WO2012073842A1

WO2012073842A1 - Communication system and method of controlling communication

Info

Publication number: WO2012073842A1
Application number: PCT/JP2011/077259
Authority: WO
Inventors: 仁也立川
Original assignee: 京セラ株式会社
Priority date: 2010-12-02
Filing date: 2011-11-25
Publication date: 2012-06-07
Also published as: JPWO2012073842A1

Abstract

When a failure occurs in a backhaul (30) and the SI communication with MME(20) becomes impossible, an eNB (10-1) selects an eNB (10-2) and an eNB(10-3) that are two relay eNBs. Further, the eNB (10-1) and the eNB (10-2) perform processing to set a detour bearer (#1) via the eNB (10-2), while the eNB (10-1) and the eNB (10-3) perform processing to set a detour bearer (#2) via the eNB (10-3). Further, the eNB (10-1) assigns packets from a UE(40) to the detour bearer (#1) and the detour bearer (#2) and transmits the packets to the MME(20).

Description

Communication system and communication control method

The present invention relates to a communication system having a plurality of radio base stations and upper nodes, and a communication control method in the communication system.

In 3GPP (Third Generation Partnership Project), in a communication system corresponding to LTE (Long Terminology Evolution) currently being developed, a radio base station (eNB) is an MME (Mobile Management Entity) and communicate with the MME.

However, when a failure occurs in the backhaul and the eNB cannot communicate with the MME, it is required to ensure communication with the MME.

In view of the above problems, an object of the present invention is to provide a communication system and a communication control method that improve the reliability of communication between a radio base station and an upper node.

In order to solve the above-described problems, the present invention has the following features.

A feature of the present invention is a communication system (communication system 1) having a plurality of radio base stations (eNB 10-1, eNB 10-2, eNB 10-3) and an upper node (MME 20, packet transfer apparatus 25), A setting unit (communication path setting unit 112) for setting a plurality of communication paths via different second radio base stations between one radio base station and the upper node, and a plurality of communications set by the setting unit The gist is to include a transmission unit (transmission processing unit 114) that distributes and transmits packets on the route.

In such a communication system, a plurality of communication paths through the second radio base station are set between the first radio base station and the upper node, and packets are distributed and transmitted to the plurality of communication paths. Let Therefore, packets transmitted between the first radio base station and the upper node are concentrated on a specific second radio base station, and the load on the second radio base station becomes excessive. It is possible to improve the certainty of communication between the first radio base station and the upper node while preventing it.

A feature of the present invention is that the communication path setting unit is different between the first radio base station and the upper node based on information on a communication path for each second radio base station. The gist is to set a plurality of communication paths through the radio base station.

A feature of the present invention is summarized in that the transmission unit sequentially distributes and transmits the packets to a plurality of communication paths set by the setting unit.

The feature of the present invention is that the information on the communication path includes information on the transmission speed of the communication path, and the transmission unit responds to the transmission speed corresponding to the plurality of communication paths set by the setting unit. The gist is to distribute the amount of packets to be transmitted.

The gist of a feature of the present invention is that it includes an updating unit (updating unit 116) that updates information on the transmission rate when the transmission rate changes.

A feature of the present invention is summarized in that the transmission unit determines a ratio for distributing packets to each communication path based on the attribute of the communication path set by the setting unit, and then distributes and transmits the packet.

A feature of the present invention is summarized in that the transmission unit transmits the same packet to the plurality of communication paths set by the setting unit.

In such a communication system, since the same packet is transmitted between the first radio base station and the upper node through different communication paths, the certainty of communication between the first radio base station and the upper node is ensured. Can be improved.

A feature of the present invention is a communication control method in a communication system having a plurality of radio base stations and an upper node, wherein a different second radio base station is provided between the first radio base station and the upper node. The gist of the present invention includes a step of setting a plurality of communication paths through which the packet is routed and a transmission step of distributing and transmitting packets to the plurality of set communication paths.

FIG. 1 is an overall schematic configuration diagram of a communication system according to an embodiment of the present invention. FIG. 2 is a diagram showing a setting state of the S1 interface in the communication system according to the embodiment of the present invention. FIG. 3 is a configuration diagram of the eNB according to the embodiment of the present invention. FIG. 4 is a configuration diagram of a relay node according to the embodiment of the present invention. FIG. 5 is a diagram showing an example of communication path information according to the embodiment of the present invention. FIG. 6 is a diagram illustrating a setting state of the detour bearer in the communication system according to the embodiment of the present invention. FIG. 7 is a sequence diagram showing a first operation of the communication system according to the embodiment of the present invention. FIG. 8 is a sequence diagram showing a second operation of the communication system according to the embodiment of the present invention. FIG. 9 is a sequence diagram showing a third operation of the communication system according to the embodiment of the present invention.

