CN102905369B

CN102905369B - User equipment calling method and system when mobile management unit fails or restarts

Info

Publication number: CN102905369B
Application number: CN201110210476.4A
Authority: CN
Inventors: 卢飞; 李振东
Original assignee: ZTE Corp
Current assignee: Changshu Intellectual Property Operation Center Co ltd
Priority date: 2011-07-26
Filing date: 2011-07-26
Publication date: 2018-04-20
Anticipated expiration: 2031-07-26
Also published as: CN102905369A

Abstract

User equipment calling method when the invention discloses a kind of failure of mobile management unit or restarting, including：When space interface signaling reduces ISR function activations, the mobile management unit failure of user equipment (UE) registration is being determined or when restarting, the mobile management unit by the unregistered mobile management units of the UE or after restarting realizes the paging to the UE.A kind of paging user equipment system when failing the present invention discloses mobile management unit for realizing the above method.Present invention ensures that can also realize the paging to UE in MME or SGSN failures or while restarting, avoid mobility management unit in CS business and restart or delay the phenomenon that UE cannot be related to after machine.Present invention ensures that the stability of UE business, the service quality of CS business is improved.

Description

Method and system for paging user equipment when mobile management unit fails or restarts

Technical Field

The present invention relates to a User Equipment (UE) paging technique under the function of Idle mode Signaling Reduction (ISR) in System Architecture Evolution (SAE), and in particular, to a method and a System for paging a UE when a mobility management unit fails or restarts.

Background

With the advent of worldwide Interoperability for microwave access (WiMax), third generation mobile communication systems must improve their network performance and reduce their network construction and operation costs to maintain their competitiveness in the mobile communication field. Therefore, the standardization working group of the third generation Partnership Project (3 GPP) is currently working on the evolution of the Packet switched Core Network (PS Core) and the Radio Access Network (UTRAN) of the universal mobile telecommunications System. The research topic is called System Architecture Evolution (SAE), and aims to enable an Evolved Packet network (EPC) to provide a higher transmission rate, a shorter transmission delay, optimize packets, and support mobility management between Evolved UTRAN (E-UTRAN), UTRAN, Wireless Local Area Network (WLAN), and other non-3 GPP access networks.

Fig. 1 is a schematic architecture diagram of SAE, and as shown in fig. 1, a Network element included in an Evolved radio access Network (E-RAN) is an Evolved node B (eNodeB) for providing a radio resource for a user to access; a Packet Data Network (PDN) is a Network that provides services to users; the EPC provides lower transmission delay and allows more radio access system access, which includes the following network elements:

a Mobility Management Entity (MME), which is a control plane function Entity, a server for temporarily storing User data, and a server for managing and storing a context (such as a UE/User identifier, a Mobility Management state, a User security parameter, and the like) of a User Equipment (UE), and allocating a temporary identifier to a User, and when the UE is camped in the tracking area or the network, the server is responsible for authenticating the User; processing all non-access stratum messages between the MME and the UE; paging at SAE is triggered. The MME is a mobility management unit of the SAE System, and in a Universal Mobile Telecommunications System (UMTS), the mobility management unit is a Serving General Packet Radio Service (GPRS) Support Node (SGSN).

The Serving Gateway (SGW) is a user plane entity, and is responsible for routing user plane data and terminating downlink data of the UE in an IDLE (ECM _ IDLE) state. And managing and storing SAE bearer (bearer) context of the UE, such as IP bearer service parameters, network internal routing information and the like. The SGW is an anchor point of the user plane in the 3GPP system, and one user only has one SGW at a time.

A packet data network Gateway (PGW, PDN Gateway), which is a Gateway responsible for UE accessing PDN, allocates user IP address, and is also a mobility anchor point of 3GPP and non-3 GPP access systems, and the function of the PGW further includes policy implementation, charging support, and the like. A user can access multiple PGWs at the same time. A Policy and Charging Enforcement Function (PCEF) is also located in the PGW.

A Policy and Charging Rules Function (PCRF) is responsible for providing Policy control and Charging Rules to the PCEF.

The Home Subscriber Server (HSS) permanently stores Subscriber subscription data, and the data stored by the HSS includes an International Mobile Subscriber Identity (IMSI) of the UE and an IP address of the PGW.

Physically, the SGW and PGW may be configured as a single entity, and the EPC system user plane network element includes the SGW and PGW.

