Patent Application
20180084525
The present invention relates to a core network node, a base station, a mobile station, a server, a communication system, a paging method, and a program.
Ever since the advent of smartphones, vast amounts of data have been flowing through networks of mobile telecommunications carriers, and the amounts of data are increasing steadily. This increase is based on several reasons. For example, more and more people connect to the Internet to download or upload videos. In addition, more and more people communicate messages by using pictures and characters through applications installed on their smartphones, instead of by using voice call functions of their smartphones. In addition, for health maintenance and management, more and more people acquire information about their heart rates, blood pressures, step numbers, calorie amounts consumed, sleeping hours, or the like from their wearable terminals, upload the data, and download data to receive services matching their purposes. There are also applications that constantly receive and transmit data, regardless of the intentions of the owners.
In addition, there is an effort called “Internet of Things” (IoT) is underway, which will be a new cause that further increases the amounts of data flowing through the networks. The purpose of IoT is to create values that have never existed before by embedding a communication function(s) into every apparatus and controlling these apparatuses. The introduction of IPv6 significantly has increased the number of IP addresses that can be allocated to apparatuses. In addition, apparatuses called Machine Type Communication (hereinafter, “MTC”) terminals that exchange information with each other, not humans exchanging information with each other, have been made installable everywhere. Thus, the realization of IoT will certainly be accelerated.
IoT assumes that MTC terminals transmit acquired data to other apparatuses such as servers through wireless connection, not wired connection. In this way, the MTC terminals can be installed more easily. In addition, as the radio communication network, not only a wireless LAN but also a cell-phone network can of course be used. There are cases in which an MTC terminal receives control information from a network. In such cases, first, a Mobility Management Entity (hereinafter, “MME”) transmits a paging message to the MTC terminal. In Long Term Evolution (hereinafter, “LTE”), the location of a terminal is managed per TAI List (a Tracking Area Identity List), and the MME transmits a paging message to all the Evolved NodeBs (base stations; hereinafter, “eNBs”) having cells to which TAIs included in a TAI List are allocated. Thus, when the MME transmits a paging message to an MTC terminal, the MME transmits the paging message to all the eNBs having cells to which the same TAI as that of the cell in which the MTC terminal exists is allocated. If individual MTC terminals regularly transmit data and the MME transmits paging messages to transmit message such as for acknowledgement of the reception of the data to the individual MTC terminals, there is a concern that the network could be congested by the processing of the paging messages.
NPLs (Non-Patent Literatures) 1 and 2 relate to processing of the above paging message. NPLs 3-6 are 3GPP specifications that could relate to the present invention.
NPL 1: 3GPP SA WG2 TD, “Paging Optimization for the low mobility devices”, S2-141884 3GPP TSG-SA-WG2 Meeting #103, May 19-23, 2014, [online], [searched on Mar. 23, 2015], Internet<URL:http://www.3gpp.org/FTP/TSG_SA/WG2_Arch/TSGS2_1 03_Phoenix/Docs/S2-141884.zip>
NPL 2: 3GPP SA WG2 TD, “Paging Load Reduction”, S2-144273 3GPP TSG-SA-WG2 Meeting #106, Nov. 17-21, 2014, [online], [searched on Mar. 23, 2015], Internet<URL:http://www.3gpp.org/ftp/tsg_sa/WG2_Arch/TSGS2_106_San _Francisco/Docs/S2-144273.zip>
NPL 3: Evolved Universal Terrestrial Radio Access Network (E-UTRAN); S1 Application Protocol (S1AP) [3GPP TS36.413 v12.4.0], [online], [searched on Mar. 23, 2015], Internet<URL:http://www.3gpp.org/ftp/Specs/archive/36_series/36.413 /36413-c40.zip>
NPL 4: General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access [3GPP TS23.401 v13.1.0], [online], [searched on Mar. 23, 2015],Internet<URL:http://www.3gpp.org/ftp/Specs/archive/23_series/23.401 /23401-d10.zip>
NPL 5: Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 [3GPP TS36.300 v12.4.0], [online], [searched on Mar. 23, 2015], Internet<URL:http://www.3gpp.org/ftp/Specs/archive/36_series/36.300 /36300-c40.zip>
NPL 6: Telecommunication management; Subscriber and equipment trace; Trace control and configuration management [3GPP TS32.422 v12.4.0], [online], [searched on Mar. 23, 2015], Internet<URL:http://www.3gpp.org/ftp/Specs/archive/32_series/32.422 /32422-c40.zip>
NPL 7: Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification [3GPP TS36.331 v12.5.0], [online], [searched on Apr. 1, 2015], Internet <URL:http://www.3gpp.org/ftp/Specs/archive/36_series/36.331 /36331-c50.zip>
As the number of terminals increases, both the number of control signals in networks and the load on processing the control signals increase. Therefore, reduction in these increases is demanded.
