CN100518394C - Idle mode location update method - Google Patents

Abstract

The present invention discloses a method for the location update of the idle mode, relating to the arrangement used for the mobile service area's coverage. It responses to the problem of the base station and the network side's message interactive increase that resulted from the 'ping-pong effect' which the existing technology aroused. The present invention comprises setting a timer for the base station. When the base station receives the corresponded security context messages, it catches these messages and set a corresponded timer. When the time comes to end, the message that the base station cached is deleted. The present invention can avoid the useless message interactive between the base station and the local paging controller, and it can save the news-bandwidth. At the same time, it accelerates the process of the location update for avoiding the 'ping-pong effect'.

Description

Idle mode location update method

technical field

The invention relates to an arrangement for mobile service area coverage, in particular to a location update method in an idle mode.

Background technique

The 802.16e standard is a fixed and mobile broadband wireless access standard formulated by the IEEE standard organization. Compared with the 802.16d standard, due to the increased support for mobility, it is necessary to adopt some technologies that can save power for the terminal, such as: sleep mode (Sleep mode) Mode) and idle mode (Idle Mode), in which the idle mode can save the energy consumption of the terminal more than the sleep mode, and increase its standby and use time. After entering the idle mode, the terminal only periodically receives downlink broadcast data (including paging messages and broadcast and multicast services) at discrete intervals, and does not need to perform handover or network reconfiguration when moving across multiple base stations. Access process.

In the prior art, multiple base stations are divided into one paging area, and the multiple paging areas are uniformly managed by one paging controller (Paging Controller, PC for short). When the terminal has downlink service data arriving, the paging controller is responsible for initiating the paging process. All base stations in the paging area where the terminal is located will send a paging broadcast message. After receiving the paging message, the terminal exits the idle mode, re-enters the network and Receive downlink data. Therefore, usually the terminal needs to complete various location update (Location Update) processes in order to register information such as its current paging area location and paging parameters with the paging controller.

In idle mode, through negotiation, the base station can save part or all of the terminal's current service and operation information, including security context information, to the paging controller, so as to speed up the network access process when re-entering the network.

In order to prevent messages from being interfered or counterfeited when propagating through the air interface, the 802.16e system stipulates corresponding security mechanisms to protect the transmission of data and messages, and the message authentication code (HMAC/CMAC) can prove the validity of the message. In order to verify the message authentication code, it is necessary to obtain security context information shared by the terminal and the base station, such as an authorization key (Authorization Key, AK for short). The authenticator (Authenticator) on the network side is responsible for generating the above security context information.

The base station can obtain the security context information belonging to the terminal from the paging controller or authenticator (Authenticator), verify the validity of the ranging request message (RNG-REQ) and return a response, while continuing to retain these security context information for the terminal to use in the next step. Used during a location update. When the terminal moves to a base station belonging to another paging area and performs a new location update, the paging controller will send a backbone message to notify the original base station to delete the retained security context information of the terminal, so as not to waste storage resources of the base station.

However, this method cannot avoid the "ping-pong effect" generated by the terminal during the mobile process, that is, the terminal returns again after leaving the paging area to which a certain base station belongs. At this time, the base station has deleted the reserved security context information of the terminal. Therefore, it is necessary to request the security context information of the terminal from the paging controller or authenticator (Authenticator) on the network side again.

Contents of the invention

In view of the defects and deficiencies in the prior art, the purpose of the present invention is to propose a location update method in idle mode of the 802.16e system, which can effectively reduce the message interaction between the base station and the network side, accelerate the location update process in idle mode, and will not The storage overhead of the base station is significantly increased.

In order to solve the above problems, the present invention proposes a location update method in idle mode, comprising the following steps:

(1) The terminal initiates a ranging request message to the base station;

(2) The base station sends a location update request message to the paging controller;

(3) The paging controller returns a location update response to the base station according to the location update request information;

(4) The base station judges whether there is security context information corresponding to the terminal, if yes, the base station uses the security context information to verify the ranging request message, if not, the base station requests to obtain the security context information corresponding to the terminal, and authenticating the ranging request message using the security context information;

(5) The base station returns location update confirmation information to the paging controller;

Also includes: setting a timer for the base station;

After receiving the security context information corresponding to the terminal, the base station caches the security context information and starts a timer corresponding to the terminal;

When the timer expires, delete the security context information cached by the base station.

