WO2018002993A1 - Wireless communication system, wireless terminal, base station, control device, and wireless communication method - Google Patents

Abstract

The wireless communication system comprises: first and second wireless terminals (110-1, 110-2) which, when registering the positions thereof with a host network (14), transmit via a base station (120) pieces of base station identification information, by which the base station (120) can be identified, to the host network (140); and a control device (130) which, upon receiving first base station identification information transmitted by the first wireless terminal (110-1) and second base station identification information transmitted by the second wireless terminal (110-2), performs control in accordance with each of the received pieces of base station identification information such that inter-terminal communication is established between the first and second wireless terminals (110-1, 110-2) via the base station (120) without passing through the host network (140).

Description

Wireless communication system, wireless terminal, base station, control device, and wireless communication method

The present invention relates to a wireless communication system, a wireless terminal, a base station, a control device, and a wireless communication method.

As an example of a wireless communication system, currently, Long Term Evolution (LTE) or LTE-Advanced (LTE-A) whose specifications are established by 3rd Generation Partnership Project (3GPP) is provided.

In 3GPP, base station loopback communication in which inter-terminal communication between wireless terminals is performed via a base station that does not pass through an upper network such as Evolved Packet Core (EPC) is being studied.

JP 2009-232106 A JP 2002-330101 A JP-A-8-237736

In a wireless communication system, information indicating a relationship between a wireless terminal and a base station for setting a return communication path may not be acquired, and it may be difficult to realize return communication.

In one aspect, an object of the present invention is to facilitate realization of inter-terminal communication via a base station that does not pass through a host network.

In addition, the present invention is not limited to the above-described object, and other effects of the present invention can be achieved by the functions and effects derived from the respective configurations shown in the embodiments for carrying out the invention which will be described later. It can be positioned as one of

In one aspect, the wireless communication system may include first and second wireless terminals and a control device. The first and second wireless terminals transmit base station identification information capable of identifying the base station to the upper network via the base station when performing location registration with respect to the upper network. Good. The control apparatus may receive the first base station identification information transmitted from the first wireless terminal and the second base station identification information transmitted from the second wireless terminal. Further, the control device controls inter-terminal communication between the first and second wireless terminals to communication via the base station that does not pass through the upper network based on the received base station identification information. Good.

In one aspect, it is possible to facilitate the inter-terminal communication via the base station that does not go through the host network.

It is a block diagram which shows the structural example of the radio | wireless communications system which concerns on 1st Embodiment. It is a figure explaining the information transmitted from the radio | wireless terminal shown in FIG. It is a block diagram which shows the structural example of the radio | wireless communications system which concerns on 2nd Embodiment. It is a figure explaining an example of return communication. It is a figure explaining an example of a near field communication service. It is a figure explaining an example of management of position registration information. It is a figure explaining the information transmitted from User か ら Equipment (UE) shown in FIG. It is a figure explaining the information transmitted from UE shown in FIG. It is a figure which shows an example of the operation | movement sequence of the radio | wireless communications system which concerns on 2nd Embodiment. 6 is a flowchart for explaining an operation example of the wireless communication system according to the second embodiment. It is a figure which shows the structural example of the radio | wireless communications system which concerns on the comparative example of 2nd Embodiment. It is a block diagram which shows the structural example of the radio | wireless communications system which concerns on 3rd Embodiment. It is a figure which shows an example of the operation | movement sequence of the radio | wireless communications system which concerns on 3rd Embodiment. 10 is a flowchart for explaining an operation example of the wireless communication system according to the third embodiment. It is a figure which shows the example of a structure of some internet protocol (IP) packet headers. It is a block diagram which shows the function structural example of a radio | wireless terminal. It is a block diagram which shows the function structural example of a base station. It is a block diagram which shows the function structural example of Mobility * Management * Entity (MME). It is a block diagram which shows the function structural example of Serving SerGateway (SGW). It is a block diagram which shows the function structural example of Packet * Data * Network (PDN) * Gateway (PGW). It is a block diagram which shows the hardware structural example of a radio | wireless terminal. It is a block diagram which shows the hardware structural example of a base station. It is a block diagram which shows the hardware structural example of a processing apparatus. It is a figure which shows an example of the operation | movement sequence of the notification of base station identification information, and a location registration.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described below. For example, the present embodiment can be implemented with various modifications without departing from the spirit of the present embodiment.

In the drawings used in the following embodiments, the same reference numerals denote the same or similar parts unless otherwise specified. Further, in the following description, when a plurality of devices are not distinguished, the numerals after the hyphen “-” may be omitted. As an example, the wireless terminals 110-1 and 110-2 shown in FIG.

[1] First Embodiment FIG. 1 is a block diagram illustrating a configuration example of a wireless communication system 100 according to a first embodiment. As shown in FIG. 1, the wireless communication system 100 according to the first embodiment exemplarily includes a plurality (two in the example of FIG. 1) of wireless terminals 110-1 and 110-2, a base station 120, and A control device 130 may be provided. Three or more wireless terminals 110 may exist in the wireless communication system 100.

Wireless terminals 110-1 and 110-2 are examples of first and second wireless terminals, respectively. As illustrated in FIG. 2, each of the wireless terminals 110-1 and 110-2, when performing location registration with respect to the upper network 140, provides base station identification information that can identify the connected base station 120, The data is transmitted to the upper network 140 via the base station 120. The location registration may be performed in a procedure for setting up a radio line with the connection destination base station 120. The base station identification information is an example of information indicating the relationship between the wireless terminal 110 and the base station 120 for setting a return communication path to be described later, for example, an identifier (ID). An example of the upper network 140 is a packet core network in LTE.

The procedure for setting the “wireless line” may include, for example, a procedure or process for enabling data (for example, user data) communication between the wireless terminal 110 and the base station 120. As an example, a procedure for setting up a wireless line is as follows. The wireless terminal 110 starts communication (for example, makes a call), establishes a bearer or a communication path in the base station 120 and the upper network 140, and connects the wireless terminal 110 and the base station 120. A procedure for establishing a wireless data line between the two may be included. Alternatively, when a part or all of the procedures relating to establishment of a bearer or a communication path become unnecessary by the method described later, the procedure may be excluded from the procedure for setting a wireless line.

Note that the “communication start” by the wireless terminal 110 may include, for example, transmitting an RA Preamble (random access preamble) in a Random Access (RA) Procedure (random access procedure) to the base station 120.

The location registration may be performed for the wireless terminal 110 to start communication, but may be performed as the wireless terminal 110 moves. In the latter case, after performing location registration, the wireless terminal 110 may disconnect from the base station 120 (for example, stop communication) and shift to a standby state. Thus, the location registration does not necessarily have to be based on communication between the wireless terminal 110 and the base station 120.

The control device 130 receives the first base station identification information transmitted from the wireless terminal 110-1 and the second base station identification information transmitted from the wireless terminal 110-2. Further, the control device 130 controls inter-terminal communication between the radio terminals 110-1 and 110-2 to communication via the base station 120 that does not pass through the upper network 140 based on the received base station identification information. Hereinafter, communication via the base station 120 that does not pass through the upper network 140 may be referred to as loopback communication. In addition, a route through the base station 120 that does not pass through the upper network 140 in return communication may be referred to as a return route.

Note that the upper network 140 may process location registration from the wireless terminal 110.

In the example of FIG. 1, the control device 130 is shown as one device included in the upper network 140, but the present invention is not limited to this, and the control device 130 includes two or more devices included in the upper network 140. It may be realized by. Alternatively, the control device 130 may be realized by one or more devices including the base station 120.

As described above, in the wireless communication system 100, the base station identification information related to the connection destination base station 120 is transmitted from the wireless terminal 110 to the upper network 140. In addition, the control device 130 receives each base station identification information, and controls inter-terminal communication to communication via the base station 120 without passing through the upper network 140 based on the received base station identification information.

Therefore, the control device 130 can efficiently acquire the relationship between the wireless terminal 110 and the base station 120 for setting the return communication path, and can efficiently control the return communication. As a result, it is possible to facilitate the inter-terminal communication via the base station 120 without passing through the upper network 140.

Further, by performing the loopback communication, it is possible to reduce the traffic flow rate of the upper network 140 in the wireless communication system 100, for example, the packet core network, and to reduce the transmission delay time of the communication between terminals as compared with the case of passing through the upper network 140. Can be shortened.

[2] Second Embodiment A second embodiment will be described below. FIG. 3 is a block diagram illustrating a configuration example of the wireless communication system 200 according to the second embodiment.

As shown in FIG. 3, the radio communication system 200 may exemplarily include a plurality (two in the example of FIG. 3) UEs 210-1 and 210-2, eNB 220, MME 230, SGW 240, and PGW 250. “UE” is an abbreviation for User Equipment, “eNB” is an abbreviation for Evolved Node B, “MME” is an abbreviation for Mobility Management Entity, “SGW” is an abbreviation for Serving Gateway, and “PGW” is Abbreviation for Packet 称 Data Network (PDN) Gateway.