In order to support Circuit domain services, 3GPP introduces a Circuit domain fallback (CSFB) mechanism in a network, in the CSFB mechanism, an MME is connected to a Mobile Switching Center (MSC) through an SGs interface, and the MSC and a Visitor Location Register (VLR) are integrated in an actual network. When the coverage Area of the UE changes, for example, when the UE moves from a coverage Area of one Radio Access Technology (RAT) to a coverage Area of another RAT, the UE finds that the UE enters an unregistered Area by monitoring a broadcast channel, and in order to ensure continuous service between the UE and a core network, the UE needs to register under the coverage Area of the new RAT, and therefore, the UE initiates a Tracking Area Update (TAU) or Routing Area Update (RAU) procedure of accessing the RAT. Fig. 2 is a flowchart of tracking area update and SGs connection activation, as shown in fig. 2, illustrating a procedure of moving a UE registered under the coverage area of UTRAN to the coverage area of E-UTRAN and activating SGs in the TAU procedure, and for the RAU procedure initiated when the UE registered under the coverage area of E-UTRAN moves to the coverage area of UTRAN, the procedure is similar to the procedure shown in fig. 2 and will not be separately described. As shown in fig. 2, the method mainly comprises the following steps:

step 201, the UE moves to an E-UTRAN coverage area under the MME, sends a tracking area update request message to the MME, requesting registration in a new area, where the update request message carries a Packet-Temporary Mobile Subscriber Identity (P-TMSI) allocated by the SGSN for the UE.

Step 202, the new MME finds the old SGSN according to the P-TMSI identification, and sends a context request signaling to the old SGSN to acquire the context of the UE.

In step 203, the old SGSN sends the mobility management and bearer information of the user to the new MME, i.e. performs context response.

Step 204, the new MME confirms the context after receiving the context response.

Step 205, the new MME initiates an update bearer request message to the SGW, where the update bearer request message carries a source GPRS Tunneling Protocol-Control Plane (GTP-C) tunnel identifier and a destination GTP-C tunnel identifier, and the SGW updates a binding relationship of the bearer.

In step 206, the SGW sends an update bearer request to the PGW, and sends parameters such as address information of the SGW, tunnel identifier information, access technology type, and the like to the PGW.

Step 207, the PGW updates its context and returns an update bearer response message to the SGW, where the content of the response message includes the address and tunnel identifier of the PGW.

And step 208, the SGW returns an update bearer response to the new MME, and brings the destination GTP-C tunnel identifier, the address of the SGW, the address of the PGW, the tunnel information, and the like, which are specified by the SGW, to the MME.

In step 209, the new MME notifies the HSS of the change of the registered location through a location update message.

Step 210, the HSS keeps the single registration principle for the UE, sends a location cancellation signaling to the old SGSN, and only maintains the registration of the new MME.

In step 211, the old SGSN returns a location cancel response to the HSS.

In step 212, the HSS confirms the location update of the new MME.

Step 213, the MME sends a Location update request message to the MSC requesting to establish an SGs connection, where the Location update request message carries parameters such as IMSI, Location Area Identity (LAI), MME name, and Location update type;

step 214, the MSC checks the subscriber and sends a location update request message to the HSS after the check is passed;

step 215, the HSS returns a location update confirmation message to the MSC;

step 216, the MSC returns a location update accept message to the MME, where the location update accept message carries a Temporary Mobile Subscriber Identity (TMSI);

step 217, if the new MME confirms that the UE is valid in the current tracking area, sending a tracking area update accept message to the UE, where the tai accept message needs to carry LAI and TMSI;

in step 218, if the new MME allocates a new Globally Unique Temporary Identifier (GUTI) to the UE through the TAU procedure, the UE returns a tracking area update complete message to confirm to the MME.

Based on the location update principle, if the UE frequently moves between UTRAN coverage areas or E-UTRAN, or frequent registration area selection due to signal strength in the same coverage area causes a large number of TAU or RAU procedures, which causes a heavy burden for the air interface. Therefore, in the EPS system, in order to reduce the air interface Signaling between the UE and the core network, an Idle mode Signaling Reduction (ISR) function is introduced. When this functionality is activated, a UE with both UTRAN and E-UTRAN access functionality may be registered to both the MME and the SGSN. Thus, when the UE frequently moves between two different access technologies, the UE will not initiate a TAU or RAU procedure for accessing the RAT, thereby reducing unnecessary air interface signaling transmission.

