Network congestion control method and terminal
Technical Field
The present invention relates to the field of mobile communications technologies, and in particular, to a network congestion control method and a terminal.
Background
The third Generation mobile communication standardization organization (3rd Generation Partnership Project, 3GPP) proposes an APN based congestion control mechanism (APN based Mobility Management control) based on an Access Point Name (APN), which is divided into APN based Mobility Management control (APN based Mobility Management control) and APN based Session Management control (APN based Session Management control), and specifies a basis for judging whether the APN is congested or not on the network side based on the APN congestion mechanism in the TS23.401 standard.
In mobility management control based on an APN, when a User Equipment (UE) subscribing to a special APN initiates an attach request (attach request) to a network side, if the network determines that the special APN is congested, the attach request of the UE is rejected, and a generated reject message carries a mobility management back-off timer (mobility management back-off timer), and the reject message is sent to the UE.
In the session management control based on the APN, when a network side judges that a certain APN is in a congestion state, a session management request aiming at the APN is rejected, a session management back-off timer (session management back-off timer) is carried in a generated rejection message, the rejection message is sent to UE, and after the UE receives the rejection message and acquires the session management back-off timer, the UE does not initiate any session management process aiming at the APN before the timer is overtime. Similarly, when the APN is not specified in the PDN connection request, congestion control is performed for the default APN according to the above procedure.
In addition to the APN based congestion control mechanism, 3GPP has also proposed a generic Non-Access Stratum (NAS) mobility management congestion control mechanism, which proposes that under a generic network overload condition, the network can reject any mobility management signaling request of the UE and carry a mobility management backoff timer in the generated reject message, and after receiving the reject message and acquiring the mobility management backoff timer, the UE does not initiate any mobility management procedure except an emergency service request and a service request with an Access class of 11-15 until the timer times out. However, the mobility management back-off timer does not prevent the UE from initiating a session management request.
Among them, the Mobility Management (MM) entity is mainly used to support the Mobility of the user equipment, such as notifying the location of the user equipment to the network and providing encryption information of the user identification. In addition, the MM entity provides a Connection Management service for a Session Management (SM) entity and a short message service for a Connection Management (CM) layer. The SM entity mainly supports the bearer context management of a Mobility Management Entity (MME) and a terminal on the network side.
According to the current 3GPP protocol, an MM entity and an SM entity work independently, the SM entity does not know back-off timer information maintained by the MM entity, and when the UE in an idle state runs with a mobility management back-off timer, a network allows a PDN connection process to be established for emergency services or high-priority services of the terminal, so that the terminal enters a connection state from the idle state. However, for UEs already in a connected state, even if a mobility management back-off timer is running, session management signaling, including PDN connection requests initiated for non-emergency services, can still be initiated, which signaling would undoubtedly exacerbate the congestion level of the network.
Disclosure of Invention
The invention provides a network congestion control method and a terminal, which are used for realizing the control of a session management request initiated by a user terminal in a connection state under the condition of network congestion and effectively avoiding the aggravation of the network congestion.
The embodiment of the invention provides the following specific technical scheme:
a method of network congestion control, comprising:
when a user terminal UE is in a connected state, before a session management SM entity of the UE initiates a session management request, inquiring running information of a mobility management backoff timer in a mobility management MM entity of the UE;
and the SM entity does not initiate the session management request after determining that the session management request is backed off by a mobility management back-off timer running in the MM entity according to the running information.
A user terminal comprises a Session Management (SM) entity and a Mobility Management (MM) entity;
when the user terminal is in a connected state, the SM entity is used for inquiring the operation information of a mobility management backoff timer in the MM entity before initiating a session management request, and does not initiate the session management request after determining that the session management request is backed off by the mobility management backoff timer operated in the MM entity according to the operation information.