Note that three or more UEs 210 may exist in the radio communication system 200, two or more eNBs 220 may exist in the radio communication system 200, and two or more MMEs 230 may exist in the radio communication system 200. Further, two or more SGWs 240 may exist in the wireless communication system 200, and two or more PGWs 250 may exist in the wireless communication system 200.

The radio communication system 200 performs radio communication according to a predetermined radio communication scheme between the eNB 220 and the UE 210. For example, the wireless communication method may be a wireless communication method of the fifth generation or later, or may be an existing wireless communication method such as LTE / LTE-A or Worldwide Interoperability for Microwave Access (WiMAX).

UE 210 and eNB 220 may be included in radio access network 270 in which radio communication is performed. The radio access network 270 may be a radio area provided by one or more eNBs 220, for example. The radio area may be formed in accordance with a range in which radio waves transmitted by the eNB 220 can be received with required quality (a range in which the required radio channel quality can be satisfied, which may be referred to as coverage). Further, the radio area formed by the eNB 220 may be referred to as a cell or a sector.

The MME 230, the SGW 240, and the PGW 250 may form a packet core network 280 in which packet communication is performed.

The packet core network 280 is an example of an upper network. The packet core network 280 is a communication network that does not include the eNB 220, and is positioned as a communication network higher than the eNB 220, for example. An example of the packet core network 280 is EPC.

In the wireless communication system 200, communication between the UEs 210 via the first route including the packet core network 280 is possible. The first route is a route that passes through the eNB 220 and the packet core network 280, for example. In the wireless communication system 200, communication between the UEs 210 via the second route that does not include the packet core network 280 is also possible. The second route is a route through eNB 220 that does not go through packet core network 280, for example. Hereinafter, inter-terminal communication between the UEs 210 on the second route may be referred to as “return communication”.

UE 210 is an example of a wireless terminal. As a wireless terminal, for example, a mobile station or user terminal having a wireless communication function, such as a mobile phone such as a smartphone, a mobile personal computer (PC) such as a laptop, a data communication device such as a mobile router, etc. Is mentioned. The mobile station may be attached to a moving body such as a vehicle and move. In addition to these mobile stations or user terminals, the UE 210 may be a device such as a sensor (including an Integrated Circuit (IC) chip) having a wireless communication function.

Each of the UEs 210-1 and 210-2 can communicate with the packet core network 280 and the network 260 via the eNB 220 by performing wireless communication with the eNB 220. Further, the UEs 210-1 and 210-2 can communicate with each other via the eNB 220.

ENB 220 is an example of a base station. Examples of the base station include a macro base station, a micro base station, a femto base station, a pico base station, a metro base station, a home base station, or a radio signal transmitting / receiving apparatus connected to a C-RAN (Centralized-RAN). There may be. RAN is an abbreviation for Radio | Access | Network. Further, the radio area formed by the base station may be a cell or a sector. The cell may include a cell such as a macro cell, a micro cell, a femto cell, a pico cell, a metro cell, or a home cell.

ENB220 relays communication between UE210 by performing radio | wireless communication between UE210. The radio communication may be performed using radio resources allocated from the eNB 220 to the UE 210. The radio resource may be a resource related to time and frequency. Further, the eNB 220 may be connected to the MME 230 via, for example, an S1 interface.

The eNB 220 can perform processing related to loopback communication between the UEs 210. In addition, eNB220 may perform the process regarding the near field communication service between UE210. The return communication and the proximity communication service will be described later.

The MME 230 accommodates the eNB 220 and performs the process of Control Plane (C-plane) for network control. In addition, the MME 230 may process and manage location registration related to the geographical location of the UE 210. Further, the MME 230 may control the return communication and the near field communication service.

The SGW 240 and the PGW 250 are examples of gateways in the packet core network 280. For example, the SGW 240 processes User Plane (U-plane) data (user data). The PGW 250 may be connected to an external network 260 and may function as a gateway between a device in the wireless communication system 200 such as the UE 210 and the external network 260. The network 260 may be a packet data network such as the Internet or a corporate intranet.

(Return communication)
Here, the loopback communication performed in the wireless communication system 200 will be described. In the wireless communication system 200, loopback communication within the eNB 220 may be performed in order to reduce the traffic flow rate of the packet core network 280. An example of the loopback communication is Enhancements for Infrastructure-based Data Communication between Devices (eICBD).

The control of the loopback communication may be performed by one of the MME 230 and the eNB 220 or may be performed by both the MME 230 and the eNB 220 as described later.

In the loopback communication, as illustrated in FIG. 4, UEs 210-1 and 210-3 located in the radio area of the eNB 220 can communicate with each other via a loopback path in the eNB 220 and not via the packet core network 280. is there.

The loopback communication can reduce the traffic flow of the core network including the packet core network 280 in the wireless communication system 200, for example, the MME 230, and the transmission delay time between the UEs 210 can be shortened compared with the packet core network 280.

Note that the loopback communication may be performed between any two or more combinations of UEs 210-1 to 210-3.

In addition, although an example of loopback communication via one eNB 220 has been described in FIG. 4, loopback communication via a plurality of eNBs 220 may be performed. For example, the UE 210-4 may not be located in the radio area of the eNB 220 but may be located in the radio area of another eNB 220, for example. In this case, return communication may be performed between at least one of the UEs 210-1 to 210-3 and the UE 210-4 through a route that passes through the eNB 220 connected to each of the UEs 210-4. Note that, for example, an X2 interface may be used as a route between the plurality of eNBs 220. The X2 interface is an example of a communication interface between base stations. Note that the X2 interface may be a network different from the host network (for example, the packet core network 280).

(Proximity communication service)
Next, a near field communication service that can be performed in the wireless communication system 200 will be described. The near field communication service is a service that enables direct communication between the UEs 210. As the near field communication service, for example, Proximity Service (ProSe) studied by 3GPP can be cited.

The control of the near field communication service may be performed by one of the MME 230 and the eNB 220, or may be performed by both the MME 230 and the eNB 220. The control of the proximity communication service may be performed by a communication device such as a ProSe Function (ProSe Func) device that provides the proximity communication service instead of the MME 230. The ProSe Func device may be included in the packet core network 280, for example.

In the near field communication service, as illustrated in FIG. 5, the UEs 210-1 and 210-2 located in the radio area of the eNB 220 can communicate with each other under the control of the eNB 220. In the example of FIG. 5, the UE 210-3 located within the radio area of the eNB 220 and the UE 210-4 located outside the radio area of the eNB 220 can communicate with each other under the control of the eNB 220 connected to the UE 210-3.

The near field communication service can also reduce the traffic flow rate of the packet core network 280 in the wireless communication system 200, and the transmission delay time between the UEs 210 can be shortened compared with the case of passing through the packet core network 280.

(Management of location registration information)
Next, management of location registration information performed in the wireless communication system 200 will be described. In the radio communication system 200, the UE 210 can notify the MME 230 of information on the area where the UE 210 is located via the eNB 220, and can register the area in the MME 230.

The term “notification” means that a signal including information to be notified is transmitted from the transmission source to the transmission destination, and the signal is received at the transmission destination (or the information to be notified is further recognized at the transmission destination. ) May be used as a term meaning. The signal including the information to be notified may include any signal form of a radio signal, an optical signal, and an electric signal, and may be converted into another signal form in the process of “notification”. A signal including information to be notified may be referred to as a control signal. The notification may be referred to as signaling.

The area information notified by the UE 210 to the MME 230 is an example of location registration information that is transmitted when the UE 210 performs location registration with respect to the packet core network 280. The location registration information of the UE 210 registered in the MME 230 may be used in the MME 230 in controlling an incoming call to the UE 210.

Note that the location registration information is transmitted from the UE 210 to the MME 230 using, for example, the Non-Access Stratum (NAS; non-access layer) protocol, so the eNB 220 does not recognize the content of the location registration information.

As the location registration information, for example, TA identity (TAI) indicating a location registration area (Tracking Area) (TA) can be mentioned. The TAI may include Public Land Mobile Mobile Network Identifier (PLMN ID) and Tracking Area Code (TAC). The PLMN ID is an example of an ID for each carrier, and may include a Mobile Country Code (MCC) number representing a country code and a Mobile Network Code (MNC) number representing a carrier code.

In the radio communication system 200, the eNB 220 may belong to a plurality of MMEs 230 by a mechanism such as S1-Flex. For example, as illustrated in FIG. 6, the eNB 220-1 indicated by eNB # 1 is controlled by the MME 230-a and MME 230-x indicated by MME # a and MME # x, respectively. The eNB 220-n indicated by eNB # n is also controlled by MME # a and MME # x.

Also, in the wireless communication system 200, a pool area (Pool Area) 290 that is mesh-connected (for example, full mesh connection) between the MME 230 and the eNB 220 may be formed. In the pool area 290, a plurality of TAs 292 may be configured. In the example of FIG. 6, TA # 1-1, TA # 1-2, and TA292-1 to 292-3 respectively indicated by TA # 1-1, TA # 1-2, and TA # 1-3 are included in the pool area 290 indicated by Pool Area # 1. It is.

In the example of FIG. 6, for simplification of explanation, eNB # 1 is configured as TA # 1-1 and eNB # n is configured as TA1-3. One TA 292 may be configured.

