CN105813146B

CN105813146B - Service flow transmission path optimization method and device and MME

Info

Publication number: CN105813146B
Application number: CN201410854999.6A
Authority: CN
Inventors: 毛玉欣; 王静
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2014-12-31
Filing date: 2014-12-31
Publication date: 2020-09-08
Anticipated expiration: 2034-12-31
Also published as: CN105813146A; WO2016107404A1

Abstract

The invention discloses a method, a device and an MME (mobility management entity) for optimizing a service flow transmission path, wherein the method comprises the following steps: when a Mobility Management Entity (MME) is switched in the switching process of User Equipment (UE), acquiring packet data gateway (P-GW) adjustment CSIPTO indication information of the UE for unloading a specified Internet Protocol (IP) flow from a source MME or a Home Subscriber Server (HSS) serving the UE before switching; according to CSIPTO indication information, a first P-GW is selected for an APN of the UE, a first packet data network PDN connection is established based on the first P-GW, a second P-GW is selected for the APN of the UE, and a second PDN connection is established based on the second P-GW; and optimizing the service flow transmission path of the UE according to the established first PDN connection and/or second PDN connection, and achieving the effect of saving network resource overhead by optimizing a data routing path.

Description

Service flow transmission path optimization method and device and MME

Technical Field

The present invention relates to the field of communications, and in particular, to a method and an apparatus for optimizing a traffic flow transmission path, and an MME.

Background

An Evolved Packet System (EPS) network architecture is developed by the third Generation Partnership Project (3rd Generation Partnership Project (3 GPP), and fig. 1 is a schematic diagram of an EPS System architecture in the related art, as shown in fig. 1. The architecture is composed of an Evolved universal Radio Access Network (Evolved universal Radio Access Network, abbreviated as E-UTRAN), a mobile management Entity (mobility management Entity, abbreviated as MME), a Serving Gateway (Serving Gateway, abbreviated as S-GW), a Packet Data Network Gateway (Packet Data Network Gateway, abbreviated as P-GW), a Home subscriber server (Home subscriber server, abbreviated as HSS), a Policy and Charging Rules Function (Policy and Charging Rules Function, abbreviated as PCRF), and other support nodes.

The MME is responsible for mobility management, processing of non-access stratum signaling, management of user mobility management context and other control plane related work, selection of P-GW and S-GW, mobile phone reachability management in an idle state, selection of a tracking area list and other functions.

The S-GW is an access gateway device connected with the E-UTRAN, and the functions of the S-GW comprise: the local anchor point serving as the inter-eNodeB handover forwards data between the E-UTRAN and the P-GW, and is responsible for caching paging waiting data, lawful monitoring, routing of data messages and realizing charging based on a user and a quality of service identifier (QoS ClassIdentifier, abbreviated as QCI) under the condition that the user accesses the inter-operator.

The P-GW is a border gateway between the EPS system and the PDN network, and its functions include: user terminal IP address allocation, user data message filtering, Quality of Service (QoS) label management of transport layer message, charging based on Service flow, Dynamic Host configuration version4/version6 protocol (Dynamic Host configuration protocol version4/version6, DHCPv4/v6) function, downlink Rate guarantee based on aggregation maximum Rate (AMBR), downlink Rate guarantee based on accumulated MBR of same Guaranteed Rate (GBR) QCI, and functions of responsible for uplink and downlink bearing binding and legal monitoring.

The PCRF is a policy and charging rule function entity, which is connected with an operator network protocol (Internet protocol for short) service network through an Rx interface to acquire service information, generates QoS and charging policies by the PCRF, and issues the QoS and charging policies to a policy execution function to execute through a Gx/Gxc interface. The Policy Enforcement Function may be Policy and Charging Enforcement Function (PCEF) located on the P-GW or Bearer Binding and Event Reporting Function (BBERF) located on the S-GW.

The 3GPP existing system defines that a User Equipment (UE) must establish a PDN connection with a PDN network via an access network, e.g., an E-UTRAN, before data services can be deployed. Fig. 2 is a flowchart of PDN connection establishment in the related art, and as shown in fig. 2, the flowchart includes the following steps:

step 1, the UE initiates a Non-Access Stratum (NAS) message, i.e. a PDN connection establishment request message. The message carries information such as an Access Point Name (APN), a PDN Type, a Protocol Configuration Option (PCO), a Request Type, and the like.

Wherein the PDN Type is used for indicating whether the Type of the IP address requested by the UE is IPv4, IPv4v6 or IPv 6; the PCO is used for transmitting information between the UE and the P-GW, and the information is transmitted on the MME and the S-GW; the Request Type is used to indicate whether "initial Request" or "handover"; and the APN is used as a basis for MME to select P-GW.

When the MME receives an APN, it needs to verify whether the APN is allowed to be used by the user according to the user subscription information. If the request message does not carry the APN, the MME selects a Default APN carried in the Default PDN Subscription Context to be used by the subsequent procedure.

And 2, the MME processes the request message.

If the Request Type in step 1 indicates "handover", the MME needs to use the P-GW address saved in the user data. The P-GW address is retrieved and saved by the MME during the location update performed in the attach procedure. And if the Request Type in the step 1 indicates 'initial Request', the MME needs to execute a P-GW selection program, and selects a P-GW for establishing connection between the UE and the PDN network corresponding to the APN according to the APN, the P-GW capacity, the UE position information and the like.