Next, an embodiment of the present invention will be described with reference to the drawings. Specifically, a schematic configuration of a communication system, a configuration of an LTE base station (eNB), a configuration of a relay node, an operation of the communication system, operations and effects, and other embodiments will be described. In the description of the drawings in the following embodiments, the same or similar parts are denoted by the same or similar reference numerals.

(1) Schematic Configuration of Communication System FIG. 1 is a schematic configuration diagram of a communication system according to the present embodiment. In the present embodiment, the communication system 1 is configured using LTE technology. 1 includes an LTE base station (eNB) 10-1, eNB 10-2, eNB 10-3, an MME (Mobile Management Entity) 20, a packet transfer device 25, an eNB 10- 1 to eNB 10-3 and a backhaul 30 connecting the MME 20, a radio terminal (UE) 40, a relay node 50-1, and a relay node 50-2.

In this embodiment, the eNB 10-1 is assigned an IP address A, the eNB 10-2 is assigned an IP address B, and the eNB 10-3 is assigned an IP address C. The MME 20 is assigned an IP address D, and the packet transfer device 25 is assigned an IP address E.

In FIG. 1, the UE 40 exists in a cell formed by the eNB 10-1. The relay node 50-1 exists in the overlapping area of the cell formed by the eNB 10-1 and the cell formed by the eNB 10-2. The relay node 50-2 exists in the overlapping area of the cell formed by the eNB 10-1 and the cell formed by the eNB 10-3.

The eNB 10-1 can perform radio communication with the UE 40 in the cell formed by the eNB 10-1 via a radio section. In LTE, the communication method between the eNB 10-1 and the UE 40 is referred to as E-UTRAN (Evolved UMTS Terrestrial Radio Access Network).

FIG. 2 is a diagram illustrating a setting state of the S1 interface in the communication system 1. In FIG. 2, an S1 interface # 1 that is a logical transmission path of the transport layer is set between the eNB 10-1 and the MME 20 via the backhaul 30. Further, an S1 interface # 2 is set between the eNB 10-2 and the MME 20 via the backhaul 30. An S1 interface # 3 is set between the eNB 10-3 and the MME 20 via the backhaul 30.

(2) Configuration of eNB FIG. 3 is a diagram illustrating a configuration of the eNB 10-1. The eNB 10-1 illustrated in FIG. 3 includes a control unit 102, a storage unit 103, an I / F unit 104, a radio communication unit 106, and an antenna 108. Note that the eNB 10-2 and the eNB 10-3 have the same configuration as the eNB 10-1.

The control unit 102 is configured using, for example, a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), and controls various functions of the eNB 10-1. The storage unit 103 is configured by a memory, for example, and stores various information used for control in the eNB 10-1.

The I / F unit 104 is connected to the backhaul 30. The I / F unit 104 performs data transmission and reception with the MME 20, the eNB 10-2, and the eNB 10-3.

The wireless communication unit 106 includes an RF circuit, a baseband circuit, etc., performs modulation and demodulation, encoding and decoding, etc., and transmits and receives wireless signals to and from the UE 40 via the antenna 108. Further, the radio communication unit 106 can transmit and receive radio signals between the relay node 50-1 and the relay node 50-2.

The control unit 102 receives the uplink data addressed to the packet transfer device 25 from the UE 40 via the antenna 108 and the wireless communication unit 106. The received uplink data has a configuration corresponding to the Uu-IF protocol.

When communication via the S1 interface # 1 set in the backhaul 30 (S1 communication) is possible, the control unit 102 converts the uplink data from the Uu-IF protocol to the S1-MME-IF protocol. Further, the control unit 102 transmits the new uplink data obtained by the conversion to the packet transfer apparatus 25 via the I / F unit 104, the S1 interface set in the backhaul 30, and the MME 20 (S1). communication).

Further, the control unit 102 receives downlink data addressed to the UE 40 from the packet transfer device 25 via the I / F unit 104 (S1 communication). The received downlink data has a configuration corresponding to the S1-MME-IF protocol. The control unit 102 converts the downlink data from the S1-MME-IF protocol to the Uu-IF protocol. Further, the control unit 102 transmits new downlink data obtained by the conversion to the UE 40 via the radio communication unit 106 and the antenna 108.

(3) Configuration of Relay Node FIG. 4 is a diagram showing a configuration of the relay node 50-1. The relay node 50 illustrated in FIG. 4 includes a control unit 502, a storage unit 503, a wireless communication unit 504, an antenna 506, a wireless communication unit 508, and an antenna 510. Relay node 50-2 has the same configuration as relay node 50-1.

The control unit 502 is configured using, for example, a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), and controls various functions of the relay node 50. The storage unit 503 is configured by a memory, for example, and stores various types of information used for control in the relay node 50-1.

