WO2016163112A1

WO2016163112A1 - Device and method for optimization of paging

Info

Publication number: WO2016163112A1
Application number: PCT/JP2016/001898
Authority: WO
Inventors: 孝法岩井; 林　貞福; 豊武田村
Original assignee: 日本電気株式会社
Priority date: 2015-04-09
Filing date: 2016-04-04
Publication date: 2016-10-13
Also published as: JPWO2016163112A1

Abstract

A control entity (31) disposed in a core network (30) is configured to receive, from a base station (21), assistance information indicating a mobility characteristic of a radio terminal (11), and to perform control relating to paging of the radio terminal (11) using the assistance information. By this means, it is possible to contribute to cooperation or interaction for optimization of paging between a base station disposed in a radio access network, and a paging control entity disposed in a core network.

Description

Apparatus and method for paging optimization

The present disclosure relates to paging of a wireless terminal in a mobile communication system, and particularly to paging optimization.

A multiple access mobile communication system shares wireless resources including at least one of time, frequency, and transmission power among a plurality of wireless terminals so that the plurality of wireless terminals can perform wireless communication substantially simultaneously. It is possible to do. Typical multiple access methods are Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or a combination thereof.

The term "mobile communication system" used in this specification means a multiple access mobile communication system unless otherwise specified. The mobile communication system includes a wireless terminal and a network. The network includes a radio access network (Radio Access Network (RAN)) and a core network (Core Network (CN)). A wireless terminal is also called a mobile station or a mobile terminal. The wireless terminal communicates with an external network (e.g., Internet, packet data network, or private enterprise network) via RAN and CN. Mobile communication systems include, for example, 3rd Generation Partnership Project (3GPP) Universal Mobile Telecommunications System (UMTS), 3GPP Evolved Packet System (EPS), 3GPP2 CDMA2000 System, Global System for Mobile Communications (GSM (registered trademark)) / General General packetet radio service (GPRS) system, WiMAX system, or mobile WiMAX system. EPS includes Long Term Evolution (LTE) system and LTE-Advanced system.

The core network transmits a paging signal to the wireless terminal when new downlink traffic (downlink data or voice incoming call) arrives for the standby wireless terminal. The wireless terminal in a standby state performs discontinuous reception (Discontinuous Reception (DRX)) in order to receive a paging signal. Then, in response to receiving the paging signal addressed to itself, the wireless terminal starts signaling for communication for receiving downlink traffic. This signaling includes a response message to paging. The response message includes a request for establishing a control connection, a service request for establishing a communication path (bearer) for transferring user data, or both. The network that has received the response message executes a procedure for setting a control connection and a communication path (bearer) necessary for transmitting downlink traffic to the wireless terminal.

The core network needs to determine an area where a paging signal is transmitted when paging a wireless terminal. In this specification, “an area where a paging signal is transmitted” is referred to as a “paging area”. The paging area includes at least one cell, and generally includes a plurality of cells (or sectors). Typically, the paging area matches the latest location registration area to which the wireless terminal belongs. The location registration area is a management unit in the network of wireless terminals in a standby state. When the wireless terminal moves across the location registration area, the wireless terminal transmits a location update request to the upper network. In addition, the wireless terminal may periodically transmit a location update request regardless of changes in the location registration area.

For example, in the packet exchange domain of 3GPP UMTS, the location registration area is called a routing area (Routing Area (RA)). Therefore, paging of a wireless terminal in a standby state (CELL_PCH state or URA_PCH state) is generally performed by broadcasting a paging signal to the entire routing area.

Also, in 3GPP （EPS (LTE), the location registration area is called the tracking area (Tracking Area (TA)). Furthermore, in EPS, it is allowed to assign a plurality of TAs to wireless terminals. Specifically, when a wireless terminal is attached or updated (Tracking 無線 Area Update (TAU)), the wireless terminal receives a TA list including one or more TAs from the CN. Thereby, the location of the wireless terminal is managed in units of TA list. Therefore, paging of a wireless terminal in a standby state (EMM-REGISTERED state but RRC_IDLE state and ECM_IDLE state) is generally performed by broadcasting a paging signal in all TAs included in the TA list.

However, in order to reduce the paging load, it is necessary to further narrow down the paging area as compared with paging in a general location registration area unit. Patent Documents 1 and 2 disclose a technique for further narrowing down the paging area as compared with a general location registration area by using a movement history of a wireless terminal. By narrowing down the paging area, the paging load of the mobile communication system can be reduced.

Patent Document 1 calculates a moving distance (ie, moving speed) of a wireless terminal per unit time using a history of position update messages transmitted from the wireless terminal, and is included in a circle whose radius is the calculated moving distance. Is determined as a paging area.

Patent Document 2 discloses that location management of a wireless terminal is performed using not only the location update message but also location information based on the Global Positioning System (GPS). The method disclosed in Patent Document 2 is limited in comparison with the location registration area based on the GPS location information when the latest location information of the wireless terminal that is grasped by the host network is GPS location information. Including determining the paging area of the range. Furthermore, Patent Document 2 discloses that the moving speed of the wireless terminal is calculated using the position update message and the GPS position information history, and the paging area is increased as the moving speed of the wireless terminal increases.

Patent Document 3 describes that the paging area of the wireless terminal is determined according to the communication state (e.g., traffic) or the operation state (e.g., movement frequency) of the wireless terminal. Specifically, the wireless terminal disclosed in Patent Document 3 monitors the communication state (eg, traffic) and operation state (eg, movement frequency) of the local station, and sets the control packet (paging request packet) as a core. Send to the network. The core network of Patent Literature 3 receives a control packet (paging request packet) transmitted from a wireless terminal, and performs paging of the wireless terminal according to the communication state or the operating state of the wireless terminal indicated by the control packet. Determine the area.

