4 is a schematic diagram of the SGSN monitoring the state of the mobile user by using the cycle scanning task triggered by the timer according to the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The method of the present invention is to set a timer, also known as a timing trigger, to trigger a cyclic scanning task regularly. The cyclic scanning task scans the MM context of the user in the SGSN device according to a certain step size. If a certain user is in the STANDBY state or the IDLE state , the current time of the SGSN device is compared with the state transition time recorded in the MM context of the user, and if the time difference exceeds the timing parameter configured by the SGSN device, the implicit separation process and the user deletion process are respectively started.

The premise of the present invention is that when a certain user transitions from other states to STANDBY or IDLE, the SGSN records the state transition time in the MM context of the user.

The biggest difference between the method of the present invention and the method of the prior art is that the prior art monitors the status of each user individually in the device, while the method of the present invention monitors the status of all users in the SGSN device as a whole.

Fig. 3 is the method flowchart according to SGSN monitoring user state of the present invention, as can be seen from Fig. 3, this method comprises the following steps:

Step 301: The SGSN sets the mobile reachable timing parameter and the PURGE timing parameter.

The mobile reachable timing parameter corresponds to the timeout duration of the mobile reachable timer in the prior art; the PURGE timing parameter corresponds to the timeout duration of the PURGE timer in the prior art.

Step 302: The SGSN sets a scheduled task, also called a cyclic scan task, which is used to scan the MM contexts of all users in the SGSN.

Set the scan step of the scan task. The scan step is the number of users in a single scan. The scan step depends on the specific needs of the network. When the load of the SGSN device increases, in order to reduce the overhead caused by this process, support The overall flow control of the SGSN device can reduce the scan step size, or suspend the cycle scan task by setting the scan step size to 0; when the load of the SGSN device decreases, the scan step size can be appropriately increased.

Step 303: A timing trigger is set in the SGSN for periodically triggering the timing task started in step 302.

The timing trigger triggers a cyclic scanning task. After each trigger, the scanning task scans the MM contexts of a certain number of mobile users according to the scanning step. After the scanning is completed, the task stops and waits for the next trigger signal of the timing trigger.

The value of the timing trigger is the scanning time interval of the cyclic scanning task. The scanning time interval and the scanning step determined in step 302 are combined to determine the scanning speed of the scanning task. The scanning speed is also determined according to the specific conditions of the network. It should be noted that the scan time interval should not be less than the minimum scan time required by the scan step.

Preferably, the scanning time interval is 0.1 second, and the scanning step is 20.

Step 304: the timing trigger sends out a trigger signal, and the SGSN starts a cyclic scanning task.

Step 305: The SGSN scans the user MM context pointed to by the location pointer and stored in the memory of the SGSN device.

Step 306: judge the state of the user, if it is READY, then go to step 313; if it is STANDBY, then go to step 307; if it is IDLE, then go to step 309.

Step 307: Comparing the current time with the time when the user's MM context records the state transition from READY to STANDBY, and calculating the time difference between the current time and the state transition time.

Step 308: Judging whether the time difference is greater than or equal to the mobile reachable timing parameter configured by the SGSN device, if yes, go to step 309; otherwise, go to step 313.

Step 309: start the implicit separation process, migrate the user's state from STANDBY to IDLE, and set the state switching time of the user's MM context as the current time, then return to step 305, and continue to scan the next user's MM context.

Step 310: Comparing the current moment with the moment when the user's state transitions from STANDBY to IDLE recorded in the MM context, and calculating the time difference between the current moment and the state transition moment.

Step 311: Judging whether the time difference is greater than or equal to the PURGE timing parameter configured by the SGSN device, if yes, go to step 312; otherwise, go to step 313.

Step 312: Start the user deletion process, the SGSN notifies the HLR, and after receiving the HLR response, deletes the MM context of the user, then returns to step 305, and continues to scan the MM context of the next user.

Step 313: The location pointer points to the next user MM context of the current user MM context, and judge whether the scanning task has scanned the MM contexts of users with the set number of scanning steps, if yes, go to step 314; otherwise, return to Step 305, continue to scan the MM context of the next user.

Step 314: Store the location pointer in the memory, then wait for the trigger signal of the timing trigger, and go to step 304.

Steps 301 to 303 are the SGSN's configuration of the cyclic scanning task. The execution of the steps has no sequence and can be executed in parallel or sequentially in any order.

Fig. 4 is the synoptic diagram that SGSN utilizes the cyclic scanning task triggered by the timer to monitor the state of mobile users according to the present invention. As can be seen from Fig. 4, SGSN scans the MM context of users in an interval according to the step size at a time, and the scanning step The length is the number of users in one scan. When the scan is completed, the scan task ends and waits for the trigger signal of the timing trigger. It can also be seen from FIG. 4 that the user's MM context includes a field storing the state switching time. When the user state changes, this field is updated to the current time.

In the method of the present invention, the state switching of the mobile user is stored in the MM context at all times, and the MM context can be backed up to the standby board in real time through the backup mechanism of the SGSN. The timeout time of each mobile user is recovered from the backup MM context, so as to ensure the normal progress of the implicit separation process and user deletion process.

The above-mentioned embodiment is the application of the present invention in the GPRS system, but the present invention is not limited to the application in the GPRS system, and can also be applied to other mobile communication systems, such as the WCDMA system.

Appropriate improvements can be made to the method according to the present invention in the specific implementation process to meet the specific needs of specific situations. Therefore, it can be understood that the specific implementation manners according to the present invention are only exemplary, and are not intended to limit the protection scope of the present invention.

Claims (3)

1, a kind of method of service universal grouping wireless business supporting node SGSN monitoring mobile subscriber state is characterized in that this method comprises the steps:

A, set in advance and be used for regularly triggering the timer that SGSN scanning comprises the user state information of User Status and User Status switching instant, be used to judge whether SGSN starts moving of implicit detach flow process and can reach timing parameters, being used to start the user deletes the removing timing parameters of flow process and is used in reference to position indicator pointer to user state information memory location in SGSN;

B, judge whether timer arrives timing, if then forward step C to; Otherwise, return step B;

The user state information of C, SGSN scanning position pointed, if User Status for awaiting orders, execution in step D then; If User Status is idle, then execution in step E; If User Status is preparation, then position indicator pointer points to next user state information, returns step C then;

Whether D, the time difference of judging current time and User Status switching instant can reach timing parameters more than or equal to moving of setting in advance, if then SGSN starts the implicit detach flow process, position indicator pointer points to next user state information, returns step C then; Otherwise position indicator pointer points to next user state information, returns step C then;

E, judge current time and User Status switching instant time difference whether more than or equal to the removing timing parameters that sets in advance, if then SGSN starts the user and deletes flow process, position indicator pointer points to next user state information, returns step C then; Otherwise position indicator pointer points to next user state information, returns step C then.

2, the method for SGSN according to claim 1 monitoring mobile subscriber state is characterized in that steps A further comprises: the scanning step that sets in advance the user state information number that is used to limit SGSN scanning;

Further comprise between step B and the step C: judge whether SGSN has scanned the user state information number that scanning step limited, if then memory location pointer in internal memory is got back to step B; Otherwise forward step C to.

3, the method for SGSN monitoring mobile subscriber state according to claim 1 and 2 is characterized in that described user state information is user's a mobile management context.

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