Based on the above technical solution, in the embodiment of the present invention, before initiating a session management request, an SM entity of a UE in a connected state queries operation information of a mobility management backoff timer in an MM entity of the UE, and after determining that the session management request is backed off by the mobility management backoff timer operated in the MM entity according to the operation information obtained by the query, the SM entity determines that a network is in a congested state and does not initiate the session management request, so that under the condition that the network is congested, specifically, under the condition that a control plane node of the network is congested and an APN is not congested, the session management request initiated by a user terminal in the connected state and excluding emergency services and services with higher access levels is controlled, and network congestion is effectively avoided from being aggravated.
Drawings
Fig. 1 is a flowchart of a method for network congestion control according to an embodiment of the present invention;
FIG. 2 is a flow chart of a method for network congestion control according to a first embodiment of the present invention;
FIG. 3 is a flow chart of a method for network congestion control according to a second embodiment of the present invention;
FIG. 4 is a schematic diagram of the logical connection of the SM entity and the MM entity;
fig. 5 is a schematic structural diagram of a ue for network congestion control according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of another ue for network congestion control according to an embodiment of the present invention.
Detailed Description
In order to realize control of session management requests initiated by a user terminal in a connected state except for emergency services and services with higher access levels under the condition of network congestion and effectively avoid aggravation of network congestion, the embodiment of the invention provides a network congestion control method and a terminal.
The network congestion control method provided by the embodiment of the invention is suitable for the situations that the nodes of the network control plane are congested and the APN is not congested. For example, the method is applicable to situations such as congestion of a Mobility Management Entity (MME) on the network side, or congestion of a serving GPRS (General Packet Radio Service) support node (SGSN) on the network side.
Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
In the following embodiments, the session management request refers to a session management request for services other than emergency services and services with higher access levels (e.g., services with access levels of 11-15).
In the following embodiments, the UE is in a connected state.
The method provided in the following embodiments may be applied to all systems supporting interaction between SM entities and MM entities, such as General Packet Radio Service (GPRS) System, Universal Mobile Telecommunications System (UMTS), Evolved Packet System (EPS), and the like.
As shown in fig. 1, in the embodiment of the present invention, a detailed method flow for performing network congestion control is as follows:
step 101: when the UE is in a connected state, before an SM entity of the UE initiates a session management request, the running information of a mobility management backoff timer in an MM entity of the UE is inquired.
The application layer entity of the UE sends a request message to the SM entity, and the SM entity needs to send a session management request to a network side when determining that the application layer entity needs to establish a bearer to the APN according to the request message.
After determining that a session management request needs to be sent to a network side, the SM entity first determines whether a related session management backoff timer is running locally, and if so, directly rejects the request of the application layer entity, otherwise, the SM entity queries running information of a mobility management backoff timer in the MM entity.
Specifically, an application layer entity sends a request message to an SM entity to trigger a session management request sending process, and if the request message carries APN information, the SM entity can inquire whether a related session management backoff timer runs locally according to the APN; if the request message does not carry the APN information, the SM entity adopts the default APN for processing, namely, whether a session management backoff timer corresponding to the default APN runs is inquired locally.
After determining that no session management backoff timer corresponding to the APN of the session management request runs, the SM entity queries running information of the mobility management backoff timer in the MM entity.
The embodiment of the invention relates to two kinds of UE, and the session management requests corresponding to different applications of an application layer entity of one kind of UE have the same priority. For example, the UE is configured as a non-access stratum (NAS) layer signaling low priority (NAS signaling low priority), which can only initiate low priority (low priority) session management requests.
The session management requests corresponding to different applications of the application layer entity of another UE have multiple (two or more) different priorities. For example, a multi-priority device (dual priority device) proposed by 3GPP, under some special scenarios (for example, sending service alarm information or notification), the multi-priority device may initiate a session management request with low priority (low priority) or a session management request with normal priority (normal priority). Therefore, the terminal may send session management requests to the network with different priorities according to different requirements of the application.
Specifically, when session management requests corresponding to different applications of an application layer entity of the UE have the same priority, and the SM entity determines that a session management backoff timer related to an APN of the session management request is running locally, the SM entity returns a rejection message to the application layer entity to reject the request of the application layer entity; otherwise, the SM entity judges that no session management back-off timer related to the APN of the session management request runs locally, and queries the running information of the mobility management back-off timer in the MM entity.