In the pool area 290, the TA292 area can be changed for the purpose of reducing the congestion of the network such as the packet core network 280 or between the MME 230 and the eNB 220. In other words, the MME 230 can manage a plurality of TAs 292.

The eNB 220 can select the MME 230 in the pool area 290 by the identification information of the MME 230, for example, the MME code.

As described above, one TA 292 may be configured by a plurality of eNBs 220, and the area of the TA 292 may change. Therefore, it may be difficult for the MME 230 to identify the eNB 220 to which the UE 210 is connected based on the TA 292 (or TAI) notified from the UE 210.

In other words, even if the TAs 292 of the two UEs 210 that communicate with each other match or are close to each other, it is unknown whether the two UEs 210 are connected to the same eNB 220. Judgment may be difficult.

[2-1] Example of Control of Return Communication According to Second Embodiment Accordingly, the wireless communication system 200 according to the second embodiment identifies the return eNB 220 as a connection destination of the UE 210 as described below. Enabling efficient control of In other words, it is possible to facilitate the inter-terminal communication via the eNB 220 not via the packet core network 280.

(A) When the UE 210 performs location registration with respect to the packet core network 280 in the procedure of setting the radio channel with the connection destination eNB 220, eNB identification information that can identify the eNB 220 is transmitted to the packet core network 280.

(B) The eNB identification information to which the source and destination UEs 210 are connected is compared, and it is determined whether or not the return communication at the eNB 220 is possible.

(C) When it is determined that the return communication at the eNB 220 is possible, the eNB 220 is notified of the start of the eNB return communication.

-Regarding the process (a) In the above (a), the eNB identification information may be, for example, identification information of a radio area provided by the eNB 220, or identification information unique to the eNB 220. A combination of these may be used. When eNB 220 configures a plurality of cells or sectors (for example, C-RAN may be included), identification information unique to eNB 220 may be used as eNB identification information.

As the identification information of the wireless area provided by the eNB 220, for example, a Cell Global Identifier (CGI) or a Cell Identifier (cell ID) may be mentioned. Examples of identification information unique to the eNB 220 include Base Station Identifier Code (BSIC). The CGI is defined by 3GPP TS23.003, TS36.331, TS36.413, and the like, for example. BSIC is defined by, for example, 3GPP TS 23.003.

For example, CGI is defined as “CellGlobalIdEUTRA IE” in section 6.3.4 of TS36.331 V13.1.0 (2016-03). The LTE CGI may be composed of a PLMN ID, which is a network ID, and a cell ID. The cell ID may be unique within the network configured by the operator, that is, the cell can be identified.

Also, “SystemInformationBlockType1” (SIB1) is defined in section 6.2.2 of TS36.331. The SIB1 is an example of system information notified from an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), for example, a base station to a wireless terminal, and may include a PLMN ID and a cell ID. SIB1 may be periodically broadcast by, for example, Broadcast Channel (BCH, broadcast channel) or Physical Broadcast Channel (PBCH, physical broadcast channel (wireless broadcast channel)).

Thus, the CGI may be substantially notified to the UE 210 by the eNB 220 notifying the UE 210 of the SIB1. Note that SIB1 may include information used for cell selection by UE 210. The UE 210 may receive SIB1 before receiving SIB5 that is information necessary for cell selection.

For example, as shown in FIG. 24, the UE 210 can know the transmission timing of SIB5 by receiving SIB1 (process C1) and receiving SIB2 (process C2). Further, the UE 210 can receive, for example, a synchronization signal / pilot (process C3) and SIB5. The UE 210 receives the SIB5 to know the parameters used for cell selection, and enables cell selection (processing C4). Note that SIB2 and SIB5 may be transmitted using a shared radio channel. In other wireless communication systems, for example, SIBs after SIB2 may be transmitted on a radio broadcast channel or a DL-SCH that is a transport channel of SDSCH.

Note that SIB5 includes parameters for performing cell selection. After performing synchronization using the synchronization signal or / and the pilot, the UE 210 receives the pilot and measures the pilot reception power and the pilot reception quality, thereby enabling cell selection. As the pilot reception power, RS Received Power (RSRP) is cited in LTE. As the pilot reception quality, RS Received Quality (RSRQ) is mentioned in LTE.

After performing the cell selection, the UE 210 can transmit and perform location registration by performing the random access procedure and the RRC connection process (process C5) (process C6). In other words, the location registration may be performed after the cell selection by the UE 210, and the CGI may be notified to the UE 210 before the location registration is performed. Note that after the location registration is completed, the UE 210 may disconnect the line (line disconnection), enter a standby state, or continue communication as it is.

Note that LTE and 3GPP assume a configuration in which one eNB 220 provides one cell. For this reason, cell ID can be recognized as base station ID. On the other hand, for example, even in the same communication area (for example, a wireless area), different cells become different if the frequency is different. Thus, in an actual base station, it is also possible for one base station to configure a plurality of cells having different frequencies. Also, one base station can constitute a plurality of sectors (cells in LTE) having different communication areas.

In the loopback communication by the wireless communication system 200, it is possible to perform the loopback communication within the same base station even if the cells are different. Thereby, the transmission delay which arises by communication via a high-order apparatus, for example, MME230, can be eliminated.

Note that, as described above, in the wireless communication system 200, eNB identification information for identifying base stations capable of configuring a plurality of cells may be used, such as identification information unique to the eNB 220 such as BSIC.

BSIC is defined as “PhysCellIdGERAN IE” in section 6.3.4 of TS36.331 V13.1.0 (2016-03). BSIC is a base station identifier defined by a GERAN, that is, a GSM (registered trademark) system, which is composed of a 3-bit “NetworkColourCode” and a 3-bit “BaseStationColourCode”. GERAN is an abbreviation for GSM-EDGE-Radio-Access-Network, and GSM is an abbreviation for Global-System-for-Mobile-Communications. EDGE is an abbreviation for Enhanced Data Data rates for GSM Evolution.

For example, an LTE base station notifies a wireless terminal of BSIC, for example, “MeasObjectGERANIE”, etc., in order to enable wireless channel quality measurement. This enables handover from LTE to GSM by the wireless terminal. The BSIC performs, for example, random access, establishes a radio link between the base station and the radio terminal, and further links (links between the radio terminal and the communication partner device or lines between the base station and the host device). Etc. (hereinafter collectively referred to as a link) may be notified from the base station to the wireless terminal as part of the control information related to the measurement notified after the establishment.

Thus, the BSIC is identification information of a base station of the GSM system, but may be used as LTE eNB identification information.

In the following description, it is assumed that the eNB identification information is CGI.

The process (a) may be performed, for example, at a timing such as after activation of each UE 210 or before the start of communication. The process (a) may be performed when the communication between the UE 210 and the eNB 220 is disconnected and the UE 210 is on standby.

As an example, as illustrated in FIG. 7, the eNB identification information may be included in a location registration request transmitted to the packet core network 280. An example of the location registration request is ATTACH REQUEST described in section 5.5.1 of TS24.301. As illustrated in FIG. 7, the ATTACH REQUEST transmitted from the UE 210 to the MME 230 via the eNB 220 may include a TAI as an example of location registration information and a CGI as an example of eNB identification information (processing A1). . Note that the ATTACH ACCEPT may be returned from the eNB 220 to the UE 210 in response to the ATTACH REQUEST (processing A2).

ATTACH is performed, for example, when the wireless terminal enters a new location registration area, for example, TA, or when the timer expires (for example, when the location registration cycle ends). In this case, the TAI is notified from the wireless terminal to a higher-level device of the base station, such as an MME or a location management server.

The location registration request may be made by an existing control signal different from ATTACH REQUEST or a newly defined control signal. As another example, as illustrated in FIG. 8, the eNB identification information is transmitted after the request for location registration to be transmitted to the packet core network 280 and before the line is set up between the eNB 220 and the packet core network 280. May be. Note that the line setting may be a procedure for the UE 210 to receive a service, for example, bearer setting.

In the example of FIG. 8, ATTACH REQUEST including TAI as an example of location registration information is transmitted from the UE 210 to the MME 230 via the eNB 220 (processing B1). Moreover, ATTACH ACCEPT is responded from eNB220 to UE210 with respect to ATTACH REQUEST (process B2). Next, a control signal including CGI as an example of eNB identification information is transmitted from the UE 210 to the MME 230 via the eNB 220 (process B3). Note that the process B2 and the process B3 may be reversed. Then, line setting is performed between the UE 210, the eNB 220, and the MME 230 (which may include other devices of the packet core network 280) (process B4).

As described above, the eNB identification information may be notified from the UE 210 to the MME 230 by the control signal after the notification of the location registration information and before the line setting. Note that the control signal including the eNB identification information may be an existing control signal or a newly defined control signal.

7 and 8, the eNB identification information is notified to the MME 230 at least before line setting (for example, bearer setting) related to the UE 210 is performed.

