WO2016122219A2

WO2016122219A2 - An overload processing method for a radio communication system and access network equipments

Info

Publication number: WO2016122219A2
Application number: PCT/KR2016/000908
Authority: WO
Inventors: Xiaowan KE; Lixiang Xu; Hong Wang
Original assignee: Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Current assignee: Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Priority date: 2015-01-29
Filing date: 2016-01-28
Publication date: 2016-08-04
Anticipated expiration: 2017-07-29
Also published as: WO2016122219A3

Abstract

The present application discloses an overload processing method for a radio communication system and access network equipments. The system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment. A specific embodiment of the method for the radio communication system comprises: receiving, by the first access network equipment, first overload information from the MME, wherein the first overload information comprises information related to situations that the MME is started to be overloaded or a public land mobile network (PLMN) supported by the MME is started to be overloaded; and transmitting second overload information to the second access network equipment based on the first overload information. The specific embodiment provides an overload processing solution for an access network equipment which is indirectly connected to MME.

Description

AN OVERLOAD PROCESSING METHOD FOR A RADIO COMMUNICATION SYSTEM AND ACCESS NETWORK EQUIPMENTS

The present application generally relates to a technical filed of communication, in particular, to a technical filed of mobile communication, more particularly, to an overload processing method for a radio communication system and access network equipments.

Modern mobile communication tends increasingly to provide multimedia service with a highspeed transmission for users. Figure 1 is a system architecture diagram for System Architecture Evolution (SAE). In the figure 1, a user equipment (UE) 101 is a terminal equipment supporting network protocols. E-UTRAN (Evolution-UMTS Terrestrial Radio Access Network) 102 is a radio access network, which includes a base station (eNode B or Node B) providing the UE with interfaces to access to radio networks. A mobility management entity (MME) 103 is responsible for managing mobility context, session context and safety information of the UE. A serving gateway (SGW) 104 provides mainly functions for a user plane, and the MME 103 and SGW 104 may be provided in the same physical entity. A packet data network gateway (PGW) 105 is responsible for biling, lawful interception and the like, and it may be provided in the same entity with the MME 103 and SGW 104. A policy charging and rules function (PCRF) entity 106 provides quality of service (QoS) policy and biling criterion. A serving GPRS support node (SGSN) 108 is a network node equipment providing routing for data transmission in a universal mobile telecommunications system (UMTS). A home subscriber server (HSS) 109 is a home subscriber subsystem for the UE and is responsible for protecting user information including a current location of the UE, address of the service node, user safety information, packet data context of the UE and the like.

In the existing network architecture, the E-UTRAN 102 further supports a variety of technical architectures, such as a radio access network composed of relay nodes (RNs) and a donor eNB (DeNB) or a radio access network composed of home nodes B (HeNBs).

Since the RN and the HeNB connecting to the MME via a HeNB GW (hereinafter referred to an indirectly connected HeNB) do not have a NAS Node Selection Function (NNSF) for selecting the MME for the UE, the RN or the indirectly connected HeNB may not determine how to process an overload when the MME is overloaded, which could lead to problems.

The present application provides an overload processing method for a radio communication system and access network equipments to solve the aforementioned problems.

In a first aspect, the present application provides an overload processing method for a radio communication system, the system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment. The method comprises: receiving, by the first access network equipment, first overload information from the MME, wherein the first overload information comprises information related to situations that the MME is started to be overloaded or a public land mobile network (PLMN) supported by the MME is started to be overloaded; and transmitting, by the first access network equipment, second overload information to the second access network equipment based on the first overload information

In some embodiments, the first overload information or the second overload information comprises one or more of an overload type indication, a PLMN identification, a globally unique MME identification (GUMMEI), a PLMN access barring indication, a PLMN reserving indication and a RRC releasing indication.

In some embodiments, the overload type indication comprises a MME overload indication or a PLMN overload indication, and the PLMN overload indication represents a situation that a PLMN is overloaded on one or more MMEs supporting the PLMN and connected to the first access network equipment, or a situation that a PLMN is overloaded on all MMEs supporting the PLMN and connected to the first access network equipment.

In some embodiments, the PLMN overload indication comprises a PLMN partly overload indication and a PLMN fully overload indication, and the PLMN partly overload indication represents a situation that a PLMN is overloaded on one or more MMEs supporting the PLMN and connected to the first access network equipment, and the PLMN fully overload indication represents a situation that a PLMN is overloaded on all MMEs supporting the PLMN and connected to the first access network equipment.

In some embodiments, the transmitting second overload information to the second access network equipment based on the first overload information further comprises: transmitting the second overload information, when the first access network equipment determines that a PLMN is fully overloaded or a PLMN is fully overloaded on the MME supporting the PLMN and overload actions reject or do not allow a radio resource control (RRC) establishment for one or more reasons, wherein the second overload information comprises information indicating the fully overloaded PLMN.

In some embodiments, the information indicating the fully overloaded PLMN comprises at least one of an identification of the PLMN, GUMMEI, information indicating access barring for the PLMN and overload type information, wherein the overload type information indicates that the PLMN is fully overloaded, and the GUMMEI comprises the identification of the fully overloaded PLMN.

In some embodiments, the transmitting second overload information to the second access network equipment based on the first overload information further comprises: determining whether all the MMEs connected to the first access network equipment are fully overloaded or the MME is fully overloaded and overload actions reject or do not allow a radio resource control (RRC) establishment for one or more reasons based on the first overload information; and transmitting the second overload information, wherein the second overload information comprises at least one of an access barring indication, an overload type indication and a GUMMEI, wherein the overload type indication indicates that the MME is fully overloaded, and the GUMMEI is an identification for the fully overloaded MME.

In some embodiments, the transmitting second overload information to the second access network equipment based on the first overload information further comprises: transmitting the second overload information only when the first access network equipment determines that all the MMEs connected to the first access network equipment are fully overloaded or the MME is fully overloaded and overload actions reject or do not allow a radio resource control (RRC) establishment for one or more reasons based on the first overload information.

In some embodiments, the first overload information and the second overload information comprise specific overload action information for the overloaded MME or specific overload action information for the overloaded PLMN.

In some embodiments, the first overload information and the second overload information comprise a MME code (MMEC), and the MMEC is provided to a dedicated MMEC for an operator, a PLMN or a PLMN list.

In a second aspect, the present application provides an overload processing method for a radio communication system, wherein the system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment. The method comprises: receiving, by the first access network equipment, information associated with a user equipment (UE) from the second access network equipment; selecting a MME and determining if the UE satisfies with an overload processing condition or not depending on the information associated with the UE; and executing an overload processing operation if the UE satisfies with the overload processing condition.

In some embodiments, the information associated with the UE comprises a RRC connection establishment reason for the UE.

In some embodiments, the overload processing condition comprises any one of: a MME selected for the UE based on the information associated with the UE is an overloaded MME; a PLMN selected by the UE is overloaded on the MME determined by the information associated with the UE; the RRC connection establishment reasons of the UE conforms to the reasons for rejecting the RRC connection establishment in the overload actions; and the RRC connection establishment reasons of the UE does not conform to the reasons only allowing the RRC connection establishment in the overload actions.

In some embodiments, the executing an overload processing operation further comprises any one of: selecting an unoverloaded MME based on the information associated with the UE, if a MME determined by the information associated with the UE is an overloaded MME; selecting an MME with an unoverloaded PLMN selected by the UE based on the information associated with the UE, if a PLMN selected by the UE is overloaded on the MME determined by the information associated with the UE; and instructing the second access network equipment to release the RRC connection of the UE, if the RRC connection establishment reasons of the UE conforms to the reasons for rejecting the RRC connection establishment in the overload actions or does not conform to the reasons only allowing the RRC connection establishment in the overload actions.

In some embodiments, the instructing the second access network equipment to release the RRC connection of the UE is achieved via any one of the following messages: a downlink non access stratum (NAS) transmission message; and a UE context releasing command message, wherein the releasing reason indicates a congestion or a location update required for load balancing.

In a third aspect, the present application provides an overload processing method for a radio communication system, wherein the system comprises a first access network equipment and a mobility management entity (MME), and the first access network equipment is connected to the MME. The method comprises: receiving, by the first access network equipment, capacity information on a MME for each public land mobile network (PLMN) or each PLMN list supported by a MME; and selecting, by the first access network equipment, a MME for a user euiqment (UE) in a load balancing way, depending on the capacity on different MMEs for the PLMN/PLMN list selected by the UE.

In some embodiments, the capacity information comprises a leftover processing capacity for the PLMN/PLMN list on the MME, or an occupied processing capacity for the PLMN/PLMN list on the MME.

In some embodiments, the processing capacity is an absolute capacity or a relative capacity, and the relative capacity represents the capacity for the PLMN/ PLMN list on the MME in a MME pool with respect to the capacity for the PLMN/ PLMN list on other MMEs supporting the PLMN/PLMN list in the MME pool.

In a fourth aspect, the present application provides an overload processing method for a radio communication system, wherein the system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment. The method comprises: receiving, by the first access network equipment, first overload information from the MME; and executing, by the first access network equipment, an overload processing operation on a user euiqment (UE) based on the first overload information, if the UE satisfies with an overload processing condition; or receiving, by the second access network equipment, second overload information from the first access network equipment; and executing, by the second access network equipment, an overload processing operation on a user euiqment (UE) based on the second overload information, if the UE satisfies with an overload processing condition.

In some embodiments, the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the second overload information further comprises: determining whether the UE satisfies with the overload processing condition and rejecting a RRC connection request of the UE or releasing the RRC connection of the UE if the UE satisfies with the overload processing condition when the first overload information or the second overload information indicates that a PLMN is overloaded, based on any one reason of: the UE selects an overloaded PLMN in the RRC establishment; and a RRC connection establishment reason of the UE conforms to the reason for rejecting or not-allowing the RRC connection establishment in overload actions of the overloaded PLMN.