Wherein, in step (4), the request of the base station to obtain the security context information refers to: the base station initiates a request to the authenticator at the network side to obtain the security context information corresponding to the terminal.

Wherein, the setting time of the timer is less than the lifetime of the security context information, and the security context information is an authorization key.

The present invention proposes a location update method in idle mode. Compared with the prior art, a timer is added on the base station side, and the time of the timer is set according to the storage capacity of the base station, which can save the security context information for a long time; and when the timer When the time comes, the base station will delete the saved security context information, which will not cause a significant increase in the storage overhead of the base station. Since the base station has stored the security context information corresponding to the terminal for a period of time, it can immediately verify the validity of the ranging request message after the terminal initiates a location update request. Once the verification fails, it can enter the non-secure location update process to speed up the location update. process; at the same time, it can effectively reduce the message interaction between the base station and the network side, saving message bandwidth. At the same time, setting the timer and storing the security context information can avoid the "ping-pong effect" caused by the terminal leaving a paging area and returning to the paging area in a short time.

Description of drawings

Figure 1 is a schematic diagram of the 802.16e system paging area division and idle mode terminal mobile process;

Fig. 2 is the existing idle mode location update method process for 802.16 system;

FIG. 3 is a flow chart of the location updating method in idle mode of the present invention.

Detailed ways

An existing 802.16e system paging area division and idle mode terminal mobile process is shown in Figure 1 . 1 and 2 are base stations, 3 is a terminal, 5 and 6 are paging areas where base stations 1 and 2 are located, and 4 is a moving route of a terminal in idle mode. The first and second location updates occur between the terminal and base station 1, then the terminal may leave the paging area where base station 1 is located and enter the paging area where base station 2 is located, and complete the third location update with base station 2, Then the terminal enters the paging area where the base station 1 is located again, and completes the fourth location update process with the base station 1 .

The existing 802.16e system idle mode location update process is shown in Figure 2. The terminal first sends a ranging request message (RNG-REQ) to base station 1 to request location update, and base station 1 sends a location update request message to the paging controller and got an answer. The response includes the updated paging information, which may or may not include the security context information of the terminal saved by the paging controller. If the security context information is not included, and the base station 1 does not originally store the security context information of the terminal, it needs to obtain the security context information of the terminal from an authenticator (Authenticator) on the network side and save it. Then use the above security context information to verify the validity of the RNG-REQ message, and return a ranging response message (RNG-RSP) to the terminal after passing, and send a location update confirmation message to the paging controller to complete the first location update The process, the flow chart of steps 1 to 10 in Figure 2.

After a certain period of time, the terminal is still in the range of base station 1 and starts the second location update. This time, base station 1 still stores the security context information of the terminal, so it can directly verify the validity of the ranging request message. Therefore, only need After the local paging controller obtains the updated paging information, it immediately sends a ranging response message to the terminal, and sends a location update confirmation message to the paging controller to complete the second location update process. The process is as shown in the steps in Figure 2. 11-18.

Then the terminal leaves the paging area where base station 1 is located, enters the paging area where base station 2 is located, and starts the third location update process with base station 2. Similar to the first location update process, the base station 2 has not stored the security context information of the terminal before, so it needs to obtain the security context information of the terminal from the authenticator (Authenticator) and save it. After verifying the validity of the ranging request message, return a ranging response message (RNG-RSP) to the terminal, and send a location update confirmation message to the paging controller, as shown in steps 19-29 in Figure 2.

After the paging controller receives the location update confirmation message, it needs to notify the original base station 1 to delete the retained security context information of the terminal through a Backbone message (Delete Context). The process flow is steps 30-32 in Figure 2.

Then the terminal leaves the paging area where base station 2 is located, enters the paging area where base station 1 is located again, and completes the fourth location update process with base station 1. Since the saved terminal security context information has been deleted, the base station 1 needs to request the paging controller or the authenticator to obtain the terminal security context information again, so the location update procedure is the same as the first location update process, as shown in Figure 2 Steps 1-10.

The technical features and functional features of the present invention will be further described below in conjunction with the accompanying drawings. The purpose is to better illustrate the present invention, but not to limit the protection scope of the present invention.