It is an object of the present invention to provide a core network node, a base station, a mobile station, a server, a communication system, a paging method, and a program that can contribute to the reduction in the increase of the number of control signals in networks and the load on processing the control signals.
According to a first aspect, there is provided a core network node including a paging candidate storage unit that holds a candidate(s) of a base station(s) as a paging message transmission destination(s). This core network node further includes a base station information storage unit that holds information about a communication function(s) of the candidate(s) of the base station(s). In addition, the core network node includes a paging destination selection unit that selects, when a certain mobile station is paged, a paging range from the candidate(s) of the base station(s), based on the communication function(s) of the candidate(s) of the base station(s). The core network node also includes a paging instruction unit that instructs a base station(s) corresponding to the selected range to perform paging.
According to a second aspect, there is provided a base station, a mobile station, or a server that transmits the information about the communication function(s) of the candidate(s) of the base station(s) to the above core network node.
According to a third aspect, there is provided a communication system including the above core network node.
According to a fourth aspect, there is provided a paging method, including: causing a core network node, which includes a paging candidate storage unit that holds a candidate(s) of a base station(s) as a paging message transmission destination(s) and a base station information storage unit that holds information about a communication function(s) of the candidate(s) of the base station(s), to select, when a certain mobile station is paged, a paging range from the candidate(s) of the base station(s), based on the communication function(s) of the candidate(s) of the base station(s); and a step of causing the core network node to instruct a base station(s) corresponding to the selected range to perform paging. This method is tied to a particular machine called a core network node that instructs a base station(s) to perform paging.
According to a fifth aspect, there is provided a computer program for realizing the functions of the above core network node. This program can be recorded in a computer-readable (non-transient) storage medium. Namely, the present invention can be embodied as a computer program product.
Each element of the above core network node, base station, mobile station, server, communication system, paging method, and program contributes to solving the above problems.
The meritorious effects of the present invention are summarized as follows.
The present invention can contribute to the reduction in the increase of the number of control signals in networks and the load on processing the control signals. In addition, the present invention can convert a core network node described in Background into a core network node having superiority in the reduction in the increase of the number of control signals in networks and the load on processing the control signals.
First, an outline of an example embodiment of the present invention will be described with reference to a drawing. In the following outline, various components are denoted by reference characters for the sake of convenience. Namely, the following reference characters are merely used as examples to facilitate understanding of the present invention, not to limit the present invention to the illustrated modes.
As illustrated in
The paging candidate storage unit 101A holds a candidate(s) of a base station(s) 200A as a paging message transmission destination(s). As the candidate(s) of the base station(s), a list of base stations having cells to which TAIs included in a TAI List of a terminal are allocated can be used.
The base station information storage unit 102A holds information a communication function(s) of the candidate(s) of the base station(s). Any communication function(s) may be used, as long as use of the communication function(s) can narrow down the base stations or exclude the base stations other than the paging base stations when a certain mobile station is paged. For example, the base station information storage unit 102A holds information that can determine a frequency(ies) supported by an individual base station. Of course, the base station information storage unit 102A may hold other information. For example, the base station information storage unit 102A may hold information indicating whether an individual base station has a function(s) corresponding to a communication function(s) of the target mobile station.
The paging destination selection unit 103A selects, when a certain mobile station is paged, a paging range from the candidate(s) of the base station(s) 200A, based on the communication function(s) of the candidate(s) of the base station(s). For example, when it is clear that the mobile station that needs to be paged supports only a certain frequency, the paging destination selection unit 103A selects a base station(s) or a cell(s) that supports the certain frequency as the paging destination.
The paging instruction unit 104A instructs a base station(s) that corresponds to the selected range to perform paging. For example, when it is clear that the paging-target mobile station supports only a certain frequency, the paging destination selection unit 103A selects, from a base station(s) as a paging message transmission destination(s), a base station(s) that supports the certain frequency as the paging destination(s). In this operation, the base stations or cells that do not support the certain frequency are excluded from the paging request destinations. In this way, the communication load on the core network node 100A and the base stations 200A can be reduced. In this case, if the rate of the paging performed on mobile terminals not supporting the certain frequency with respect to the number of occurrences of paging performed on all terminals is increased, the advantageous effect is improved further.