In some embodiments, the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the second overload information further comprises: executing any of the following steps when the first overload information or the second overload information indicates that the PLMN is fully overloaded or the PLMN access is barred: rejecting the RRC connection or releasing the RRC connection of the UE for the RRC establishment of the UE selecting the fully overloaded PLMN; providing the fully overloaded PLMN to non-reserved state; and stopping to broadcast an identification of the fully overloaded PLMN.

In some embodiments, the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the second overload information further comprises: determining whether the UE satisfies with the overload processing condition and rejecting a RRC connection request of the UE or releasing the RRC connection of the UE if the UE satisfies with the overload processing condition when the first overload information or the second overload information indicates that a PLMN is fully overloaded and the overload actions indicated in the second overload information are all rejecting or not-allowing the RRC establishment for one or more reasons, based on any one reason of: the UE selects a fully overloaded PLMN in the RRC establishment; and a RRC connection establishment reason of the UE conforms to the reason for rejecting or not-allowing the RRC connection establishment in overload actions.

In some embodiments, the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the second overload information further comprises: executing any of the following steps when the second overload information indicates that the MME is fully overloaded or the MME access is barred: rejecting RRC connection requests of all the UE; and providing a cell barring indication in a cell broadcast.

In some embodiments, the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the second overload information further comprises: rejecting a RRC establishment for one or more reasons when the first overload information or the second overload information indicates that a MME is fully overloaded and overload actions of all the MMEs are all rejecting or not-allowing the RRC establishment for one or more reasons.

In some embodiments, the method further comprises: receiving, by the first access network equipment, mapping relationship information between a MME connected to the first access network equipment and a PLMN supported by the MME from the MME; receiving, by the second access network equipment, relationship information between a MME connected with the first access network equipment and a PLMN supported by the MME from the first access network equipment.

In some embodiments, the mapping relationship information between a MME and a PLMN supported by the MME comprises any one of: mapping relationship information between each MME code (MMEC) or all the MMEC of a MME and a list of PLMN identifications supported by the MMEs; mapping relationship information between each MMEC or all MMEC of a MME group identification or all MMEC of MME and a list of PLMN identifications supported by the MMEs or the MMEC, in a scope of a MME group identification; mapping relationship information between each PLMN and MMEC of a MME supporting the PLMN; mapping relationship information between each PLMN and a list of MME group identification and MMEC of a MME supporting the PLMN; mapping relationship information between each PLMN identification and a list of MME group identification of a MME supporting the PLMN and a list of MMEC of a MME supporting the PLMN; mapping relationship information between each PLMN identification and a list of MME group identification of a MME supporting the PLMN, and mapping relationship information between each MME group identification and a list of MMEC of the MME supporting the PLMN; mapping relationship information between each PLMN identification and a list of MMEC of a MME supporting the PLMN, and mapping relationship information between each MMEC and a list of MME group identification of a MME supporting the PLMN and the MMEC; and a GUMMEI list supported by the MME.

In some embodiments, the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the second overload information further comprises: determining whether the first overload information or the second overload information indicates that a MME is overloaded or the MME is overloaded for one or more PLMNs supported by the MME based on the mapping relationship information, when the first overload information or the second overload information comprises a GUMMEI identification; and executing an overload processing operation on the UE satisfied with the overload processing condition based on the determined result.

In a fifth aspect, the present application provides an overload processing method for a radio communication system, wherein the system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment. The method comprises: receiving, by the first access network equipment, MME sharing related information from the MME; and executing, by the first access network equipment, an overload processing operation on a user euiqment (UE) based on the MME sharing related information, if the UE satisfies with an overload processing condition; or receiving, by the second access network equipment, MME sharing related information from the first access network equipment; and executing, by the second access network equipment, an overload processing operation on a user euiqment (UE) based on the MME sharing related information, if the UE satisfies with an overload processing condition.

In some embodiments, the MME sharing related information comprises one or more of a MME sharing indication, a MME code (MMEC) of a shared MME, a MME group identification and MMEC of the shared MME, and a shared MME identification.

In some embodiments, the executing an overload processing operation on a user euiqment (UE) based on the MME sharing related information further comprises: executing the same overload processing operation on the UE satisfied with the overload processing condition, when the UE selects an overloaded shared MME or the UE selects an overloaded PLMN supported by the shared MME.

In a sixth aspect, the present application provides an overload processing method for a radio communication system, wherein the system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment. The method comprises: establishing a radio resource control (RRC) connection, by the second access network equipment, to a user equipment (UE); transmitting information associated with the UE to the first access network equipment; and receiving an indication for releasing the RRC connection of the UE from the first access network equipment, wherein the indication transmitted by the first access network equipment when the first access network equipment determines that the UE satisfies with the overload processing condition based on the information associated with the UE.

In some embodiments, the overload processing condition comprises any one of: a selected MME for the UE is an overloaded MME, based on the information associated with the UE; a PLMN selected by the UE is overloaded on the MME determined by the information associated with the UE; the RRC connection establishment reason of the UE conforms to the reason for rejecting the RRC connection establishment in the overload actions; and the RRC connection establishment reasons of the UE does not conform to the reasons only allowing the RRC connection establishment in the overload actions.

In a seventh aspect, the present application provides a first access network equipment connected between a second access network equipment for UE access and a mobility management entity (MME), the first access network equipment comprises a receiver, a transmitter and a processor, wherein the receiver is configured to receive first overload information from the MME, wherein the first overload information comprises information related to situations that the MME is started to be overloaded or a public land mobile network (PLMN) supported by the MME is started to be overloaded; the processor is configured to control the transmitter to send second overload information to the second access network equipment based on the first overload information.

In a eighth aspect, the present application provides a first access network equipment connected between a second access network equipment for UE access and a mobility management entity (MME), the first access network equipment comprises a receiver, a transmitter and a processor, wherein the receiver is configured to receive information associated with a user equipment (UE) from the second access network equipment; the processor is configured to select a MME and determining if the UE satisfies with an overload processing condition or not depending on the information associated with the UE; and the transmitter is configured to execute an overload processing operation if the UE satisfies with the overload processing condition.

In a nineth aspect, the present application provides a first access network equipment connected between a second access network equipment for UE access and a mobility management entity (MME), the first access network equipment comprises a receiver, a transmitter and a processor, wherein the receiver is configured to receive capacity information on a MME for each public land mobile network (PLMN) or each PLMN list supported by a MME; the processor is configured to select a MME for a user euiqment (UE) in a load balancing way, depending on the capacity on different MMEs for the PLMN/PLMN list selected by the UE.

In some embodiments, the first access network equipment according to the sixth to eighth aspects is a Donor eNB (DeNB) or a home node B gateway (HeNB GW).

In a tenth aspect, the present application provides a second access network equipment connected to a mobility management entity (MME) through a first access network equipment, the second access network equipment comprises a receiver, a transmitter and a processor, wherein the receiver is configured to receive second overload information from the first access network equipment, wherein the second overload information transmitted by the first access network equipment depending on first overload information received by the first access network equipment from the MME, and the first overload information comprises information related to situations that the MME is started to be overloaded or a public land mobile network (PLMN) supported by the MME is started to be overloaded; the processor is configured to control the transmitter to execute an overload processing operation on a user euiqment (UE) based on the second overload information, if the UE satisfies with an overload processing condition.

In a eleventh aspect, the present application provides a second access network equipment connected to a mobility management entity (MME) through a first access network equipment, the second access network equipment comprises a receiver, a transmitter and a processor, wherein the processor is configured to control the receiver and transmitter to establish a radio resource control (RRC) connection to a user equipment (UE); the transmitter is configured to send information associated with the UE to the first access network equipment; and the receiver is configured to receive an indication for releasing the RRC connection of the UE from the first access network equipment, wherein the indication transmitted by the first access network equipment when the first access network equipment determines that the UE satisfies with the overload processing condition based on the information associated with the UE.

In some embodiments, the second access network equipment according to the nineth to tenth aspects is a relay node (RN) or a home node B (HeNB)

According to the particular embodiments of technology described in the present application, the first access network equipment receives the first overload information from the MME, in which the first overload information comprises information related to situations that the MME is overloaded or PLMN supported by the MME is overloaded, and the first access network equipment sends the second overload information to the second access network equipment based on the first overload information, the second access network equipment obtains information or instructions related to the overload, so as to determine the overload processing to support the overload mechanism.

From the above technical solutions, either in a scenario shared by radio access network or non-radio access network, the RN/HeNB may execute correctly the overload actions indicated by the MME. Therefore, the high priority user’s access is guaranted in order to ensure implementation of the emergency services when the network congestion occurs.

Further features, objects and advantages of the present application will be more apparent with a review of a detailed description of the non-limiting embodiments set forth below with reference to the attached drawings, in which:

Figure 1 illustrates a system architecture diagram for system architecture evolution (SAE) in the prior art;

Figures 2 and 3 illustrate an architecture diagram of an example radio access network which may apply embodiments of the present application;

Figure 4 shows an example flow chart illustrating a method for a first access network equipment according to an embodiment of the present application;

Figure 5 shows an example for a signaling traffic among the first access network equipment, a second access network equipment and the MME, according to an embodiment of the present application;

Figure 6 shows another example for a signaling traffic among the first access network equipment, the second access network equipment and the MME, according to an embodiment of the present application;

Figure 7 shows a further example for a signaling traffic among the first access network equipment, the second access network equipment and the MME, according to an embodiment of the present application;

Figure 8 shows another example flow chart illustrating a method for the first access network equipment according to an embodiment of the present application;

Figure 9 shows a further example flow chart illustrating a method for the first access network equipment according to an embodiment of the present application;

Figure 10 shows an example for a signaling traffic among the UE, the first access network equipment, and the second access network equipment corresponding to the method shown in Figure 9;

Figure 11 shows a yet further example flow chart illustrating a method for the first access network equipment according to an embodiment of the present application;

Figure 12 shows an example flow chart illustrating a method for the first access network equipment and the second access network equipment according to an embodiment of the present application;

Figure 13 shows another example flow chart illustrating a method for the first access network equipment and the second access network equipment according to an embodiment of the present application;

Figure 14 shows an example for a signaling traffic between the first access network equipment and the second access network equipment, according to an embodiment of the present application;

Figure 15 shows another example for a signaling traffic between the first access network equipment and the second access network equipment, according to an embodiment of the present application;

Figure 16 shows a further example flow chart illustrating a method for the second access network equipment according to an embodiment of the present application;

Figure 17 shows a yet further example flow chart illustrating a method for the first access network equipment or the second access network equipment according to an embodiment of the present application;

Figure 18 shows a further example for a signaling traffic between the first access network equipment and the second access network equipment, according to an embodiment of the present application;

Figure 19 shows a yet further example for a signaling traffic between the first access network equipment and the second access network equipment, according to an embodiment of the present application; and

Figure 20 shows a simplied block diagram of an entity adapted to implement example embodiments of the present application.