Patent Document 4 discloses a communication method including the following steps (a) to (c).
(A) transmitting an indicator from the wireless terminal to the communication network that indicates that the wireless terminal (typically a machine-to-machine (M2M) device) is low mobility;
(B) Notifying the position (typically sector) of the wireless terminal from the wireless terminal to the communication network, and (c) Paging message limited to the notified position (typically sector) of the wireless terminal. To send.

Patent Document 5 discloses that a base station or a network determines a mobility state of a wireless terminal and determines a tracking area (TA) to be allocated to the wireless terminal based on the determined mobility state. For example, in an architecture that allows multiple TAs to be assigned to a wireless terminal, the base station or network assigns only one TA to a stationary or low mobility wireless terminal, and to a high mobility wireless terminal Assign multiple TAs. Alternatively, in an architecture where each cell can belong to multiple TAs, the network assigns only a TA that covers a small geographic area to a stationary or low mobility wireless terminal, and the high mobility wireless terminal Assign a TA that covers a large geographic area. Further, Patent Document 5 describes (a) a count value of the number of times of location update (ie, TAU) of a radio terminal, or (b) cell reselection performed by the radio terminal in order to determine the mobility state of the radio terminal It discloses that at least one of the count value of the number of times and (c) the measurement result of the position of the wireless terminal (eg, longitude and latitude) is used.

JP 2011-49616 A JP 2006-2111335 A Japanese Patent Laying-Open No. 2005-20726 US Patent Application Publication No. 2012/0149383 International Publication No. 2008/112161

The inventors of the present application have found various problems related to paging of wireless terminals. For example, Patent Documents 1 to 5 described above are received by a paging control entity (eg, “Mobility Management” Node (MME) or a base station) in a network using information measured by the control entity or from a wireless terminal. It discloses that paging optimization is performed using control information. However, Patent Documents 1 to 5 disclose cooperation or interaction for paging optimization between a base station arranged in a radio access network and a paging control entity (eg, MME) arranged in a core network. Not.

Accordingly, one of the objectives that the embodiments disclosed herein seek to achieve is between a base station located in a radio access network and a paging control entity (eg, MME) located in a core network. The present invention provides an apparatus, a method, and a program that contribute to cooperation or interaction for paging optimization. Other objects or problems and novel features will become apparent from the description of the present specification or the accompanying drawings.

In the first aspect, the control entity arranged in the core network includes a memory and at least one processor coupled to the memory. The at least one processor is configured to receive assistance information indicating mobility characteristics of a wireless terminal from a base station, and to perform control related to paging of the wireless terminal using the assistance information.

In the second aspect, the base station device arranged in the radio access network includes a memory and at least one processor coupled to the memory. The at least one processor is configured to transmit assistance information indicating mobility characteristics of the wireless terminal to the core network. The assistance information is used in the core network for control related to paging of the wireless terminal.

In a third aspect, a method performed by a control entity arranged in a core network includes receiving assistance information indicating a mobility characteristic of a wireless terminal from a base station, and using the assistance information for paging of the wireless terminal Performing control.

In the fourth aspect, the method performed by the base station apparatus arranged in the radio access network includes transmitting assistance information indicating mobility characteristics of the radio terminal to the core network. The assistance information is used in the core network for control related to paging of the wireless terminal.

In the fifth aspect, the program includes a group of instructions (software code) for causing the computer to perform the method according to the third or fourth aspect described above when read by the computer.

According to the above aspect, an apparatus that contributes to cooperation or interaction for paging optimization between a base station located in the radio access network and a paging control entity (eg, MME) located in the core network, Methods and programs can be provided.

It is a figure which shows the structural example of the mobile communication system which concerns on some embodiment. It is a flowchart which shows an example of operation | movement of the mobility management node which concerns on 1st Embodiment. It is a sequence diagram which shows an example of the paging control procedure which concerns on 1st Embodiment. It is a sequence diagram which shows an example of operation | movement of the base station which concerns on 2nd Embodiment. It is a block diagram which shows the structural example of the mobility management node which concerns on some embodiment. It is a block diagram which shows the structural example of the base station which concerns on some embodiment. It is a block diagram which shows the structural example of the radio | wireless terminal which concerns on some embodiment.

Hereinafter, specific embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted as necessary for clarification of the description.

A plurality of embodiments shown below will be described mainly for an Evolved Packet System (EPS). However, these embodiments are not limited to EPS, and may be applied to other mobile communication networks or systems such as 3GPP UMTS, 3GPP2 CDMA2000 systems, GSM / GPRS systems, WiMAX systems, and the like.

<First Embodiment>
FIG. 1 shows a configuration example of a mobile communication system 1 according to some embodiments including this embodiment. In the example of FIG. 1, the mobile communication system 1 includes an E-UTRAN 20 and an EPC 30. The E-UTRAN 20 is an EPS radio access network and includes a plurality of base stations (ie, evolved NodeB (eNB)) 21. A wireless terminal (ie, User Equipment (UE)) 11 communicates with the external network 40 via the E-UTRAN 20 and the EPC 30. Each eNB 21 generates a cell 22, connects to the UE 11 by radio access technology, and relays user data between the UE 11 and the EPC 30. In the following description, at least one of the plurality of cells 22 may be a sector.

The EPC 30 is an EPS core network, and includes a plurality of control plane entities and a plurality of user plane (data plane) entities. The plurality of control plane entities include, for example, one or more MMEs, one or more Home Subscriber Server (HSS), one or more Policy 複数 and Charging Rule Function (PCRF), and one or more Call Session Control Function ( SCSF). The plurality of user plane entities include, for example, one or more Serving Gateways (S-GW) and one or more Packet Data Network Gateways (P-GW).

FIG. 1 shows an MME 31 as a control plane entity and an S / P-GW 32 as a user plane entity. The MME 31 performs mobility management including paging control of the UE 11. The S / P-GW 32 performs user data packet transfer processing (e.g., routing and forwarding).