Next, a first example embodiment of the present invention will be described in detail with reference to drawings.
The MME 100 includes a transceiving unit 101, a processing unit 102, and a storage unit 103. The MME 100 is a node that performs various kinds of management such as management of the location of the UE 300, calling, and handover between base stations (an example of the above core network node). The MME 100 can communicate with the eNBs 210 to 230 by using S1AP (S1 Application Protocol). Regarding the MME 100, the transceiving unit 101 transmits and receives information, the processing unit 102 generates and analyzes information received and transmitted, and the storage unit 103 holds information received and transmitted. The storage unit 103 corresponds to the above paging candidate storage unit 101A and base station information storage unit 102A. The transceiving unit 101 and the processing unit 102 function as the paging destination selection unit 103A and the paging instruction unit 104A.
Each of the eNBs 200 to 220 (corresponding to the above base station) includes a transceiving unit 201 (211,221), a processing unit 202 (212,222), and a storage unit 203 (213,223). The eNBs 200 to 220 exchange messages with the MME 100 by using S1AP. The eNBs 200 to 220 exchange messages with each other by using X2AP (X2 Application Protocol).
In addition, each of the eNBs 200 to 220 can communicate with the UE 300 via a Uu interface. Regarding the eNBs 200 to 220, the transceiving unit 201 transmits and receives information, the processing unit 202 generates and analyzes information transmitted and received, and the storage unit 203 holds information transmitted and received.
The UE 300 includes a transceiving unit 301, a processing unit 302, and a storage unit 303. The UE 300 wirelessly communicates with an eNB (for example, the eNB 200) as described above. Regarding the UE 300, the transceiving unit 301 transmits and receives information, the processing unit 302 generates and analyzes information transmitted and received, and the storage unit 303 holds information transmitted and received.
Next, an operation according to the present example embodiment will be described in detail with reference to drawings.
First, an operation flow in which the MME 100 acquires base station information in a state in which S1 connection has not been established between the eNB 200 and the MME 100 will be described with reference to
In contrast, an operation flow performed when S1 connection has already been established between the eNB 200 and the MME 100 will be described (see S120 in a dashed line in
Next, the MME 100 refers to the ENB Supporting Frequency Lists in the above received S1AP messages and stores information indicating that the eNBs 200 and 210 can use the frequency F0 and the eNB 220 can use the frequency F1 in a table 103-1 of the storage unit 103 (S131). As described above, in this example, the information indicating that the eNBs 200 and 210 correspond to the frequency F0 and the eNB 220 corresponds to the frequency F1 is stored in the storage unit 103 of the MME 100 (see
Next, the above information element eNB Identity and ENB Supporting Frequency List will be described with reference to
An operation flow performed when paging occurs according to the present example embodiment will be described with reference to
Next, the MME 100 receives an incoming request directed to the UE 300 from an MTC-InterWorking Function (MTC-IWF) not illustrated in
When receiving the incoming request, the MME 100 refers to UE location registration information and determines eNBs having cells to which TAIs included in a TAI List of the UE 300 are allocated. In addition, the MME 100 refers to the table 103-1 and determines whether any of the determined eNBs can use the frequency F0 supported by the UE 300. In this example, the MME 100 determines that the eNBs 200 and 210 are the matching eNBs and determines to transmit a paging message to the eNBs 200 and 210 (S135).
Next, the MME 100 transmits a paging message to the eNBs 200 and 210 (S136). Details of the S1AP: PAGING message are described in NPL 3.
Next, the eNBs 200 and 210 transmit an RRC Paging message to the cells operated at currently used frequencies among the usable frequencies. In the present example embodiment, the eNB 200 transmits a paging message to the cells 200-1, 200-2, and 200-3, and the eNB 210 transmits a paging message to the cells 210-1, 210-2, and 210-3 (S137).
As described above, the MME 100 according to the first example embodiment determines eNBs having cells to which TAIs included in a TAI List of the paging message transmission destination UE are allocated. Next, the MME 100 selects eNBs as the paging message transmission destinations based on the frequencies usable by the eNBs (namely, the eNBs that do not match the frequency supported by the UE are excluded from the paging destinations). Thus, compared with the case in which the MME transmits a paging message to all eNBs having cells to which TAIs included in a TAI List of the paging message transmission destination UE are allocated, the number of paging messages can significantly be reduced. Consequently, paging messages transmitted to MTC terminals that are integrated with sensors and that can be installed anywhere do not increase the processing load on the MME, the communication load on the individual S1 interface, the processing load on the individual eNB, and the communication load on the individual Uu interface. Namely, convenience of normal users is not deteriorated.