Hereinafter, the present application will be further explained in detail with reference to the accompanying drawings and the exemplary embodiments. It should be understood that specific embodiments described herein are intended to explain the relevant invention, rather than to limit the invention. In addition, it should be noted that only a portion related to the present invention is shown in the accompanying drawings for ease of description.

Provided that there is no conflict, it should be noted that the embodiments, and features in the embodiments of the present application may be combined. Hereinafter, the present application will be explained in detail with reference to the accompanying drawings in connection with the embodiments.

In the following description, a base station (BS) is an access equipment for accessing a communication device to a cellular network and is used to assign communication resource to the communication device. The BS may be any entity of an eNode B, a Node B, a radio access unit, a BS controller, a Base Transceiver Station (BTS) and the like. The communication device may be any device which is intended to access to services via access networks and may be configured to communicate through the access networks. For example, the communication device may comprise, but not limited to, a UE, a mobile station (MS), a cellular phone, a smart phone, a computer or a multimedia system with communication functions. It should be noted that terms “communication device”, “user equipment” and "user terminal" may be used interchangeably hereinafter.

Considering the problems described in the background portion, the present application provides overload processing solutions for a radio communication system. As mentioned above, the E-UTRAN further supports a variety of technical architectures. Figures 2 and 3 illustrate an architecture diagram of an example radio access network which may apply embodiments of the present application.

With reference to figure 2, which is a schematic diagram illustrating a radio access network composed of the RN and the DeNB. The RN 201 provides the UE with an interface to access to the radio network. The RN 201 does not have the function for selecting MME for the UE and it will send the necessary information to the DeNB 202, such that the DeNB 202 selects the MME for the UE. A radio interface Un is provided between the RN 201 and the DeNB 202. The DeNB supports functions of the gateway and provides IP address for the RN. The DeNB also provides the RN with a proxy for accessing to a core network and ends signaling associated with the interface S1.

Refer to figure 3, which is a schematic diagram illustrating a radio access network composed of home nodes (HeNBs). The HeNBs 301 may directly access to the core network such as Evolved Packet Core (EPC), or access to the core network via a HeNB gateway (HeNB GW) 302. The HeNBs 301 which access the core network via the HeNB GW 302 does not have the function for selecting the MME for the UE, and will sends the necessary information to the HeNB GW 302, such that the HeNB GW 302 selects the MME for the UE. The HeNB GW provides the proxy function for accessing the HeNB to the core network and ends signaling associated with the interface S1.

When nodes in the core network are overloaded, an overload start will be indicated to the BS to ask the BS to proceed with overload actions. A variety of overload actions may be defined. For example, “reject RRC connection establishments for non-emergency mobile originated data transfer”, or “reject RRC connection establishments for signalling”, or “only permit RRC connection establishments for emergency sessions and mobile terminated services”, or “only permit RRC connection establishments for high priority sessions and mobile terminated services”, or “reject only RRC connection establishment for delay tolerant access”

to reject a Radio Resource Control (RRC) establishment with the following reasons: rejecting RRC connection establishments for non-emergency mobile originated data transfer; rejecting RRC connection establishments for signalling; and a RRC connection establishment which can tolerate a delay access. Alternatively, only to permit a RRC establishment with the following reasons: only permitting RRC connection establishments for emergency sessions and mobile terminated services; only permitting RRC connection establishments for high priority sessions and mobile terminated services; and only permitting RRC connection establishment for delay tolerant access.

The BS often connects to a plurality of core network nodes. Generally, the BS or the HeNB GW preferally selects the core network nodes which served the UE before when a UE connection is established. Depending on the actual scenario, the BS or the HeNB selects the core network nodes for the UE on the basis of S-TMSI (S-temporary user ID, an ID for UE in the Long Term Evolution, including MME Code and M-TMSI ) of the UE, or a Public Land Mobile Network (PLMN) selected by the UE and a Globally Unique MME Identifier (GUMMEI) of the UE. If the UE neither provide S-TMSI nor provide GUMMEI, or the MME indicated by the provided GUMMEI does not connect to the BS, then the BS selects the MME for the UE generally based on the principle of load balancing, that is, based on a current weight factor of the MME. Additionally, the load rebalancing function of the MME allows to reselect the MME for the UE in a MME pool, which may be accomplished by releasing the S1 connection of the UE and instructing the UE to initiate the RRC connection without providing S-TMSI or GUMMEI.

It can be known from the architecture shown in figures 2 and 3, that the RN and the indirectly connected HeNB may not have the selecting function for selecting MME for the UE (NAS node selecting function, NNSF). When the MME is overloaded, the RN and the indirectly connected HeNB receives a message of overload start transmitted by the DeNB/HeNB GW, indicating the GUMMEI of the overloaded MME. There may be two situations when the UE initiates a RRC connection to the RN/HeNB:

Situation 1: The UE provides S-TMSI/GUMMEI in a RRC connection establishment request transmitted to the RN and indirectly connected HeNB. Here, the RN/HeNB may determine whether the MMEC in the GUMMEI of the overloaded MME corresponds to the MMEC in the received S-TMSI/GUMMEI or not. If yes, the RN/HeNB proceeds with the overload actions, such as rejecting the RRC establishment request of the UE.

Situation 2: The UE neither provides S-TMSI nor provides GUMMEI in the RRC connection establishment request transmitted to the RN and indirectly connected HeNB, or the MME indicated by the provided GUMMEI does not relate to MME connecting with the DeNB/HeNB GW. Here, the RN/HeNB cannot determine the MME for the UE, and in turn cannot determine the overload actions, because the DeNB/HeNB GW may select an unoverloaded MME for the UE based on the principle of load balancing, or there is no unoverloaded MME for selecting as all the MMEs may be overloaded. The RN and indirectly connected HeNB cannot determine whether the finally selected MME is an overloaded MME.

Additionally, in the scenario of radio access network sharing, particularly, in the scenario of core network sharing, the MME may support a plurality of PLMNs. When a PLMN supported by a MME is overloaded, the MME as a whole may not be overloaded. Here, the DeNB/HeNB GW may receive an overload start message with regard to the PLMN transmitted by the MME. The message comprises a GUMMEI (composed of PLMN+MMEI) of the MME, and the overloaded PLMN is indicated in the GUMMEI. Accordingly, the overload start message with regard to that a PLMN is overloaded on a MME and the overload start message with regard to that overloaded MME node is overload, which are transmitted by the DeNB/HeNB GW and are received by the RN and indirectly connected HeNB, both indicate the overload through the GUMMEI. The following problems raise under the above situations.

Problem 1: When the RN and indirectly connected HeNB receive the overload start message transmitted by the DeNB/HeNB GW, the RN/HeNB may not determine whether a) the whole MME is overloaded, or b) the PLMN is overloaded.

In the situation 1, if a) the whole MME is overloaded, then the RN/HeNB may proceed with the overload actions in the case that the MMEC in the GUMMEI of the overloaded MME corresponds to the MMEC in the S-TMSI/GUMMEI received from UE. That is, the RN/HeNB may determine whether MMEC in the GUMMEI of the overloaded MME matches with the MMEC in the S-TMSI/GUMMEI in the RRC connection establishment request of the UE. If yes, the RN/HeNB proceeds with the overload actions for the UE, such as rejecting the RRC establishment request of the UE. However, if b) the PLMN is overloaded, then the RN/HeNB may determine whether to release the RRC connection of the UE depending on the situation if the PLMN selected by the UE is an overloaded PLMN or not, only when the RN/HeNB receive the RRC establishment completion message from the UE because there is no information for the PLMN in the S-TMSI. Otherwise, in the case that b) the PLMN is overloaded, if the RN/HeNB proceeds with the overload actions based on the MMEC in the GUMMEI, then the UE requests with other PLMNs supported by the MME may be rejectd to lead to incorrect operations.

Problem 2: The RN/HeNB may not determine that the PLMN overload situation is c) a PLMN is overloaded for a MME supporting a PLMN is overloaded for this PLMN or d) a PLMN is overloaded for all the MMEs supporting this PLMN. Based on that, in the case of c), the BS may reselect a MME for the UE depending on the selected PLMN and the load balancing principle without proceeding with the overload actions. In the case of d) a PLMN is overloaded for all the MMEs supporting this PLMN all MME supporting a PLMN is overloaded for this PLMN, the BS may proceed with the overload actions on the UE which selects the overloaded PLMN.

Problem 3: The BS/HeNB GW is now required to support selecting MME for a UE based on the load balancing principle. When the MME is selected for the UE, the DeNB/HeNB GW needs to refer to the load information in the load indicator indicated by MME. However, if a MME is shared, the DeNB/HeNB GW does not have the information related to the loads dedicated for different PLMN supported by the MME, which lead to the load inbalance for a PLMN on different MMEs supporting the PLMN when the MME is selected depending on the PLMN selected by the UE.