MME 31 determines the paging area of UE11. And MME31 requests | requires transmission of the paging signal with respect to one or some eNB21 in the paging area of UE11 in response to the downlink data with respect to UE11 of a standby state having arrived in EPC30. Note that the EPS 11 Mobility Management (EMM) state of the UE 11 is EMM-REGISTERED, the EPS Connection Management (ECM) state is ECM_IDLE, and the Radio Resource Control (RRC) state is RRC_IDLE. Sometimes it corresponds.

Subsequently, paging control according to the present embodiment will be described below. FIG. 2 is a flowchart showing an example of the operation of the MME 31 (process 200). In block 201, the MME 31 receives assistance information indicating the mobility characteristics of the UE 11 from the radio access network. In block 202, MME31 performs paging control of the said UE11 using the received assistance information. The paging control includes (a) determining a paging area for UE11, (b) determining a cell or eNB list for paging for UE11, and (c) determining a paging area or cell / eNB list. It may include at least one of selecting an algorithm to be used.

Assistance information for paging control may explicitly indicate the mobility characteristics of the UE 11 or may indicate implicitly. The mobility characteristic can also be called a mobility pattern. The mobility characteristic indicated by the assistance information includes at least one of presence / absence of mobility (mobility), magnitude of mobility, restriction on a movement range, movement randomness, movement frequency, handover frequency, movement speed, and stay cell history. One may be included.

The presence / absence of mobility means whether or not the UE 11 has substantial mobility. For example, the eNB 21 may determine that the UE 11 does not have substantial mobility when the inter-cell movement (i.e., handover) of the UE 11 is never performed beyond a predetermined period. In this case, the eNB 21 may transmit assistance information that explicitly indicates that the UE 11 does not have mobility or is stationary to the MME 31. Instead, the eNB 21 may transmit the stay cell history of the UE 11 (indicating that the stay cell does not change for a long time) to the MME 31 as assistance information that implicitly indicates the presence or absence of mobility.

The size of mobility means the mobility level that UE 11 has. For example, the eNB 21 may transmit assistance information explicitly indicating the mobility level (eg, high mobility, low mobility) determined based on the frequency of UE 11 inter-cell movement (ie, high handover, low mobility) to the MME 31. . Instead, the eNB 21 may transmit the stay cell history of the UE 11 to the MME 31 as assistance information that implicitly indicates the presence or absence of mobility.

In some implementations, when the MME 31 determines that the UE 11 is stationary or low mobility based on the assistance information of the UE 11, the MME 31 has a smaller geographical area than when the UE 11 is not stationary or low mobility. The paging area (or cell / eNB list) to be covered may be determined. In some implementations, the MME 31 may determine the paging area of the UE 11 according to an algorithm for low mobility when the UE 11 is determined to be low mobility based on the assistance information of the UE 11.

The restriction on the movement range means that there is some restriction on the geographical range in which the mobile station 100 can substantially move, or that some regularity can be found in the movement direction or movement locus of the UE 11. The “constraint on the movement range” can also be called “movement repeatability”. For example, when UE11 is mounted on a railway vehicle, the geographical range in which the mobile station UE11 is substantially movable is restricted to a one-dimensional area along the railway track. For example, eNB21 may determine the presence or absence of restrictions with respect to the movement range of UE11 based on the history (or stay cell history) of movement between cells (i.e., handover) of UE11. In this case, eNB21 may transmit the assistance information which shows explicitly that the restrictions with respect to the movement range of UE11 exist to MME31. Instead, the eNB 21 may transmit the stay cell history of the UE 11 (the stay cell is geographically restricted) to the MME 31 as assistance information that implicitly indicates the presence of the restriction on the movement range.

In some implementations, the MME 31 selects one or more cells included in the movement range as the paging area of the UE 11 when it is estimated that there is a restriction on the movement range of the UE 11 based on the assistance information of the UE 11 May be. In other words, MME31 is good also considering the geographical area with large dependence to the moving direction of UE11 as the paging area of UE11. The geographical area having a large movement direction dependency may be, for example, a non-circular geographical area in which the movement direction of the UE 11 is preferentially included compared to other directions.

The movement randomness means that the movement direction of the UE 11 is an irregular direction regardless of the past movement history, in other words, the movement locus of the UE 11 has no substantial regularity. For example, the eNB 21 may determine the presence of randomness when there is no substantial regularity in the UE 11 staying cell history. In this case, the eNB 21 may transmit assistance information that explicitly indicates that the mobility of the UE 11 has randomness to the MME 31. Instead, the eNB 21 transmits the stay cell history of the UE 11 (indicating that there is no substantial regularity in the movement trajectory of the UE 11) to the MME 31 as assistance information that implicitly indicates that there is randomness. Also good.

In some implementations, when the MME 31 determines that the UE 11 has randomness in movement based on the assistance information of the UE 11, the geography has a small dependence on the moving direction of the UE 11 and a variable size. The target area may be specified, and one or more cells included in the geographical area may be selected as the paging area. The geographical area with small movement direction dependency is, for example, a circular area. The size of the geographical area may be determined according to the moving speed of the UE 11.

That is, the assistance information transmitted from the eNB 21 to the MME 31 may be an indicator or an identifier indicating the type or class of the mobility characteristic (or mobility pattern) of the UE 11. Alternatively, the assistance information may be measurement information or history information regarding the UE 11 acquired (observed) by one or a plurality of eNBs 21. For example, the assistance information includes (a) measurement information related to UE 11 acquired by one or more eNBs 21, (b) history information related to UE 11 acquired by one or more eNBs 21, and (c) one or more eNBs 21. It may include at least one of setting information on the determined UE 11, (d) a list of recommended cells, and (e) a list of recommended base stations. The list of recommended cells (list of recommended cells) may indicate one or more cells that are likely to reach the UE 11 selected based on the staying cell history of the UE 11. The list of recommended base stations may indicate an identifier of one or more eNBs 21 deduced from the list of recommended cells. These pieces of information are used by the MME 31 to effectively transmit paging.