MME allocates a Bearer ID for user request and initiates a create session request message to S-GW. The message carries Information such as International Mobile subscriber identity (International Mobile subscriber identity Number, abbreviated as IMSI), Mobile subscriber ISDN Number (Mobile subscriber International ISDN Number, abbreviated as MSISDN), RAT Type (radio access Type), P-GW Address (P-GW Address), PDN Address (PDN Address), Default Bearer QoS (Default Bearer QoS), PDN Type (PDN Type), Subscribed APN-AMBR (APN-AMBR), APN, EPS Bearer ID (EPS Bearer identity), PCO, ECGI (User Location Information ), and the like.

If the Request Type indicates "Handover", it is also necessary to include Handover Indication information.

And 3, the S-GW creates a new record on the EPS Bearer table of the S-GW and sends a session creation request message to the P-GW. Wherein the P-GW address is obtained by the MME performing the P-GW selection procedure in step 2. The message carries: IMSI, MSISDN, RAT Type, PDN Type, Default EPS Bearer QoS, Subscribed APN-AMBR, PDNAddress, APN, EPS Bearer ID, PCO, ECGI and other information.

After this step is completed, the S-GW buffers the downlink data from the P-GW until receiving the step 13 message from the MME.

And 4, after the P-GW receives the session establishment request, if the session establishment request is not the switching situation, initiating IP-CAN session establishment to the PCRF. The PCRF returns the default PCC rules for the UE to the P-GW. And simultaneously, the establishment process of the special bearer can be triggered.

If the P-GW receives the instruction of the Handover Indication, the P-GW initiates the process of modifying the IP-CAN session and reports the new IP-CAN Type to the PCRF.

And 5, the P-GW creates a new record in the EPS bearer context list and creates a Charging ID (Charging identification) for the default bearer. This record allows the P-GW to interact data between the S-GW and the PDN network and initiate charging.

The P-GW returns a create session response message to the S-GW. The message carries information such as P-GW Address, PDN Address, PDNType, EPS Bearer ID, EPS Bearer QoS, PCO, Charging ID, MS Info Change action (Start), APN-AMBR and the like.

The PDN Type is used to return the address of the PDN network to the UE. If it is a handover case, the PDN network address returned to the UE should remain unchanged before and after the handover.

If the situation is 'switching', the P-GW can not send the downlink data message to the S-GW.

And 6, the S-GW returns a session creation response message to the MME. Carrying messages: PDN Type, PDN Address, P-GW Address, EPS Bearer ID, EPS Bearer QoS, PCO, MS Info Change Reporting Action (Start), APN-AMBR and other information.

If it is a handover situation, sending the message to the MME also indicates that the bearer between the S-GW and the P-GW has been established.

Step 7, if the MME receives MS Info Change Reporting Action (Start) information from the bearer context, the MME needs to store the information for the bearer context. When the terminal location information changes, the MME needs to report the UE location information to the P-GW through the S-GW. The MME needs to modify the UE-AMBR allocated to the eNodeB based on the UE-AMBR the user has subscribed to and all APN-AMBRs currently in use.

And the MME returns a PDN connection establishment response message to the UE. The message carries: APN, PDN Type, PDN Address, EPS Bearer ID, Session Management Request, PCO, and the like.

This message is sent to the eNodeB in an S1_ MME control message, i.e. a bearer setup request message. The message also includes: a response message of PDN connection establishment, EPS Bearer QoS, UE-AMBR, S-GW Address and other information.

If it is the case of SIPTO at the Local Network (selective IP flow is offloaded from Local Network), the S1_ MME control message, i.e. the bearer establishment request message, further contains a SIPTO Correlation ID (SIPTO association ID). SIPTO Correlation ID is used to identify the direct transmission channel of HeNB and L-GW.

The Session Management Request carries APN-AMBR and QCI information. If UE supports UTRAN or GERAN (GSM EDGE Radio Access Network, GSM/EDGE Radio Access Network) Access, MME also generates corresponding information such as QoS negotiation parameters, Radio Priority, Packet Flow ID, TI and the like above and below PDP according to the EPSBearer QoS parameters, and the information is also included in the session management request.

And 8, the eNodeB sends an RRC link reconfiguration message to the UE. The message carries a PDN connection establishment response message.

The UE stores the message in the session management request, namely parameters such as QoS negotiation parameter, Radio Priority, Packet FlowID, TI and the like, so that the UE can be accessed through GERAN or UTRAN.

The UE provides the EPS Bearer QoS parameter to the application for handling traffic flow.

If the IPv4 address value received by the UE is 0.0.0.0, the UE performs IPv4 address negotiation using DHCPv 4. And if the UE receives the IPv6 interface identifier, waiting for IPv6prefix information carried in the Router Advertisement message from the network.

And 9, the UE sends an RRC link reconfiguration completion message to the eNodeB.

And step 10, the eNodeB returns an S1-AP bearer establishment response message to the MME.

If the SIPTO Correlation ID is included in step 7, the eNodeB uses this information to establish a direct data channel between the eNodeB and the L-GW.

And step 11, establishing a PDN connection establishment response message by the NAS layer of the UE, wherein the message comprises EPS Bearer ID information. The UE sends a direct transfer message (PDN connection setup response) to the eNodeB.

And step 12, the eNodeB sends an uplink NAS transmission message (PDN connection establishment response) to the MME.

After sending the PDN connection establishment response message, if the UE has acquired the PDN address information, the UE may send an uplink data packet through the eNodeB, and the data packet may be transmitted to the S-GW and the P-GW through a tunnel.

And step 13, after receiving the response message of the bearer establishment in the step 10 and the response message of the PDN connection establishment in the step 12, the MME sends a request message of bearer modification to the S-GW. The message carries: EPS Bearer ID, eNodeB address, Handover Indication and the like. The Handover Indication is provided in the case where the Request Type indicates "Handover".