Problem 4: In the case that all the MMEs connected to the BS are overloaded, the BS may carry on an access barring operation. Although the overload indication received by the RN/HeNB contains the GUMMEI of all the MMEs connected to the DeNB/HeNB GW, the RN/HeNB does not know that all the MMEs are overloaded. Therefore, the RN/HeNB may allow the RRC connection establishment request of the UE in the situation 2, but there is no MME which can serve the UE actually.

In order to resolve the above-mentioned one or more problems, an overload processing solution for a radio communication system is provided in the present application. A first access network equipment may be an eNB, a DeNB or a HeNB GW, and a second access network equipment may be a HeNB and RN. Figure 4 shows an example flow chart illustrating a method for the first access network equipment according to an embodiment of the present application. It should be understood by one skilled in the art that one or more specific technical details are described in the following description for purposes of illustration and ease of understanding, but the embodiments of the present application may be implemented without these features. In the embodiment shown in Fig. 4, the communication between the two groups of access network equipments and the MME is explained as an example, in which the first access network equipment is directly connected to the MME and the second access network equipment is indirectly connected to the MME through the first access network equipment.

As shown in Figure 4, in step 401, the first access network equipment receives first overload information from the MME.

The first access network equipment, such as eNB, DeNB or HeNB GW, may receive the first overload information from one or more MMEs connected to the first access network equipment.

The first overload information and/or the source MME of the first overload information may indicate which MME is overloaded or the PLMN supported by which MME is overloaded.

The first overload information may further contain an indication that indicates the MME starts to be overloaded or the MME starts to be overload for a PLMN supported by the MME.

In step 402, the first access network equipment sends second overload information to the second access network equipment.

The first access network equipment may know that the MME starts to be overloaded or a MME starts to be overload for a PLMN based on the first overload information and/or the first overload information source MME.

The first access network equipment may generate the second overload information based on the first overload information, and may send the second overload information to the second access network equipment such as RN or HeNB.

In some alternative implementations, the first and second overload information may comprise specific overload actions for the overloaded MME. That is, the overload actions of each GUMMEI may be different.

In some alternative implementations, the first and second overload information may comprise specific overload actions for the overloaded PLMN. That is, a) the overload actions of each PLMN may be different, or b) PLMNs in the same PLMN list may have same overload actions but the overload actions of different PLMN list may be different.

The first access network equipment may take a variety of treatments to decide when to send the second overload information to the second access network equipment and to incorporate what contents in the second overload information.

Figure 5 shows an example for a signaling traffic among the first access network equipment, the second access network equipment and the MME, according to an embodiment of the present application. In the example, the first overload information is carried in the first overload start message, and the second overload information is carried in the second overload start message. The method shown in Figure 5 is an example embodiment of Figure 4.

As shown in Figure 5, the method may comprise the following steps.

Step 501, the first access network equipment receives the first overload start message. The first access network equipment determines that the MME is started to be overloaded or a MME starts to be overload for a PLMN based on the first overload information in the first overload start message.

As an example, the first access network equipment may determine that a PLMN is overloaded for a MME supporting the PLMN depending on a MME identification contained in the first overload start message. The MME identification may be a GUMMEI list. PLMN identification included in the MME identification may indicate the overloaded PLMN supported by the MME. The first access network equipment maydetermine that the MME is overloaded based on the situation that there is no MME identification (such as GUMMEI) in the first overload start message.

As an example, the first access network equipment may determine that a PLMN is overloaded for a MME supporting the PLMN based on the situation that the first overload start message contains an overload type indication. The first access network equipment may determine that a PLMN is overloaded for a MME supporting the PLMN based on the situation that there is no overload type indication in the first overload start message. In some embodiments, the first access network equipment may determine if a PLMN is overloaded for a MME supporting the PLMN or a MME is overloaded based on the value of the overload type indication in the first overload start message. The value of the overload type indication may comprise one or more of the following values: a PLMN is overloaded for a MME supporting the PLMN or MME is overloaded.

As an example, the first access network equipment may determine that a PLMN is overloaded for a MME supporting the PLMN based on a PLMN identification contained in the first overload start message. The first access network equipment may determine that a PLMN is overloaded for a MME supporting the PLMN based on the situation that there is no PLMN identification in the first overload start message. The PLMN identification may indicate the overloaded PLMN supported by the MME.

As an example, the first access network equipment may comfirm a PLMN is fully overloaded based on the first overload start message associated with the PLMN received from all the MME supporting the PLMN.

As an example, the first access network equipment may comfirm that a PLMN is fully overloaded for a RRC establishment rejection reason based on the first overload start message associated with the PLMN received from all the MME supporting the PLMN as well as the situation that the overload actions all require the RRC establishment rejection for some reason.

In step 502, the first access network equipment generates the second overload start message including the second overload information and sends the information to the second access network equipment.

In some embodiments, the second overload information may comprise one or more of the overload type indication, PLMN identification, GUMMEI identification, PLMN access barring indication, PLMN reserving indication and RRC releasing indication. In some alternative implementation, the first overload information may comprise the above information.

Specifically, in some implementation, the second overload information may be the PLMN identification or the GUMMEI identification. The PLMN identification refers to the overloaded PLMN. The GUMMEI identification indicates that the MME is overloaded. The overloaded PLMN refers to the situation that 1) a PLMN is overloaded on one or more MMEs supporting the PLMN, or 2) a PLMN is overloaded on all MMEs supporting the PLMN. Such MMEs are connected to the first access network equipment.

In some other implementation, the second overload information may be the overload type indication and GUMMEI identification. The GUMMEI identification refers to the identification for the overloaded MME, in which the PLMN identification refers to the identification for the overloaded PLMN.

In some embodiments, the overload type indication may comprise MME overload indication or PLMN overload indication.

The PLMN overload refers to the situation that 1) a PLMN is overloaded on one or more MMEs supporting the PLMN, or 2) a PLMN is overloaded on all MMEs supporting the PLMN. Such MMEs are connected to the first access network equipment. Alternatively or additionally, the PLMN overload indication may be divided into one or more indications comprising a PLMN partly overload indication and a PLMN fully overload indication which represent the above two meanings, respectively. The PLMN partly overload refers to the situation 1) and the PLMN fully overload refers to the situation 2).

Specifically, in some implementation, the second overload information may be the PLMN access barring indication or the PLMN reserving indication, and it will be indicated to the second overload equipment when the PLMN is fully overloaded. The second access network equipment may stop to broadcast the fully overloaded PLMN or provide the fully overloaded PLMN to non-reserve state.

Specifically, in some implementation, the second overload information may be the RRC releasing indication or the MME sharing indication, to indicate that the second overload equipment proceeds with the same overload operations on the PLMN overload of the MME or the MME overload, for example, to release the RRC connection corresponding to the overload reasons.

In some alternative implementation, the first and second overload information comprise specific overload actions of the overloaded MME. The specific overload actions of the overloaded MME have been described in step 402, and thus its detailed description is omitted here.

In some alternative implementation, the first and second overload information comprises specific overload actions of the overloaded PLMN. The specific overload actions of the overloaded PLMN have been described in step 402, and thus its detailed description is omitted here.

In step 503, the second access network equipment receives the second overload start message and executes appropriate overload processing operations on the UE which satisfies with overload processing conditions based on the second overload information in the received second overload start message.

Based on the second overload information, if the second access network equipment may know that: the PLMN is overloaded (the meaning of PLMN overload has been described in ths step 502 and thus is omitted here), the second access network equipment may determine if the UE satisfies with the overload processing condition or not based on the following reasons: 1) in the RRC establishment, the UE selects the overloaded PLMN; 2) the reason for the RRC connection establishement of the UE conforms to some reason of rejecting establishment or not-allowing establishment in the overload actions for the overloaded PLMN. For the UE which satisfies with the above reason 1) and/or 2), the second access network equipment executes the overload processing operation, that is, to reject the RRC connection request of the UE or to release the RRC connection of the UE. In an appropriate applied scenario such as a RRC establishment, the UE provides the S-TMSI or GUMMEI scenario.

Based on the second overload information, if the second access network equipment may know that: the PLMN is fully overloaded (the meaning of PLMN fully overload has been described in ths step 502 and thus is omitted here), or if the second overload information indicates the PLMN access barring, alternatively, the second access network equipment may reject the RRC connection request of the UE or release the RRC connection of the UE for the RRC establishment which selects the overloaded PLMN. Alternatively, the second access network equipment may stop to broadcast the PLMN identification. Alternatively, the second access network equipment may provide the PLMN to a non-reserve state.

Based on the second overload information, if the second access network equipment may know that: the PLMN is fully overloaded (the meaning of PLMN fully overload has been described in ths step 502 and thus is omitted here), and the overload actions indicated in the second overload information are all to reject the RRC establishment for some reasons, then the second access network equipment may determine if the UE satisfies with the overload processing condition or not based on the following reasons: 1) in the RRC establishment, the UE selects the fully overloaded PLMN; 2) the reason for the RRC connection establishement of the UE conforms to the reason for rejecting establishment or not-allowing establishment in the overload actions. For the UE which satisfies with the above reasons 1) and/or 2), the second access network equipment executes the overload processing operation, that is, to reject the RRC connection request of the UE or to release the RRC connection of the UE.

With the above-mentioned embodiments, the second access network equipment may identify if the MME is overloaded or the PLMN is overloaded in order to execute the overload processing accordingly. In some embodiments, for the PLMN overload, the second access network equipment may further identify if a PLMN is overloaded on a MME or the PLMN is fully overloaded on all the MMEs, in order to execute the overload processing accordingly. That is, the embodiment shown in figure 5 may address the above-mentioned

problems

1 and 2.

Figure 6 shows another example for a signaling traffic among the first access network equipment, the second access network equipment and the MME, according to an embodiment of the present application. The method shown in Figure 6 is another example embodiment of Figure 4.

As shown in Figure 6, the method may comprise the following steps.

Since step 601 is the same as the step 501, its description is omitted here.