Assistance information transmitted from the eNB 21 to the MME 31 may be in units of UEs or in units of UEs (UE groups). The UE group may be defined by, for example, the type of UE, or may be defined by an application or service used by the UE.

ENB21 may transmit the assistance information regarding UE11 to EPC30 at arbitrary timing. The eNB 21 may transmit the assistance information to the EPC 30 periodically or aperiodically. However, it should be noted that frequent transmission of assistance information increases the load of control signaling (i.e., S1 signaling) between the eNB 21 and the EPC 30.

The MME 31 needs to perform paging of the UE 11 when the UE 11 is in the IDLE state. Therefore, in some implementations, the eNB 21 may transmit the assistance information to the EPC 30 in response to the acquisition of the assistance information related to the UE 11 by the eNB 21 being stopped. In other words, the EPC 30 (MME 31) may receive the assistance information from the eNB 21 in response to the acquisition of the assistance information regarding the UE 11 by the eNB 21 being stopped. More specifically, the eNB 21 may transmit assistance information of the UE 11 to the EPC 30 (MME 31) in response to the UE 11 transitioning from the CONNECTED state to the IDLE state. Thereby, the eNB 21 can supply the latest assistance information to the EPC 30 in a timely manner when paging by the EPC 30 (MME 31) is required. In addition, suppression of frequent occurrence of S1 signaling is expected.

Here, the definitions of the terms “CONNECTED state” and “IDLE state” used in the present specification and claims will be described. The “IDLE state” means that the wireless terminal (eg, UE11) does not continuously exchange control signals for session management and mobility management with CN (eg, EPC30), and RAN (eg, This means that the wireless connection in E-UTRAN 20) has been released. An example of the IDLE state is an ECM-IDLE state and an RRC_IDLE state. When the UE is RRC_IDLE, the RRC connection of the UE is released.

On the other hand, the “CONNECTED state” refers to session management and mobility management between at least the wireless terminal (eg, UE11) and CN (eg, EPC30) as in the ECM-CONNECTED state and RRC_CONNECTED state of EPS. A wireless connection for sending and receiving control signals (control messages) is established in the RAN (eg, E-UTRAN 20), and a connection capable of sending and receiving control signals (control messages) is established between the wireless terminal and the CN Means state. In other words, the “CONNECTED state” may be a state in which the wireless terminal is connected to the CN so that at least control signals (control messages) for session management and mobility management can be transmitted and received. The “CONNECTED state” may be a state in which a data bearer for transmitting / receiving user data between the wireless terminal and the external network is set. The “CONNECTED state” indicates that the mobile terminal has a control connection with the CN but data The state which does not have a bearer may be sufficient. The “CONNECTED state” can also be called the “ACTIVE state”.

Also, typically, the CN manages the position of a wireless terminal in the CONNECTED state in units of cells, and the position of the wireless terminal in the IDLE state is in units of location registration areas (eg, tracking area, routing area) including a plurality of cells Manage with. When the wireless terminal in the IDLE state moves from one location registration area to another location registration area, the wireless terminal transmits a message indicating the update of the location registration area to the CN. When the downlink traffic (downlink data or voice incoming) for the wireless terminal in the IDLE state arrives, the CN transmits a paging signal to the paging area of the wireless terminal.

As understood from the above description, in the present embodiment, the MME 31 is configured to execute paging control (or paging optimization) of the UE 11 using the assistance information of the UE 11 received from the eNB 21. Therefore, the eNB 21 and the MME 31 according to the present embodiment can contribute to cooperation or interaction for paging optimization between the E-UTRAN 20 and the EPC 30.

FIG. 3 is a sequence diagram showing an example (processing 300) of the paging control procedure according to the present embodiment. In block 301, UE11 is in CONNECTED state, ie RRC_CONNECTED and ECM-CONNECTED. That is, the UE 11 has an RRC connection with the eNB 21A, and transmits and receives a Non-Access の間 Stratum (NAS) message with the MME 31 using the S1AP signaling connection between the eNB 21A and the MME 31. it can.

In blocks 302 and 303, the eNB 21A performs a procedure for releasing the setting information (S1 UE context) regarding the UE 11 in accordance with the transition of the UE 11 from the CONNECTED state to the IDLE state. The procedure may be triggered by an instruction (i.e., S1AP: S1 UE Context Release Command message) not shown. Instead, when the eNB 21A detects the necessity of releasing the signaling connection and the radio bearer (eg, user inactivity, or release due to UE generated signalling connection release) related to the UE11, the eNB 21A determines that S1AP: S1 UE Context Release Request An S1 release may be triggered by sending a message to the MME 31.

In block 302, the eNB 21A releases the RRC connection with the UE 11. In block 303, eNB21A transmits the assistance information regarding the mobility characteristic of UE11 to MME31. Block 303 may be performed before block 302. The assistance information in block 303 may be transmitted to the MME 31 using an S1AP: S1 UE Context Release Request message or an S1AP: S1 UE Context Release Complete message, as shown in FIG.

In block 304, MME31 performs paging control regarding UE11 using the assistance information received from eNB21A. For example, MME31 determines the paging area of UE11. In the example of FIG. 3, the determined other paging areas include eNB 21A, eNB 21B, and eNB 21C.

In block 305, the MME 31 requests the paging of the UE 11 from the eNB 21A, the eNB 21B, and the eNB 21C in the paging area of the UE 11 in response to the arrival of the downlink traffic for the UE 11 at the EPC 30. In block 306, eNB21A, eNB21B, and eNB21C transmit the paging signal for calling UE11.