The wireless communication unit 504 includes an RF circuit, a baseband circuit, etc., performs modulation and demodulation, encoding and decoding, etc., and transmits and receives wireless signals to and from the eNB 10-1 via the antenna 506. . The radio communication unit 508 includes an RF circuit, a baseband circuit, etc., performs modulation, demodulation, encoding, decoding, etc., and transmits and receives radio signals to and from the eNB 10-2 via the antenna 510. . Note that the radio communication unit 508 in the relay node 50-2 transmits and receives radio signals to and from the eNB 10-3 via the antenna 510.

(4) Operation of Communication System Here, consider a case where a failure of the backhaul 30 occurs and S1 communication between the eNB 10-1 and the MME 20 becomes impossible. In this case, in this embodiment, uplink communication between the eNB 10-1 and the MME 20 includes uplink communication via the relay node 50-1 and the eNB 10-2, and uplink communication via the relay node 50-2 and the eNB 10-3. Both are performed. Details will be described below.

(4.1) Processing of the control unit 102 of the eNB 10-1 in uplink communication The communication path setting unit 112 in the control unit 102 of the eNB 10-1 uses the IP function of the S1-MME-IF protocol to It is detected that S1 communication between the eNB 10-1 and the MME 20 is disabled.

In this case, the communication path setting unit 112 in the control unit 102 of the eNB 10-1 has a plurality of eNBs to be relay stations based on the communication path information stored in the storage unit 103 in communication with the MME 20. (Relay eNB) is selected.

FIG. 5 is a diagram showing an example of communication path information. The communication path information illustrated in FIG. 5 is set for each of the eNB 10-2 and the eNB 10-3 that are eNBs other than the eNB 10-1 and capable of wireless communication with the eNB 10-1 via the relay node. The communication path information corresponding to the eNB 10-2 includes the cell ID that is the identification information of the eNB 10-2 and the identification of the relay node 50-1 that relays when the eNB 10-1 performs wireless communication with the eNB 10-2. The relay node ID is information, and the transmission rate information between the eNB 10-2 and the MME 20 is configured. The communication path information corresponding to the eNB 10-3 includes the cell ID that is the identification information of the eNB 10-3 and the identification of the relay node 50-2 that relays when the eNB 10-1 performs wireless communication with the eNB 10-3. The relay node ID is information, and information on the transmission rate between the eNB 10-3 and the MME 20.

The communication path setting unit 112 in the control unit 102 of the eNB 10-1 reads the communication path information from the storage unit 103. The communication path setting unit 112 selects the eNB 10-2 and the eNB 10-3 corresponding to the cell ID included in each communication path information.

Next, the communication path setting unit 112 in the control unit 102 of the eNB 10-1 sets an avoidance bearer # 1 between the relay node 50-1 that relays radio communication between the eNB 10-1 and the eNB 10-2. Set. In addition, the communication path setting unit 112 in the control unit 102 of the eNB 10-1 sets an avoidance bearer # 2 between the relay node 50-2 that relays wireless communication between the eNB 10-1 and the eNB 10-3. To do.

Next, the communication path setting unit 112 in the control unit 102 of the eNB 10-1 transmits the alternative bearer generation instruction information 1 to the relay node 50-1 via the set avoidance bearer # 1. The alternative bearer generation instruction information 1 is information for instructing generation of a bearer via the eNB 10-2. Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-1 transmits the alternative bearer generation instruction information 2 to the relay node 50-2 via the set avoidance bearer # 2. The alternative bearer generation instruction information 2 is information for instructing generation of a bearer via the eNB 10-3.

The control unit 502 of the relay node 50-1 receives the alternative bearer generation instruction information 1 from the eNB 10-1 via the avoidance bearer # 1. Further, the control unit 502 of the relay node 50-2 receives the alternative bearer generation instruction information 2 from the eNB 10-1 via the avoidance bearer # 2.

The control unit 502 of the relay node 50-1 is connected to the eNB 10-2 via a wireless section. In addition, the control unit 502 of the relay node 50-2 connects to the eNB 10-3 via a radio section.

Thereafter, the control unit 502 of the relay node 50-1 transmits the alternative bearer generation instruction information 1 to the eNB 10-2 through wireless communication. The control unit 502 of the relay node 50-2 transmits the alternative bearer generation instruction information 2 to the eNB 10-3 through wireless communication.

The communication path setting unit 112 in the control unit 102 of the eNB 10-2 receives the alternative bearer generation information 1 from the relay node 50-1. Further, the communication path setting unit 112 in the control unit 102 in the eNB 10-2 receives the alternative bearer generation information 2 from the relay node 50-1.

