Method, apparatus, and system for location update

1. A location update method, comprising:

when detecting that a location update needs to be performed in a first mobile communication network, sending a first request message comprising instruction information to a mobile management device in the first mobile communication network such that the mobile management device in the first mobile communication network sends a second request message to a mobile management device in a second mobile communication network when executing the location update according to the instruction information, wherein the second request message enables the mobile management device in the second mobile communication network to reset a periodic update timer and send a first accept message comprising a periodic update timer reset instruction of the second mobile communication network to the mobile management device in the first mobile communication network;

receiving a second accept message sent by the mobile management device in the first mobile communication network, wherein the second accept message comprises the periodic update timer reset instruction of the second mobile communication network; and

resetting the periodic update timer of the second mobile communication network according to the periodic update timer reset instruction of the second mobile communication network.

2. The method according to claim 1 , wherein detecting that the location update needs to be performed in the first mobile communication network comprises detecting a location change in the first mobile communication network.

3. The method according to claim 1 , wherein detecting that the location update needs to be performed in the first mobile communication network comprises detecting timeout of a periodic update timer of the first mobile communication network.

4. The method according to claim 1 , wherein the first request message is a tracking area update request message, and the second request message is a location update request message.

5. The method according to claim 1 , wherein the first request message is a location area update request message, and the second request message is a tracking area update request message.

6. The method according to claim 1 , wherein the instruction information is carried in an update type field or a newly added field of the first request message.

7. A location update method, comprising:

receiving a first request message comprising instruction information, where the first request message is sent by a single-card dual-standby user equipment when detecting that a location update needs to be performed in a first mobile communication network;

executing the location update according to the instruction information, and sending a second request message to a mobile management device in a second mobile communication network such that the mobile management device in the second mobile communication network resets a periodic update timer;

receiving a first accept message sent by the mobile management device in the second mobile communication network, wherein the first accept message comprises a periodic update timer reset instruction of the second mobile communication network; and

sending a second accept message comprising the periodic update timer reset instruction of the second mobile communication network to the single-card dual-standby user equipment such that the single-card dual-standby user equipment resets the periodic update timer of the second mobile communication network according to the periodic update timer reset instruction of the second mobile communication network.

8. The method according to claim 7 , wherein the first request message is a tracking area update request message, and the second request message is a location update request message.

9. The method according to claim 7 , wherein the first request message is a location area update request message, and the second request message is a tracking area update request message.

10. A single-card dual-standby user equipment, comprising:

a radio frequency transceiver; and

at least one processor coupled to the radio frequency transceiver,

wherein the processor is configured to,

when detecting that a location update needs to be performed in a first mobile communication network, trigger the radio frequency transceiver to send a first request message comprising instruction information to a mobile management device in the first mobile communication network such that the mobile management device in the first mobile communication network sends a second request message to a mobile management device in a second mobile communication network when executing the location update according to the instruction information, wherein the second request message enables the mobile management device in the second mobile communication network to reset a periodic update timer and send a first accept message comprising a periodic update timer reset instruction of the second mobile communication network to the mobile management device in the first mobile communication network; and

when the radio frequency transceiver receives a second accept message comprising the periodic update timer reset instruction of the second mobile communication network and sent by the mobile management device in the first mobile communication network, reset the periodic update timer of the second mobile communication network according to the periodic update timer reset instruction of the second mobile communication network.

11. The single-card dual-standby user equipment according to claim 10 , further comprising a display and a display controller that are coupled to the processor, and wherein the processor is further configured to detect whether a location in the first mobile communication network changes.

12. The single-card dual-standby user equipment according to claim 10 , further comprising a display and a display controller that are coupled to the processor, and wherein the processor is further configured to detect whether a periodic update timer of the first mobile communication network times out.