Next, a second example embodiment will be described in detail with reference to drawings. The second example embodiment is achieved by adding a paging destination selection function per cell to the first example embodiment of the present invention. Since an overall configuration is the same as that according to the first example embodiment, the following description will be made with a focus on the difference between the first and second example embodiments.
Next, an operation according to the present example embodiment will be described in detail with reference to drawings.
S410 and S420 in
Next, the MME 100 refers to the ENB Supporting Frequency List in the above received S1AP messages and stores information indicating that, among the cells created by the eNB 200, the cell 200-1 uses the frequency F0 and the cells 200-2 and 200-3 use the frequency F1 in a table 103-2 of a storage unit 103. Likewise, the MME 100 stores information indicating that, among the cells created by the eNB 210, the cell 210-1 uses the frequency F0 and the cells 210-2 and 210-3 use the frequency F1 in the table 103-2 of the storage unit 103. Likewise, the MME 100 stores information indicating that, among the cells created by the eNB 220, the cell 220-1 uses the frequency F0 and the cells 220-2 and 220-3 use the frequency F1 in the table 103-2 of the storage unit 103 (S431).
Next, the subsequent processing will be described with reference to
Next, the MME 100 transmits a paging message to the eNBs 200, 210, 220 (S436). Details of the S1AP: PAGING message are described in NPL 3.
Next, the eNBs 200 to 220 receive the UE Supporting Frequency Lists in the S1AP: PAGING messages and determine the cells 200-1, 210-1, 220-1 to be the cells to which a paging message needs to be transmitted, respectively (S437). Next, the eNBs 200 to 220 transmit an RRC: Paging message to the cells 200-1, 210-1, and 220-1, respectively (S438).
As described above, according to the present example embodiment, the paging range can be determined per cell, not per eNB. In this way, the present example embodiment can reduce the processing load on the individual eNB and the communication load on the individual Uu interface even more than the first example embodiment. The following specific example will be described based on a case in which the technique according to the first example embodiment is applied to the configuration according to the second example embodiment. In this case, the eNBs 200 to 220 can use the frequencies F0 and F1 and are using the frequencies F0 and F1. Thus, a paging message is also transmitted to the cells 200-2, 200-3, 210-2, 210-3, 220-2, and 220-3, which are operated at the frequency supported by MTC terminals other than the UE 300. The second example embodiment is advantageous in that such unnecessary transmission of the paging message can be reduced even more.
Next, a third example embodiment will be described in detail with reference to drawings. In the third example embodiment, instead of the frequencies, information that can determine the frequencies is stored as the base station information, and a paging destination(s) is selected based on the corresponding value(s). Since an overall configuration is the same as that according to the first example embodiment, the following description will be made with a focus on the difference between the first and third example embodiments. The present example embodiment assumes that a frequency F0 belongs to E-UTRA Operating Band 1 in Table 5.5-1 in 3GPP TS36.101 v12.6.0 and that a frequency F1 belongs to E-UTRA Operating Band 5.
Next, an operation according to the present example embodiment will be described in detail with reference to drawings.
S510 and S520 in
Next, the MME 100 refers to the ENB Supporting E-UTRA Operating Band Indicator Lists in the above received S1AP messages and stores information indicating that the eNBs 200 and 210 can use E-UTRA Operating Band 1 and the eNB 220 can use E-UTRA Operating Band 5 in a table 103-3 of a storage unit 103 (S531).
Next, the subsequent processing will be described with reference to
The processing in S535 in
Next, the MME 100 transmits a paging message to the eNBs 200 and 210 (S536). Details of the S1AP: PAGING message are described in NPL 3.
Next, each of the eNBs 200 and 210 refers to the UE Supporting E-UTRA Operating Band Indicator List in its received S1AP: PAGING message and transmits an RRC Paging message to the cells created at the frequency included in E-UTRA Operating Band 1 among the currently used frequencies. According to the present example embodiment, the eNB 200 transmits a paging message to the cells 200-1, 200-2, and 200-3, and the eNB 210 transmits a paging message to the cells 210-1, 210-2, and 210-3 (S537).
As described above, the present example embodiment can achieve an advantageous effect equivalent to that achieved according the first example embodiment while using, instead of the frequencies, the information elements called the E-UTRA Operating Band Indicators. The above second and third example embodiments may be combined with each other. In this way, paging can be instructed per cell by using the E-UTRA Operating Band Indicators.