Specifically, when session management requests corresponding to different applications of an application layer entity of the UE have different priorities, if a session management backoff timer locally running by the SM has priority indication information and a request message of the application layer entity carries priority information, the SM entity returns a rejection message to the application layer entity to reject the request of the application layer entity when determining that the priority of the request message is within a backoff range of the session management backoff timer; otherwise, when the SM entity judges that the priority of the request message is not in the backoff range of the session management backoff timer, or when the SM entity judges that no related session management backoff timer runs, the SM entity inquires the running information of the mobility management backoff timer in the MM entity.
Step 102: and the SM entity does not initiate the session management request after determining that the session management request is backed off by a mobility management back-off timer running in the MM entity according to the running information.
Specifically, the MM entity responds to the query request of the SM entity, and the response message returned to the SM entity carries the operation information of the mobility management back-off timer.
When the session management requests corresponding to different applications of the application layer entity of the UE have the same priority, the operation information may be information indicating whether a mobility management backoff timer operates, and optionally, the operation information may be a remaining time value of the mobility management backoff timer, where when the remaining time value is a zero value, it indicates that the MM entity does not have the mobility management backoff timer to operate, and when the remaining time value is a non-zero value, it indicates that the MM entity has the mobility management backoff timer to operate.
Specifically, when session management requests corresponding to different applications of an application layer entity of the UE have the same priority, the SM entity determines, according to the operation information, that the MM entity has a mobility management back-off timer running, and determines that the session management request is backed off by the mobility management back-off timer running in the MM entity; and the SM entity determines that the MM entity does not have a mobility management backoff timer to run according to the running information, determines that the session management request is not backed off, and sends the session management request to the network side.
When session management requests corresponding to different applications of an application layer entity of the UE have different priorities, the operation information includes a priority identifier of an operating mobility management back-off timer, and the priority identifier is used to indicate a highest priority of the back-off of the mobility management back-off timer. In practical application, if the operation information carries the priority identifier, it indicates that a mobility management back-off timer is operating, and the priority identifier indicates the highest priority to be backed off, and if the operation information does not carry the priority identifier, it indicates that no mobility management back-off timer is operating. Optionally, the running information further includes a remaining time value of the mobility management back-off timer.
Specifically, when session management requests corresponding to different applications of an application layer entity of the UE have different priorities, the SM entity determines that the MM entity has a mobility management backoff timer to operate according to the operation information, and when it is determined that the priority of the session management request is within a backoff range of the mobility management backoff timer, the SM entity determines that the session management request is backed off by the mobility management backoff timer operating in the MM entity. And the SM entity determines the backoff range of the mobility management backoff timer according to the priority identifier of the mobility management backoff timer carried in the operation information.
Specifically, the SM entity determines that the MM entity has a mobility management backoff timer to operate according to the operation information, and initiates a session management request after determining that the priority of the session management request is not in the backoff range of the mobility management backoff timer; or, the SM entity determines that the MM entity does not have a mobility management backoff timer to operate according to the operation information, and initiates a session management request.
Optionally, when the running information carries the remaining time value of the mobility management backoff timer, the SM entity may set the remaining time value as an initial value and start the session management backoff timer.
Specifically, when session management requests corresponding to different applications of an application layer entity of the UE have the same priority, the SM entity obtains a remaining time value in the running information, uses the remaining time value as an initial value of a session management backoff timer, and starts to run the session management backoff timer.
Specifically, when session management requests corresponding to different applications of an application layer entity of the UE have multiple different priorities, the SM entity obtains a remaining time value in the running information, uses the remaining time value as an initial value of a session management backoff timer, uses a priority identifier of a mobility management backoff timer carried in the running information as a priority identifier of the session management backoff timer, and starts to run the session management backoff timer.
In this embodiment, the SM entity does not initiate the session management request, may directly return a reject message to the application layer entity to reject the request of the application layer entity, or may locally cache the session management request, wait for the timeout or stop of the session management backoff timer and the mobility management backoff timer of the MM entity, and then send the session management request to the network side.