Next, the communication path setting unit 112 in the control unit 102 of the eNB 10-2 transmits the alternative bearer notification information 1 to the MME 20 via the backhaul 30 by S1 communication. The alternative bearer notification information 1 is information for notifying that a bearer needs to be generated between the eNB 10-1 and the packet transfer apparatus 25 via the eNB 10-2, and the IP address B of the eNB 10-2 It is included. Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-3 transmits the alternative bearer notification information 2 to the MME 20 through the backhaul 30 by S1 communication. The alternative bearer notification information 2 is information for notifying that a bearer needs to be generated between the eNB 10-1 and the packet transfer apparatus 25 via the eNB 10-3, and the IP address C of the eNB 10-3 It is included.

The MME 20 receives the alternative bearer notification information 1 from the eNB 10-2. Further, the MME 20 transmits the IP address E of the packet transfer device 25 held in advance to the eNB 10-2 via the backhaul 30 by S1 communication. Further, the MME 20 receives the alternative bearer notification information 2 from the eNB 10-3. Further, the MME 20 transmits the IP address E of the packet transfer device 25 held in advance to the eNB 10-3 via the backhaul 30 by S1 communication.

Thereafter, the MME 20 includes the IP address B of the eNB 10-2 that is the transmission source of the alternative bearer notification information 1 in the alternative bearer notification information 1. Further, the MME 20 transmits the alternative bearer notification information 1 including the IP address B to the packet transfer device 25. Further, the MME 20 includes the IP address C of the eNB 10-3 that is the transmission source of the alternative bearer notification information 2 in the alternative bearer notification information 2. Further, the MME 20 transmits the alternative bearer notification information 2 including the IP address C to the packet transfer device 25.

The packet transfer device 25 receives the alternative bearer notification information 1 and the alternative bearer notification information 2 from the MME 20.

Further, the packet transfer device 25 transmits the alternative bearer generation permission information 1 corresponding to the alternative bearer notification information 1 to the eNB 10-2. The packet transfer apparatus 25 can recognize the transmission destination of the alternative bearer generation permission information 1 by the IP address B of the eNB 10-2 included in the alternative bearer notification information 1. Further, the packet transfer apparatus 25 transmits the alternative bearer generation permission information 2 corresponding to the alternative bearer notification information 2 to the eNB 10-3. The packet transfer apparatus 25 can recognize the transmission destination of the alternative bearer generation permission information 2 based on the IP address C of the eNB 10-3 included in the alternative bearer notification information 2.

The communication path setting unit 112 in the control unit 102 of the eNB 10-2 receives the alternative bearer generation permission information 1. Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-2 transmits the alternative bearer generation permission information 1 to the relay node 50-1. Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-3 receives the alternative bearer generation permission information 2. Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-3 transmits the alternative bearer generation permission information 2 to the relay node 50-2.

Thereafter, the communication path setting unit 112 in the control unit 102 of the eNB 10-2 sets a bearer (alternative bearer # 1) via the eNB 10-2 between the relay node 50-1 and the packet transfer device 25. Between the eNB 10-1 and the packet transfer apparatus 25, the alternative bearer # 1 and the avoidance bearer # 1 set a detour bearer # 1 that is a communication path via the eNB 10-2.

Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-3 sets a bearer (alternative bearer # 2) via the eNB 10-3 between the relay node 50-2 and the packet transfer device 25. Between the eNB 10-1 and the packet transfer apparatus 25, the alternate bearer # 2 and the avoidance bearer # 2 set a detour bearer # 2 that is a communication path via the eNB 10-3.

Thereafter, the transmission processing unit 114 in the control unit 102 of the eNB 10-1 receives the packet from the UE 40. Further, the transmission processing unit 114 in the control unit 102 of the eNB 10-1 sorts the received packet into a packet for transmitting the bypass bearer # 1 and a packet for transmitting the bypass bearer # 2.

Specifically, the transmission processing unit 114 in the control unit 102 of the eNB 10-1 alternately distributes the same amount of packets to the detour bearer # 1 and the detour bearer # 2. Although the description has been given using two bypass bearers, even when there are three or more bypass bearers, the transmission processing unit 114 sequentially distributes and transmits the received packets to the respective bypass bearers.

Alternatively, the transmission processing unit 114 in the control unit 102 of the eNB 10-1 recognizes the transmission rate between the eNB 10-2 and the MME 20 based on the communication path information corresponding to the eNB 10-2, and Based on the corresponding communication path information, the transmission rate between the eNB 10-3 and the MME 20 is recognized. Further, the transmission processing unit 114 in the control unit 102 of the eNB 10-1 determines that the ratio between the amount of packets that transmit the detour bearer # 1 and the amount of packets that transmit the detour bearer # 2 is the eNB 10-2 and the MME 20 Between the detour bearer # 1 and the detour bearer # so as to match or approximate (a difference within a predetermined value) the ratio between the transmission rate between the eNB 10-3 and the MME 20 Alternating between 2 and 2.

Alternatively, the transmission processing unit 114 in the control unit 102 of the eNB 10-1 distributes the same packet to the bypass bearer # 1 and the bypass bearer # 2.