Next, a fourth example embodiment will be described in detail with reference to drawings. In the fourth example embodiment, instead of the frequencies, information indicating a communication methods or the like of individual base stations are stored as the base station information, and a paging destination(s) is selected based on this information. Since an overall configuration is the same as that according to the first example embodiment, the following description will be made with a focus on the difference between the first and fourth example embodiments. The present example embodiment assumes that, regarding base stations 200 and 210, the Duplex mode is Half-Duplex Frequency Division Duplex (HD-FDD), the frequency bandwidth is 1.4 MHz, and the MIMO antenna configuration is 1×1. The present example embodiment also assumes that, regarding an eNB 220, the Duplex mode is FDD, the frequency bandwidth is 20 MHz, and the MIMO antenna configuration is 2×2. Also, the present example embodiment assumes that a UE 300 cannot connect to the eNB 220. In addition, as in the first and third example embodiments, the UE 300 can connect to the base stations 200 and 210. In addition, “MIMO” is the abbreviation of Multiple-Input and Multiple-Output. The above information elements indicating the communication methods, etc. of the base stations are only examples. The UE 300, which is an MTC terminal, may use another Duplex mode, frequency bandwidth, and MIMO configuration.
Next, an operation according to the present example embodiment will be described in detail with reference to drawings.
S610 and S620 in
Next, the MME 100 refers to the ENB Supporting Configuration Lists of the received S1AP messages and stores information indicating that the eNBs 200 and 210 support the Duplex mode HD-FDD, the frequency bandwidth 1.4 MHz, and the MIMO antenna configuration 1×1 and that the eNB 220 supports the Duplex mode FDD, the frequency bandwidth 20 MHz, and the MIMO antenna configuration 2×2 in a table 103-4 of a storage unit 103 (S631).
Next, the subsequent processing will be described with reference to
Next, the MME 100 transmits a paging message to the eNBs 200 and 210 (S636). Details of the S1AP: PAGING message are described in NPL 3.
Next, each of the eNBs 200 and 210 refers to the UE Supporting Configuration List of its received S1AP: PAGING message and transmits an RRC Paging message to the cells corresponding to the Duplex mode HD-FDD, the frequency bandwidth 1.4 MHz, and the MIMO antenna configuration 1×1. According to the present example embodiment, the eNB 200 transmits a paging message to cells 200-1, 200-2, and 200-3, and the eNB 210 transmits a paging message to cells 210-1, 210-2, and 210-3 (S637).
As described above, the present example embodiment can achieve an advantageous effect equivalent to that achieved according the first example embodiment while using, instead of the frequencies, the information elements indicating the communication methods, etc. of the base stations such as the Duplex modes, the frequency bandwidths, and the MIMO configurations. The above second and fourth example embodiments may be combined with each other. In this way, paging can be instructed per cell by using the Duplex modes, the frequency bandwidths, and the MIMO configurations.
Next, a fifth example embodiment will be described in detail with reference to drawings. According to the fifth example embodiment, instead of the frequencies, the operation modes, which are variations of the base station communication function, are stored as the base station information, and a paging destination(s) is selected based on these values. Since an overall configuration is the same as that according to the first example embodiment, the following description will be made with a focus on the difference between the first and fifth example embodiments. According to the present example embodiment, base stations 200 and 210 has an operation mode in which the base stations 200 and 210 communicate with only MTC terminals, and an eNB 220 has an operation mode in which the eNB 220 communicates with normal terminals other than MTC terminals. While not illustrated, there may be a base station having an operation mode in which the base station communicates with MTC terminals and normal terminals. For example, a base station having an operation mode in which the base station communicates with only MTC terminals and a base station having an operation mode in which the base station communicates with MTC terminals and normal terminals may be reported by including an information element called category 0 Allowed defined in NPL 7 in SystemInformationBlockType1. In addition, as in the first and third example embodiments, the present example embodiment assumes that a UE 300 can connect to the base stations 200 and 210.
Next, an operation according to the present example embodiment will be described in detail with reference to drawings.
S710 and S720 in
Next, the MME 100 refers to the ENB Supporting Capability Lists of the received S1AP messages and stores information indicating that the eNBs 200 and 210 have an operation mode in which the eNBs 200 and 210 operate as base stations for only MTC terminals and that the eNB 220 has an operation mode in which the eNB 220 operates as a normal base station for not only MTC terminals but also normal terminals in a table 103-5 of a storage unit 103 (S731).
Next, the subsequent processing will be described with reference to
Next, the MME 100 transmits a paging message to the eNBs 200 and 210 (S736). Details of the S1AP: PAGING message are described in NPL 3.