The line setting, for example, bearer setting, may include charging in the packet core network 280 and control such as Quality of Service (QoS). According to the process (a), the eNB identification information used for the determination of the return communication is notified to the MME 230 before the bearer setting. Therefore, when the return communication is possible, the user packet does not pass through the packet core network 280, and therefore part or all of the bearer setting, for example, at least control such as charging is not required. As a result, the processing becomes simpler than the bearer setting including control such as charging, so that the loopback communication can be controlled at an early timing. For example, without performing bearer setting (or without executing a part thereof), inter-terminal communication of UE 210 can be set as a return path in eNB 220 from the initial communication, and the transmission delay time of inter-terminal communication can be shortened.

Note that billing, QoS, and the like may be controlled as Policy Charging Control (PCC), for example. PCC is an example of a control method related to policy and charging, and QoS corresponds to a policy of PCC.

The PCC may be composed of three entities: Policy and Charging Rules Function (PCRF), Policy and Charging Enforcement Function (PCEF), and Bearer Binding and Event Reporting Function (BBERF). For example, the PCEF may be provided in the PGW 250 and the BBERF may be provided in the SGW 240.

The PCRF determines policy information to be applied to a packet, charging rules, information for specifying a packet to be controlled based on the information, and the like according to user contract information and / or an application used by the user. Thus, the PCRF may manage, for example, QoS and / or QCI.

The policy information may include, for example, priority control or a transfer permission / prohibition rule in the gateway. The charging rule may include a rule such as charging according to the packet amount, for example. The information specifying the packet to be controlled may include the IP address and port number of the source and destination.

PCEF performs policy control and charges for each IP flow according to the information notified from the PCRF.

BBERF performs the same processing as PCEF, but does not perform billing processing. Further, BBERF performs cooperation processing with QoS control unique to the access system. The cooperation processing may include, for example, identification of an LTE radio access bearer that transfers a packet received from the PGW 250 to the eNB 220.

In this way, in bearer setting including control such as charging and QoS, processing by each entity (including PCRF, PCEF, and BBERF, not shown in FIG. 3) of the packet core network 280 of the wireless communication system 200 is performed. The Among such processes, when return communication is possible, at least the process related to charging is not required, and therefore the processing load on the packet core network 280 can be reduced.

-Regarding the process (b) The process (b) may be performed by the MME 230 of the packet core network 280, for example. The MME 230 may compare eNB identification information notified from each UE 210 via the eNB 220, and may determine whether or not to implement loopback communication via the eNB 220 that does not pass through the packet core network 280, based on the comparison result.

Note that the MME 230 does not need to confirm the coincidence of the location registration information notified from the UE 210, for example, TA292 (or TAI), when determining whether or not return communication is possible. When the TA 292 managed by the MME 230 changes, such as when the UE 210 moves between the TAs 292, the MME 230 determines the location registration information such as the TA 292 (or TAI) when determining whether or not return communication is possible. A match may be confirmed.

As described above, the eNB 220 may be different even if the TA292 (or TAI) matches. On the other hand, MME230 can control communication between terminals to return communication by the comparison result of the eNB identification information received from UE210 used as the object of communication between terminals. Therefore, for example, it can be determined that the loopback communication is performed when the eNB identification information matches, so that it is possible to efficiently determine whether the loopback communication is possible or to improve the determination accuracy.

Process (c) The process (c) may be performed by the MME 230 in the packet core network 280, for example. When the MME 230 determines that the return communication is possible based on the determination result of the process (b), the MME 230 may notify the eNB 220 of the start of the return communication. For example, the MME 230 may transmit control information including a return communication start instruction to the eNB 220 via the S1 interface. The S1 interface is an example of a communication interface between the base station and the control device.

The return communication start instruction may include, for example, information indicating that the return communication is performed and identification information that can identify the UE 210 that performs the return communication. Examples of identification information that can identify the UE 210 include IMSI, TMSI, C-RNTI, and EPUID. IMSI is an abbreviation for International Mobile Subscriber Identity, and is an example of a terminal number assigned to UE 210. TMSI is an abbreviation for “Temporary Mobile Subscriber 、 Identity”, which is randomly generated between the UE 210 and the network and used instead of the IMSI. C-RNTI is an abbreviation for Cell-> Radio-Network-Temporary-Identifier, assigned by eNB 220 and used between eNB 220 and UE 210. EPUID is an abbreviation for EPC ProSe User ID.

When notified of the start of the loopback communication from the MME 230, the eNB 220 controls the inter-terminal communication between the UEs 210 that are the target of the loopback communication to the communication via the eNB 220 not via the packet core network 280 according to the loopback communication start instruction. It's okay.

As described above, when the UEs 210-1 and 210-2 perform location registration with respect to the packet core network 280, the eNB identification information that can identify the destination eNB 220 is transmitted via the eNB 220 to the packet core network 280. It is an example of the 1st and 2nd radio | wireless terminal which transmits to. The location registration may be performed in a procedure in which the UE 210 sets a radio channel with the eNB 220.

In addition, at least one of the MME 230 and the eNB 220 is an example of a control device that receives the first eNB identification information transmitted from the eNB 220-1 and the second eNB identification information transmitted from the UE 210-2. The control device may control the inter-terminal communication between the UEs 210-1 and 210-2 to the communication via the eNB 220 that does not pass through the packet core network 280 by the received eNB identification information.

In order to avoid an increase in upstream traffic due to frequent reports, there may be cases where loopback communication is not performed. Note that the “report” includes transmission of information that is an index as to whether or not to continue loopback communication from the UE 210 to the eNB 220 or the packet core network 280 (for example, the MME 230), for example, communication different from the service.

For example, the eNB 220 or the MME 230 acquires information on periodic position information measurement results, communication status, service changes, and the like from the UE 210, and continues whether or not to implement loopback communication based on the acquired information. It may be determined whether or not to do so. The reporting of such information may increase the amount of uplink communication and cause a transmission delay due to traffic congestion.

Therefore, the UE 210 sets a threshold value, for example, according to the report target information, and reports the information when the report target information is deteriorated below the threshold value or when it is determined to change the loopback communication control. May be. Thereby, the amount of uplink communication can be reduced.

Further, the MME 230 or the eNB 220 may limit the implementation of the loopback communication according to at least one parameter of the type requested by the UE 210, the required quality, and the allowable delay time (for example, Max Delay). Examples of the type include service. The required quality includes QoS and the like.

[2-2] Operation Example of Second Embodiment Next, an operation example of the wireless communication system 200 configured as described above will be described with reference to FIG. 9 and FIG. Hereinafter, the UE 210 that is the call source for inter-terminal communication may be referred to as UE # 1 or UEs (Source UE), and the UE 210 that is the call destination may be referred to as UE # 2 or UEd (Destination UE).

As shown in FIG. 9, UE 210-1 shown as UE # 1 transmits ATTACH REQUEST including TAI and CGI to MME 230 via eNB 220 (process T1; step S1 in FIG. 10). Thereby, in MME230, the location registration of UEs is performed. The eNB identification information included in the ATTACH REQUEST may be BSIC instead of CGI. The same applies to the following description.

Further, UE 210-2 indicated as UE # 2 transmits ATTACH REQUEST including TAI and CGI to MME 230 via eNB 220 (process T2; step S2 in FIG. 10). Thereby, in MME230, the location registration of UEd is performed.

Next, UE # 1 initiates communication with UE # 2 (step S3 in FIG. 10). Note that an RA procedure and a radio resource control (RRC) connection process may be performed between the UE 210 and the eNB 220 by communication call. In addition, after RRC connection, a plurality of devices including the UE 210, the eNB 220, and the MME 230 may perform at least a part of the bearer setting (for example, QoS setting) between these devices. Then, a radio channel between UE # 1 and eNB 220 and between UE # 2 and eNB 220 is set.

The MME 230 determines whether or not the communication between the UE # 1 and the UE # 2 (for example, from UEs to the UEd) can be set or controlled to be the return communication in the eNB 220 based on the CGI notified from each UE 210 ( Process T3; Step S4 in FIG.

When the CGI notified from each UE 210 matches and the return communication is possible (Yes in step S4 in FIG. 10), the MME 230 instructs the eNB 220 to communicate between the UE # 1 and the UE # 2. The start of loopback communication at the eNB 220 is notified (process T4).

The eNB 220 performs the loopback communication in the eNB220 for the communication between the UE # 1 and the UE # 2 (for example, from the UEs to the UEd) based on the notification of the start of the loopback communication received from the MME 230 (processing T5 and T6). ; Step S5 in FIG. 10).

On the other hand, when the CGI notified from each UE 210 does not match and the return communication is not possible (No in step S4 in FIG. 10), the MME 230 sends a message between UE # 1 and UE # 2 to the eNB 220. With respect to communication, notification of not performing return communication may be made. Or MME230 does not need to notify eNB220.

When the eNB 220 does not perform the loopback communication (when the loopback communication start notification (or control information; hereinafter collectively referred to as the start notification) is not received), the eNB 220 is configured between the UE # 1 and the UE # 2 (for example, UEs to UEd). As for communication, normal communication via the packet core network 280 is performed (step S6 in FIG. 10). In addition, when performing normal communication, UE # 1 and UE # 2 may perform bearer setting including control such as charging with the MME 230, respectively.