In step 602, in the case that the first access network equipment determines that a PLMN is fully overloaded or a PLMN for a RRC establishment reason is fully overloaded, the first access network equipment generates the second overload information including the related information of the fully overloaded PLMN. The second overload information is transmitted to the second access network equipment through the second overload start message. The second overload information has been described in the step 502, and thus its detailed description is omitted here.

As an example, if the first access network equipment receives the overload start message from all the MMEs connected to it and all the messages indicate that a PLMN is overloaded on all the MMEs, then the first access network equipment determines that the PLMN is fully overloaded. The step of determining that the PLMN is overloaded on the MME by the first access network equipment is the same as the step 501.

The meaning of PLMN fully overload has been described in the step 502, and thus is omitted here. A PLMN fully overload for a RRC establishment reason indicates that the PLMN is fully overloaded and the overload actions in the second overload information require the RRC establishment rejection for some reasons.

In some embodiments, the first access network equipment may not send the second overload start message to the second access network equipment, when the first access network equipment determines that the PLMN is partly overloaded or the PLMN is fully overloaded but all the overload actions of the overloaded PLMN do not reject the RRC establishment for the same reason based on the first overload start message. The meaning of the PLMN partly overload has been described in the step 502, and thus is omitted here.

Step 603 is the same as the step 503, and thus is omitted here.

With the embodiment shown in Figure 6, the second access network equipment may identify the situation that the MME is overloaded or the PLMN is fully overloaded so as to execute the overload processing accordingly. That is, the embodiment shown in Figure 6 may address the above-mentioned

problems

1 and 2.

Figure 7 shows a further example for a signaling traffic among the first access network equipment, the second access network equipment and the MME, according to an embodiment of the present application. The method shown in Figure 7 is another example embodiment of Figure 4.

As shown in Figure 7, the method may comprise the following steps.

Since step 701 is the same as the step 501, its description is omitted here.

In step 702, the first access network equipment determines if all the MMEs connected to the first access network equipment are fully overloaded or all the MMEs are fully overloaded for a RRC establishment reason based on the received first overload start message including the first overload information. In the case that the first access network equipment determines that all the MMEs are fully overloaded or all the MMEs are fully overloaded for a RRC establishment reason, the first access network equipment sends the second overload start message including the second overload information.

As an example, the first access network equipment may determine if all the MMEs are fully overloaded by receiving the first overload start message from all the MMEs connected to the first access network equipment.

As an example, the first access network equipment may determine that all the MMEs are fully overloaded for a RRC establishment reason by receiving the first overload start message from all the MMEs connected to the first access network equipment and depending on that the overload actions requiring the RRC connection rejection for some reason.

In some embodiments, the second overload information may be one or more of the access barring indication, overload type indication or GUMMEI identification. The GUMMEI identification is the identification of the fully overloaded MME. The overload type indication refers to the situation that MME is fully overloaded.

Alternatively, the first access network equipment sends the second overload start message only when the first access network equipment determines that all the MMEs connected to the first access network equipment are fully overloaded or all the MMEs are fully overloaded for a RRC establishment reason based on the first overload start message. In some embodiments, if the first access network equipment determines that part of the MMEs connected to the first access network equipment are overloaded or all the MMEs are fully overloaded but the overload actions of all the overloaded MMEs do not reject the RRC connection for the same reason based on the first overload start message, the first access network equipment may not send the second overload start message to the second access network equipment.

In step 703, the second access network equipment executes the overload operations based on the second overload information in the received second overload start message.

Based on the second overload information, if the second access network equipment may know that all the MMEs connected to the first access network equipment are fully overloaded or the second overload information indicates the access barring, alternatively, the second access network equipment may reject the RRC connection request of all the UE. Alternatively, the second access network equipment may provide a cell barring indication in the cell broadcast.

Based on the second overload information, if the second access network equipment may know that the MMEs connected to the first access network equipment are fully overloaded and the overload actions of all the overloaded MMEs are rejecting or not-allowing the RRC establishment for some reason, the second access network equipment may reject the RRC establishment for the above reason. That is, to reject the RRC request for the reason or to release the RRC connection.

In some alternative implementation, the first and second overload information may include specific overload actions for the overloaded MME. The specific overload actions for the overloaded MME have been described in the step 402, and thus their detailed description is omitted here.

With the embodiment shown in Figure 7, the second access network equipment may identify whether the MME is fully overloaded so as to execute the overload processing accordingly. That is, the embodiment shown in Figure 7 may address the above-mentioned problem 4.

Figure 8 shows another example flow chart illustrating a method for the first access network equipment according to an embodiment of the present application. The method shown in Figure 8 may be executed independently from or combined with the steps in the method shown in Figure 4.

As shown in Figure 8, the method may comprise the following steps.

In step 801, the first access network equipment receives capacity information of each PLMN or each operator of a MME from the MME. Alternatively, the capacity information may include leftover processing capacity for each PLMN/each PLMN list supported by the MME, or occupied processing capacity (i.e. the load) of each PLMN/each operator/each PLMN list supported by the MME. Alternatively, the processing capacity may be absolute capacity or relative capacity. The relative capacity represents the capacity for specific PLMN/specific PLMN list in a MME in the MME pool with respect to the capacity for the specific PLMN/specific PLMN list in other MMEs supporting the specific PLMN/specific PLMN list in the MME pool.

In an implementation, the PLMN list includes one or more PLMNs. One operator may support multiple PLMNs, and the PLMNs supported by the operator may constitute one or more PLMN lists. The capacity information of the PLMN list represents the capacity configured for the operator or the capacity configured for the PLMN list in the MME. In an implementation, an operator or a PLMN list may be identified through the MMEC in the MME, that is, different MMECs are configured for different operator or PLMN list when the MME is shared by multiple operators. The capacity information of the MMEC represents the capacity configured for the operator or PLMN list represented by the MMEC in the shared MME or the capacity configured for the MMEC.

In an implementation, the capacity information of each PLMN on the MME is included in the MME configuration updating message and S1 establishment message, and transmitted through the MME to the first access network equipment.

In step 802, the first access network equipment selects a MME for the UE in a load balancing way, depending on the capacity for the PLMN/PLMN list selected by the UE on different MME. For example, the MME whose load ratio is consistent with a load factor is selected or the MME with the largest leftover capacity is selected.

With the method shown in Figure 8, the load of the same PLMN/PLMN list in different MME supporting the PLMN/PLMN list is balanced, so as to address the aforementioned problem 3. If the particular PLMN/PLMN list on a MME in the MME pool is overloaded, means that the particular PLMN/PLMN list on other MMEs is also overloaded because of the load balancing. In this regard, the second access network equipment may address the aforementioned problem 2 without identifying the PLMN overload type is the PLMN partly overload or the PLMN fully overload.

Figure 9 shows a further example flow chart illustrating a method for the first access network equipment according to an embodiment of the present application. The method shown in Figure 9 may be executed independently from or combined with the steps in the method shown in Figure 4. In the embodiment shown in Figure 9, the second access network equipment may establish a RRC connection with the UE without executing overload processing on the UE first, then the first access network equipment may determine if there is a need to execute the overload processing.

As shown in Figure 9, the method may comprise the following steps.

In step 901, the first access network equipment receives information associated with the UE from the second access network equipment, in which the UE has established a RRC connection with the second access network equipment.

The information associated with the UE may comprise S-TMSI, GUMMEI or PLMN identification.

In an implementation, the information associated with the UE may further comprise the RRC connection establishment reason of the UE.

In step 902, the first access network equipment selects a MME and determines if the UE satisfies with an overload processing condition according to the information associated with the UE.

Alternatively, when the first access network equipment selects or reselects MME for the UE, it may select one of the following MME preferably: an unoverloaded MME; an MME of which the overload action(s) allow the RRC connection establishment reason of the UE from the overloaded MME (if all MMEs are overloaded); a MME on which the PLMN selected by the UE is not overloaded from the MMEs supporting the PLMN selected by the UE; a MME on which the PLMN selected by the UE is overloaded but the overload action(s) allows the RRC connection establishment reason of the UE from the MMEs supporting the PLMN selected by the UE. (if the PLMN is fully overloaded).

The first access network equipment determines if the UE satisfies with an overload processing condition according to at least one of the following reasons:

a MME selected for the UE is an overloaded MME; or the PLMN selected by the UE is overloaded on the MME selected for the UE.

The RRC connection establishment reason of the UE conforms to some reason for rejecting or not-allowing the RRC connection establishment in the overload actions.

If the first access network equipment determines that the UE satisfies with the overload processing conditions 1) and/or 2), and it may execute the overload processing operation. The overload processing operation may comprise reseleting the MME for the UE or instructing the second access network equipment to release the RRC connection of the UE, that is, entering into the step 903.

In step 903, the first access network equipment instructs the second access network equipment to release the RRC connection.

Figure 10 shows an example for a signaling traffic among the UE, the first access network equipment, and the second access network equipment corresponding to the method shown in Figure 9.

As shown in Figure 10, the method may comprise the following steps.

In step 1001, the UE has established the RRC connection with the second access network equipment.

In step 1002, the first access network equipment receives an initial UE message including the information associated with the UE from the second access network equipment. The information associated with the UE has been described in the step 901, and thus its detailed description is omitted here.

The step 1003 is the same as the step 902, and thus is omitted here.

In step 1004, the first access network equipment transmits a downlink non access stratum (NAS) transmission message or a UE context releasing command message to the second access network equipment.

In an implementation, the message comprises an indication for releasing the RRC connection.

In an implementation, the message releasing reasons indicates congestion or a tracking area update (TAU) required for load balancing. When the second access network equipment receives those messages, it may directly release the RRC connection of the UE. Alternatively, the NAS packet in the message may be a Dummy packet. The second access network equipment does not need to transmit these received packets to the UE. Alternatively, the NAS packet in the message may be the rejecting message requested by the corresponding UE. For example, if the UE initiates a service request, then a service rejectment is returned. If the UE initiates a attachment request, then an attachment rejectment is returned. If a locaton update request is initiated, then the tracking area update reject is returned. The reasons for rejecting may be “congestion” or “a tracking area update required for load balancing”.