As described above, the present example embodiment can achieve an advantageous effect equivalent to that achieved according to the first example embodiment while using, instead of the frequencies, the information elements indicating the operation modes, which are variations of the base station communication function. The above second and fifth example embodiments may be combined with each other. In this way, paging can be instructed per cell by using the operation modes.
Next, a sixth example embodiment will be described in detail with reference to drawings. In the sixth example embodiment, frequency information per cell is collected from a Non Access Stratum (NAS) message from a UE, instead of eNBs. Since an overall configuration is the same as that according to the second example embodiment, the following description will be made with a focus on the difference between the second and sixth example embodiments. The present example embodiment also assumes that, among the cells created by an eNB 200, a cell 200-1 is operated at a frequency F0, and cells 200-2 and 200-3 are operated at a frequency F1. Likewise, among the cells created by an eNB 210, a cell 210-1 is operated at the frequency F0, and cells 210-2 and 210-3 are operated at the frequency F1. Likewise, among the cells created by an eNB 220, a cell 220-1 is operated at the frequency F0, and cells 220-2 and 220-3 are operated at the frequency F1.
Next, an operation according to the present example embodiment will be described in detail with reference to drawings.
As illustrated in
Next, the UE 300 sets an information element corresponding to the ENB Supporting Frequency List illustrated in
The MME 100 refers to the ENB Supporting Frequency Lists in the above received NAS messages and stores information indicating that, among the cells created by the eNB 200, the cell 200-1 uses the frequency F0 and the cells 200-2 and 200-3 use the frequency F1 in a table 103-2 of a storage unit 103. Likewise, the MME 100 stores information indicating that, among the cells created by the eNB 210, the cell 210-1 uses the frequency F0 and the cells 210-2 and 210-3 use the frequency F1 in the table 103-2 of the storage unit 103. Likewise, the MME 100 stores information indicating that, among the cells created by the eNB 220, the cell 220-1 uses the frequency F0 and the cells 220-2 and 220-3 use the frequency F1 in the table 103-2 of the storage unit 103 (S813).
Next, the subsequent processing will be described with reference to
Next, the MME 100 transmits a paging message to the eNB 200, 210, and 220 (S818). Details of the S1AP: PAGING message are described in NPL 3. The MME 100 transmits the same paging message as that illustrated in
Next, the eNBs 200 to 220 refer to the UE Supporting Frequency Lists in the received S1AP: PAGING messages and determine that the cells 200-1, 210-1, and 220-1 are the cells to which the paging message needs to be transmitted (S819). In addition, the eNBs 200, 210, and 220 transmit an RRC: Paging message to the cells 200-1, 210-1, and 220-1, respectively (S820).
As described above, in the present example embodiment, no S1AP message is used to collect base station information. However, the present example embodiment can achieve an equivalent advantageous effect to that achieved according to the second example embodiment.
Next, a seventh example embodiment will be described in detail with reference to drawings. In the seventh example embodiment, UE information including frequencies of eNBs is collected by using an external server.
The external server 900 includes a transceiving unit 901, a processing unit 902, and a storage unit 903. For example, the external server 900 receives measurement results of frequencies of base stations from the UE 300 and manages the measurement results. In addition, when receiving a request from the MME 100, the external server 900 answers base stations that need to perform the paging, based on the measurement results of the frequencies of the base stations, for example.
Next, an operation according to the present example embodiment will be described in detail with reference to drawings.
As illustrated in
Next, the external server 900 stores the received measurement results in the storage unit 903 (S1003). For example, the external server 900 stores information indicating that the eNBs 200 and 210 can use a frequency F0 and the eNB 220 can use a frequency F1 in a table equivalent to the table 103-1 in
Next, the subsequent processing will be described with reference to
When receiving a response from the external server 900, the MME 100 refers to UE location registration information and determines eNBs having cells to which TAIs included in a TAI List of the UE 300 are allocated. In addition, based on the information received from the external server 900, the MME 100 determines whether any of the determined eNBs is an eNB estimated by the external server 900. Herein, the MME 100 determines that the eNBs 200 and 210 are the matching eNBs and determines to transmit a paging message to the eNBs 200 and 210 (S1008).
Next, the MME 100 transmits a paging message to the eNBs 200 and 210 (S1009). Next, the eNBs 200 and 210 transmit an RRC Paging message to the cells operated at the currently used frequency among the frequencies that can be used. In the present example embodiment, the eNB 200 transmits a paging message to the cells 200-1, 200-2, and 200-3, and the eNB 210 transmits a paging message to the cells 210-1, 210-2, and 210-3 (S1010).