Alternatively, the transmission processing unit 114 in the control unit 102 of the eNB 10-1 distributes packets based on the attribute of the detour bearer. In the case where attribute information is included in the communication path information, the transmission processing unit 114 determines a distribution ratio of packets to the detour bearer # 1 and the detour bearer # 2 based on the attribute information and then distributes the packets. For example, the attribute information is information indicating whether the physical configuration of the communication path is wired or wireless. The wired section is between eNB 10-2 and MME 20, and the wireless section is between eNB 10-3 and MME 20. In some cases, the transmission processing unit 114 in the control unit 102 of the eNB 10-1 performs the detour bearer via the eNB 10-3 corresponding to the radio section with respect to the detour bearer # 1 via the eNB 10-2 corresponding to the wired section. Distribute more packets than # 2.

Alternatively, when the transmission processing unit 114 in the control unit 102 of the eNB 10-1 can acquire the attribute information of the UE 40, the transmission processor 114 transfers the packet to the bypass bearer # 1 and the bypass bearer # 2 based on the attribute information of the UE 40. Distribute. For example, when each UE is classified, and the transmission processing unit 114 in the control unit 102 of the eNB 10-1 can obtain information on the class of the UE 40, the higher the class, the faster the communication speed is. , Sort packets.

The transmission processing unit 114 in the control unit 102 of the eNB 10-1 transmits a packet for transmitting the detour bearer # 1 distributed by the above-described process to the eNB 10-2 via the detour bearer # 1. Also, the transmission processing unit 114 in the control unit 102 of the eNB 10-1 transmits a packet for transmitting the detour bearer # 2 distributed by the above-described process to the eNB 10-3 via the detour bearer # 2.

The transmission processing unit 114 in the control unit 102 of the eNB 10-2 receives the packet transmitted through the detour bearer # 1, and transmits the packet to the packet transfer apparatus 25 via the detour bearer # 1. Further, the transmission processing unit 114 in the control unit 102 of the eNB 10-3 receives the packet transmitted through the detour bearer # 2, and transmits the packet to the packet transfer apparatus 25 through the detour bearer # 2.

In parallel with the packet transmission process described above, the update unit 116 in the control unit 102 of the eNB 10-1 updates the communication path information as needed. For example, when a new eNB is installed in the vicinity of the eNB 10-1, the update unit 116 in the control unit 102 of the eNB 10-1 generates communication path information corresponding to the new eNB. When the transmission rate between the eNB 10-2 and the MME 20 or the transmission rate between the eNB 10-3 and the MME 20 changes, the update unit 116 in the control unit 102 of the eNB 10-1 Update the transmission rate information in

Furthermore, if any of avoidance bearer # 1, avoidance bearer # 2, alternative bearer # 1, and alternative bearer # 2 is disconnected during the packet transmission process, eNB 10-1, eNB 10-2, and eNB 10- 3 performs again the setting process of the avoidance bearer or the alternative bearer described above.

Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-1 recovers from the failure of the backhaul 30 by the IP function of the S1-MME-IF protocol, and performs S1 communication between the eNB 10-1 and the MME 20 Detect that is possible.

In this case, the communication path setting unit 112 in the control unit 102 of the eNB 10-1 transmits the alternative bearer release instruction information 1 to the relay node 50-1 via the avoidance bearer # 1. The alternative bearer release instruction information 1 is information for instructing the release of the bearer via the eNB 10-2. Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-1 transmits the alternative bearer release instruction information 2 to the relay node 50-2 via the avoidance bearer # 2. The alternative bearer release instruction information 2 is information for instructing the release of a bearer via the eNB 10-3. The communication path setting unit 112 in the control unit 102 of the eNB 10-1 releases the avoidance bearer # 1 after transmitting the alternative bearer release instruction information 1, and releases the avoidance bearer # 2 after transmitting the alternative bearer release instruction information 2. To do.

The control unit 502 of the relay node 50-1 receives the alternative bearer release instruction information 1 from the eNB 10-1 via the avoidance bearer # 1. Also, the control unit 502 of the relay node 50-2 receives the alternative bearer release instruction information 2 from the eNB 10-1 via the avoidance bearer # 2.

Thereafter, the control unit 502 of the relay node 50-1 transmits the alternative bearer release instruction information 1 to the eNB 10-2 by wireless communication. The control unit 502 of the relay node 50-2 transmits the alternative bearer release instruction information 2 to the eNB 10-3 through wireless communication.

The communication path setting unit 112 in the control unit 102 of the eNB 10-2 receives the alternative bearer release information 1 from the relay node 50-1. Further, the communication path setting unit 112 in the control unit 102 in the eNB 10-2 receives the alternative bearer release information 2 from the relay node 50-1.