The process of UE activating ISR is also performed by TAU or RAU procedures, which differ only in some specific implementation steps. The difference between the TAU flow and the ISR function will be described by taking the TAU flow as an example, and the flow for activating the ISR function by the RAU flow is similar to this case. Fig. 3 is a flowchart of activating ISR function and SGs connection through tracking area update procedure, as shown in fig. 3, which mainly includes the following steps:

step 301, the UE moves to an E-UTRAN coverage area under the MME, and the tracking area update request message sent to the MME carries information on whether the UE supports ISR capability in addition to the P-TMSI allocated by the UE under the SGSN.

Step 302, the new MME finds the old SGSN according to the P-TMSI identification, and sends a context request signaling to the old SGSN to perform a context acquisition process.

Step 303, the old SGSN sends the mobility management and bearer information of the user to the new MME, and carries the information whether the old SGSN supports ISR capability in the returned context response message.

And step 304, the new MME judges whether ISR activation is carried out or not according to the context information received from the old SGSN, and if the ISR activation is carried out, the new MME carries an ISR indication in a context confirmation message replied to the old SGSN so as to inform the old SGSN to keep the original context information of the UE.

And 305, the new MME initiates a bearer updating request message to the SGW, the bearer updating request message carries a source GTP-C tunnel identifier and a target GTP-C tunnel identifier, and the SGW updates the binding relationship of the bearer. The update bearer request message also includes an indication of activating ISR, and informs the SGW to retain the bearer context information owned by the UE under the old SGSN.

In step 306, the SGW sends an update bearer request message to the PGW due to the change of RAT.

Step 307, the PGW updates its context and returns an update bearer response message to the SGW.

And step 308, the SGW returns an update bearer response message to the new MME, where the update bearer response message carries the destination GTP-C tunnel identifier specified by the SGW, the address of the PGW, the tunnel information, and the like.

In step 309, the new MME notifies the HSS of the change of location through the location update message, and the HSS keeps the registration information of the two domains, i.e. E-UTRAN and UTRAN, and does not send the location cancellation information to the old SGSN any more.

In step 310, the HSS confirms the location update of the new MME.

Step 311, the MME sends a location update request message to the MSC requesting to establish SGs connection, where the location update request message carries parameters such as IMSI, LAI, MME name, location update type, and the like;

step 312, the MSC checks the subscriber and sends a location update request message to the HSS after the check is passed;

step 313, the HSS returns a location update confirmation message to the MSC;

step 314, the MSC returns a location update accept message to the MME, where the location update accept message carries the TMSI;

step 315, if the new MME confirms that the UE is valid in the current tracking area, sending a tracking area update accept message to the UE; and the MME informs the UE that the ISR function is activated through the tracking area update acceptance message, wherein the tracking area update acceptance message carries the LAI and the TMSI.

In step 316, if the new MME allocates a new GUTI identifier to the UE through the TAU procedure, the UE returns a tracking area update complete message to confirm to the MME.

When ISR is activated, the MSC can only establish SGs connection with the MME, but cannot establish SGs connection with the SGSN at the same time, that is, when the MSC establishes SGs connection with the SGSN, ISR association cannot be established between the MME and the SGSN. Fig. 4 is a paging flow chart of UE in idle state when ISR is activated, and as shown in fig. 4, when an MSC receives downlink paging service when ISR is activated and a user is in idle state, a processing procedure includes the following steps:

step 401, when receiving the terminating call service, the MSC sends a paging request message to the MME, where the paging request message carries the IMSI, TMSI, and location information of the user;

step 402, MME sends paging request message to eNodeB, the paging request message carries CS domain indication;

step 403, the eNodeB forwards a paging request message to the UE, where the paging request message carries a CS domain indication;

step 404, the MME forwards a CS paging indication message to the SGSN;

step 405, SGSN sends paging request message to RNC, the paging request message carries CS domain indication;

step 406, the RNC sends a paging request message to the UE, where the paging request message carries a CS domain indication.

And after receiving the paging, the UE returns a paging response.

In an actual network, an MME or SGSN may fail for some reason, resulting in a restart or downtime. When the mobile management unit is restarted or crashed, the UE cannot be contacted, so that the UE cannot receive the paging service.