As described above, according to the wireless communication system 200 according to the second embodiment, when the UE 210 performs location registration with respect to the packet core network 280, the eNB identification information that can identify the connection-target eNB 220 is the eNB 220. Via the packet core network 280.

Therefore, for example, the MME 230 can easily determine whether or not return communication is possible. In addition, since return communication is possible, the transmission delay time of communication between terminals can be shortened.

(Comparative example)
Here, a comparative example of the wireless communication system 200 according to the second embodiment will be described with reference to FIG. As illustrated in FIG. 11, the wireless communication system 1000 as a comparative example illustratively includes two UEs 1010, three eNBs 1020, an MME 1030, a ProSe Func device 1040, an S / PGW 1050, and an HSS 1060. HSS is an abbreviation for Home Subscriber Server. The HSS 1060 performs service control and subscriber data processing. Note that the MME 1030, the ProSe Func device 1040, the S / PGW 1050, and the HSS 1060 constitute an EPC.

The MME 1030 supports NAS communication, and can receive a request from the UE 1010 based on the NAS protocol via the eNB 1020 and the S1 interface.

The ProSe Func device 1040 controls the ProSe layer. The ProSe Func device 1040 can acquire geographical location information of the UE 1010, for example, Location Service (LCS) information, in cooperation with a location information server (eg, the MME 1030).

The radio communication system 1000 implements a ProSe layer in the eNB 1020, uses a ProSe discovery procedure defined on the core network (EPC) side, grasps the geographical proximity between the UEs 1010, and performs return communication in the eNB 1020 Is realized.

For example, the ProSe Func device 1040 notifies the eNB 1020 of the acquired location information (eg, LCS information) and identification information (eg, ProSe UE ID) of the UE 1010, so that the eNB 1020 grasps the individual location information of each UE 1010. . Thereby, eNB1020 can implement routing optimization, for example, return communication, when each UE1010 is geographically close.

In the example of FIG. 11, the EPC can acquire the identifier of the base station to which the UE 1010 is connected in the procedure of setting a bearer in order to efficiently determine whether or not return communication is possible.

On the other hand, according to the wireless communication system 200 according to the second embodiment, as described above with reference to FIGS. 7 and 8, part or all of the bearer setting, for example, at least control such as charging is not required. The return communication can be controlled at an early timing. For example, the inter-terminal communication of the UE 210 can be set as a return path in the eNB 220 from the initial communication, and the transmission delay time of the inter-terminal communication can be shortened.

[3] Third Embodiment Next, a third embodiment will be described. In the third embodiment, in addition to the first or second embodiment, the UE may notify the eNB of the connection destination of the Internet Protocol Address (IP address) of the UE. The eNB may control the terminal-to-terminal communication to return communication based on the IP address received from each UE. The IP address is an example of terminal identification information that can identify the UE.

Note that the eNB may control the return communication using the IP address when receiving a start notification of the return communication from the MME.

ENB can cope with multi-service by controlling loopback communication by IP address.

For example, when a plurality of IP addresses are assigned to the UE, or when the UE communicates with a plurality of IP addresses (communication destinations), an IP address that performs loopback communication and an IP address that does not perform loopback communication are separated. Good. The IP address for performing / not performing the return communication may be divided for each service, for example. As a result, loopback communication is performed for communication (for example, service) between IP addresses that perform loopback communication, and loopback communication is determined to be unnecessary for communication (for example, service) between IP addresses that do not perform loopback communication. Good.

FIG. 12 is a block diagram illustrating a configuration example of a wireless communication system 300 according to the third embodiment. The wireless communication system 300 is illustratively connected to a plurality (two in the example of FIG. 12) UEs 310-1 and 310-2, eNB 320, MME 330, SGW 340, and network 360, as shown in FIG. A PGW 350 may be provided.

UE 310 and eNB 320 may be included in a radio access network 370 in which radio communication is performed. Further, the MME 330, the SGW 340, and the PGW 350 may form a packet core network 380 in which packet communication is performed.

The radio communication system 300 according to the third embodiment may be the same as the radio communication system 200 according to the second embodiment unless otherwise specified. The UE 310, the eNB 320, the MME 330, the SGW 340, the PGW 350, the network 360, the radio access network 370, and the packet core network 380 may be the same as the devices of the same name in the radio communication system 200 unless otherwise specified.

Hereinafter, an operation example of the third embodiment will be described with reference to FIGS. 13 and 14. Hereinafter, the UE 310 that is a call source for inter-terminal communication may be referred to as UE # 1 or UEs, and the UE 310 that is the call destination may be referred to as UE # 2 or UEd.

As shown in FIG. 13, UE 310-1 shown as UE # 1 transmits ATTACH REQUEST including TAI and CGI to MME 330 via eNB 320 (process T11; step S11 in FIG. 14). Thereby, the location registration of UEs is performed in MME330. The eNB identification information included in the ATTACH REQUEST may be BSIC instead of CGI. The same applies to the following description.

Further, UE 310-2 indicated as UE # 2 transmits ATTACH REQUEST including TAI and CGI to MME 330 via eNB 320 (process T12; step S12 in FIG. 14). Thereby, in MME330, the location registration of UEd is performed.

Next, UE # 1 initiates communication with UE # 2 (step S13 in FIG. 14). Note that the RA procedure and the RRC connection process may be performed between the UE 310 and the eNB 320 by communication call. Further, after RRC connection, at least a part of the bearer setting may be performed between a plurality of devices including the UE 310, the eNB 320, and the MME 330. Then, a radio channel between UE # 1 and eNB 320 and between UE # 2 and eNB 320 is set.

Next, an IP address is assigned to UE # 1 by a plurality of devices including UE # 1, eNB 320, MME 330, and PGW 350 (process T13). In addition, an IP address is assigned to UE # 2 by a plurality of devices including UE # 2, eNB320, MME330, and PGW350 (process T14).

The MME 330 determines whether or not communication between the UE # 1 and the UE # 2 (for example, from UEs to UEd) can be turned back to the eNB 320 based on the CGI notified from each UE 310 (process T15; Step S14 in FIG.

When the CGI notified from each UE 310 matches and the return communication is possible (Yes in step S14 in FIG. 14), the MME 330 transmits a control request for eNB return communication permission to the eNB 320 (process T16). ).

The control request as to whether or not eNB return communication is possible may be notified in the same manner as the start notification of return communication in the second embodiment, or may be transmitted by an existing control signal or a new control signal.

The eNB loopback communication control request may include the IP addresses of UE # 1 and UE # 2 that are the targets of loopback communication (steps S15 and S16 in FIG. 14). The MME 330 may acquire the IP address of each UE 310 from the PGW 350. Or eNB320 may request | require transmission of an IP address with respect to UE310, UE310 may include an IP address in the signal addressed to eNB320, and may transmit, when a request | requirement is received from eNB320 (process T17).

The eNB 320 can acquire the IP address of each UE 310 that is a control target of whether or not return communication is possible by at least one of the process T16 and the process T17. Note that when the control request in process T16 includes the IP address of the target UE 310, the process T17 may not be executed.

The eNB 320 registers and manages the IP address of each UE 310 that is received from the MME 330 or each UE 310 and is subject to control of whether or not return communication is possible (step S17 in FIG. 14). For example, the eNB 320 may manage the IP addresses of UE # 1 and UE # 2, respectively.

Next, the eNB 320 acquires the source and destination IP addresses included in the signal transmitted from the UE 310, for example, the UE # 1. The source and destination IP addresses may be acquired from the signal by the eNB 320, or may be acquired from the signal by the packet core network 380, for example, the MME 330, and the acquired IP address may be notified to the eNB 320.

The acquisition of the source and destination IP addresses from the signal may be performed by confirming the source IP address and the destination IP address from the header of the transmitted IP packet, as illustrated in FIG.

Note that conventionally, the eNB does not confirm the content of a signal, for example, an IP packet. Moreover, since the IP address of the UE is assigned from the PGW, the eNB does not grasp the IP address of the UE. On the other hand, in the third embodiment, the eNB 320 can determine whether or not return communication by the IP address is possible by acquiring the IP address of the source and destination from the header of the transmitted IP packet. .

Note that the eNB 320 does not have to acquire an IP address for a packet header such as UDP or GTP or a header used for transmission (for example, a source address or a destination address of a relay source or a relay destination). UDP is an abbreviation for User Datagram Protocol, and GTP is an abbreviation for General Packet Radio Switching (GPRS) Tunneling Protocol.

Returning to the description of FIG. 13, the eNB 320 compares the IP address of the transmission source and the transmission destination acquired from the received signal with the IP address to be managed, and whether or not the communication between the UEs 310 can be the return communication in the eNB 320. Is determined (process T18; step S18 in FIG. 14).

When the IP address matches (Yes in step S18 in FIG. 14), for example, when the source of the received IP address is UE # 1 and the destination is UE # 2, loopback communication at the eNB 320 is possible. . In this case, the eNB 320 transmits an eNB return communication start notification to the MME 330 (process T19; step S19 in FIG. 14).

Also, the eNB 320 transmits an eNB return communication start notification to the PGW 350 (process T20; step S19 in FIG. 14). Note that the MME 330 may transfer the eNB return communication start notification received in the process T19 to the PGW 350, and in this case, the process T20 may not be performed.