As described above, the present invention is applicable to the mode in which the external server 900 is used. In particular, the present example embodiment provides an advantageous effect that base stations or cells that need to perform paging can further be narrowed down by using information in the external server 900 (for example, UE location information). In the example in
While example embodiments of the present invention have thus been described, the present invention is not limited thereto. Further variations, substitutions, or adjustments can be made without departing from the basic technical concept of the present invention. For example, the configurations of the systems, the configurations of the elements, and the representation modes of the messages illustrated in the drawings have been used only as examples to facilitate understanding of the present invention. Namely, the present invention is not limited to the configurations illustrated in the drawings.
An individual unit (processing means) of the individual core network node (MME), base station (eNB), and terminal (UE) illustrated in
In addition, while the above first example embodiment has been described assuming that the MME 100 acquires frequencies usable by eNBs from the eNBs, these items of information may be set previously as station data in the MME 100.
In addition, in the above second example embodiment, the MME 100 notifies an individual eNB of a frequency that constitutes the cells to which a paging message needs to be transmitted. However, the frequency may be set as station data in the eNB. For example, the eNB 200 may hold the frequency F0 as the frequency supported by an MTC terminal and determine that a paging message is directed to the MTC terminal based on information such S-TMSI in UE Paging Identity, Paging DRX, or UE Radio Capability for Paging included in an S1AP: paging message received from the MME 100. Next, the eNB 200 may transmit a paging message only to a cell(s) at the frequency supported by the MTC terminal.
In addition, while the present example embodiment has mainly been described assuming that the present invention is applied to LTE, the present invention is applicable to radio communication systems other than LTE. For example, the present invention is applicable to other radio communication systems such as WCDMA (Wideband Code Division Multiple Access) (registered trademark), GSM (global system for mobile communications) (registered trademark), CDMA2000, and WiMAX (Worldwide Interoperability for Microwave Access).
In addition, while an individual one of the above example embodiments has been described by using a configuration including an MME, eNBs, and a UE, the present invention is applicable to other networks having different configurations. For example, the present invention is applicable to a network including small cell gateways, a network including relay nodes and donor eNBs, and a network in which connection means called dual connectivity is realized.
In addition, in the above second example embodiment, the MME collectively sets ECGIs, which are identifiers of cells that an eNB needs to page, and a frequency in a list format in a UE Supporting Frequency List in a paging message. However, the MME may set only the ECGIs of the paging targets in a list format, as illustrated in
In addition, the above fourth example embodiment has been described by using an example in which a single eNB performs an LTE service, the present invention is applicable to a case in which a single eNB simultaneously provides service areas constituted by a plurality of radio communication techniques such as 3G and WLAN. In this case, the MME 100 is notified of information about the radio communication systems simultaneously provided by the eNB, and the MME 100 can use the information when determining paging message transmission destination(s).
Analysis on the existing proposals (NPLs 1 and 2) described in Background and advantageous effects of the present invention will hereinafter be described. NPL 1 proposes optimization of paging for low-mobility terminals. More specifically, NPL 1 proposes narrowing down the eNBs to which a paging message needs to be transmitted by determining that an MTC terminal rarely moves from its travel history. However, an MTC terminal could be a part of a moving machine such as an automobile. An individual terminal that operates in an LTE radio communication system including MTC terminals has two states, i.e., a connected mode and an idle mode. When a terminal is in the idle mode, the core network can determine the location of the terminal only per TAI List. Thus, even if the eNBs to which a paging message needs to be transmit have been narrowed down from the travel history of the terminal in the connected mode and even if a paging message is transmitted to the eNBs, the transmission fails. It is eventually necessary to transmit a paging message to all the eNBs having cells to which TAIs included in a TAI List are allocated. According to the present invention, irrespective of the state of the above terminal, the number of paging messages flowing through networks and the load of the MME and the eNBs on processing the paging messages can be reduced.