Step 14, if the Handover Indication is included in step 13, the S-GW sends a bearer modification request message to the P-GW, which triggers the P-GW to change the tunnel with the non-3 GPP IP access to the tunnel between the 3GPP access systems, and immediately routes the messages on the default EPS bearer and all dedicated EPS bearers to the S-GW.

And 15, the P-GW returns a bearing modification response to the S-GW.

And step 16, the S-GW returns a bearer modification response to the MME. The S-GW may then send the locally blocked downlink message to the UE.

Step 17, after the MME receives the bearer modification response message in step 16, if the Request Type does not indicate "handover" and an EPS bearer is established, if the user subscription data indicates that the UE is allowed to perform handover to the non-3 GPP access system, and if the PDN connection is the first PDN connection corresponding to the APN and the P-GW address selected by the MME is different from the P-GW address in the PDN user context indicated by the HSS before, the MME needs to send an information report Request message to the HSS. The message carries the address of the P-GW and the APN used for establishing the PDN connection, and in addition, needs to carry information indicating which PLMN the P-GW is located in.

And step 18, the HSS stores the P-GW identification and the APN corresponding to the P-GW identification, and returns an information reporting response message to the MME.

The UE will establish a default PDN connection during the attach to the network. In the subsequent service development process, the UE may also establish PDN connections to other PDN networks, as needed. Each PDN network corresponds to one APN, and the UE needs to send the corresponding APN to the MME when the UE wants to establish connection with the PDN network, so that the MME can select a P-GW for the user. And the P-GW is a connection point between the UE and the PDN network, and the UE establishes PDN connection with the P-GW according to the P-GW selected by the MME. Furthermore, multiple PDN connections may be established between the UE and the same PDN network, if necessary, i.e. multiple PDN connections may be established for the same APN, but existing systems provide that these multiple PDN connections must use the same P-GW.

The 3GPP system also defines that reference is needed for APN information, geographical location of the user, P-GW capability (e.g., capacity), etc. when selecting the P-GW needed for establishing PDN connection for the UE. And finally, a P-GW selection functional entity, such as MME, determines a P-GW list for the UE to establish the PDN connection according to the reference information. Each P-GW in the list has a corresponding weight information, and a suitable P-GW (with the highest or lowest weight) is selected for the UE to establish the PDN connection.

Fig. 3 is a schematic diagram of data routing performed in a user handover scenario in the related art, and as shown in fig. 3, when a User Equipment (UE) accesses from a wireless network in an area a, a P-GW selection mechanism selects a P-GW1, a P-GW2, and a P-GW3 according to information such as an APN, a P-GW capacity, and a UE geographical location provided when the UE accesses, so that the UE can establish a PDN connection corresponding to the APN.

The current access location of the UE is closer to P-GW1, selecting P-GW1 to establish PDN connection 1. The dotted line a is the data service that is carried out through the PDN connection 1 after the UE access.

Thereafter, the UE moves from area a to area B, i.e., handover across access areas occurs. In order to ensure that the user service experience is not affected during the handover process, the network mechanism of the related art provides that the service continuity must be ensured, that is, when the UE accesses through the area B, although the S-GW2 closer to the area B is selected to access the UE, and the P-GW2 closer to the area B can also provide the PDN connection between the UE and the PDN network, the UE must still use the PDN connection 1 established by the P-GW1, as shown by the dashed line B in the figure, to develop the service. Thus, the data service developed when the UE moves to the area B is not interrupted.

In the UE moving process, the P-GW1 is used as the anchor point, which ensures that the service experience in the user moving process is not affected, but also causes data routing detour, that is, a closer P-GW2 can be selected for data routing after the original movement, and now the P-GW1 farther from the access area B must still be used for data routing, which inevitably results in unreasonable use of network resources.

Therefore, the transmission path of the data stream in the related art has a problem of resource waste.

Disclosure of Invention

The invention provides a method and a device for optimizing a transmission path of a service flow and an MME (mobility management entity), which are used for at least solving the problem of resource waste of the transmission path of the data flow in the related technology.

According to an aspect of the present invention, there is provided a method for optimizing a traffic stream transmission path, including: when a Mobility Management Entity (MME) is switched in the switching process of User Equipment (UE), acquiring packet data gateway (P-GW) adjustment CSIPTO indication information of the UE for unloading an appointed Internet Protocol (IP) stream from a source MME or a Home Subscriber Server (HSS) serving the UE before switching; according to the CSIPTO indication information, selecting a first P-GW for an APN of the UE, establishing a first Packet Data Network (PDN) connection based on the first P-GW, selecting a second P-GW for the APN of the UE, and establishing a second PDN connection based on the second P-GW; and optimizing the service flow transmission path of the UE according to the established first PDN connection and/or the established second PDN connection.

Preferably, before the UE is switched, when all services of the UE are carried in one PDN connection, according to the CSIPTO indication information, selecting a first P-GW for an APN of an access point name of the UE, establishing a first packet data network PDN connection based on the first P-GW, selecting a second P-GW for the APN of the UE, and establishing a second PDN connection based on the second P-GW; and optimizing the traffic flow transmission path of the UE according to the established first PDN connection and/or second PDN connection comprises the following steps: and in the UE switching process, reserving the PDN connection before UE switching as the first PDN connection, releasing the service without service continuity requirement in the first PDN connection, continuously carrying the service with service continuity requirement, selecting the second P-GW to establish the second PDN connection according to the current access position of the UE, and adopting the second PDN connection to carry the service without service continuity requirement and all services newly developed after UE switching.

Preferably, the optimizing a traffic flow transmission path of the UE according to the established first PDN connection and/or the established second PDN connection includes: and allocating PDN connection priority to the first PDN connection and the second PDN connection, wherein the priority of the second PDN connection is higher than that of the first PDN connection, and the newly-developed service of the UE after switching is carried by using the second PDN connection preferentially according to the PDN connection priority.