Note that the return communication start notification may include information for charging. As described above, user data does not pass through the packet core network 380 in loopback communication. Therefore, the eNB 320 may transmit a start notification to the MME 330 or the PGW 350 as a trigger for performing control such as charging. The transmission destination of the start notification is not limited to the MME 330 or the PGW 350, and may be, for example, at least one device of the PCC.

Note that, for example, the eNB 320 may measure the usage amount instead of the PGW 350 or the like, and notify the PGW 350 of the information measured periodically.

The start notification of the eNB return communication may be transmitted as a response to the eNB return communication availability control request notified from the MME 330 in the process T16, or may be transmitted by an existing control signal or a new control signal. .

Then, the eNB 320 performs the return communication in the eNB by transmitting the signal received from the UE 310 to the signal transmission destination by the return communication in the eNB 320 (processing T21 and T22; step S20 in FIG. 14). For example, the eNB 320 may control communication from the UE # 1 to the UE # 2 to return communication at the eNB 320.

Note that, in step S20, the eNB 320 also performs loopback communication for the IP packet if the source and destination IP addresses match the IP address to be managed for other (for example, subsequent) signals received from the UE 310. May be implemented.

In other words, when the IP address of the IP packet received from the UE 310 is the IP address of the UE 310 connected to the same eNB 320, the eNB 320 performs loopback communication for the IP packet. It's okay.

On the other hand, if the IP addresses do not match in step S18 of FIG. 14 (No in step S18), the eNB 320 performs normal communication via the packet core network 380 for communication between UE # 1 and UE # 2. It implements (step S21 of FIG. 14).

Moreover, in step S14 of FIG. 14, when CGI notified from each UE310 does not correspond and return communication is impossible (No in step S14 of FIG. 14), the eNB 320 determines that UE # 1 and UE # 2 Normal communication is performed between them (step S21 in FIG. 14).

Note that, in the case of No in step S14 of FIG. 14, the MME 330 may notify the eNB 320 that the communication between the UE # 1 and the UE # 2 is not performed. Alternatively, the MME 330 may not notify the eNB 320. In this case, a bearer including control such as charging and QoS may be set by the MME 330, the PGW 350, and the like.

As described above, according to the wireless communication system 300 according to the third embodiment, the same effects as those of the second embodiment can be obtained. In addition, since eNB 320 can determine whether or not return communication is possible for each IP packet, it can also be applied to multiservice.

Note that the processing of the MME 330 and the eNB 320 may be performed by the MME 330 or the eNB 320.

[4] Fourth Embodiment The third embodiment may not be based on the first or second embodiment. For example, in FIG. 13, the processes T15 and T16 of the MME 330 may not be performed, and in FIG. 14, step S14 may not be performed. In this case, the notification of the IP address in steps S15 and S16 may be performed from the UE 310 as in process T17 of FIG.

Also in the fourth embodiment, since eNB 320 can determine whether or not return communication is possible for each IP packet, it can also be applied to a multi-service.

[5] Device Configuration Examples of First to Fourth Embodiments Next, device configuration examples of the wireless communication systems 100, 200, and 300 according to the first to fourth embodiments described above will be described.

[5-1] Functional Configuration Example FIG. 16 is a block diagram illustrating a functional configuration example of the wireless terminal 410. FIG. 17 is a block diagram illustrating a functional configuration example of the base station 420. FIG. 18 is a block diagram illustrating a functional configuration example of the MME 430. FIG. 19 is a block diagram illustrating a functional configuration example of the SGW 440. FIG. 20 is a block diagram illustrating a functional configuration example of the PGW 450.

The wireless terminal 410 is an example of the wireless terminal 110, the UE 210, and the UE 310. Base station 420 is an example of base station 120, eNB 220, and eNB 320. The MME 430 is an example of the control device 130, the MME 230, and the MME 330. The SGW 440 is an example of the SGW 240 and the SGW 340. The PGW 450 is an example of the PGW 250 and the PGW 350.

(Wireless terminal)
As illustrated in FIG. 16, the wireless terminal 410 may exemplarily include an antenna 411, a wireless reception unit 412, a terminal-side control unit 413, a control signal generation unit 414, and a wireless transmission unit 415.

The antenna 411 receives a DL (Downlink) radio signal transmitted from the base station 420. Further, the antenna 411 transmits a UL (Uplink) radio signal to the base station 420.

The radio reception unit 412 performs a predetermined reception process on the DL reception signal received by the antenna 411, and acquires the DL signal transmitted by the base station 420. The reception process may include, for example, low-noise amplification of the received signal, frequency conversion (down-conversion) to a baseband frequency, gain adjustment, demodulation, decoding, and the like.

The signal acquired by the wireless reception unit 412 may be output to the terminal-side control unit 413. In addition, the signal acquired by the wireless reception unit 412 may be output to a processing unit (not shown) or the like, and may be used for a purpose other than processing in the terminal-side control unit 413 in the processing unit or the like.

The terminal-side control unit 413 performs various processes relating to control signals and user data transmitted to and received from the base station 420. The processing by the terminal side control unit 413 may include processing executed by at least one of the radio terminal 110, the UE 210, and the UE 310 in the first to fourth embodiments.

The control signal generation unit 414 generates various control signals to be transmitted to the base station 420. The control signal may include a control signal including eNB identification information (for example, CGI or BSIC) transmitted at the time of location registration addressed to the MME 430, a control signal for notifying the eNB 420 of the IP address, and the like.

The wireless transmission unit 415 performs a predetermined transmission process on the UL signal, generates a transmission signal, and outputs the transmission signal to the antenna 411. The transmission processing may include, for example, signal encoding, modulation, frequency conversion (up-conversion) to a radio frequency, power amplification, and the like. The UL signal may include a control signal generated by the control signal generation unit 414 and / or user data generated by the terminal-side control unit 413 or a processing unit (not shown).

The control signal generation unit 414 and the wireless transmission unit 415 described above, when performing location registration with respect to the packet core network, transmit the base station identification information that can identify the connection destination base station 420 via the base station 420. It is an example of the transmission part which transmits to a core network.

(base station)
As illustrated in FIG. 17, the base station 420 exemplarily includes an antenna 421, a radio reception unit 422, SWs 423 and 427, a base station side control unit 424, a control signal generation unit 425, a loopback control unit 426, and radio transmission. A portion 428 may be provided.

The antenna 421 receives a UL radio signal transmitted from the radio terminal 410. The antenna 421 transmits a DL radio signal to the radio terminal 410.

The wireless reception unit 422 performs a predetermined reception process on the UL reception signal received by the antenna 421 and acquires the UL signal transmitted by the wireless terminal 410. The reception process may include, for example, low-noise amplification of the received signal, frequency conversion (down-conversion) to a baseband frequency, gain adjustment, demodulation, decoding, and the like.

The signal acquired by the wireless reception unit 422 may be output to the SW 423. Note that the UL signal transmitted by the wireless terminal 410 may include a signal addressed to another wireless terminal 410 connected to the base station 420, in other words, a signal that is a target of loopback communication.

The SW (switch) 423 selectively outputs the signal acquired by the wireless reception unit 422 to the base station side control unit 424, SW 427, or SGW 440 under the control of the loopback control unit 426. For example, the SW 423 outputs user data targeted for loopback communication at the base station 420 to the SW 427, and outputs a control signal, user data outside loopback communication target, and the like to the base station side control unit 424 or the SGW 440. You can do it.

The base station side control unit 424 performs various processes related to control signals or user data transmitted / received to / from the wireless terminal 410 or the MME 430. The processing by the base station side control unit 424 may include processing executed by at least one of the base station 120, the eNB 220, and the eNB 320 in the first to fourth embodiments.

The control signal generation unit 425 generates various control signals to be transmitted to the wireless terminal 410. The control signal may include a control signal that requests the wireless terminal 410 to notify the IP address.

The loopback control unit 426 controls loopback communication at the base station 420 with respect to the signal received from the wireless terminal 410. The process by the loopback control unit 426 may include a process related to loopback control executed by at least one of the base station 120, the eNB 220, and the eNB 320 in the first to fourth embodiments.

For example, the loopback control unit 426 may transmit / receive control information or the like by a control signal to / from the MME 430. The control signal transmitted to the MME 430 may include a control signal including eNB identification information transmitted by the radio terminal 410, control information for loopback communication, or the like. The control signal received from the MME 430 may include a return communication start notification or a request for control of return communication.

Further, the loopback control unit 426 may store and manage the IP address information of the wireless terminal 410 received from the wireless terminal 410 or the MME 430, for example, in the memory 522 of FIG.

Further, the loopback control unit 426 may determine whether or not loopback communication is possible based on a signal received from the wireless terminal 410, and may control switching of the SW423 and 427 based on the determination result. For the determination by the loopback control unit 426, for example, the source and destination IP addresses are acquired from the header of the IP packet input to the SW 423 or output from the SW 423, and the acquired IP address is managed. A process of comparing with an IP address may be included.