3, when the UE 11 transitions from the CONNECTED state to the IDLE state, the eNB 21 transmits assistance information related to the UE 11 to the MME 31. Therefore, the eNB 21 can supply the latest assistance information to the EPC 30 in a timely manner when paging by the EPC 30 (MME 31) is required.

<Second Embodiment>
This embodiment demonstrates the example which transfers assistance information between eNBs21. Transfer of assistance information between the eNBs 21 described in the present embodiment may be performed in addition to the transmission of the assistance information described in the first embodiment from the eNB 21 to the EPC 30 (MME 31). A configuration example of the wireless communication system according to the present embodiment is the same as that of FIG. 1 described in the first embodiment.

FIG. 4 is a sequence diagram illustrating an example of a procedure for transmitting assistance information between two eNBs 21 (processing 400). In step S401, the eNB 21S transmits a control message (e.g., X2.Application Protocol (X2AP) message) including assistance information regarding the UE 11 to the eNB 21T.

The eNB 21S may transmit the assistance information of the UE 11 to the eNB 21T when the UE 11 in the CONNECTED state moves between cells (i.e., handover). For example, the eNB 21S may transmit an X2AP: HANDOVER REQUEST message including assistance information related to the UE 11 to the eNB 21T in response to determining the handover of the UE 11.

According to the present embodiment, assistance information can be transferred between the eNBs 21. Therefore, in this embodiment, several eNB21 can acquire the continuous assistance information (e.g., drowning cell history) regarding UE11 which moves between cells in cooperation with each other. Furthermore, eNB21 should just transmit the assistance information obtained by cooperation of several eNB21 to EPC30 (MME31), when UE11 changes to an IDLE state. Thereby, for example, an improvement in the accuracy of paging optimization can be expected.

Finally, configuration examples of the MME 31, the eNB 21, and the UE 11 according to the above-described plurality of embodiments will be described. FIG. 5 is a block diagram illustrating a configuration example of the MME 31. Referring to FIG. 5, the MME 31 includes a network interface 501, a processor 502, and a memory 503. The network interface 501 is used to communicate with one or more network entities (e.g., eNB 21, S / P-GW 32, and HSS). The network interface 501 may include a plurality of logical or physical interfaces. The network interface 501 may include, for example, one or a plurality of network interface cards (NICs) conforming to IEEE 802.3 series.

The processor 502 reads out and executes software (computer program) from the memory 503, thereby executing processing related to the MME 31. The processor 502 may be, for example, a microprocessor, a Micro Processing Unit (MPU), or a Central Processing Unit (CPU). The processor 502 may include a plurality of processors.

The memory 503 is configured by a combination of a volatile memory and a nonvolatile memory. The volatile memory is, for example, Static Random Access Memory (SRAM), Dynamic RAM (DRAM), or a combination thereof. The nonvolatile memory is, for example, a mask Read Only Memory (MROM), Programmable ROM (PROM), flash memory, hard disk drive, or any combination thereof. Memory 503 may include storage located physically separate from processor 502. In this case, the processor 502 may access the memory 503 via the network interface 501 or another I / O interface not shown.

The memory 503 may store a software module (computer program) including an instruction group and data for performing processing by the MME 31 described in the plurality of embodiments. In some implementations, the processor 502 may be configured to perform the processing of the MME 31 described in the above-described embodiment by reading the software module from the memory 503 and executing the software module.

More specifically, in the example of FIG. 5, the memory 503 is used to store a software module group including the paging control module 504. The paging control module 504 includes an instruction group and data for performing paging control related to the UE 11 using assistance information indicating the mobility characteristic of the UE 11 received from the E-UTRAN 20. The processor 502 reads out and executes the software module including the paging control module 504 from the memory 503, so that the processing by the MME 31 described in the above embodiment can be performed.

FIG. 6 is a block diagram illustrating a configuration example of the eNB 21 according to the above-described embodiment. Referring to FIG. 18, the eNB 12 includes a Radio Frequency (RF) transceiver 601, a network interface 603, a processor 604, and a memory 605. The RF transceiver 601 performs analog RF signal processing to communicate with the UE 11. The RF transceiver 601 may include multiple transceivers. RF transceiver 601 is coupled to antenna 602 and processor 604. The RF transceiver 601 receives modulation symbol data (or OFDM symbol data) from the processor 604, generates a transmission RF signal, and supplies the transmission RF signal to the antenna 602. The RF transceiver 601 also generates a baseband received signal based on the received RF signal received by the antenna 602 and supplies this to the processor 604.

The network interface 603 is used to communicate with network nodes (e.g., MME and S / P-GW). The network interface 603 may include, for example, a network interface card (NIC) compliant with IEEE 802.3 series.

The processor 604 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. For example, in the case of LTE and LTE-Advanced, the digital baseband signal processing by the processor 604 is performed by signals in the Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, Medium Access Control (MAC) layer, and PHY layer. Processing may be included. Further, the control plane processing by the processor 604 may include processing of S1 protocol, RRC protocol, and MAC-> Control--Element (CE).

The processor 604 may include a plurality of processors. For example, the processor 604 may include a modem processor (e.g., Digital Signal Processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., CPU or MPU) that performs control plane processing.

The memory 605 is configured by a combination of a volatile memory and a nonvolatile memory. The volatile memory is, for example, SRAM or DRAM or a combination thereof. The non-volatile memory is, for example, an MROM, PROM, flash memory, hard disk drive, or a combination thereof. Memory 605 may include storage located remotely from processor 604. In this case, the processor 604 may access the memory 605 via the network interface 603 or an I / O interface not shown.

The memory 605 may store a software module (computer program) including an instruction group and data for performing processing by the eNB 21 described in the above-described plurality of embodiments. In some implementations, the processor 604 may be configured to perform the processing of the eNB 21 described in the above-described embodiment by reading the software module from the memory 605 and executing the software module.