Disclosure of Invention

In view of the above, the main objective of the present invention is to provide a method and a system for paging a UE when a mobility management unit fails or restarts, which can successfully implement paging for the UE when an MME or an SGSN fails or restarts.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a method for paging user equipment when a mobile management unit fails or restarts comprises the following steps:

when the ISR function is activated, when the mobile management unit registered by the UE is determined to be invalid or restarted, the UE is paged through the mobile management unit unregistered by the UE or the restarted mobile management unit.

Preferably, the mobility management unit is an MME and/or an SGSN.

Preferably, the UE registered mobility management unit fails or restarts to:

one of the MME and the SGSN registered by the UE fails or restarts.

Preferably, when the MME registered by the UE fails or is restarted, the paging of the UE by the unregistered mobility management unit of the UE or the restarted mobility management unit is implemented as follows:

when receiving the terminal call service aiming at the UE, the MSC selects other non-invalid MME or restarted MME to send a paging request message; the selected MME triggers the SGSN registered by the UE in the ISR to carry out paging.

Preferably, the triggering, by the selected MME, the paging by the SGSN registered by the UE in the ISR is:

the selected MME sends a location update message to a Home Subscriber Server (HSS); the location update message carries a recovery indication;

the HSS returns the SGSN address information to the selected MME;

the selected MME sends a circuit domain CS paging indication message to the SGSN;

and after receiving the CS paging indication message, the SGSN inquires the packet temporary mobile subscriber identity (P-TMSI) of the UE and pages the UE.

Preferably, the method further comprises:

the SGSN adopts the P-TMSI reallocation process to ensure that the UE carries out routing area updating again;

or, the UE carries out paging according to the obtained international mobile subscriber identity IMSI and carries out attachment again; wherein the CS paging indication message carries the IMSI of the UE.

Preferably, when the SGSN registered by the UE is invalid or restarted, the paging of the UE by the unregistered mobility management unit or the restarted mobility management unit of the UE is:

and after receiving the paging request message sent by the MSC, the MME registered by the UE in the ISR selects other non-failed SGSNs or restarted SGSNs, and triggers the selected SGSN to page the UE.

Preferably, the triggering the selected SGSN to page the UE is:

the MME registered by the UE in ISR sends a CS paging indication message to the selected SGSN; the CS paging indication message carries the location information of the UE in the MME or MSC registered by the UE;

after receiving the CS paging indication message, the SGSN directly pages the UE or pages the UE according to the area determined by the position information of the UE.

Preferably, the method further comprises:

the MME re-allocates a globally unique temporary identifier GUTI to enable the UE to re-initiate a tracking area update TAU process;

A paging system of user equipment when a mobile management unit fails or restarts comprises the mobile management unit, the mobile management unit comprises an MME and/or an SGSN, and the system supports an ISR function; wherein,

the method and the device are used for realizing paging of the UE through the unregistered mobile management unit or the restarted mobile management unit of the UE when the ISR function is activated and the mobile management unit registered by the UE is determined to be invalid or restarted.

Preferably, the UE registered mobility management unit fails or restarts to: one of the MME and the SGSN registered by the UE fails or restarts.

Preferably, the system further comprises an MSC;

the MSC is used for selecting other non-failed MME or restarted MME to send a paging request message when MME registered by the UE fails or is restarted and receives a terminal call service aiming at the UE;

the selected MME is further configured to trigger paging by the SGSN of the UE registration in ISR.

Preferably, the system further comprises a HSS;

the selected MME is further configured to send a location update message to the HSS; the location update message carries a recovery indication; and sending a circuit domain CS paging indication message to the SGSN;

the HSS is further configured to return the SGSN address information to the selected MME;

the SGSN is further used for inquiring the P-TMSI of the UE after receiving the CS paging indication message and paging the UE.

Preferably, the SGSN is further configured to cause the UE to perform the routing area update again using a P-TMSI reallocation procedure.

Preferably, the MME registered by the UE in the ISR is configured to, after receiving a paging request message sent by the MSC when an SGSN registered by the UE fails or is restarted, select another SGSN that has not failed or a restarted SGSN, and trigger the selected SGSN to page the UE.

Preferably, the MME registered by the UE in ISR is further configured to send a CS paging indication message to the selected SGSN; the CS paging indication message carries the location information of the UE in the MME or MSC registered by the UE;

the SGSN is further configured to directly page the UE after receiving the CS paging indication message, or page the UE according to an area determined by the location information of the UE.