For example, when the packet acquired by the wireless reception unit 422 is a packet (for example, a MAC PDU) obtained by dividing an IP packet and combining the packets in a predetermined procedure, the loopback control unit 426 uses the MAC PDU including the header of the IP packet. An IP address may be acquired. In this case, the loopback control unit 426 controls the loopback communication using the determination result made earlier without performing the determination for the same destination (for example, the subsequent MAC PDU including the data of the original IP packet). Also good.

For the determination by the loopback control unit 426, for example, a buffer may be provided between the SW423 and the wireless reception unit 422 or in the SW423. The buffer may be used for storing the IP packet until the return control unit 426 determines whether or not return communication is possible based on the IP address in the header of the IP packet and controls the SW 423. For example, a part of the storage area of the memory 522 in FIG. 22 may be used as the buffer.

The SW 427 selectively outputs a signal input from the SW 423, the control signal generation unit 425, or the SGW 440 to the wireless transmission unit 428 under the control of the return control unit 426. For example, the SW 427 sends the user data addressed to the wireless terminal 410 received from the SGW 440, the control signal generated by the control signal generation unit 425, or the user data targeted for loopback communication input from the SW 423 to the wireless transmission unit 428. You may output.

The wireless transmission unit 428 performs a predetermined transmission process on the DL signal to generate a transmission signal, and outputs the transmission signal to the antenna 421. The transmission processing may include, for example, signal encoding, modulation, frequency conversion (up-conversion) to a radio frequency, power amplification, and the like. The DL signal may include a control signal generated by the control signal generation unit 425 or / and user data addressed to the wireless terminal 410 received from the SGW 440 or the like.

Note that a buffer may be provided between the SW 427 and the wireless transmission unit 428 or in the SW 427 in order to determine whether or not return communication is possible by the return control unit 426.

The above-described antenna 421, wireless reception unit 422, SW 423, and loopback control unit 426 are examples of a communication unit. The communication unit receives the base station identification information that can be used to identify the connection-destination base station 420 and is transmitted to the MME 430 in the packet core network. It's okay.

Further, the above-described SW 423 and 427 and the loopback control unit 426 are examples of the control unit. The control unit, according to the control from the MME 430 that has received the first base station identification information transmitted by the first wireless terminal 410 and the second base station identification information transmitted by the second wireless terminal 410, Inter-terminal communication may be controlled to return communication.

(MME)
As illustrated in FIG. 18, the MME 430 may include a line control unit 431, for example.

The line control unit 431 performs various controls on signals transmitted to and received from the base station 420, the SGW 440, or the PGW 450. The processing by the line control unit 431 may include processing related to line control in the wireless communication system, and may include processing executed by at least one of the control device 130, the MME 230, and the MME 330 in the first to fourth embodiments. .

For example, the line control unit 431 may receive the eNB identification information transmitted from the wireless terminal 410 via the base station 420 and control the return communication. Further, the line control unit 431 may transmit / receive various control information including control information of loopback communication to / from the base station 420, the SGW 440, or the PGW 450 by a control signal.

The line control unit 431 described above is an example of a communication unit that receives base station identification information that can be used to identify a connection destination base station 420 that is transmitted when the wireless terminal 410 performs location registration with respect to the packet core network. .

In addition, the above-described line control unit 431 uses the first base station identification information transmitted from the first wireless terminal 410 and the second base station identification information transmitted from the second wireless terminal 410 to communicate between terminals. It is an example of the control part which controls communication to return communication.

(SGW)
As illustrated in FIG. 19, the SGW 440 may include a data control unit 441, for example.

The data control unit 441 performs various controls on signals transmitted to and received from the base station 420, the MME 430, or the PGW 450. The processing by the data control unit 441 may include processing related to user data control, and may include processing executed by at least one of the SGW 240 and the SGW 340 in the second to fourth embodiments.

For example, the data control unit 441 may transmit / receive user data to / from the base station 420 and the PGW 450. Further, the data control unit 441 may transmit / receive various control information including control information for loopback communication to / from the MME 430 by a control signal.

(PGW)
As shown in FIG. 20, the PGW 450 may include a line control unit 451, for example.

The line control unit 451 performs various controls on signals transmitted to and received from the MME 430, the SGW 440, or a network (not shown) (for example, a core network). The processing by the line control unit 451 may include processing related to line control in the wireless communication system, and may include processing executed by at least one of the PGW 250 and the PGW 350 in the second to fourth embodiments.

For example, the line control unit 451 may transmit and receive user data between the SGW 440 and the network. The line control unit 451 may transmit and receive various control information including control information for loopback communication with the MME 430 by a control signal.

[5-2] Hardware Configuration Example FIG. 21 is a block diagram illustrating a hardware configuration example of the wireless terminal 410 illustrated in FIG. FIG. 22 is a block diagram illustrating a hardware configuration example of the base station 420 illustrated in FIG. FIG. 23 is a block diagram illustrating a hardware configuration example of the MME 430, the SGW 440, or the PGW 450 illustrated in FIGS.

(Wireless terminal)
As illustrated in FIG. 21, the wireless terminal 510 may include a processor 511, a memory 512, an RF unit 513, and an antenna 514, for example. Note that RF is an abbreviation for Radio Frequency.

The processor 511 performs various controls and calculations. The processor 511 may be communicably connected to each block in the wireless terminal 510 via a bus. Examples of the processor 511 include an integrated circuit (IC) such as a Central / Processing / Unit (CPU), a Micro / Processing / Unit (MPU), an Application / Specific / Integrated / Circuit (ASIC), or a Field / Programmable / Gate Array (FPGA).

The memory 512 is an example of hardware that stores various data such as control signals and user data, and information such as programs. As the memory 512, at least one of a volatile memory and a nonvolatile memory may be used. Examples of the volatile memory include Random Access Memory (RAM). Non-volatile memory includes, for example, Read Only Memory (ROM), flash memory, or Electrically Erasable Programmable Read-Only Memory (EEPROM).

The RF unit 513 may include an RF circuit, for example. The RF unit 513 is an example of the wireless reception unit 412 and the wireless transmission unit 415 illustrated in FIG. The antenna 514 is an example of the antenna 411 illustrated in FIG. 16, and may transmit and receive a radio signal to and from the base station 520 (see FIG. 22).

For example, the processor 511 can implement the function of the wireless terminal 410 illustrated in FIG. 16 by executing a program stored in the memory 512. As an example, the functions of the terminal-side control unit 413 and the control signal generation unit 414 illustrated in FIG. 16 may be realized by the processor 511. In addition, at least some of the functions of the wireless reception unit 412 and the wireless transmission unit 415 may be realized by the processor 511.

(base station)
As illustrated in FIG. 22, the base station 520 may include a processor 521, a memory 522, an RF unit 523, an antenna 524, and a network IF 525, for example. IF is an abbreviation for Interface.

The processor 521 performs various controls and calculations. The processor 521 may be communicably connected to each block in the base station 520 via a bus. The processor 521 may be an integrated circuit (IC) such as a CPU, MPU, ASIC, or FPGA.

The memory 522 is an example of hardware that stores various data such as control signals and user data, and information such as programs. As the memory 522, at least one of a volatile memory and a nonvolatile memory may be used. Examples of the volatile memory include a RAM. Examples of the non-volatile memory include a ROM, a flash memory, and an EEPROM.

The RF unit 523 may include an RF circuit, for example. The RF unit 523 is an example of the wireless reception unit 422 and the wireless transmission unit 428 illustrated in FIG. The antenna 524 is an example of the antenna 421 illustrated in FIG. 17, and may transmit / receive a radio signal to / from the wireless terminal 510.

The network IF 525 is an example of a communication interface that controls connection and communication with a network (upper network), for example, a packet core network, and transmits and receives signals to and from the processing device 530 (see FIG. 23). It's okay.

For example, the processor 521 can implement the function of the base station 420 shown in FIG. 17 by executing a program stored in the memory 522. As an example, the functions of the base station side control unit 424, the control signal generation unit 425, and the loopback control unit 426 illustrated in FIG. 17 may be realized by the processor 521. In addition, at least some of the functions of the wireless reception unit 422 and the wireless transmission unit 428 may be realized by the processor 521.

Although not shown in FIG. 22, the base station 520 may include a switch circuit as an example of the SWs 423 and 427 shown in FIG.

(MME, SGW, and PGW)
The MME 430, the SGW 440, and the PGW 450 shown in FIGS. 18 to 20 may all have the same hardware configuration. Therefore, hereinafter, the processing apparatus 530 will be described as an example of the hardware configuration of each of the MME 430, the SGW 440, and the PGW 450.

23, the processing device 530 may include a processor 531, a memory 532, and a network IF 533 exemplarily.

The processor 531 performs various controls and calculations. The processor 531 may be communicably connected to each block in the processing device 530 via a bus. Note that examples of the processor 531 include an integrated circuit (IC) such as a CPU, MPU, ASIC, or FPGA.

The memory 532 is an example of hardware that stores various data such as control signals and user data, and information such as programs. As the memory 532, at least one of a volatile memory and a nonvolatile memory may be used. Examples of the volatile memory include a RAM. Examples of the non-volatile memory include a ROM, a flash memory, and an EEPROM.