Figure 11 shows a yet further example flow chart illustrating a method for the first access network equipment according to an embodiment of the present application.

The MME may be shared by multiple operators, and one operator may support multiple PLMNs. The MMEC of the MME may be configured to a dedicated MMEC for an operator or a PLMN list. Alternatively, the PLMN list may be all the PLMNs or a subset of the PLMNs supported by an operator.

As shown in Figure 11, the method may comprise the following steps.

In step 1101, the first access network equipment receives the first overload information from the MME and transmits the first overload information as the second overload information to the second access network equipment. The first overload information is carried on the first overload start message, and the second overload information is carried on the second overload start message.

The first access network equipment may find the overloaded MMEC from the GUMMEI in the first overload information. The overloaded MMEC may be the MMEC corresponding to the overloaded MME or the MMEC corresponding to the overloaded PLMN or PLMN list on the MME. There is no need for the first access network equipment to differentiate the PLMN overload or the MME overload.

In step 1102, the second access network equipment determines if the UE satisfies with an overload processing condition according to the received second overload information, and executes an overload processing operation to the UE satisfied with the overload processing condition.

The second access network equipment may find the overloaded MMEC from the GUMMEI in the second overload information. The overloaded MMEC may be the MMEC corresponding to the overloaded MME or the MMEC corresponding to the overloaded PLMN or PLMN list on the MME. There is no need for the second access network equipment to differentiate the PLMN overload or the MME overload.

The second access network equipment determines if the UE satisfies with an overload processing condition according to at least one of the following reasons:

If the UE selects the overloaded MMEC, for example, the GUMMEI or S-TMSI indicated during the RRC establishment of the UE comprises the overloaded MMEC.

The RRC connection establishment reason of the UE conforms to some reason for rejecting the RRC connection establishment in the overload actions or does not conform to the reasons only allowing the RRC connection establishment in the overload actions.

If the second access network equipment determines that the UE satisfies with the overload processing conditions 1) and/or 2), and it may execute the overload processing operation.

The overload processing operation may refer to rejecting the RRC request or releasing the RRC connection.

Figure 12 shows an example flow chart illustrating a method for the first access network equipment and the second access network equipment according to an embodiment of the present application.

In step 1201, the second access network equipment transmits information associated with the UE to the first access network equipment. The information associated with the UE may be carried on the initial UE message. The UE has established a RRC connection with the second access network equipment.

In step 1202, the second access network equipment receives indication for releasing the RRC connection.

In an implementation, the specific operations in the step 1202 are the same as that in the step 1004.

Figure 13 shows another example flow chart illustrating a method for the first access network equipment or the second access network equipment according to an embodiment of the present application.

In step 1301, the MME transmits mapping relationship information between the MME and a PLMN supported by the MME to the first access network equipment or the first access network equipment transmits relationship information between each MME connected with the first access network equipment and a PLMN supported by the MME to the second access network equipment.

In step 1302, when the first access network equipment or the second access network equipment receives the overload start message, for the received GUMMEI identification, the first access network equipment or the second access network equipment may determine if the MME is overloaded or a PLMN/PLMNs supported by the MME are overloaded on the MME according to the mapping relationship information between the PLMN and the MME supporting this PLMN. In this regard, the first access network equipment or the second access network equipment may execute appropriate overload operation according to different overload type.

Each MME node may be reflected through the MMEC supported by the MME or MME group ID and MMEC identification. The mapping relationship information between each MME and the PLMN identification supported by the MME may be reflected through at least one of the following manners:

mapping relationship information between each MME code (MMEC) or all the MMEC of a MME and a list of PLMN identifications supported by the MME;

mapping relationship information between each MMEC or all MMEC of a MME and a list of PLMN identifications supported by the MME or the MMEC, in a scope of a MME group identification;

mapping relationship information between each PLMN and a list of MMEC of a MME supporting the PLMN;

mapping relationship information between each PLMN and a list of MME group identification and MMEC of a MME supporting the PLMN;

mapping relationship information between each PLMN identification and a list of MME group identification of a MME supporting the PLMN and a list of MMEC of a MME supporting the PLMN;

mapping relationship information between each PLMN identification and a list of MME group identification of a MME supporting the PLMN, and mapping relationship information between each MME group identification and a list of MMEC of the MME supporting the PLMN;

mapping relationship information between each PLMN identification and a list of MMEC of a MME supporting the PLMN, and mapping relationship information between each MMEC and a list of MME group identification of a MME supporting the PLMN and the MMEC; and

a GUMMEI list supported by the MME, in which the GUMMEI list is constituted of the PLMN identification supported by the MME, the MME group identification and the MMEC. As an example, the GUMMEI list may be divided into the PLMN identification sequence, the MME group identification sequence and MMEC sequence. The PLMN identification, MME group identification and MMEC identification at the same position in the three sequences correspond to each other to constitute the GUMMEI supported by the MME. For example, the PLMNs supported by the MME1, MME2 and MME3 are (PLMN1 and PLMN2), (PLMN1 and PLMN2) and PLMN 3, respectively. The MME group identifications of the three are all MMEG1. The MMEC of the three are MMEC1, MMEC2 and MMEC3, respectively. The PLMN sequence in the GUMMEI list may be PLMN 1, PLMN2, PLMN 1, PLMN2, PLMN 3, the MME group identification sequence may be MMEG1, MMEG1, MMEG1, MMEG1, MMEG1, and the MMEC sequence may be MMEC1, MMEC1, MMEC2, MMEC2, MMEC3. The PLMN identification, MME group identification and MMEC identification at the same position constitute together five GUMMEIs, i.e. (PLMN1+MMEG1+MMEC1), (PLMN2+MMEG1+MMEC1), (PLMN1+MMEG1+MMEC2), (PLMN2+MMEG1+MMEC2), (PLMN3+MMEG1+MMEC3).

Figure 14 shows an example for a signaling traffic between the first access network equipment and the second access network equipment, according to an embodiment of the present application.

In step 1401, the first access network equipment (eNB，HeNB GW, DeNB) receives S1 setup request transmitted by the second access network equipment (HeNB，RN) or the MME receives S1 setup request transmitted by the first access network equipment.

In step 1402, the first access network equipment transmits S1 setup response message to the second access network equipment or the MME transmits S1 setup response message to the first access network equipment. The message comprises relationship information between the MME transmitting the message and PLMN supported by the MME or relationship information between each MME connected with the first access network equipment andPLMN supported by the MME. The relationship between each MME and PLMN supported by the MME is the same as that described in the step 1302 of the method shown in Figure 13.

Figure 15 shows another example for a signaling traffic between the first access network equipment and the second access network equipment, according to an embodiment of the present application.

In step 1501, the second access network equipment (such as HeNB，RN) receives the MME configuration updating message transmitted by the first access network equipment (such as eNB，HeNB GW, DeNB) or the first access network equipment receives the MME configuration updating message transmitted by the MME, and the message comprises mapping relationship information between the MME transmitting the message and PLMN supported by the MME or mapping relationship information between each MME connected with the first access network equipmentand PLMN supported by the MME. The mapping relationship information between each MME and PLMN supported by the MME is the same as that described in the step 1302 of the method shown in Figure 13. The MME or the first access network equipment may transmit the mapping relationship between the updated MME and PLMN supported by the MME through the MME configuration updating message to the first access network equipment or the second access network equipment.

Figure 16 shows a further example flow chart illustrating a method for the second access network equipment according to an embodiment of the present application.

In step 1601, the first access network equipment receives the first overload start message transmitted by the MME or the second access network equipment (such as HeNB，RN) receives the second overload start message transmitted by the first access network equipment (such as eNB, HeNB GW, DeNB).

In step 1602, for the mapping relationship information between the MME and the PLMN supported by the MME in the received second overload start message, or for the mapping relationship information between the the GUMMEI identification or MME and the PLMN supported by the MME in the received second overload start message, the first access network equipment or the second access network equipment determines if the MME is overloaded or the PLMN on the MME is overloaded according to the relationship between the MMEC or MME group identification and MMEC and PLMN supported by the MME (as described in the step 1302 of the method shown in Figure 13). In this regard, the first access network equipment or the second access network equipment may execute appropriate overload operation according to different overload type. The mapping relationship information between the MME and the PLMN supported by the MME is the same as that described in the step 1301 and thus is omitted here.

Figure 17 shows a yet further example flow chart illustrating a method for the first access network equipment or the second access network equipment according to an embodiment of the present application.

In step 1701, the MME node connected to the first access network equipment is a shared MME supporting multiple PLMNs. The MME transmits one of the following as MME sharing related information to the first access network equipment or the first access network equipment transmits one of the following as MME sharing related information to the second access network equipment: 1) RRC releasing indication; 2) MME sharing indication; 3) MMEC of the shared MME; and 4) MME group identification and MMEC of the shared MME.

In step 1702, based on the MME sharing related information, the first access network equipment or the second access network equipment execute the same overload operation on the PLMN overload on the MME or the MME overload, for example to release the RRC connection conformed to the overload reasons.

Figure 18 shows a further example for a signaling traffic between the first access network equipment and the second access network equipment, according to an embodiment of the present application.

In step 1801, the MME receives S1 setup request transmitted by the first access network equipment or the first access network equipment (such as eNB, HeNB GW, DeNB) receives S1 setup request transmitted by the second access network equipment (such as HeNB，RN).

In step 1802, the MME transmits S1 setup response message to the first access network equipment or the first access network equipment transmits S1 setup response message to the second access network equipment. The message comprises one of the following: 1) MME sharing indication; 2) MMEC of the shared MME; and 3) MME group identification and MMEC of the shared MME.

The first access network equipment or the second access network equipment may identify which MME is shared and execute the same sharing operation to the shared MME, for example to release the RRC connection, no matter whether the MME is overloade or the PLMN on the MME is overloaded.