Next, the communication path setting unit 112 in the control unit 102 of the eNB 10-2 transmits the alternative bearer release notification information 1 to the MME 20 via the backhaul 30 by S1 communication. The alternative bearer release notification information 1 is information for notifying that the bearer needs to be released between the eNB 10-1 and the packet transfer apparatus 25 via the eNB 10-2, and the IP address of the eNB 10-2 B is included. Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-3 transmits the alternative bearer release notification information 2 to the MME 20 via the backhaul 30 by S1 communication. The alternative bearer release notification information 2 is information for notifying that the bearer needs to be released between the eNB 10-1 and the packet transfer apparatus 25 via the eNB 10-2, and the IP address of the eNB 10-3 C is included.

The MME 20 receives the alternative bearer release notification information 1 from the eNB 10-2 and also receives the alternative bearer release notification information 2 from the eNB 10-3.

The MME 20 includes the IP address B of the eNB 10-2 that is the transmission source of the alternative bearer release notification information 1 in the alternative bearer release notification information 1. Further, the MME 20 transmits the alternative bearer release notification information 1 including the IP address B to the packet transfer device 25. Further, the MME 20 includes the IP address C of the eNB 10-3 that is the transmission source of the alternative bearer release notification information 2 in the alternative bearer release notification information 2. Further, the MME 20 transmits the alternative bearer release notification information 2 including the IP address C to the packet transfer device 25.

Further, the packet transfer device 25 transmits the alternative bearer release permission information 1 corresponding to the alternative bearer release notification information 1 to the eNB 10-2. The packet transfer apparatus 25 can recognize the transmission destination of the alternative bearer release permission information 1 by the IP address B of the eNB 10-2 included in the alternative bearer release notification information 1. Further, the packet transfer apparatus 25 transmits the alternative bearer release permission information 2 corresponding to the alternative bearer release notification information 2 to the eNB 10-3. The packet transfer apparatus 25 can recognize the transmission destination of the alternative bearer release permission information 2 based on the IP address C of the eNB 10-3 included in the alternative bearer release notification information 2.

The communication path setting unit 112 in the control unit 102 of the eNB 10-2 receives the alternative bearer release permission information 1. Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-2 transmits the alternative bearer release permission information 1 to the relay node 50-1. Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-3 receives the alternative bearer release permission information 2. Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-3 transmits the alternative bearer release permission information 2 to the relay node 50-2.

Further, the communication path setting unit 112 in the control unit 102 of the eNB 10-2 releases the alternative bearer # 1. Similarly, the communication path setting unit 112 in the control unit 102 of the eNB 10-3 releases the alternative bearer # 2.

The detour bearer # 1 and detour bearer # 2 are released through the above procedure.

Next, the operation of the communication system 1 will be described with reference to the sequence diagram. 7, 8, and 9 are sequence diagrams illustrating the operation of the communication system 1.

In step S101, the UE 40 transmits a packet addressed to the packet transfer device 25 to the eNB 10-1. The eNB 10-1 receives the packet from the UE 40. Further, the eNB 10-1 transmits the packet to the MME 20. The MME 20 receives the packet from the eNB 10-1. Further, the MME 20 transmits the packet to the packet transfer device 25. The packet transfer device 25 receives a packet from the MME 20.

In step S102, when a failure of the backhaul 30 occurs and S1 communication between the eNB 10-1 and the MME 20 becomes impossible, in step S103, the eNB 10-1 uses a plurality of relays based on the communication path information. Select an eNB. Here, eNB 10-2 and eNB 10-3 are selected.

In step S104, the eNB 10-1 sets an avoidance bearer # 1 with the relay node 50-1 that relays wireless communication with the relay eNB 10-2. In step S105, the eNB 10-1 sets an avoidance bearer # 2 with the relay node 50-2 that relays wireless communication with the relay eNB 10-3.

In step S106, the eNB 10-1 transmits the alternative bearer generation instruction information 1 to the relay node 50-1 via the set avoidance bearer # 1. The relay node 50-1 receives the alternative bearer generation instruction information 1. In step S107, the eNB 10-1 transmits the alternative bearer generation instruction information 2 to the relay node 50-2 via the set avoidance bearer # 2. The relay node 50-2 receives the alternative bearer generation instruction information 2.

In step S108, the relay node 50-1 is connected to the eNB 10-2 via a wireless section. In step S109, the relay node 50-2 is connected to the eNB 10-3 via the radio section.

In step S110, the relay node 50-1 transmits the alternative bearer generation instruction information 1 to the eNB 10-2. The eNB 10-2 receives the alternative bearer generation instruction information 1. In step S111, the relay node 50-2 transmits the alternative bearer generation instruction information 2 to the eNB 10-3. The eNB 10-3 receives the alternative bearer generation instruction information 2.

In step S112, the eNB 10-2 transmits the alternative bearer notification information 1 to the MME 20. The MME 20 receives the alternative bearer notification information 1. In step S113, the eNB 10-3 transmits the alternative bearer notification information 2 to the MME 20. The MME 20 receives the alternative bearer notification information 2.