The network IF 533 is an example of a communication interface that controls connection and communication with a network (upper network), for example, a packet core network or an external network.

For example, the MME 430 may transmit and receive signals to and from the base station 420, the SGW 440, and the PGW 450 through the network IF 533. The SGW 440 may transmit and receive signals to and from the base station 420, the MME 430, and the PGW 450 through the network IF 533. Furthermore, the PGW 450 may transmit / receive signals to / from the MME 430 and the SGW 440 and an external network via the network IF 533.

For example, the processor 531 can implement the functions of the MME 430, the SGW 440, or the PGW 450 shown in FIGS. 18 to 20 by executing a program stored in the memory 532.

As an example, the function of the line control unit 431 of the MME 430 illustrated in FIG. 18 may be realized by the processor 531. Alternatively, the function of the data control unit 441 of the SGW 440 illustrated in FIG. 19 may be realized by the processor 531. Alternatively, the function of the line control unit 451 of the PGW 450 illustrated in FIG. 20 may be realized by the processor 531.

[6] Others The first to fourth embodiments described above can be implemented with various modifications without departing from the spirit of each embodiment. Each configuration and each process of each embodiment can be selected as necessary, or may be appropriately combined.

For example, in the first to fourth embodiments, the base station loopback communication may be performed using a plurality of base station paths that do not pass through the core network, using the inter-base station interface. Thereby, even if the radio | wireless terminal which performs communication between terminals is not connected with the same base station, communication between terminals can be controlled to base station return communication. The control device may control the inter-terminal communication to the base station loopback communication when a plurality of base stations identified by the base station identification information received from each radio terminal can communicate with each other through the inter-base station interface. .

Also, for example, in any of the first to fourth embodiments, at least one of the wireless terminals that perform inter-terminal communication is used as a server, so that edge computing (Edge Computing) or mobile edge computing (Mobile Edge Computing: (MEC). In this case, the server connected to the base station may be positioned as a wireless terminal. The server may be connected to the base station wirelessly or by wire.

Edge computing is a method of connecting a server to a base station in order to speed up communication between a wireless terminal and a server connected to a network, for example. In edge computing, communication between a wireless terminal and a server can be speeded up by communication via a core network not via a network. The server connected to the base station may have, for example, at least a partial function of a server connected to the network, a specific application, or the like.

When loopback communication is possible by applying any of the first to fourth embodiments to edge computing, communication between terminals between the wireless terminal and the server is performed via the base station without passing through the core network. Can be controlled. Therefore, the transmission delay time can be further shortened compared to normal edge computing.

100, 200, 300 Wireless communication system 110, 110-1, 110-2, 410, 510 Wireless terminal 120, 420, 520 Base station 130 Controller 140 Host network 210, 210-1 to 210-4, 310, 310- 1, 310-2 UE
220, 220-1 to 220-n eNB
230, 230-a to 230-x, 330, 430 MME
240, 340, 440 SGW
250, 350, 450 PGW
260, 360 Network 270, 370 Radio access network 280, 380 Packet core network 292, 292-1 to 292-3 TA
290 Pool area 411, 421 Antenna 412, 422 Radio reception unit 413 Terminal side control unit 414, 425 Control signal generation unit 415, 428 Radio transmission unit 423, 427 SW
424 Base station side control unit 426 Loopback control unit 431, 451 Line control unit 441 Data control unit 511, 521, 531 Processor 512, 522, 532 Memory 513, 523 RF unit 514, 524 Antenna 525, 533 Network IF
530 processing equipment

Claims (23)

1. First and second wireless terminals that transmit base station identification information capable of identifying the base station to the upper network via the base station when performing location registration with respect to the upper network;
   The first base station identification information transmitted by the first wireless terminal and the second base station identification information transmitted by the second wireless terminal are received, and each received base station identification information A control device for controlling inter-terminal communication between the first and second wireless terminals to communication via the base station not via the upper network;
   A wireless communication system comprising:
2. The base station identification information is included in a location registration request to be transmitted to the upper network.
   The wireless communication system according to claim 1.
3. The base station identification information is transmitted from the first or second wireless terminal after transmission of a location registration request to be transmitted to the upper network and before setting a line between the base station and the upper network. To be
   The wireless communication system according to claim 1.
4. The base station identification information is system information transmitted from the base station to a radio area provided by the base station, and is included in the system information used for cell selection by a radio terminal located in the radio area,
   Each of the first and second wireless terminals receives the system information from the base station and acquires the base station identification information before performing the location registration.
   The wireless communication system according to any one of claims 1 to 3.
5. The control device compares the received base station identification information, and controls the inter-terminal communication to the communication via the base station not via the upper network according to the comparison result.
   The wireless communication system according to any one of claims 1 to 4.
6. Each of the first and second wireless terminals transmits terminal identification information capable of identifying the wireless terminal to the connection destination base station,
   The control device performs the inter-terminal communication based on the first terminal identification information transmitted from the first wireless terminal and the second terminal identification information transmitted from the second wireless terminal. Control to communicate via the base station without going through the network,
   The wireless communication system according to any one of claims 1 to 5.
7. The base station, according to the control from the control device, each received terminal identification information, transmission source and destination terminal identification information included in the wireless signal received from the first or second wireless terminal, And according to the comparison result, the received radio signal is transmitted to the destination of the received radio signal via the base station not via the upper network.
   The wireless communication system according to claim 6.
8. The base station identification information includes radio area identification information provided by the base station,
   The wireless communication system according to any one of claims 1 to 7.
9. The control device limits the implementation of the inter-terminal communication according to at least one parameter of the type of communication between terminals, required quality, and allowable delay time.
   The wireless communication system according to any one of claims 1 to 8.
10. A wireless terminal comprising: a transmission unit that transmits base station identification information capable of identifying the base station to the upper network via the base station when performing location registration with respect to the upper network.
11. The base station identification information is included in a location registration request to be transmitted to the upper network.
    The wireless terminal according to claim 10.
12. The base station identification information is transmitted after transmission of a location registration request to be transmitted to the upper network and before setting a line between the base station and the upper network.
    The wireless terminal according to claim 10.
13. The base station identification information is system information transmitted from the base station to a radio area provided by the base station, and is included in the system information used for cell selection by a radio terminal located in the radio area,
    Before performing the location registration, receiving the system information from the base station to obtain the base station identification information,
    The wireless terminal according to any one of claims 10 to 12.
14. The transmitting unit transmits terminal identification information capable of identifying the wireless terminal to the connection destination base station.
    The wireless terminal according to any one of claims 10 to 13.
15. A communication unit that transmits when a wireless terminal performs location registration with respect to an upper network, receives base station identification information that can identify the base station, and transmits the information to a control device in the upper network;
    In accordance with control from the control device that has received the first base station identification information transmitted by the first wireless terminal and the second base station identification information transmitted by the second wireless terminal, the first and A control unit for controlling communication between terminals between the second wireless terminals to communication via the base station not via the upper network;
    With a base station.
16. The base station identification information is included in a location registration request to be transmitted to the upper network.
    The base station according to claim 15.
17. The base station identification information is transmitted from the first or second wireless terminal after transmission of a location registration request to be transmitted to the upper network and before setting a line between the base station and the upper network. To be
    The base station according to claim 15.
18. A radio unit located in a radio area provided by the base station, which is system information used for cell selection and includes the base station identification information, and a transmitter that transmits the system information to the radio area,
    Each of the first and second wireless terminals receives the system information from the base station and acquires the base station identification information before performing the location registration.
    The base station according to any one of claims 15 to 17.
19. The communication unit receives terminal identification information capable of identifying each of the first and second wireless terminals from the first and second wireless terminals,
    In accordance with control from the control device, the control unit includes the first terminal identification information transmitted from the first wireless terminal and the second terminal identification information transmitted from the second wireless terminal. , Control the communication between the terminals to the communication via the base station not via the upper network,
    The base station according to any one of claims 15 to 18.
20. The control unit, according to control from the control device, each received terminal identification information, transmission source and transmission destination terminal identification information included in the wireless signal received from the first or second wireless terminal, And according to the comparison result, the received radio signal is transmitted to the destination of the received radio signal via the base station not via the upper network.
    The base station according to claim 19.
21. The base station identification information includes radio area identification information provided by the base station,
    The base station according to any one of claims 15 to 20.
22. A communication unit that receives base station identification information that can be used to identify the base station, which is transmitted when a wireless terminal performs location registration with respect to an upper network;
    The first and second base station identification information transmitted by the first wireless terminal and the second base station identification information transmitted by the second wireless terminal, received by the communication unit, A control unit for controlling communication between terminals between the wireless terminals to communication via the base station not via the upper network;
    A control device comprising:
23. When each of the first and second wireless terminals performs location registration with respect to the upper network, base station identification information that can identify the base station is transmitted to the upper network via the base station. ,
    The control device receives the first base station identification information transmitted by the first wireless terminal and the second base station identification information transmitted by the second wireless terminal, and receives each received Controls inter-terminal communication between the first and second wireless terminals based on base station identification information to communication via the base station not via the upper network.
    Wireless communication method.

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