Preferably, the MME is further configured to cause the UE to re-initiate the TAU procedure with GUTI re-allocation.

Preferably, the UE performs reattachment according to the obtained IMSI paging; wherein the CS paging indication message carries the IMSI of the UE.

In the invention, when the MME or SGSN under the ISR function is invalid or restarted, the system re-determines other non-invalid SGSNs or MMEs, or re-determines the restarted SGSN or MME to initiate paging to the UE, thereby ensuring that the paging to the UE can be realized when the MME or SGSN is invalid or restarted, and avoiding the phenomenon that the UE cannot be contacted after the mobility management unit in the CS service is restarted or crashed. The invention ensures the continuity and stability of the UE service and improves the service quality of the CS service.

Drawings

FIG. 1 is a schematic diagram of an SAE architecture;

FIG. 2 is a flow chart of tracking area update and SGs connection activation;

FIG. 3 is a flow chart for activating ISR functionality and SGs connectivity through a tracking area update procedure;

FIG. 4 is a paging flowchart of the UE in idle state when ISR is activated;

fig. 5 is a flowchart of a method for paging a UE when an MME fails or is restarted when ISR is activated according to an embodiment of the present invention;

fig. 6 is a flowchart of a method for paging a UE when an SGSN is disabled or restarted when ISR is activated according to an embodiment of the present invention;

fig. 7 is a flowchart of a method for paging a ue when a mobility management unit fails or restarts in accordance with a first embodiment of the present invention;

fig. 8 is a flowchart of a method for paging a ue when a mobility management unit fails or restarts in accordance with a second embodiment of the present invention;

fig. 9 is a flowchart of a method for paging a ue when a mobility management unit fails or restarts in accordance with a third embodiment of the present invention;

fig. 10 is a flowchart of a method for paging a ue when a mobility management unit fails or restarts in accordance with a fourth embodiment of the present invention.

Detailed Description

The basic idea of the invention is as follows: when the MME or SGSN under the ISR function is invalid or restarted, the system will re-determine other non-invalid SGSNs or MMEs, or re-determine the restarted SGSN or MME to initiate paging to the UE, so as to ensure that the paging to the UE can be realized when the MME or SGSN is invalid or restarted.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings by way of examples.

Fig. 5 is a flowchart of a method for paging a UE when an MME fails or restarts when ISR is activated according to an embodiment of the present invention, and as shown in fig. 5, in order to avoid a phenomenon that the MME restarts or cannot contact the UE after the MME restarts or cannot normally operate when ISR is activated in a CS service, the method for paging a UE when the MME fails or restarts of the present invention mainly includes the following steps:

step 501, when detecting that the MME restarts or cannot work normally, the MSC may reselect an MME or a recovered MME; the MSC sends a paging request message to the selected MME, the message carries the IMSI,

step 502, MME performs IMSI paging;

step 503, because the UE may be registered in the MME and the SGSN at the same time, the MME sends a location update request message to the HSS, and the location update request message carries a recovery indication for indicating the HSS to return to the address of the SGSN;

step 504, MME sends CS paging indication message to SGSN according to SGSN address returned by HSS, the CS paging indication message carries IMSI of UE, SGSN can make P-TMSI inquiry and P-TMSI paging according to IMSI of UE;

step 505, after receiving the P-TMSI paging, the UE performs a service request process, the SGSN may also use a P-TMSI reallocation process to make the UE perform an RAU process again, and in the RAU process, the SGSN may notify the UE to release ISR; if the UE receives the IMSI paging of the MME, the UE will perform the attachment process again.

Fig. 6 is a flowchart of a method for paging a UE when an SGSN fails or is restarted when ISR is activated according to an embodiment of the present invention, and as shown in fig. 6, the method for paging a UE when an MME fails or is restarted when ISR is activated mainly includes the following steps:

step 601, when ISR is activated, MME receives paging request message sent by MSC;

step 602, the MME performs a packet Temporary Mobile Subscriber Identity (S-TMSI, Service-Temporary Mobile Subscriber Identity) paging in the TAI list;

step 603, the MME selects a normal SGSN (other SGSNs or a restored SGSN), sends a CS paging indication message, where the message carries the IMSI of the UE and may carry location information of the UE in the MME or the MSC; the SGSN determines an area in which the IMSI paging is carried out on the UE according to the position information provided by the UE in the MME or the MSC;

step 604, after receiving the S-TMSI paging, the UE initiates a service request procedure, the MME may initiate a GUTI re-allocation procedure to trigger the UE to re-initiate a TAU procedure, and in the TAU procedure, the MME may notify the UE to release ISR; if the UE receives an IMSI page from the SGSN, the UE will re-attach.