In step S114, the MME 20 transmits the IP address E of the packet transfer device 25 to the eNB 10-2. The eNB 10-2 receives the IP address E. In step S115, the MME 20 transmits the IP address E of the packet transfer device 25 to the eNB 10-3. The eNB 10-3 receives the IP address E.

In step S116, the MME 20 transmits the alternative bearer notification information 1 including the IP address B to the packet transfer device 25. The packet transfer device 25 receives the alternative bearer notification information 1 including the IP address B. In step S117, the MME 20 transmits the alternative bearer notification information 2 including the IP address C to the packet transfer device 25. The packet transfer device 25 receives the alternative bearer notification information 2 including the IP address C.

In step S151 of FIG. 8, the packet transfer apparatus 25 transmits the alternative bearer generation permission information 1 to the eNB 10-2. The eNB 10-2 receives the alternative bearer generation permission information 1. In step S152, the packet transfer apparatus 25 transmits the alternative bearer generation permission information 2 to the eNB 10-3. The eNB 10-3 receives the alternative bearer generation permission information 2.

In step S153, the eNB 10-2 transmits the alternative bearer generation permission information 1 to the relay node 50-1. The relay node 50-1 receives the alternative bearer generation permission information 1. In step S154, the eNB 10-3 transmits the alternative bearer generation permission information 2 to the relay node 50-2. The relay node 50-2 receives the alternative bearer generation permission information 2.

In step S155, the eNB 10-2 sets an alternative bearer # 1 via the eNB 10-2 between the relay node 50-1 and the packet transfer device 25. In step S156, the eNB 10-3 sets an alternative bearer # 2 via the eNB 10-3 between the relay node 50-2 and the packet transfer device 25.

After the bypass bearer # 1 consisting of the avoidance bearer # 1 and the alternative bearer # 1 is set and the bypass bearer # 2 consisting of the avoidance bearer # 2 and the alternative bearer # 2 is set, in step S159, the UE 40 Send packet to -1. The eNB 10-1 receives the packet.

In step S160, the eNB 10-1 distributes the received packet to the detour bearer # 1 and the detour bearer # 2.

In step S161, the eNB 10-1 transmits the packet distributed to the detour bearer # 1 to the packet transfer apparatus 25 via the detour bearer # 1. The packet transfer device 25 receives the packet from the eNB 10-1 via the detour bearer # 1. In step S162, the eNB 10-1 transmits the packet distributed to the detour bearer # 2 to the packet transfer apparatus 25 via the detour bearer # 2. The packet transfer device 25 receives the packet from the eNB 10-2 via the detour bearer # 2.

When the failure of the backhaul 30 is recovered in step S201 in FIG. 9 and S1 communication between the eNB 10-1 and the MME 20 becomes possible, the eNB 10-1 substitutes for the relay node 50-1 in step S202. Bearer release instruction information 1 is transmitted. The relay node 50-1 receives the alternative bearer release instruction information 1. In step S203, the eNB 10-1 transmits the alternative bearer release instruction information 2 to the relay node 50-2. The relay node 50-2 receives the alternative bearer release instruction information 2.

In step S204, the relay node 50-1 transmits the alternative bearer release instruction information 1 to the eNB 10-2. The eNB 10-2 receives the alternative bearer release instruction information 1. In step S205, the relay node 50-2 transmits the alternative bearer release instruction information 2 to the eNB 10-3. The eNB 10-3 receives the alternative bearer release instruction information 2.

In step S206, the eNB 10-2 transmits the alternative bearer release notification information 1 to the MME 20. The MME 20 receives the alternative bearer release notification information 1. In step S207, the eNB 10-3 transmits the alternative bearer release notification information 2 to the MME 20. The MME 20 receives the alternative bearer release notification information 2.

In step S208, the MME 20 transmits the alternative bearer release notification information 1 including the IP address B to the packet transfer device 25. The packet transfer apparatus 25 receives the alternative bearer release notification information 1 including the IP address B. In step S209, the MME 20 transmits the alternative bearer release notification information 2 including the IP address C to the packet transfer device 25. The packet transfer apparatus 25 receives the alternative bearer release notification information 2 including the IP address C.

In step S210, the packet transfer device 25 transmits the alternative bearer release permission information 1 to the eNB 10-2. The eNB 10-2 receives the alternative bearer release permission information 1. In step S211, the packet transfer apparatus 25 transmits the alternative bearer release permission information 2 to the eNB 10-3. The eNB 10-3 receives the alternative bearer release permission information 2.

In step S212, the eNB 10-2 transmits the alternative bearer release permission information 1 to the relay node 50-1. The relay node 50-1 receives the alternative bearer release permission information 1. In step S213, the eNB 10-3 transmits the alternative bearer release permission information 2 to the relay node 50-2. The relay node 50-2 receives the alternative bearer release permission information 2.