Preferably, the policy and charging rule functions PCRF selected by the first P-GW and the second P-GW are the same.

Preferably, when an MME handover occurs in the UE handover process, the obtaining the CSIPTO indication information of the UE from the source MME or the HSS serving the UE before the UE handover includes: after receiving a tracking area update TAU request of the UE, acquiring the CSIPTO indication information from the source MME in a context channel established with the source MME; or, after the UE completes the TAU procedure, acquiring the CSIPTO indication information from the HSS.

According to still another aspect of the present invention, there is provided a traffic flow transmission path optimization apparatus, including: an obtaining module, configured to obtain packet data gateway P-GW adjustment CSIPTO indication information for offloading an IP stream of a designated internet protocol from a source MME or a home subscriber server HSS serving a UE before handover when a mobility management entity MME handover occurs in a handover process of the UE; an establishing module, configured to select a first P-GW for an access point name APN of the UE according to the CSIPTO indication information, establish a first packet data network PDN connection based on the first P-GW, select a second P-GW for the APN of the UE, and establish a second PDN connection based on the second P-GW; and the processing module is used for optimizing the service flow transmission path of the UE according to the established first PDN connection and/or the established second PDN connection.

Preferably, the establishing module is further configured to, when all services of the UE are carried in one PDN connection before the UE is handed over, reserve the PDN connection before the UE is handed over as the first PDN connection in the UE handover process; the processing module is further configured to release a service without a service continuity requirement in the first PDN connection, and continue to carry the service with the service continuity requirement; the establishing module is further configured to select the second P-GW to establish the second PDN connection according to the current access location of the UE; and the processing module is further configured to use the second PDN connection to carry the service without the service continuity requirement and all services newly developed after the UE is switched.

Preferably, the processing module comprises: and the allocation unit is used for allocating PDN connection priority to the first PDN connection and the second PDN connection, wherein the priority of the second PDN connection is higher than that of the first PDN connection, and after the switching, the newly-developed service of the UE is loaded by using the second PDN connection according to the PDN connection priority.

Preferably, the obtaining module includes: a first obtaining unit, configured to obtain, after receiving a tracking area update TAU request of the UE, the CSIPTO indication information from the source MME in a context channel established with the source MME; or, a second obtaining unit, configured to obtain the CSIPTO indication information from the HSS after the UE completes a TAU procedure.

According to a further aspect of the present invention, there is provided a mobility management entity MME, including the apparatus in any of the above.

According to the invention, when a Mobile Management Entity (MME) is switched in the switching process of User Equipment (UE), the packet data gateway (P-GW) adjustment CSIPTO indication information of the UE for unloading the specified internet protocol IP flow is acquired from a source MME or a Home Subscriber Server (HSS) serving the UE before switching; according to the CSIPTO indication information, selecting a first P-GW for an APN of the UE, establishing a first Packet Data Network (PDN) connection based on the first P-GW, selecting a second P-GW for the APN of the UE, and establishing a second PDN connection based on the second P-GW; and optimizing the service flow transmission path of the UE according to the established first PDN connection and/or the established second PDN connection, so that the problem of resource waste of the transmission path of the data flow in the related technology is solved, and the effect of saving network resource overhead is achieved by optimizing a data routing path on the premise of not influencing user service experience when the UE is subjected to MME switching.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a schematic diagram of an EPS system architecture in the related art;

fig. 2 is a flowchart of PDN connection establishment in the related art;

FIG. 3 is a diagram illustrating data routing in a user handover scenario in the related art;

fig. 4 is a flowchart of a traffic flow transmission path optimization method according to an embodiment of the present invention;

fig. 5 is a block diagram of a structure of a traffic flow transmission path optimizing apparatus according to an embodiment of the present invention;

fig. 6 is a block diagram of a preferred structure of the processing module 56 in the traffic flow transmission path optimization apparatus according to the embodiment of the present invention;

fig. 7 is a block diagram of a preferred structure of the obtaining module 52 in the traffic flow transmission path optimizing apparatus according to the embodiment of the present invention;

fig. 8 is a block diagram of a mobility management entity MME according to an embodiment of the present invention;

FIG. 9 is a diagram illustrating data routing optimization in a user handover scenario, according to an embodiment of the present invention;

FIG. 10 is a flow chart according to a first embodiment of the present invention;

FIG. 11 is a flowchart according to a second embodiment of the present invention;

fig. 12 is a flowchart according to a third embodiment of the present invention.

Detailed Description

The invention will be described in detail hereinafter with reference to the accompanying drawings in conjunction with embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

In this embodiment, a method for optimizing a service flow transmission path is provided, and fig. 4 is a flowchart of a method for optimizing a service flow transmission path according to an embodiment of the present invention, as shown in fig. 4, the flowchart includes the following steps:

step S402, when MME switching occurs in the switching process of user equipment UE, obtaining packet data gateway P-GW adjusting CSIPTO indication information of UE for unloading appointed IP flow from a source MME or a home subscriber server HSS serving the UE before switching;

step S404, according to the CSIPTO indication information, selecting a first P-GW for the APN of the UE, establishing a first packet data network PDN connection based on the first P-GW, selecting a second P-GW for the APN of the UE, and establishing a second PDN connection based on the second P-GW;

and step S406, optimizing the service flow transmission path of the UE according to the established first PDN connection and/or second PDN connection.

Through the steps, when MME switching occurs in the UE switching process, based on CSIPTO indication information, a first PDN connection is established for the UE based on a first P-GW, a second PDN connection is established for the UE based on a second P-GW, and the second PDN connection carries out optimization processing on a service flow transmission path of the UE according to the established first PDN connection, so that the problem of resource waste of the transmission path of data flow in the related technology is solved, and the effect of saving network resource overhead is achieved by optimizing a data routing path on the premise of not influencing user service experience.