FIG. 7 is a block diagram illustrating a configuration example of the UE 11. The Radio-Frequency (RF) transceiver 701 performs analog RF signal processing to communicate with the eNB 21. Analog RF signal processing performed by the RF transceiver 701 includes frequency up-conversion, frequency down-conversion, and amplification. RF transceiver 701 is coupled to antenna 702 and baseband processor 703. That is, the RF transceiver 701 receives modulation symbol data (or OFDM symbol data) from the baseband processor 703, generates a transmission RF signal, and supplies the transmission RF signal to the antenna 702. Further, the RF transceiver 701 generates a baseband received signal based on the received RF signal received by the antenna 702, and supplies this to the baseband processor 703.

The baseband processor 703 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Digital baseband signal processing consists of (a) data compression / decompression, (b) data segmentation / concatenation, (c) 生成 transmission format (transmission frame) generation / decomposition, and (d) transmission path encoding / decoding. , (E) modulation (symbol mapping) / demodulation, and (f) generation of OFDM symbol data (baseband OFDM signal) by Inverse Fast Fourier Transform (IFFT). On the other hand, control plane processing includes layer 1 (eg, transmission power control), layer 2 (eg, radio resource management, hybrid automatic repeat request (HARQ) processing), and layer 3 (eg, attach, mobility, and call management). Communication management).

For example, in the case of LTE and LTE-Advanced, the digital baseband signal processing by the baseband processor 703 may include PDCP layer, RLC layer, MAC layer, and PHY layer signal processing. The control plane processing by the baseband processor 703 may include NAS protocol, RRC protocol, and MAC-CE processing.

The baseband processor 703 may include a modem processor (e.g., Digital Signal Processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., CPU) that performs control plane processing, or an MPU). In this case, a protocol stack processor that performs control plane processing may be shared with an application processor 704 described later.

Application processor 704 is also called a CPU, MPU, microprocessor, or processor core. The application processor 704 may include a plurality of processors (a plurality of processor cores). The application processor 704 is a system software program (Operating System (OS)) read from the memory 706 or a memory (not shown) and various application programs (for example, call application, web browser, mailer, camera operation application, music playback) Various functions of the UE 11 are realized by executing the application.

In some implementations, the baseband processor 703 and application processor 704 may be integrated on a single chip, as shown by the dashed line (705) in FIG. In other words, the baseband processor 703 and the application processor 704 may be implemented as one System on Chip (SoC) device 705. An SoC device is sometimes called a system Large Scale Integration (LSI) or chipset.

The memory 706 is a volatile memory, a nonvolatile memory, or a combination thereof. The memory 706 may include a plurality of physically independent memory devices. The volatile memory is, for example, SRAM or DRAM or a combination thereof. The non-volatile memory is MROM, EEPROM, flash memory, or hard disk drive, or any combination thereof. For example, the memory 706 may include an external memory device accessible from the baseband processor 703, the application processor 704, and the SoC 705. Memory 706 may include an embedded memory device integrated within baseband processor 703, application processor 704, or SoC 705. Further, the memory 706 may include a memory in a Universal Integrated Circuit Card (UICC).

The memory 706 may store a software module (computer program) including an instruction group and data for performing processing by the UE 11 described in the above-described plurality of embodiments. In some implementations, the baseband processor 703 or the application processor 704 may be configured to perform the processing of the UE 11 described in the above-described embodiment by reading the software module from the memory 706 and executing the software module.

As described with reference to FIGS. 5 to 7, the one or more processors included in each of the MME 31, the eNB 21, and the UE 11 according to the above embodiment cause the computer to execute the algorithm described with reference to the drawings. One or a plurality of programs including a group of instructions may be executed. The program can be stored and supplied to a computer using various types of non-transitory computer readable media. Non-transitory computer readable media include various types of tangible storage media (tangible storage medium). Examples of non-transitory computer-readable media are magnetic recording media (eg flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg magneto-optical discs), Compact Disc Read Only Memory (CD-ROM), CD-ROM R, CD-R / W, semiconductor memory (for example, mask ROM, Programmable ROM (PROM), Erasable PROM (EPROM), flash ROM, Random Access Memory (RAM)). The program may also be supplied to the computer by various types of temporary computer-readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

<Other embodiments>
In some implementations, assistance information indicating mobility characteristics of the UE 11 may be transmitted from the eNB 21 to the UE 11. Further or alternatively, the assistance information indicating the mobility characteristics of the UE 11 may be transmitted from the UE 11 to the MME 31. In some implementations, assistance information indicating mobility characteristics of the UE 11 may be transmitted from the UE 11 to the MME 31. In this case, the UE 11 may transmit assistance information using any NAS message (eg, Attach Request message, Service Request message). MME31 may be comprised so that the paging control (or paging optimization) of the said UE11 may be performed using the assistance information of UE11 received from UE11.

In some implementations, the MME 31 sends to the eNB 21 with a paging request the E-UTRAN Cell Global Identifier (ECGI) (ie, last known ECGI) of the cell to which the UE 11 last belonged when the UE 11 is in the CONNECTED state. Also good. The last known ECGI may be used by the eNB 21 to limit paging to the specific cell.

In some implementations, the MME 31 may send a paging request to the last used eNB 21 (last used eNB) by the UE 11. In this case, the eNB 21 that has received the paging request may transfer the paging request (paging message) to an appropriate adjacent eNB via the inter-eNB interface (i.e., X2 interface).

In some implementations, when the eNB 21 releases the S1 の UE context as the UE11 transitions to the IDLE state (S1 release), the eNB 21 is based on information when the UE11 is in the CONNECTED state. Cell coverage information (current UE's cell coverage information) may be transmitted to the MME 31. The cell coverage information indicates one or a plurality of eNBs 21 that provide overlapping coverage (overlapping cells) for the cell in which the UE 11 was located last. The MMR 31 may select one or a plurality of eNBs 21 that transmit a paging request to page the UE 11 based on the received cell coverage information (current | UE's | cell | coverage | information).