NPL 2 proposes a load reduction technique relating to paging. More specifically, NPL 2 proposes a technique for reducing MME communication load and S1 interface communication load and a technique for reducing eNB processing load and radio section (Uu interface) communication load between an individual eNB and MTC terminal. With the former technique, a paging message is transmitted to an eNB used by an MTC terminal most recently, and the eNB forwards the paging message to an appropriate eNB via an interface connecting the eNBs called an X2 interface. The eNB that has received the paging message transmits the paging message to the MTC terminal (the eNB processing load and the Uu interface connection load are reduced consequently, since the number of eNBs that transmit the paging message to the MTC terminal is reduced). With the latter technique, when an eNB receives a parameter called an UE Radio Capability from an MTC terminal, the eNB extracts information about the frequency that can be used by the UE from the parameter, generates a new information element, and transmits the new information element to the MME. The MME sets this information element in a paging message and transmits the paging message to all the eNBs having cells to which TAIs included in a TAI List are allocated, and the eNBs transmit a paging message to cells operated at the corresponding frequency. As with NPL 1, it is clear that there are cases in which the former technique does not operate well. While the latter technique can reduce the eNB processing load and the Uu interface communication load, since a paging message is transmitted to all the eNBs having cells to which TAIs included in a TAI List are allocated, the MME processing load and the S1 interface communication load are not reduced. Considering that a macro base station has a service area with a several-kilometer radius, many MTC terminals can exist in the service area. Thus, since paging processing for an MTC terminal can increase the MME processing load and the Si interface communication load, there is a high possibility that incoming signals of Voice over LTE (VoLTE) transmitted to normal terminals could be affected, for example. The present invention can more effectively reduce the number of paging messages flowing through networks and the load of the MME and eNB on processing the paging messages than the techniques in the above NPL 2.
Finally, suitable modes of the present invention will be summarized.
(See the core network node according to the above first aspect)
The core network node according to mode 1, wherein the information about the communication function(s) is information that can determine a frequency(ies) used by the candidate(s) of the base station(s), and the paging destination selection unit selects a base station(s) or a cell(s) that can perform paging at a frequency supported by the certain mobile station.
The core network node according to mode 2, including a base station information acquisition unit which acquires the information that can determine the frequency(ies) used by the candidate(s) of the base station(s) from an information element(s) included in a message(s) exchanged with the base station(s) and stores the acquired information in the base station information storage unit.
The core network node according to mode 1, including a base station information acquisition unit which acquires, from an information element(s) included in a message(s) exchanged with the base station(s), information that can determine a frequency(ies) used by a cell(s) of the candidate(s) of the base station(s) and stores the acquired information in the base station information storage unit.
The core network node according to mode 1;
wherein the information about the communication function(s) includes information about a duplex mode(s), a frequency bandwidth(s), and a MIMO configuration(s) of the candidate(s) of the base station(s); and
wherein the paging destination selection unit selects a base station(s) or a cell(s) that can perform paging with a communication method supported by the certain mobile station.
The core network node according to mode 1;
wherein the information about the communication function(s) is information indicating an operation mode(s) of the candidate(s) of the base station(s); and
wherein the paging destination selection unit selects a base station(s) or a cell(s) operating in an operation mode supported by the certain mobile station.
The core network node according to any one of modes 1 to 6, the core network node acquires the information about the communication function(s) of the candidate(s) of the base station(s) from an information element(s) included in a message(s) exchanged with the mobile station, instead of from the information element(s) included in the message(s) exchanged with the base station(s).
The core network node according to any one of modes 1 to 6, the core network node acquires information for selecting the paging range via an external server that receives the information about the communication function(s) of the candidate(s) of the base station(s) from the mobile station, instead of from the information element(s) included in the message(s) exchanged with the base station(s).
(See the according to the base station, the mobile station, or the server according to the above second aspect)
(See the communication system according to the above third aspect)
(See the paging method according to the above fourth aspect)
(See the computer program according to the above fifth aspect)
Modes 9 to 12 can be expanded in the same way as mode 1 is expanded to modes 2 to 8.
The disclosure of the above NPLs is incorporated herein by reference thereto. Variations and adjustments of the example embodiments and examples are possible within the scope of the overall disclosure (including the claims) of the present invention and based on the basic technical concept of the present invention. Various combinations and selections of various disclosed elements (including the elements in the claims, example embodiments, examples, drawings, etc.) are possible within the scope of the disclosure of the present invention. Namely, the present invention of course includes various variations and modifications that could be made by those skilled in the art according to the overall disclosure including the claims and the technical concept. The description discloses numerical value ranges.
However, even if the description does not particularly disclose arbitrary numerical values or small ranges included in the ranges, these values and ranges should be deemed to have been specifically disclosed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-077066 | Apr 2015 | JP | national |
This application is a National Stage of International Application No. PCT/JP2016/060940 filed Apr. 1, 2016, claiming priority based on Japanese patent application No. 2015-077066, filed on Apr. 3, 2015, the disclosures of which are incorporated herein in their entirety by reference thereto.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/060940 | 4/1/2016 | WO | 00 |