Figure 19 shows a yet further example for a signaling traffic between the first access network equipment and the second access network equipment, according to an embodiment of the present application. In step 1901, the first access network equipment receives the MME configuration updating message or the first overload start message transmitted by the MME; the second access network equipment (such as HeNB，RN) receives the MME configuration updating message or the second overload start message transmitted by the first access network equipment (such as HeNB GW, DeNB), and the message comprises one of the following: 1) MME sharing indication; 2) MMEC of the shared MME; 3) MME group identification and MMEC of the shared MME; and 4) shared MME identification, such as GUMMEI. As an example, the first access network equipment may receive the content included in the aforementioned messages from the core network.

The first access network equipment or the second access network equipment (such as HeNB, RN) may identify which MME is shared according to the information in the received messages and execute the same sharing operation to the shared MME, for example to release the RRC connection, no matter whether the MME is overloade or the PLMN on the MME is overloaded.

Figure 20 shows a simplied block diagram of an entity 2000 adapted to implement example embodiments of the present application. The entity 2000 may be configured to be the first access network equipment, such as DeNB or HeNB GW, or the entity 2000 may be configured to be the second access network equipment, such as RN or HeNB.

As shown in Fig. 20, the entity 2000 comprises a processor 2001, a memory 2002 coupled to the processor 2001 and a suitable RF transmitter/receiver 2004 coupled to the processor 2001. The memory 2002 stores programs 2003. The transmitter/receiver 2004 is suitable for two-way communication. It should be noted that the transmitter/receiver 2004 has at least one antenna for assisting the communication. In practice, the first access network equipment or the second access network equipment may have multiple antennas. The entity 2000 may be coupled to one or more external networks or systems, such as MME, via data paths.

The program 2003 may comprise program commands. When the program commands are executed by associated processor 2001, the entity 2000 may operate according to the respective exemplary embodiments of the present application.

The embodiments of the present application may be implemented by computer software which could be executed by the processor 2001 of the entity 2000, or hardware, or the combination of software and hardware.

The memory 2002 may be any appropriate type of memory suitable for local technical environment, and may be achieved by any appropriate data-storage technology, for example, a memory device and system based on semiconductor, a magnetic memory device and system, an optical memory device and system, a fixed memory and a removable memory, which are only some non-restrictive examples. Although only one memory is illustrated in the entity 2000, a plurality of physically independent memory units may be contained by the entity 2000. The processor 2001 may be any appropriate type of processor suitable for local technical environment, and may comprise one or more of the followings: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP) and a processor based on multi-core architecture, which are only some non-restrictive examples.

When the entity 2000 is configured as the first access network equipment, in some embodiments, the receiver of the transmitter/receiver 2004 is configured to receive the first overload information from the MME, and the first overload information comprises information related to situations that the MME is overloaded or a PLMN supported by the MME is overloaded.

The processor 2001 is configured to control the transmitter of the transmitter/receiver 2004 to transmit second overload information to the second access network equipment based on the first overload information.

When the entity 2000 is configured as the second access network equipment, in some embodiments, the receiver of the transmitter/receiver 2004 is configured to receive second overload information from the first access network equipment, wherein the second overload information transmitted by the first access network equipment depending on first overload information received by the first access network equipment from the MME, and the first overload information comprises information related to situations that the MME is overloaded or a PLMN supported by the MME is overloaded.

The receiver of the transmitter/receiver 2004 is configured to receive RRC connection establishment request from the UE.

The processor 2001 is configured to control the transmitter of the transmitter/receiver 2004 to execute an overload processing operation based on the second overload information and the RRC connection establishment request.

It should be comprehended that, each unit comprised in the entity 2000 is configured to implement the exemplary embodiments disclosed in the present application. Therefore, the above operations and feathers described by combining Figure 4 to Figure 12 are also applicable to the entity 2000 and the units therein, and a detailed description thereof will be omitted herein.

In addition, there is provided a computer readable storage medium, which may be the computer readable storage medium contained in the first access network equipment or second access network equipment in the above embodiments, or a computer readable storage medium individually exists rather than being fitted into any apparatus. There are one or more computer programs stored on the computer readable storage medium, and one or more processors run the one or more computer programs to perform the overload processing method mentioned in the present application.

The above description is only the preferred embodiments of the present application and the description of the principles of applied techniques. It will be appreciated by those skilled in the art that, the scope of the claimed solutions as disclosed in the present application are not limited to those consisted of particular combinations of features described above, but should cover other solutions formed by any combination of features from the foregoing or an equivalent thereof without departing from the inventive concepts, for example, a solution formed by replacing one or more features as discussed in the above with one or more features with similar functions disclosed (but not limited to) in the present application.

Claims

An overload processing method for a radio communication system, wherein the system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment, and the method comprises:

receiving, by the first access network equipment, first overload information from the MME, wherein the first overload information comprises information related to situations that the MME is started to be overloaded or a public land mobile network (PLMN) supported by the MME is started to be overloaded; and

transmitting, by the first access network equipment, second overload information to the second access network equipment based on the first overload information.
The method according to claim 1, wherein the first overload information or the second overload information comprises one or more of an overload type indication, a PLMN identification, a globally unique MME identification (GUMMEI), a PLMN access barring indication, a PLMN reserving indication and a RRC releasing indication.
The method according to claim 2, wherein the overload type indication comprises a MME overload indication or a PLMN overload indication,

wherein the PLMN overload indication represents a situation that a PLMN is overloaded on one or more MMEs supporting the PLMN and connected to the first access network equipment, or a situation that a PLMN is overloaded on all MMEs supporting the PLMN and connected to the first access network equipment.
The method according to claim 3, wherein the PLMN overload indication comprises a PLMN partly overload indication and a PLMN fully overload indication, and the PLMN partly overload indication represents a situation that a PLMN is overloaded on one or more MMEs supporting the PLMN and connected to the first access network equipment, and the PLMN fully overload indication represents a situation that a PLMN is overloaded on all MMEs supporting the PLMN and connected to the first access network equipment.
The method according to any one of claims 1-4, wherein the transmitting the second overload information to the second access network equipment based on the first overload information further comprises:

transmitting the second overload information, when the first access network equipment determines that a PLMN is fully overloaded or a PLMN is fully overloaded on the MME supporting the PLMN and overload actions reject or do not allow a radio resource control (RRC) establishment for one or more reasons, wherein the second overload information comprises information indicating the fully overloaded PLMN.
The method according to claim 5, wherein the information indicating the fully overloaded PLMN comprises at least one of an identification of the PLMN, GUMMEI, information indicating access barring for the PLMN and overload type information, wherein the overload type information indicates that the PLMN is fully overloaded, and the GUMMEI comprises the identification of the fully overloaded PLMN.
The method according to claim 1, wherein the transmitting second overload information to the second access network equipment based on the first overload information further comprises:

determining whether all the MMEs connected to the first access network equipment are fully overloaded or the MME is fully overloaded and overload actions reject or do not allow a radio resource control (RRC) establishment for one or more reasons, based on the first overload information; and

transmitting the second overload information, wherein the second overload information comprises at least one of an access barring indication, an overload type indication and a GUMMEI, wherein the overload type indication indicates that the MME is fully overloaded, and the GUMMEI is an identification for the fully overloaded MME.
The method according to claim 7, wherein the transmitting the second overload information to the second access network equipment based on the first overload information further comprises:

transmitting the second overload information only when the first access network equipment determines that all the MMEs connected to the first access network equipment are fully overloaded or the MME is fully overloaded and overload actions reject or do not allow a radio resource control (RRC) establishment for one or more reasons, based on the first overload information.
The method according to any one of claims 1-8, wherein the first overload information and the second overload information comprise specific overload action information for the overloaded MME or specific overload action information for the overloaded PLMN.
The method according to claim 1, wherein the first overload information and the second overload information comprise a MME code (MMEC), and the MMEC is provided to a dedicated MMEC for an operator, a PLMN or a PLMN list.
An overload processing method for a radio communication system, wherein the system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment, and the method comprises:

receiving, by the first access network equipment, information associated with a user equipment (UE) from the second access network equipment;

selecting a MME according to the information associated with the UE;

determining if the UE satisfies with an overload processing condition according to the information associated with the UE; and

executing an overload processing operation, if yes.
The method according to claim 11, wherein the information associated with the UE comprises a RRC connection establishment reasons for the UE.
The method according to claim 12, wherein the overload processing condition comprises any one of:

a MME selected for the UE based on the information associated with the UE is an overloaded MME;

a PLMN selected by the UE is overloaded on the MME determined by the information associated with the UE;

the RRC connection establishment reason of the UE conforms to some reason for rejecting the RRC connection establishment in the overload actions; and

the RRC connection establishment reason of the UE does not conform to the reason only allowing the RRC connection establishment in the overload actions.
The method according to claim 13, wherein the executing an overload processing operation further comprises any one of:

selecting an unoverloaded MME based on the information associated with the UE, if a MME determined by the information associated with the UE is an overloaded MME;

selecting a MME on which the PLMN selected by the UE is not overloaded based on the information associated with the UE, if a PLMN selected by the UE is overloaded on the MME determined by the information associated with the UE; and

instructing the second access network equipment to release the RRC connection of the UE, if the RRC connection establishment reason of the UE conforms to the reason for the RRC connection establishment rejection in the overload actions or does not conform to the reasons only allowing the RRC connection establishment in the overload actions.
The method according to claim 13, wherein the instructing the second access network equipment to release the RRC connection of the UE is achieved via any of the following messages:

a downlink non access stratum (NAS) transmission message; and

a UE context releasing command message, wherein the releasing reason indicates a congestion or a location update required for load balancing.
An overload processing method for a radio communication system, wherein the system comprises a first access network equipment and a mobility management entity (MME), and the first access network equipment is connected to the MME, and the method comprises:

receiving, by the first access network equipment, capacity information on a MME for each public land mobile network (PLMN) or each PLMN list supported by the MME; and