The above-described embodiments may be implemented independently or may be implemented in combination as appropriate.

The above-described embodiment has mainly described LTE / LTE-Advanced and its improvements. However, the above-described embodiments may be applied to other wireless communication systems such as UMTS. The eNB 21 described in the above embodiment can also be called a radio station or a base station. The radio station or base station in this specification is a control node (eg, Radio Network Controller (RNC) in UMTS, or Base Station Controller (BSC) in GSM system) and radio transmission node (eg, UMTS). NodeB or Base transceiver (station) (BTS) in the GSM system.

Furthermore, the above-described embodiments are merely examples relating to application of the technical idea obtained by the present inventors. That is, the technical idea is not limited to the above-described embodiment, and various changes can be made.

For example, a part or all of the above embodiment can be described as in the following supplementary notes, but is not limited thereto.

(Appendix 1)
A control entity located in the core network,
Memory,
At least one processor coupled to the memory;
With
The at least one processor is configured to receive assistance information indicating mobility characteristics of a wireless terminal from a base station and perform control related to paging of the wireless terminal using the assistance information.
Control entity.

(Appendix 2)
The mobility characteristics include at least one of presence / absence of mobility, mobility size, movement range restriction, movement randomness, movement frequency, handover frequency, movement speed, and stay cell history.
The control entity according to attachment 1.

(Appendix 3)
The at least one processor is configured to receive the assistance information in response to the acquisition of the assistance information by the base station being stopped.
The control entity according to attachment 1 or 2.

(Appendix 4)
The at least one processor is configured to receive the assistance information in response to the wireless terminal transitioning from a CONNECTED state to an IDLE state;
The control entity according to attachment 1 or 2.

(Appendix 5)
The paging control includes (a) determining a paging area of the wireless terminal, (b) determining a list of cells or base stations for paging of the wireless terminal, and (c) the paging area or Selecting at least one of the algorithms used to determine the list;
The control entity according to any one of appendices 1 to 4.

(Appendix 6)
The assistance information includes (a) measurement information regarding the wireless terminal acquired by one or more base stations, (b) history information regarding the wireless terminal acquired by the one or more base stations, (c) Including at least one of configuration information regarding the wireless terminal determined in one or more base stations, (d) a list of recommended cells, and (e) a list of recommended base stations.
The control entity according to any one of appendices 1 to 5.

(Appendix 7)
The assistance information is acquired by the one or more base stations when the wireless terminal is in a CONNECTED state.
The control entity according to appendix 6.

(Appendix 8)
A base station device arranged in a radio access network,
Memory,
At least one processor coupled to the memory;
With
The at least one processor is configured to transmit assistance information indicating mobility characteristics of the wireless terminal to the core network;
The assistance information is used in the core network for control related to paging of the wireless terminal.
Base station device.

(Appendix 9)
The mobility characteristics include at least one of presence / absence of mobility, mobility size, movement range restriction, movement randomness, movement frequency, handover frequency, movement speed, and stay cell history.
The base station apparatus according to appendix 8.

(Appendix 10)
The at least one processor is configured to transmit the assistance information to the core network in response to the acquisition of the assistance information by the base station device being stopped.
The base station apparatus according to appendix 8 or 9.

(Appendix 11)
The at least one processor is configured to transmit the assistance information to the core network in response to the wireless terminal transitioning from a CONNECTED state to an IDLE state.
The base station apparatus according to appendix 8 or 9.

(Appendix 12)
The at least one processor is configured to transmit the assistance information to the other base station upon handover of the wireless terminal from the base station device to another base station.
The base station apparatus according to any one of appendices 8 to 11.

(Appendix 13)
The assistance information includes: (a) measurement information related to the wireless terminal acquired by at least one base station including the base station device; (b) history information related to the wireless terminal acquired by the at least one base station; (C) at least one of configuration information regarding the wireless terminal determined by the at least one base station, (d) a list of recommended cells, and (e) a list of recommended base stations.
Item 13. The base station device according to any one of appendices 8 to 12.

(Appendix 14)
The assistance information is acquired by the at least one base station when the wireless terminal is in a CONNECTED state.
The base station apparatus according to attachment 13.

(Appendix 15)
A method performed by a control entity located in a core network,
Receiving assistance information indicating mobility characteristics of a wireless terminal from a base station, and performing control related to paging of the wireless terminal using the assistance information;
A method comprising:

(Appendix 16)
The mobility characteristics include at least one of presence / absence of mobility, mobility size, movement range restriction, movement randomness, movement frequency, handover frequency, movement speed, and stay cell history.
The method according to appendix 15.

(Appendix 17)
The receiving includes receiving the assistance information in response to the acquisition of the assistance information by the base station being stopped;
The method according to appendix 15 or 16.

(Appendix 18)
The receiving includes receiving the assistance information in response to the wireless terminal transitioning from a CONNECTED state to an IDLE state;
The method according to appendix 15 or 16.

(Appendix 19)
The paging control includes (a) determining a paging area of the wireless terminal, (b) determining a list of cells or base stations for paging of the wireless terminal, and (c) the paging area or Selecting at least one of the algorithms used to determine the list;
The method according to any one of appendices 15 to 18.

(Appendix 20)
The assistance information includes (a) measurement information regarding the wireless terminal acquired by one or more base stations, (b) history information regarding the wireless terminal acquired by the one or more base stations, (c) Including at least one of configuration information regarding the wireless terminal determined in one or more base stations, (d) a list of recommended cells, and (e) a list of recommended base stations.
The method according to any one of appendices 15 to 19.

(Appendix 21)
The assistance information is acquired by the one or more base stations when the wireless terminal is in a CONNECTED state.
The method according to appendix 20.