As shown in Figure 3, the preferred embodiment of the present invention includes the following steps:

The terminal first sends a ranging request message (RNG-REQ) to base station 1 to request location update, and base station 1 sends a location update request message to the paging controller and gets a response. The response includes the updated paging information, which may or may not include the security context information of the terminal saved by the paging controller. If the security context information is not included, and the base station 1 does not originally store the security context information of the terminal, it needs to request the authenticator (Authenticator) on the network side to obtain the security context information of the terminal, and the base station 1 saves the obtained terminal security context information, And set a timer, and the timer starts timing at the same time. Then use the above security context information to verify the validity of the RNG-REQ message, and return a ranging response message (RNG-RSP) to the terminal after passing, and send a location update confirmation message to the paging controller to complete the first location update The process, the flow chart of steps 1 to 10 in Figure 3.

After a certain period of time, the terminal is still in the range of base station 1 and starts the second location update. This time, base station 1 still stores the security context information of the terminal, so it can directly verify the validity of the ranging request message. Therefore, only need After the local paging controller obtains the updated paging information, it immediately sends a ranging response message to the terminal, and sends a location update confirmation message to the paging controller to complete the second location update process. The process is as shown in the steps in Figure 3. 11-18.

Then the terminal leaves the paging area where base station 1 is located, enters the paging area where base station 2 is located, and starts the third location update process with base station 2. Similar to the first location update process, the base station 2 has not stored the security context information of the terminal before, so it needs to obtain the security context information of the terminal from the authenticator (Authenticator) and save it. After verifying the validity of the ranging request message, return a ranging response message (RNG-RSP) to the terminal, and send a location update confirmation message to the paging controller, as shown in steps 19-29 in Figure 3.

After the paging controller receives the location update confirmation message, it no longer needs to notify the original base station 1 to delete the retained security context information of the terminal through a Backbone message (DeleteContext).

Then the terminal leaves the paging area where base station 2 is located, enters the paging area where base station 1 is located again, and completes the fourth location update process with base station 1. Since base station 1 still has terminal security context information, base station 1 can directly verify the validity of the ranging request message, so it only needs to send a ranging response message to the terminal immediately after the local paging controller obtains the updated paging information , and send a location update confirmation message to the paging controller to complete the fourth location update process. The steps are the same as the second location update process.

When the timer of base station 1 expires, base station 1 deletes the saved security context information of the terminal.

The position update method in idle mode provided by the present invention can effectively reduce the message interaction between the base station and the network side, and prevent the paging controller from notifying the original base station to delete the security context information after the terminal performs position update in a new paging area.

By adopting the idle mode position update method provided by the present invention, due to the adoption of the timer, the expired security context information can be deleted after the timer expires, without significantly increasing the storage overhead of the base station.

The location update method in idle mode provided by the present invention avoids the "ping-pong effect" generated during the mobile process of the terminal, that is, the terminal needs to report to the base station again after a period of time after the terminal leaves the paging area where the base station is located. The network side requests the security context information of the terminal, which speeds up the idle mode location update process.

By adopting the idle mode position update method provided by the present invention, the security context information of the terminal can be saved for a long time until the timer expires. According to the storage capacity of the system, the timer can be set longer. During this period, the validity of the ranging request message can be verified immediately after the terminal initiates the location update request. Once the verification fails, the non-safe location update process can be entered to avoid Generate invalid message interaction with the local paging controller, save message bandwidth, and speed up the location update process at the same time.

Claims (4)

1. A location update method in idle mode, comprising the following steps: (1) The terminal initiates a ranging request message to the base station; (2) The base station sends a location update request message to the paging controller; (3) The paging controller returns a location update response to the base station according to the location update request information; (4) The base station judges whether there is security context information corresponding to the terminal, if yes, the base station uses the security context information to verify the ranging request message, if not, the base station requests to obtain the security context information corresponding to the terminal, and authenticating the ranging request message using the security context information; (5) After passing the verification, the base station returns a ranging response message to the terminal, and returns location update confirmation information to the paging controller; It is characterized in that it also includes: setting a timer for the base station; After receiving the security context information corresponding to the terminal, the base station caches the security context information and starts a timer corresponding to the terminal; When the timer expires, delete the security context information cached by the base station. 2. The location update method in idle mode according to claim 1, wherein in step (4), the base station requests to obtain security context information means: the base station initiates a request to the authenticator located on the network side to obtain the terminal Corresponding security context information. 3. The location updating method in idle mode according to claim 1 or 2, characterized in that the setting time of the timer is shorter than the lifetime of the security context information. 4. The location update method in idle mode according to claim 3, wherein the security context information is an authorization key.

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