Before UE is switched, under the condition that all services of the UE are carried in a PDN connection, according to CSIPTO indication information, selecting a first P-GW for an APN (access point name) of the UE, establishing a first packet data network PDN connection based on the first P-GW, selecting a second P-GW for the APN of the UE, and establishing a second PDN connection based on the second P-GW; and optimizing the traffic flow transmission path of the UE according to the established first PDN connection and/or second PDN connection, wherein the optimizing process comprises the following steps: in the UE switching process, the PDN connection before UE switching is reserved as a first PDN connection, services without service continuity requirements in the first PDN connection are released, the services with the service continuity requirements are continuously loaded, a second P-GW is selected according to the current access position of the UE to establish a second PDN connection, and the second PDN connection is adopted to load the services without the service continuity requirements and all services newly developed after the UE switching.

Preferably, the optimizing the traffic flow transmission path of the UE according to the established first PDN connection and/or second PDN connection includes: and distributing PDN connection priority for the first PDN connection and the second PDN connection, wherein the priority of the second PDN connection is higher than that of the first PDN connection, and after the switching, the newly-developed service of the UE is carried by using the second PDN connection according to the PDN connection priority.

And the policy and charging rule functions PCRF selected by the first P-GW and the second P-GW are the same.

It should be noted that, when MME handover occurs in the UE handover process, the CSIPTO indication information of the UE is obtained from the source MME or the HSS serving the UE before the UE handover may be obtained in various ways, for example, after a tracking area update TAU request of the UE is received, the CSIPTO indication information is obtained from the source MME in a context channel established with the source MME; alternatively, the CSIPTO indication information may be acquired from the HSS after the UE completes the TAU procedure.

In this embodiment, a device for optimizing a transmission path of a service stream is further provided, where the device is used to implement the foregoing embodiment and preferred embodiments, and details are not repeated for what has been described. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.

Fig. 5 is a block diagram of a structure of a traffic flow transmission path optimization apparatus according to an embodiment of the present invention, and as shown in fig. 5, the apparatus includes an obtaining module 52, an establishing module 54, and a processing module 56, which is described below.

An obtaining module 52, configured to obtain packet data gateway P-GW adjustment CSIPTO indication information for offloading an IP stream of a designated internet protocol from a source MME or a home subscriber server HSS serving a UE before handover when a mobility management entity MME handover occurs in a handover process of a user equipment UE; an establishing module 54, connected to the obtaining module 52, configured to select a first P-GW for an APN of an access point name of the UE according to the CSIPTO indication information, establish a first packet data network PDN connection based on the first P-GW, select a second P-GW for the APN of the UE, and establish a second PDN connection based on the second P-GW; and a processing module 56, connected to the establishing module 54, configured to perform optimization processing on a traffic flow transmission path of the UE according to the established first PDN connection and/or second PDN connection.

Preferably, the access establishing module 54 is further configured to, in a UE handover process, reserve a PDN connection before the UE handover as a first PDN connection when all services of the UE are carried over one PDN connection before the UE handover; the processing module 56 is further configured to release a service without a service continuity requirement in the first PDN connection, and continue to carry the service with the service continuity requirement; the establishing module 54 is further configured to select a second P-GW according to the current access location of the UE to establish a second PDN connection; the processing module 56 is further configured to use the second PDN connection to carry services without service continuity requirements and all services newly developed after the UE is switched.

Fig. 6 is a block diagram of a preferred structure of the processing module 56 in the traffic flow transmission path optimization apparatus according to the embodiment of the present invention, and as shown in fig. 6, the processing module 56 includes an allocation unit 62, and the allocation unit 62 is described below.

And the allocating unit 62 is configured to allocate PDN connection priorities to the first PDN connection and the second PDN connection, where the priority of the second PDN connection is higher than the priority of the first PDN connection, and a service newly developed by the UE after the handover is preferentially carried by using the second PDN connection according to the PDN connection priority.

Fig. 7 is a block diagram of a preferred structure of an obtaining module 52 in a traffic flow transmission path optimizing apparatus according to an embodiment of the present invention, and as shown in fig. 7, the obtaining module 52 includes: the first acquiring unit 72 or the second acquiring unit 74, which will be described below with respect to the acquiring module 52.

A first obtaining unit 72, configured to obtain, after receiving a tracking area update TAU request of the UE, CSIPTO indication information from a source MME in a context channel established with the source MME; or, the second obtaining unit 74 is configured to obtain the CSIPTO indication information from the HSS after the UE completes the TAU procedure.

Fig. 8 is a block diagram of a mobility management entity MME according to an embodiment of the present invention, and as shown in fig. 8, the MME80 includes the traffic flow transmission path optimization apparatus 82 in any one of the above.

In the related art, the service experience of the user is not influenced when switching is achieved by sacrificing the use efficiency of network resources. In practical application, although services developed by users are various, requirements for time delay can be divided into two major categories, one is a service with higher requirements for service continuity, such as IP telephone, VPN and the like, the service cannot be interrupted in the transmission process, once interruption occurs, service experience is greatly influenced, and the service is called as real-time service; the other type is services with low requirements on service continuity, such as short messages, web browsing and the like, and even if the services are interrupted in the transmission process, the services do not have great influence on the service experience of the user, and even the users cannot feel short interruption, and the services are called non-real-time services.

In the implementation of the related art, a routing detour mode is adopted in the switching process for both real-time services and non-real-time services, so that data is routed through a P-GW1 anchor point, and service continuity is ensured.