(5) Actions / Effects In the communication system 1 according to the present embodiment, the eNB 10-1 operates in the normal state, specifically, in the state before the failure of the backhaul 30 occurs, by the S1 communication. To the packet transfer device 25. On the other hand, when a failure occurs in the backhaul 30 and S1 communication with the MME 20 becomes impossible, the eNB 10-1 selects two eNBs, eNB 10-2 and eNB 10-3. Further, the eNB 10-1 and the eNB 10-2 perform processing for setting the bypass bearer # 1 via the eNB 10-2, and the eNB 10-1 and the eNB 10-3 set the bypass bearer # 2 via the eNB 10-3. Process. Further, the eNB 10-1 distributes the packet addressed to the packet transfer apparatus 25 to the detour bearer # 1 and the detour bearer # 2, and transmits the packet to the MME 20.

Therefore, when a failure occurs in the backhaul 30 and S1 communication with the MME 20 becomes impossible, a packet transmitted between the eNB 10-1 and the MME 20 is transferred to one relay eNB for detouring. Thus, the reliability of communication between the eNB 10-1 and the packet transfer apparatus 25 can be improved while preventing the load on the relay eNB from becoming excessive.

(6) Other Embodiments As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

In the embodiment described above, the eNB 10-1 distributes the packet to the detour bearer # 1 via the eNB 10-2 that is two relay eNBs and the detour bearer # 2 via the eNB 10-3. However, the eNB 10-1 may select three or more relay eNBs, perform processing for setting detour bearers via each of the relay eNBs, and then distribute packets to each detour bearer. .

In the embodiment described above, when a failure occurs in the backhaul 30 and S1 communication between the eNB 10-1 and the MME 20 becomes impossible, the detour bearer # 1 and the detour bearer # 2 are set, and the eNB 10-1 The packets are distributed and transmitted to the detour bearer # 1 and the detour bearer # 2. However, the eNB 10-1 may distribute and transmit packets to the detour bearer # 1 and the detour bearer # 2 when conditions other than that the S1 communication is disabled are satisfied.

For example, the control unit 102 in the eNB 10-1 is necessary for setting the detour bearer # 1 and the detour bearer # 2 when the traffic volume in communication with the MME 20 is less than a predetermined threshold. Thus, the packet may be distributed and transmitted to the detour bearer # 1 and the detour bearer # 2.

Further, in the above-described embodiment, when relaying is performed by the relay node 50-1, different frequency channels are used in the cell formed by the eNB 10-1 and the cell formed by the eNB 10-2. It is assumed that when relaying by relay node 50-2 is performed, it is assumed that different frequency channels are used in the cell formed by eNB 10-1 and the cell formed by eNB 10-3. However, even when the same frequency channel is used, interference can be suppressed by using SDMA or OFDM subchannels. Further, by TDMA, the relay node 50-1 and the relay node 50-2 can switch the connection destination eNB in a time division manner to suppress interference.

Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure. Note that the entire content of Japanese Patent Application No. 2010-269317 (filed on Dec. 2, 2010) is incorporated herein by reference.

ADVANTAGE OF THE INVENTION According to this invention, the reliability of communication with a radio base station and a high-order node can be improved, without making the load of another radio base station excessive.

Claims

A communication system having a plurality of radio base stations and upper nodes,
A setting unit configured to set a plurality of communication paths via different second radio base stations between the first radio base station and the upper node;
A communication system comprising: a transmission unit that distributes and transmits packets to a plurality of communication paths set by the setting unit.
The communication path setting unit communicates between the first radio base station and the upper node via different second radio base stations based on information on a communication path for each second radio base station. The communication system according to claim 1, wherein a plurality of routes are set.
The communication system according to claim 1, wherein the transmission unit sequentially distributes and transmits the packets to a plurality of communication paths set by the setting unit.
The information on the communication path includes information on the transmission speed of the communication path,
3. The communication system according to claim 2, wherein the transmission unit distributes and transmits an amount of the packet corresponding to the transmission rate corresponding to the plurality of communication paths set by the setting unit.
The communication system according to claim 4, further comprising an update unit that updates information on the transmission rate when the transmission rate is changed.
3. The communication system according to claim 2, wherein the transmission unit distributes and transmits the packet after determining a ratio of distributing the packet to each communication path based on the attribute of the communication path set by the setting unit.
2. The communication system according to claim 1, wherein the transmission unit transmits the same packet to the plurality of communication paths set by the setting unit.
A communication control method in a communication system having a plurality of radio base stations and upper nodes,
Setting a plurality of communication paths through different second radio base stations between the first radio base station and the upper node;
A communication control method comprising: a transmission step of distributing and transmitting packets to a plurality of set communication paths.