Example one

The application scenario of the first embodiment of the invention is as follows: the UE is in an idle state under the MME and the SGSN, the MME is in a fault and restarts or can not work normally, and the UE receives IMSI paging. Fig. 7 is a flowchart of a method for paging a user equipment when a mobility management unit fails or restarts in a first embodiment of the present invention, and as shown in fig. 7, the method for paging a user equipment when a mobility management unit fails or restarts mainly includes the following steps:

step 701, after the MME restarts or fails to work normally, the MSC receives the terminating service, the MSC reselects an MME or an MME that has recovered from the failure and sends a CS paging message, where the message carries the IMSI of the UE;

step 702, after the MME receives the CS paging message, because the MME has no related information of the UE, the MME uses the IMSI to perform paging, and the MME sends an IMSI paging message to the eNodeB;

step 703, the eNodeB sends an IMSI paging message to the UE;

step 704, the MME sends a location update request message to the HSS, where the message carries the IMSI and carries a recovery indication for indicating the HSS to return to the address of the SGSN;

step 705, the HSS returns a location update response message to the MME, where the message carries the address of the SGSN;

step 706, after the MME acquires the SGSN address, the MME sends a CS paging indication message to the SGSN, where the message carries the IMSI;

step 707, the SGSN searches the P-TMSI of the UE according to the IMSI and sends a paging message to the RNC; if UE related information does not exist in the SGSN, the SGSN sends an IMSI paging message to the RNC;

step 708, the RNC forwards the paging message to the UE;

step 709, after the UE receives the IMSI paging message of the eNodeB or RNC, the UE releases its own information and reattaches to the network.

Example two

The second embodiment of the present invention has the following application scenarios: the UE is in an idle state under the MME and the SGSN, the MME is in a fault restart state or can not work normally, and the UE receives the P-TMSI paging. Fig. 8 is a flowchart of a method for paging a user equipment when a mobility management unit fails or restarts in accordance with a second embodiment of the present invention, and as shown in fig. 8, the method for paging a user equipment when a mobility management unit fails or restarts mainly includes the following steps:

step 801, after the MME restarts or fails to work normally, the MSC receives the terminating service, the MSC reselects one MME or the MME that has recovered from the failure and sends a CS paging message, where the message carries the IMSI of the UE;

step 802, after the MME receives the CS paging message, because the MME has no related information of the UE, the MME uses the IMSI to perform paging, and the MME sends an IMSI paging message to the eNodeB;

step 803, the eNodeB sends an IMSI paging message to the UE;

step 804, the MME sends a location update request message to the HSS, wherein the message carries the IMSI and carries a recovery indication for indicating the HSS to return to the address of the SGSN;

step 805, the HSS returns a location update response message to the MME, where the message carries the address of the SGSN;

step 806, after the MME acquires the SGSN address, the MME sends a CS paging indication message to the SGSN, where the message carries the IMSI;

step 807, SGSN searches for P-TMSI of UE according to IMSI and sends paging message to RNC;

step 808, the RNC sends a paging message to the UE;

step 809, after the UE receives the P-TMSI paging message, the UE initiates a service request process;

step 810, the RNC forwards the service request message to the SGSN;

step 811, after the SGSN receives the service request message, the SGSN sends a P-TMSI reallocation message to the RNC, and the message carries the P-TMSI and the new RAI;

step 812, the RNC forwards the P-TMSI reallocation message to the UE;

step 813, after the UE receives the new RAI, the UE sends an RAU request message to the RNC;

step 814, the RNC forwards the RAU request message to the SGSN;

step 815, the SGSN returns an RAU accept message to the RNC, and the RAU accept message does not carry an ISR activation indication, so that the RAU accept message can be used to release the ISR of the UE;

step 816; and the RNC forwards an RAU acceptance message to the UE, and the RAU acceptance message does not carry an ISR activation indication, so that the UE can release the ISR.

In this example, signaling interaction between the MME/SGSN and the SGW and PGW, which is not related to implementation of the technical solution of the present invention, is omitted.