In view of the above problems in the related art, in this embodiment, a method for optimizing a traffic stream transmission path is provided, where the method includes: in the process of switching User Equipment (UE), under the condition of cross-MME switching, a target MME acquires indication information for carrying out PGW adjustment (Coordinated PGW change for Selected IPtraffic Offload, CSIPTO for short) on the unloading of a specified IP flow from a source MME or an HSS, wherein the indication information is used for explaining that the UE supports the transmission path optimization of service flow on the developed service, and two different P-GWs are Selected for APN of a user according to the indication information to establish two PDN connections. The user terminal optimizes the access connection in the moving process so as to achieve the purposes of achieving the optimal transmission path of the service flow on the premise of not influencing the service experience of the user, lightening the routing roundabout and saving network resources. The method is briefly described below.

The method comprises the steps that two different P-GWs are selected for the same APN of a PDN network to establish two PDN connections to achieve the purposes of ensuring user service experience and optimizing a routing path, wherein one PDN connection is used for bearing services with service continuity requirements, the PDN connection is not interrupted all the time in the switching process, namely the P-GW used by the PDN connection is kept unchanged in the switching process; and another PDN connection is used for bearing the service without the service continuity requirement, the P-GW used by the PDN connection is close to the user access position, the PDN connection is released in the switching process, and the MME selects the other P-GW close to the user position after the switching to reestablish the PDN connection for bearing the service without the service continuity requirement. The realization mode can not affect the service experience of the user, simultaneously realizes the optimization of the data routing path and saves the network resources.

Fig. 9 is a schematic diagram of data routing optimization in a user handover scenario according to an embodiment of the present invention, where, as in fig. 9, a PDN connection 1 (established using P-GW 1) bearer is used for both real-time and non-real-time traffic before user handover. During and after the user switching, for the non-real-time service, selecting the P-GW2 closer to the area B as shown by the dotted line C in fig. 9 to establish the PDN connection 2 for routing; while for real-time traffic the PDN connection 1, indicated by the dashed line B, is still used for routing.

By the data routing mode, the effect of saving part of network resource overhead can be achieved by optimizing the data routing path on the premise of not influencing the user service experience.

The following describes preferred embodiments of the present invention.

Example one

This embodiment describes a TAU handover procedure occurring in a user, that is, when the user moves, a latest TA (Tracking Area) of the user is not in a TAI (Tracking Area Identity) list of the user, handover across MMEs needs to occur, and a new MME needs to be selected for the user to access a service. In this embodiment, it is assumed that the user is conducting real-time services and non-real-time services before the handover. During the handover process, the target MME (new MME) may obtain CSIPTO indication information of the user from the source MME.

The UE may subscribe to multiple APNs, and the user terminal may establish one PDN connection or multiple PDN connections using each APN. The following flow messages are for the PDN connection level. If the UE establishes multiple PDN connections by using multiple APNs before switching, or establishes multiple APN connections by using a single APN, each PDN connection has a corresponding message flow. For convenience of explanation, this embodiment assumes that the user has only one APN and one PDN connection is established between the network (this assumption is also used in embodiments two and three).

Fig. 10 is a flowchart according to a first embodiment of the present invention, and as shown in fig. 10, the flowchart includes the following steps:

1. the system detects that the UE has moved and its latest TA is not in the TAI list, triggering a TAU (tracking area update) procedure.

The UE initiates a TAU request message to the eNodeB. The message carries RRC parameters.

And 3, the eNodeB selects a new MME (namely the target MME) according to the RRC parameter. The eNodeB may also select a target MME according to the MME selection procedure. The eNodeB initiates a TAU request to the MME.

4. The target MME acquires a source MME address according to GUTI (Globally Unique Temporary identifier) information received from the UE, and sends a context request message to the source MME for acquiring user information.

5. The source MME returns a response to the context request to the target MME. The context information of the user is sent to the target MME in a response message. And if the source MME has the user subscription information, the user subscription information is also provided to the target MME. The user subscription information includes CSIPTO indication information.

6. The target MME returns an acknowledgement message to the source MME. The source MME marks in its context that the information on GW and HSS is no longer valid according to the message. And the MME is enabled to follow the information on the new GW and the HSS subsequently.

7. And if the MME changes, the target MME receives the bearing context information of the user from the source MME and maintains the bearing context information. And the target MME establishes the EPS bearing for the user again.

And according to the CSIPTO indication information acquired in the step 5, the target MME determines to select P-GW1 and P-GW2 for the APN of the user to establish two PDN connections. The target MME receives the status of the EPS bearer from the UE and compares it to the EPS bearer context maintained on the MME. The EPS bearer that is already no longer active on the UE is released. The target MME initiates a bearer modification request operation to the S-GW and generates a PDN connection priority for PDN connection 1 (established using P-GW 1) set to low. And then sending the APN, PDN connection 1 priority information to the S-GW.

And 8, initiating a bearer modification request to the P-GW1 by the S-GW, and sending the priority information of the APN and PDN connection 1 of the UE to the P-GW1.

The P-GW1 initiates an IP-CAN session 1 modification procedure to the PCRF and provides APN, PDN connection 1 priority information to the PCRF.

P-GW1 returns a response message to the S-GW for bearer modification.

And the S-GW returns a response message of the bearer modification to the target MME.

12. And according to the CSIPTO indication acquired in the step 5, the target MME decides to select P-GW2 for the APN to establish PDN connection 2, generates the priority of PDN connection 2 for the APN, and sets the priority higher than that of PDN connection 1. The target MME initiates a request for establishing the bearing session 2 to the S-GW, and the request message contains APN and PDN connection 2 priority information.