selecting, by the first access network equipment, a MME for a user euiqment (UE) in a load balancing way, depending on the capacity on different MMEs for the PLMN/PLMN list selected by the UE.
The method according to claim 16, wherein the capacity information comprises a leftover processing capacity for the PLMN/PLMN list on the MME, or an occupied processing capacity for the PLMN/PLMN list on the MME.
The method according to claim 17, wherein the processing capacity is an absolute capacity or a relative capacity, and the relative capacity represents the capacity for the PLMN/ PLMN list on the MME in a MME pool with respect to the capacity for the PLMN/ PLMN list on other MMEs supporting the PLMN/PLMN list in the MME pool.
An overload processing method for a radio communication system, wherein the system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment, the method comprises:

receiving, by the first access network equipment, first overload information from the MME; and

executing, by the first access network equipment, an overload processing operation on a user euiqment (UE) based on the first overload information, if the UE satisfies with an overload processing condition; or

receiving, by the second access network equipment, second overload information from the first access network equipment; and

executing, by the second access network equipment, an overload processing operation on a user euiqment (UE) based on the second overload information, if the UE satisfies with an overload processing condition.
The method according to claim 19, wherein the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the second overload information further comprises:

determining whether the UE satisfies with the overload processing condition and rejecting a RRC connection request of the UE or releasing the RRC connection of the UE if the UE satisfies with the overload processing condition when the first overload information or the second overload information indicates that a PLMN is overloaded, based on any one reason of:

the UE selects an overloaded PLMN in the RRC establishment; and

RRC connection establishment reason of the UE conforms to the reason for rejecting or not-allowing the RRC connection establishment in overload actions of the overloaded PLMN.
The method according to claim 19, wherein the the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the second overload information further comprises:

executing any of the following steps when the first overload information or the second overload information indicates that the PLMN is fully overloaded or the PLMN access is barred:

rejecting the RRC connection or releasing the RRC connection of the UE for the RRC establishment of the UE selecting the fully overloaded PLMN;

providing the fully overloaded PLMN to non-reserved state; and

stopping to broadcast an identification of the fully overloaded PLMN.
The method according to claim 19, wherein the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the second overload information further comprises:

determining whether the UE satisfies with the overload processing condition and rejecting a RRC connection request of the UE or releasing the RRC connection of the UE if the UE satisfies with the overload processing condition when the first overload information or the second overload information indicates that a PLMN is fully overloaded and the overload actions indicated in the first overload information or the second overload information are all rejecting or not-allowing the RRC establishment for one or more reasons, based on any one reason of:

the UE selects a fully overloaded PLMN in the RRC establishment; and

RRC connection establishment reason of the UE conforms to the reason for rejecting or not-allowing the RRC connection establishment in overload actions.
The method according to claim 19, wherein the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the second overload information further comprises:

executing any of the following steps when the first overload information or the second overload information indicates that the MME is fully overloaded or the MME access is barred:

rejecting RRC connection requests of all the UE; and

providing a cell barring indication in a cell broadcast.
The method according to claim 19, wherein the executing by the first access network equipment an overload processing operation on a user euiqment (UE) based on the first overload information or the executing by the second access network equipment an overload processing operation on a user euiqment (UE) based on the second overload information further comprises:

rejecting RRC establishment for one or more reasons when the first overload information or the second overload information indicates that a MME is fully overloaded and overload actions of all the MMEs are all rejecting or not-allowing the RRC establishment for one or more reasons.
The method according to claim 19, further comprising:

receiving, by the first access network equipment, mapping relationship information between a MME connected to the first access network equipment and a PLMN supported by the MME from the MME;

receiving, by the second access network equipment, mapping relationship information between a MME connected with the first access network equipment and a PLMN supported by the MME from the first access network equipment.
The method according to claim 25, wherein the mapping relationship information between a MME and a PLMN supported by the MME comprises any one of:

Mapping relationship information between each MME code (MMEC) or all the MMEC of a MME and a list of PLMN identifications supported by the MME;

Mapping relationship information between each MMEC or all MMEC of a MME and a list of PLMN identifications supported by the MME or the MMEC, in a scope of a MME group identification;

Mapping relationship information between each PLMN and a list of MMEC of a MME supporting the PLMN;

Mapping relationship information between each PLMN and a list of MME group identification and MMEC of a MME supporting the PLMN;

Mapping relationship information between each PLMN identification and a list of MME group identification of a MME supporting the PLMN and a list of MMEC of a MME supporting the PLMN;

Mapping relationship information between each PLMN identification and a list of MME group identification of a MME supporting the PLMN, and mapping relationship information between each MME group identification and a list of MMEC of the MME supporting the PLMN;

Mapping relationship information between each PLMN identification and a list of MMEC of a MME supporting the PLMN, and mapping relationship information between each MMEC and a list of MME group identification of a MME supporting the PLMN and the MMEC; and

a GUMMEI list supported by a MME.
The method according to claim 25 or 26, wherein the executing an overload processing operation on a user euiqment (UE) based on the second overload information further comprises:

determining whether the second overload information indicates that a MME is overloaded or a MME is overloaded for one or more PLMNs supported by the MME based on the relationship information, when the second overload information comprises a GUMMEI identification; and

executing an overload processing operation on the UE satisfied with the overload processing condition based on the determined result.
An overload processing method for a radio communication system, wherein the system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment, the method comprises:

receiving, by the first access network equipment, MME sharing related information from the MME; and

executing, by the first access network equipment, an overload processing operation on a user euiqment (UE) based on the MME sharing related information, if the UE satisfies with an overload processing condition; or

receiving, by the second access network equipment, MME sharing related information from the first access network equipment; and

executing, by the second access network equipment, an overload processing operation on a user euiqment (UE) based on the MME sharing related information, if the UE satisfies with an overload processing condition.
The method according to claim 28, wherein the MME sharing related information comprises one or more of a MME sharing indication, a MME code (MMEC) of a shared MME, a MME group identification and a MMEC of the shared MME, and a shared MME identification.
The method according to claim 29, wherein the executing an overload processing operation on a user euiqment (UE) based on the MME sharing related information further comprises:

executing the same overload processing operation on the UE satisfied with the overload processing condition, when the UE selects an overloaded shared MME or the UE selects an overloaded PLMN supported by the shared MME.
An overload processing method for a radio communication system, wherein the system comprises a first access network equipment, a second access network equipment and a mobility management entity (MME), and the second access network equipment is connected to the MME through the first access network equipment, and the method comprises:

establishing a radio resource control (RRC) connection, by the second access network equipment, to a user equipment (UE);

transmitting information associated with the UE to the first access network equipment; and

receiving an indication for releasing the RRC connection of the UE from the first access network equipment, wherein the indication transmitted by the first access network equipment when the first access network equipment determines that the UE satisfies with the overload processing condition based on the information associated with the UE.
The method according to claim 31, wherein the information associated with the UE comprises RRC connection establishment reasons for the UE.
The method according to claim 32, wherein the overload processing condition comprises any one of:

a selected MME for the UE is an overloaded MME, based on the information associated with the UE;

a PLMN selected by the UE is overloaded on the MME selected based on the information associated with the UE;

the RRC connection establishment reason of the UE conforms to the reason for rejecting the RRC connection establishment in the overload actions; and

the RRC connection establishment reason of the UE does not conform to the reason only allowing the RRC connection establishment in the overload actions.
A first access network equipment connected between a second access network equipment for UE access and a mobility management entity (MME), the first access network equipment comprises a receiver, a transmitter and a processor, wherein

the receiver is configured to receive first overload information from the MME, wherein the first overload information comprises information related to situations that the MME is started to be overloaded or a public land mobile network (PLMN) supported by the MME is started to be overloaded;

the processor is configured to control the transmitter to transmit second overload information to the second access network equipment based on the first overload information.
A first access network equipment connected between a second access network equipment for UE access and a mobility management entity (MME), the first access network equipment comprises a receiver, a transmitter and a processor, wherein

the receiver is configured to receive information associated with a user equipment (UE) from the second access network equipment;

the processor is configured to select a MME and determining if the UE satisfies with an overload processing condition or not depending on the information associated with the UE; and

the transmitter is configured to execute an overload processing operation if the UE satisfies with the overload processing condition.
A first access network equipment connected between a second access network equipment for UE access and a mobility management entity (MME), the first access network equipment comprises a receiver, a transmitter and a processor, wherein

the receiver is configured to receive capacity information on the MME for each public land mobile network (PLMN) or each PLMN list supported by a MME;

the processor is configured to select a MME for a user euiqment (UE) in a load balancing way, depending on the capacity on different MMEs for the PLMN/PLMN list selected by the UE.
The first access network equipment according to any one of claims 34-36, wherein the first access network equipment is a Donor eNB (DeNB) or a home node B gateway (HeNB GW).
A second access network equipment connected to a mobility management entity (MME) through a first access network equipment, the second access network equipment comprises a receiver, a transmitter and a processor, wherein

the receiver is configured to receive second overload information from the first access network equipment, wherein the second overload information transmitted by the first access network equipment depending on first overload information received by the first access network equipment from the MME, and the first overload information comprises information related to situations that the MME is started to be overloaded or a public land mobile network (PLMN) supported by the MME is started to be overloaded;

the processor is configured to control the transmitter to execute an overload processing operation on a user euiqment (UE) based on the second overload information, if the UE satisfies with an overload processing condition.
A second access network equipment connected to a mobility management entity (MME) through a first access network equipment, the second access network equipment comprises a receiver, a transmitter and a processor, wherein

the processor is configured to control the receiver and transmitter to establish a radio resource control (RRC) connection to a user equipment (UE);

the transmitter is configured to send information associated with the UE to the first access network equipment; and

the receiver is configured to receive an indication for releasing the RRC connection of the UE from the first access network equipment, wherein the indication transmitted by the first access network equipment when the first access network equipment determines that the UE satisfies with the overload processing condition based on the information associated with the UE.
The second access network equipment according to claim 38 or 39, wherein the second access network equipment is a relay node (RN) or a home node B (HeNB).