(Appendix 22)
A method performed by a base station device arranged in a radio access network,
Transmitting assistance information indicating mobility characteristics of the wireless terminal to the core network,
The assistance information is used in the core network for control related to paging of the wireless terminal.
Method.

(Appendix 23)
The mobility characteristics include at least one of presence / absence of mobility, mobility size, movement range restriction, movement randomness, movement frequency, handover frequency, movement speed, and stay cell history.
The method according to appendix 22.

(Appendix 24)
The transmitting includes transmitting the assistance information to the core network in response to the acquisition of the assistance information by the base station device being stopped.
The method according to appendix 22 or 23.

(Appendix 25)
The transmitting includes transmitting the assistance information to the core network in response to the wireless terminal transitioning from a CONNECTED state to an IDLE state.
The method according to appendix 22 or 23.

(Appendix 26)
Further comprising transmitting the assistance information to the other base station upon handover of the wireless terminal from the base station device to the other base station,
The method according to any one of appendices 22 to 25.

(Appendix 27)
The assistance information includes: (a) measurement information related to the wireless terminal acquired by at least one base station including the base station device; (b) history information related to the wireless terminal acquired by the at least one base station; (C) at least one of configuration information regarding the wireless terminal determined by the at least one base station, (d) a list of recommended cells, and (e) a list of recommended base stations.
The method according to any one of appendices 22 to 26.

(Appendix 28)
The assistance information is acquired by the at least one base station when the wireless terminal is in a CONNECTED state.
The method according to appendix 27.

(Appendix 29)
A first base station located in a radio access network;
A paging control entity located in the core network;
With
The first base station is configured to transmit assistance information indicating mobility characteristics of a wireless terminal to the core network;
The paging control entity is configured to receive the assistance information and perform control related to paging of the wireless terminal using the assistance information.
Mobile communication system.

(Appendix 30)
The mobility characteristics include at least one of presence / absence of mobility, mobility size, movement range restriction, movement randomness, movement frequency, handover frequency, movement speed, and stay cell history.
The mobile communication system according to attachment 29.

(Appendix 31)
The first base station is configured to transmit the assistance information to the core network in response to the acquisition of the assistance information by the first base station being stopped.
The mobile communication system according to attachment 29 or 30.

(Appendix 32)
The first base station is configured to transmit the assistance information to the core network in response to the wireless terminal transitioning from a CONNECTED state to an IDLE state.
The mobile communication system according to attachment 29 or 30.

(Appendix 33)
A second base station disposed in the radio access network;
The first base station is configured to receive the assistance information from the second base station upon handover of the wireless terminal from the second base station to the first base station. ,
The mobile communication system according to any one of appendices 29 to 32.

(Appendix 34)
The assistance information includes (a) measurement information related to the wireless terminal acquired by at least one base station including the first base station, and (b) history related to the wireless terminal acquired by the at least one base station. At least one of information, (c) configuration information about the wireless terminal determined by the at least one base station, (d) a list of recommended cells, and (e) a list of recommended base stations Including,
34. The mobile communication system according to any one of appendices 29 to 33.

(Appendix 35)
The assistance information is acquired by the at least one base station when the wireless terminal is in a CONNECTED state.
The mobile communication system according to attachment 34.

(Appendix 36)
A program for causing a computer to perform the method according to any one of appendices 15 to 21.

(Appendix 37)
A program for causing a computer to perform the method according to any one of appendices 22 to 28.

This application claims priority based on Japanese Patent Application No. 2015-080343 filed on April 9, 2015, the entire disclosure of which is incorporated herein.

11 Wireless terminal (UE)
20 Radio access network (E-UTRAN)
21 Base station (eNB)
30 Core network (EPC)
31 Mobility management node (MME)

Claims

A control entity located in the core network,
Memory,
At least one processor coupled to the memory;
With
The at least one processor is configured to receive assistance information indicating mobility characteristics of a wireless terminal from a base station and perform control related to paging of the wireless terminal using the assistance information.
Control entity.
The mobility characteristics include at least one of presence / absence of mobility, mobility size, movement range restriction, movement randomness, movement frequency, handover frequency, movement speed, and stay cell history.
The control entity according to claim 1.
The at least one processor is configured to receive the assistance information in response to the acquisition of the assistance information by the base station being stopped.
The control entity according to claim 1 or 2.
The at least one processor is configured to receive the assistance information in response to the wireless terminal transitioning from a CONNECTED state to an IDLE state;
The control entity according to claim 1 or 2.
The paging control includes (a) determining a paging area of the wireless terminal, (b) determining a list of cells or base stations for paging of the wireless terminal, and (c) the paging area or Selecting at least one of the algorithms used to determine the list;
The control entity according to any one of claims 1 to 4.
The assistance information includes (a) measurement information regarding the wireless terminal acquired by one or more base stations, (b) history information regarding the wireless terminal acquired by the one or more base stations, (c) Including at least one of configuration information regarding the wireless terminal determined in one or more base stations, (d) a list of recommended cells, and (e) a list of recommended base stations.
The control entity according to any one of claims 1 to 5.
The assistance information is acquired by the one or more base stations when the wireless terminal is in a CONNECTED state.
The control entity according to claim 6.
A base station device arranged in a radio access network,
Memory,
At least one processor coupled to the memory;
With
The at least one processor is configured to transmit assistance information indicating mobility characteristics of the wireless terminal to the core network;
The assistance information is used in the core network for control related to paging of the wireless terminal.
Base station device.
A method performed by a control entity located in a core network,
Receiving assistance information indicating mobility characteristics of a wireless terminal from a base station, and performing control related to paging of the wireless terminal using the assistance information;
A method comprising:
A method performed by a base station device arranged in a radio access network,
Transmitting assistance information indicating mobility characteristics of the wireless terminal to the core network,
The assistance information is used in the core network for control related to paging of the wireless terminal.
Method.