S-GW initiates a request to P-GW2 to create bearer session 2, carrying APN, priority information for PDN connection 2.

The P-GW2 initiates the creation process of IP-CAN session 2 to the PCRF and sends APN and PDN connection 2 priority information to the PCRF. When P-GW1 and P-GW2 respectively establish an IP-CAN session with PCRF, APN and the like are the same according to user information, so that P-GW1 and P-GW2 select the same PCRF to establish the IP-CAN session for the user.

P-GW2 returns a response message to the S-GW to create bearer session 2.

The S-GW returns a response message to the target MME to create bearer session 2.

17. The target MME initiates a location update request to the HSS and provides the user information to the HSS.

HSS initiates cancellation information of location update to source MME.

19. And deleting the bearing context information related to the user on the source MME, and returning a confirmation message to the HSS.

HSS returns an acknowledgement message to the target MME.

21. The target MME returns a TAU accept message to the UE.

22. If the GUTI is changed, the UE needs to return a TAU complete message to the target MME, and provide the latest GUTI to the target MME.

So far, the TAU switching of the user is completed, the new MME selects two P-GWs for the APN of the user to respectively establish PDN connection, wherein the PDN connection 1 is used for bearing the real-time service developed by the user before the switching, so that the real-time service developed by the user is not interrupted in the TAU process, and the user experience is ensured. When the partial real-time service deployment is finished, the PDN connection 1 is released. The PDN connection 2 is used to carry the non-real-time services developed by the user before the handover and all the services developed by the user after the handover. In the switching process, the non-real-time service is changed from the PDN connection 1 to the PDN connection 2, and then the non-real-time service is interrupted in the TAU switching process, but the interruption in the switching process does not significantly affect the service experience of the user.

Example two

This embodiment describes a TAU handover procedure that occurs for a user, that is, when the user moves, the latest TA of the user is not in the TAI list of the user, a handover across MMEs needs to occur, and a new MME needs to be selected for the user to access a service. In this embodiment, it is assumed that the user is conducting real-time services and non-real-time services before the handover. In the switching process, the target MME (new MME) acquires CSIPTO indication information of the user from the HSS.

Fig. 11 is a flowchart according to the second embodiment of the present invention, and as shown in fig. 11, the flowchart includes the following steps:

1. the system detects that the UE has moved and its latest TA is not in the TAI list, triggering a TAU procedure.

4. And the target MME acquires the address of the source MME according to the GUTI information received from the UE and sends a context request message to the source MME for acquiring the user information.

5. The source MME returns a response to the context request to the target MME. The context information of the user is sent to the target MME in a response message.

The target MME receives the status of the EPS bearer from the UE and compares it to the EPS bearer context maintained on the MME. The EPS bearer that is already no longer active on the UE is released. And the target MME initiates a load modification request operation to the S-GW.

The S-GW initiates a bearer modification request to P-GW1.

The P-GW1 initiates an IP-CAN session 1 modification procedure towards the PCRF.

P-GW1 returns a response message to the S-GW for bearer modification.

12. The target MME initiates a location update request to the HSS and provides the user information to the HSS. And if the target MME does not have the subscription information of the user at the moment, requesting the HSS for the subscription information of the user.

HSS initiates cancellation information of location update to source MME.

14. And deleting the bearing context information related to the user on the source MME, and returning a confirmation message to the HSS.

HSS returns acknowledgement message to target MME. If the user subscription information is not contained in the context transfer of the user in the step 4-6, the HSS provides the user subscription information containing the CSIPTO indication information to the target MME.

16. And according to the CSIPTO indication information acquired in the step 15, the target MME determines to select P-GW1 and P-GW2 for the APN to establish two PDN connections. The target MME initiates a bearer modification process to release the special bearer for bearing the non-real-time service in the PDN connection 1. The target MME simultaneously generates priority information for PDN connection 1 and sets to low. The target MME provides the S-GW, P-GW1 and PCRF with the APN, PDN connection 1 priority information.

MME selects P-GW2 to establish PDN connection 2 and generates a priority for PDN connection 2 for it, setting the priority higher than PDN connection 1. The target MME initiates a request for establishing the bearing session 2 to the S-GW, and the request message contains APN and PDN connection 2 priority information.

P-GW2 returns a response message to the S-GW to create bearer session 2.

22. The target MME returns a TAU accept message to the UE.

23. If the GUTI is changed, the UE needs to return a TAU complete message to the target MME, and provide the latest GUTI to the target MME.

So far, the TAU handover by the user is completed. The difference from the first embodiment is that the target MME acquires the user subscription information containing the CSIPTO indication from the HSS. The target MME selects two P-GWs for the APN of the user to respectively establish PDN connection, wherein the PDN connection 1 is used for bearing real-time services developed by the user before switching, so that the real-time services developed by the user are not interrupted in the TAU process, and the user experience is ensured. When the partial real-time service deployment is finished, the PDN connection 1 is released. The PDN connection 2 is used to carry the non-real-time services developed by the user before the handover and all the services developed by the user after the handover. In the switching process, the non-real-time service is changed from the PDN connection 1 to the PDN connection 2, and then the non-real-time service is interrupted in the TAU switching process, but the interruption in the switching process does not significantly affect the service experience of the user.

EXAMPLE III

In the S1 handover scenario described in embodiment three, during the S1 handover, handover across MMEs also needs to occur.

Prior to handover, the traffic developed by the UE is data routed using the PDN connection established between the UE, the source eNodeB, the source S-GW, and the P-GW1. The services developed by the UE include real-time services and non-real-time services.

Thereafter the UE has S1 handover, i.e. handover across MMEs needs to occur.