Wherein the SM entity initiates the session management request when determining that the MM entity does not have a mobility management backoff timer running.
The method for controlling network congestion in the embodiment of the present invention is described in detail below with two specific embodiments.
In a specific embodiment, in the embodiment, the UE is Rel-10 release, configured as non-access stratum signal low priority and in a connected state, and for the UE configured as non-access stratum signal low priority, the session management requests of different applications for its application layer entity have the same priority (i.e., low priority), and the embodiment is based on an Evolved Packet System (EPS), as shown in fig. 2, a detailed process of performing network congestion control is as follows:
step 201: the application app1 of the UE application layer entity requests the esm (eps sm) entity to establish a Packet Data Network (PDN) connection to APN1 for it.
Step 202: after the ESM entity judges that no session management backoff timer of APN1 runs, the ESM entity sends a query request to an EMM (EPS MM) entity to query whether the EMM entity runs by a mobility management backoff timer.
Step 203: the EMM entity inquires a local mobility management back-off timer (for example, the back-off time value is T3346) to run according to the inquiry request, and returns the inquiry result to the ESM entity.
Wherein, the remaining time value of the mobility management back-off timer can be carried in the query result.
Step 204: and the ESM entity determines that the mobility management backoff timer is running according to the query result returned by the EMM entity, does not initiate a PDN connection request for app1, and returns a rejection message to app 1.
The ESM entity also determines that a mobility management back-off timer is running according to a query result returned by the EMM entity, sets the residual time value as an initial value and starts a corresponding session management back-off timer when the query result is determined to carry the residual time value of the mobility management back-off timer, caches the session management request locally, and queries whether the EMM entity runs the corresponding mobility management back-off timer or directly sends the session management request to a network side after waiting for the local session management back-off timer to be overtime.
In a second embodiment, in the embodiment, the UE is in a connected state and has multiple priorities, for example, the UE is configured as a non-access stratum normal priority, that is, the UE may initiate a session management request with a normal priority and a session management request with a low priority, and as shown in fig. 3, based on the EPS system, a detailed process of performing network congestion control in the embodiment is as follows:
step 301: the application app2 with priority of normal priority in the application layer entity requests the ESM entity to modify the established bearer to APN2 for it.
Step 302: the ESM entity judges that the local session management backoff timer without the APN2 runs, and the ESM entity sends a query request to the EMM entity to query whether the EMM entity runs by the mobility management backoff timer.
Step 303: the EMM entity queries a local mobility management back-off timer (the back-off time value of the EMM entity is T3346) to operate according to the query request, the back-off of the mobility management back-off timer is a request with the priority of low priority, the EMM entity returns a query result to the ESM entity, and the query result carries a priority identifier used for indicating the low priority.
Step 304: the ESM entity learns that the mobility management backoff timer runs according to the query result returned by the EMM entity, determines that the priority limited by the ESM entity is low priority according to the priority identifier carried in the query result, determines that the priority normalrivity of the request for modifying the bearer to the APN2 is higher than the priority low priority indicated by the priority identifier, and initiates a bearer modification process to the APN2 to the network side according to the existing protocol.
The SM entity and the MM entity provided in the above embodiments perform information interaction through a logical interface, and a logical connection relationship between the SM entity (or SM layer or SM sublayer) and the MM entity (or MM layer or MM sublayer) involved in the 3GPP protocol is as shown in fig. 4. In a General Packet Radio Service (GPRS) system, a GPRS Mobility Management (GMM) is equivalent to an EMM in an EPS system, and a connection relationship between the GMM and a session management entity is the same as that between an MM and an SM. When the congestion control method provided by the embodiment of the invention is applied, the session management entity can send a query request for querying the operation information of the mobility management backoff timer in the GMM entity to the GMM entity, the GMM entity returns a response message and returns a query result to the session management entity, the query result comprises the operation information of the mobility management backoff timer, and the session management entity judges whether to initiate the session management request according to the query result.