EXAMPLE III

The third application scenario of the embodiment of the invention is as follows: the UE is in an idle state under the MME and the SGSN, the SGSN is in a fault state and is restarted or can not work normally, and the UE receives S-TMSI paging. Fig. 9 is a flowchart of a method for paging a user equipment when a mobility management unit fails or restarts in a third embodiment of the present invention, and as shown in fig. 9, the method for paging a user equipment when a mobility management unit fails or restarts mainly includes the following steps:

step 901, after receiving the terminating call service, the MSC sends a CS paging message to the MME, where the message carries IMSI, TMSI, and location information;

step 902, the MME sends an S-TMSI paging to the eNodeB;

step 903, eNodeB forwards S-TMSI paging to UE;

step 904, the MME reselects a normal SGSN, which may be another normal SGSN or a SGSN that has been restarted and recovered, and the MME sends a CS paging indication message to the selected SGSN, where the message carries the IMSI of the UE, the location information of the UE in the MME, or the location information in the MSC;

step 905, the SGSN determines an IMSI paging range according to the location information obtained in step 904, and then the SGSN sends an IMSI paging in the IMSI paging range;

step 906, the RNC forwards the IMSI paging;

step 907, after receiving the S-TMSI paging sent by the MME, the UE initiates a service request process;

step 908, the eNodeB sends a service request to the MME;

step 909, the MME sends an initial context setup request message to the eNodeB, where the message carries the user plane address and TEID of the SGW, EPS bearer QoS;

step 910, the eNodeB sends a radio bearer establishment request message to the UE;

911, the UE returns a radio bearer establishment response message to the eNodeB;

step 912, the eNodeB returns an initial context setup complete message to the MME, where the message carries the user plane address and TEID of the eNodeB;

step 913, the MME initiates a GUTI re-allocation message to the eNode B, where the message carries the GUTI and the new TAI list;

step 914, the eNodeB sends a GUTI re-allocation message to the UE;

step 915, after receiving the new TAI list, the UE initiates a TAU procedure;

step 916, the eNodeB forwards the TAU request message to the MME;

step 917, the MME sends a TAU accept message to the eNodeB, and the RAU accept message does not carry an ISR activation indication, so that it can be used to release ISR of the UE;

step 918; the eNodeB forwards the TAU acceptance message to the UE, and the TAU acceptance message does not carry the ISR activation indication, so that the UE can release the ISR.

Example four

The fourth application scenario of the embodiment of the invention is as follows: the UE is in an idle state under the MME and the SGSN, the SGSN is in a fault state and is restarted or can not work normally, and the UE receives IMSI paging sent by the SGSN. Fig. 10 is a flowchart of a method for paging a user equipment when a mobility management unit fails or restarts in a fourth embodiment of the present invention, and as shown in fig. 10, the method for paging a user equipment when a mobility management unit fails or restarts mainly includes the following steps:

1001, after receiving the terminating call service, the MSC sends a CS paging message to the MME, where the message carries IMSI, TMSI, and location information;

step 1002, MME sends S-TMSI paging to eNodeB;

step 1003, eNodeB forwards S-TMSI paging to UE;

step 1004, the MME reselects a normal SGSN, which may be another SGSN or a SGSN that has been restarted and recovered, and the MME sends a CS paging indication message to the selected SGSN, where the message carries the IMSI of the UE, the location information of the UE in the MME, or the location information in the MSC;

step 1005, the SGSN determines the IMSI paging range according to the position information obtained in step 1004, and then the SGSN sends IMSI paging in the IMSI paging range;

step 1006, the RNC forwards the IMSI paging;

step 1007, after the UE receives the IMSI page, the UE will reinitiate the attach procedure.

The invention also discloses a paging system of the user equipment when the mobile management unit fails or restarts, which comprises the mobile management unit, wherein the mobile management unit comprises an MME and/or an SGSN, and the system supports an ISR function;

when the ISR function is activated and the mobile management unit registered by the UE is determined to be invalid or restarted, the UE is paged through the unregistered mobile management unit or the restarted mobile management unit of the UE.

Those skilled in the art will understand that the present invention has no modification to the existing network system structure, and therefore, the related network elements and their structure can be understood by referring to the system architecture shown in fig. 1. In the following, the new functionality implemented by the network element, the functionality of which is improved, is described with emphasis.