Fig. 12 is a flowchart according to a third embodiment of the present invention, and as shown in fig. 12, the flowchart includes the following steps:

steps 1 to 17 describe that in the S1 handover process, the service data is forwarded from the source access network to the target access network after handover by a mechanism of establishing an indirect data forwarding channel. The process refers to the prior art flow.

Step 18 describes that after the service data is sent to the target access network through the indirect data forwarding channel, a TAU handover procedure needs to be initiated. In the process, the target MME needs to select P-GW1 and P-GW2 to respectively establish PDN connection 1 and PDN connection 2 for the APN of the user according to the CSIPTO instruction acquired from the source MME or the HSS. The process is described in reference to example one and example two.

Step 19 is releasing the indirect data forwarding path after the switching is completed at S1.

After the handover is completed at S1, a PDN connection 1 is established between the UE and the P-GW1 for carrying real-time traffic before the handover; a PDN connection 2 is established between the UE and the P-GW2 for carrying non-real time traffic before the handover and all traffic after the handover. Both the PDN connection 1 and the PDN connection 2 are established for the same APN, and the priority of the PDN connection 2 is higher than that of the PDN connection 1, that is, the PDN connection 2 is preferentially used for data routing for a new service developed by the user. And when the real-time service on the PDN connection 1 is finished, releasing the PDN connection 1.

It will be apparent to those skilled in the art that the modules or steps of the present invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and alternatively, they may be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described may be performed in an order different than that described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple ones of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for optimizing a transmission path of a service stream, comprising:

when a Mobility Management Entity (MME) is switched in the switching process of User Equipment (UE), acquiring packet data gateway (P-GW) adjustment CSIPTO indication information of the UE for unloading an appointed Internet Protocol (IP) stream from a source MME or a Home Subscriber Server (HSS) serving the UE before switching;

according to the CSIPTO indication information, selecting a first P-GW for an APN of the UE, establishing a first Packet Data Network (PDN) connection based on the first P-GW, selecting a second P-GW for the APN of the UE, and establishing a second PDN connection based on the second P-GW;

optimizing a service flow transmission path of the UE according to the established first PDN connection and the established second PDN connection;

before the UE is switched, under the condition that all services of the UE are carried in a PDN connection, according to the CSIPTO indication information, selecting a first P-GW for an APN (access point name) of the UE, establishing a first packet data network PDN connection based on the first P-GW, selecting a second P-GW for the APN of the UE, and establishing a second PDN connection based on the second P-GW; and optimizing the traffic flow transmission path of the UE according to the established first PDN connection and the established second PDN connection, wherein the optimizing process comprises the following steps:

in the UE switching process, reserving the PDN connection before UE switching as the first PDN connection, releasing the service without service continuity requirement in the first PDN connection, continuously carrying the service with service continuity requirement, selecting the second P-GW to establish the second PDN connection according to the current access position of the UE, and adopting the second PDN connection to carry the service without service continuity requirement and all services newly developed after UE switching;

when an MME handover occurs in the UE handover process, acquiring the CSIPTO indication information of the UE from the source MME or the HSS serving the UE before the UE handover includes: after receiving a tracking area update TAU request of the UE, acquiring the CSIPTO indication information from the source MME in a context channel established with the source MME; or, after the UE completes the TAU procedure, acquiring the CSIPTO indication information from the HSS.

2. The method of claim 1, wherein optimizing a traffic flow transmission path of the UE according to the first PDN connection and the second PDN connection established comprises:

and allocating PDN connection priority to the first PDN connection and the second PDN connection, wherein the priority of the second PDN connection is higher than that of the first PDN connection, and the newly-developed service of the UE after switching is carried by using the second PDN connection preferentially according to the PDN connection priority.

3. The method according to any one of claims 1 to 2,

and the policy and charging rule function PCRF selected by the first P-GW and the second P-GW is the same.

4. A traffic flow transmission path optimization apparatus, comprising:

an obtaining module, configured to obtain packet data gateway P-GW adjustment CSIPTO indication information for offloading an IP stream of a designated internet protocol from a source MME or a home subscriber server HSS serving a UE before handover when a mobility management entity MME handover occurs in a handover process of the UE;

an establishing module, configured to select a first P-GW for an access point name APN of the UE according to the CSIPTO indication information, establish a first packet data network PDN connection based on the first P-GW, select a second P-GW for the APN of the UE, and establish a second PDN connection based on the second P-GW;

a processing module, configured to perform optimization processing on a traffic flow transmission path of the UE according to the established first PDN connection and the established second PDN connection;

the establishing module is further configured to, when all services of the UE are carried in one PDN connection before the UE is handed over, reserve the PDN connection before the UE is handed over as the first PDN connection in the UE handover process;

the processing module is further configured to release a service without a service continuity requirement in the first PDN connection, and continue to carry the service with the service continuity requirement;

the establishing module is further configured to select the second P-GW to establish the second PDN connection according to the current access location of the UE;

the processing module is further configured to use the second PDN connection to carry the service without the service continuity requirement and all services newly developed after the UE is switched;

the acquisition module includes: a first obtaining unit, configured to obtain, after receiving a tracking area update TAU request of the UE, the CSIPTO indication information from the source MME in a context channel established with the source MME; or, a second obtaining unit, configured to obtain the CSIPTO indication information from the HSS after the UE completes a TAU procedure.

5. The apparatus of claim 4, wherein the processing module comprises:

and the allocation unit is used for allocating PDN connection priority to the first PDN connection and the second PDN connection, wherein the priority of the second PDN connection is higher than that of the first PDN connection, and after the switching, the newly-developed service of the UE is loaded by using the second PDN connection according to the PDN connection priority.

6. A Mobility Management Entity (MME), characterized in that it comprises the apparatus of any of claims 4 to 5.