In practical application, a user terminal equipment manufacturer only needs to agree on a message format and an analysis mode of interaction between the SM entity and the MM entity, and the interaction between the SM entity and the MM entity can be realized through physical connection. For example, for a query request for querying operation information of a mobility management back-off timer in an MM entity, an SM entity and the MM entity agree on a message structure of the query request message, and for a query result returned by the MM entity, it is agreed whether there is bit and a message structure occupied by the indication information of the operation of the mobility management back-off timer, the remaining duration of the mobility management back-off timer, the priority identifier of the mobility management back-off timer, and the like, so that interaction between the SM entity and the MM entity can be realized.
Based on the above principle, the embodiment of the present invention further provides a user equipment for network congestion control, the principle of congestion control is similar to the above congestion control method, and the same parts are not repeated, as shown in fig. 5, the user equipment mainly includes an SM entity 501 and an MM entity 502, wherein,
when the user terminal is in a connected state, before the SM entity 501 is configured to initiate a session management request, it queries the operation information of the mobility management backoff timer in the MM entity 502, and determines, according to the operation information, that the session management request is backed off by the mobility management backoff timer operating in the MM entity 502, and then does not initiate the session management request.
As shown in fig. 6, the user terminal further includes an application layer entity 503, configured to send a session management request to the APN to the SM entity 501 before the SM entity 501 queries the running information of the mobility management backoff timer in the MM entity 502.
The SM entity 501 determines that the session management backoff timer corresponding to the local APN is running, and does not initiate the session management request; after determining that no session management backoff timer corresponding to the APN of the session management request runs, the SM entity 501 queries running information of the mobility management backoff timer in the MM entity 502.
The UE can be divided into two types, and session management requests corresponding to different applications of the application layer entity 503 of one type of UE have the same priority; a UE has a plurality of different priorities for session management requests corresponding to different applications of the application layer entity 503.
Specifically, the SM entity 501 is specifically configured to determine that the session management request is backed off by the mobility management backoff timer running in the MM entity 502 after determining that the MM entity 502 has a mobility management backoff timer running according to the running information when the session management requests corresponding to different applications of the application layer entity 503 have the same priority. SM entity 501 is also used to directly initiate a session management request when EMM entity 502 does not have a mobility management back-off timer running.
Specifically, the SM entity 501 is specifically configured to determine, when session management requests corresponding to different applications of the application layer entity 503 have multiple different priorities, that the MM entity 502 has a mobility management backoff timer to operate according to the operation information, and after determining that the priority of the session management request is within a backoff range of the mobility management backoff timer, not initiate the session management request. The SM entity 501 is further configured to initiate a session management request when it is determined that the MM entity 502 has a mobility management backoff timer running and the priority of the session management request is not within the range limited by the mobility management backoff timer; alternatively, the SM entity 501 is further configured to initiate the session management request upon determining that the MM entity 502 does not have a mobility management backoff timer running.
When session management requests corresponding to different applications of the application layer entity 503 have different priorities, the SM entity 501 is specifically configured to determine a backoff range of the mobility management backoff timer according to a priority identifier of the mobility management backoff timer carried in the running information, where the priority identifier is used to indicate a highest priority of backoff of the mobility management backoff timer.
Optionally, the SM entity 501 is further configured to set a remaining time value of the mobility management backoff timer carried in the running information as an initial value and start the session management backoff timer after determining that the session management request is backed off by the mobility management backoff timer running in the MM entity 502.
Optionally, the SM entity 501 is further configured to, when session management requests corresponding to different applications of the application layer entity have multiple different priorities, before starting the session management backoff timer, use a priority identifier of the mobility management backoff timer carried in the running information as an identifier of the session management backoff timer.
Based on the technical scheme, in the embodiment of the invention, before initiating the session management request, the SM entity of the connected UE queries the running information of the mobility management backoff timer in the MM entity of the UE, and after determining that the session management request is backed off by the mobility management backoff timer running in the MM entity according to the running information obtained by the query, the SM entity determines that the network is in a congested state and does not initiate the session management request, so that the session management request initiated by the connected user terminal except for emergency service and service with higher access level can be controlled under the condition of network congestion, and network congestion is effectively avoided from being aggravated.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.