The failure of the mobility management unit registered by the UE is: one of the MME and the SGSN with which the UE is registered is failed. In the present invention, the term "failure" mainly means that the mobility management unit is unavailable, such as being in an unavailable state, such as a failure or a dropped connection, or being powered off and being reset.

The above-mentioned UE registered mobility management unit fails or restarts to: one of the MME and the SGSN registered by the UE fails or restarts.

The paging system of the user equipment when the mobile management unit is invalid also comprises an MSC;

The paging system of the user equipment when the mobile management unit is invalid also comprises an HSS;

The SGSN is further used for adopting a P-TMSI reallocation process to enable the UE to carry out routing area updating again.

And the MME registered by the UE in the ISR is used for selecting other non-failed SGSNs or restarted SGSNs after receiving the paging request message sent by the MSC when the SGSN registered by the UE fails or is restarted, and triggering the selected SGSN to page the UE.

The MME registered by the UE in ISR is further used for sending a CS paging indication message to the selected SGSN; the CS paging indication message carries the location information of the UE in the MME or MSC registered by the UE;

The MME is further used for enabling the UE to initiate TAU procedures again by adopting GUTI reallocation.

The UE carries out paging according to the obtained IMSI and carries out attachment again; wherein the CS paging indication message carries the IMSI of the UE.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

Claims

1. A method for paging a user equipment when a mobility management unit fails or restarts, the method comprising:

when an air interface signaling reduction ISR function is activated, when determining that a mobile management unit registered by User Equipment (UE) is invalid or restarted, paging the UE is realized through a mobile management unit unregistered by the UE or the restarted mobile management unit and an International Mobile Subscriber Identity (IMSI);

the mobile management unit is a mobile management entity MME and/or a serving general packet radio service GPRS support node SGSN; the UE is registered at an MME and an SGSN simultaneously; the MME which is not registered by the UE is selected through a Mobile Switching Center (MSC); and the SGSN of the UE which is not registered is selected by the MME.

2. The method of claim 1, wherein the mobility management unit that the UE is registered with fails or restarts as:

one of the MME and the SGSN registered by the UE fails or restarts.

3. The method of claim 2, wherein when the MME registered by the UE fails or is restarted, the paging of the UE performed by the MME unregistered by the UE or the MME that is restarted is:

when receiving a terminal call service aiming at the UE, a Mobile Switching Center (MSC) selects other non-invalid MME or a restarted MME to send a paging request message; the selected MME triggers the SGSN registered by the UE in the ISR to carry out paging.

4. The method of claim 3, wherein the selected MME triggers the SGSN of the ISR with which the UE is registered to page:

the HSS returns the SGSN address information to the selected MME;

5. The method of claim 4, further comprising:

or, the UE performs attachment again according to the obtained IMSI paging; wherein the CS paging indication message carries the IMSI of the UE.

6. The method of claim 2, wherein when the SGSN registered by the UE fails or is restarted, the paging of the UE performed by the UE unregistered mobility management unit or the restarted mobility management unit is:

7. The method of claim 6, wherein the triggering the selected SGSN to page the UE is:

8. The method of claim 7, further comprising:

9. A paging system of user equipment when a mobile management unit fails or restarts comprises the mobile management unit, wherein the system supports an ISR function; it is characterized in that the preparation method is characterized in that,

the method comprises the steps that when the ISR function is activated and the mobile management unit registered by the UE is determined to be invalid or restarted, paging of the UE is achieved through the unregistered mobile management unit or the restarted mobile management unit of the UE and an International Mobile Subscriber Identity (IMSI);

wherein, the mobile management unit is MME and/or SGSN; the UE is registered at an MME and an SGSN simultaneously; the MME which is not registered by the UE is selected through the MSC; and the SGSN of the UE which is not registered is selected by the MME.

10. The system of claim 9, wherein the mobility management unit that the UE is registered with is disabled or restarted as: one of the MME and the SGSN registered by the UE fails or restarts.

11. The system of claim 10, wherein the system further comprises an MSC;

12. The system of claim 11, further comprising an HSS;

13. The system of claim 12,

14. The system of claim 10,

15. The system of claim 14,

16. The system of claim 15,

17. The system according to any of claims 9 to 16, wherein the UE re-attaches according to the obtained IMSI page; wherein the CS paging indication message carries the IMSI of the UE.