JP5274979B2 - Base station and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base station that prevents connection with a macrocell before hand-off from being disconnected when an unregistered terminal, which is not registered as a user in the own station, tries hand-off to the own station. <P>SOLUTION: A base station (FAP) of a mobile communication system includes: a registration part (122) for registering a number unique to a mobile unit of a mobile unit (AT) using the own station; a request part (124) for making a request for transmission of the number unique to the mobile unit of the mobile unit (AT) if receiving an update assignment request of an identifier, assigned to the mobile unit (AT) by the mobile communication system, of the mobile unit (AT) from the mobile unit (AT); and a control part (120) that controls so as to prepare neighboring base station information on the basis of a unique number of the mobile unit received from the mobile unit (AT) in response to the request by the request part (124) and numbers unique to the mobile unit of the mobile units registered in the registration part (122) and using the own station (FAP) and to transmit the prepared neighboring base station information to the mobile unit (AT). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a base station of a mobile communication system and a control method thereof, and more particularly to a base station connected to a mobile communication network via a general line and a control method thereof.

  In recent years, mobile communication devices, particularly mobile phone terminals, have spread rapidly, and areas with a certain population have been almost covered. However, in a place where the space and location of the interior of a house or building are poor, there is an area where radio waves from normal existing base stations (that is, wide area base stations) do not reach and are out of service area, and radio waves are weak and communication is not stable. Yes. In order to deal with such an out-of-service area, a small base station has been developed that provides a cell (service area) with a small output power and a radius of several meters to several tens of meters. Such an ultra-small cell itself or a small base station that provides the cell is called a femto cell. This femtocell is connected to a mobile communication network via a general line (a broadband line such as ADSL).

  On the other hand, in general households, the constant connection of broadband lines such as optical lines and ADSLs has become widespread, and the environment (ie, backbone) for connecting the femtocell and the mobile communication system is being prepared. Furthermore, there is a merit that a telecommunications carrier does not need to use a band of a normal existing base station that should have been originally consumed by using a femtocell and a broadband line. Therefore, full-scale development of femtocells will be carried out in the near future due to the relaxation of regulations of relevant laws and regulations and changes in operation, and the use of individual users other than telecommunications carriers is expected.

  When such a femtocell is purchased by an individual user and installed at home, a mobile station that has entered the coverage area provided by the femtocell must be wirelessly connected to the femtocell in the same manner as a public base station (macrocell). Is possible. However, if a femtocell purchased / installed by an individual user is freely accessed by another person, when the individual himself / herself wants to use the femtocell, the radio band of the femtocell is consumed by another person, resulting in insufficient throughput. Problems occur. Therefore, it is assumed that a function for performing user registration in the femtocell and rejecting use by other users is added.

  In such an assumption, it is assumed that a mobile station using a macro cell hands off to a femto cell (for handoff, see, for example, Patent Document 1). FIG. 4 shows how a mobile station (wireless communication terminal) performs handoff based on the conventional CDMA2000 1xEV-DO protocol. Hereinafter, a terminal that has not performed user registration with the femtocell is referred to as a “non-registered terminal”, and a terminal that has performed user registration is referred to as a “registered terminal”. In FIG. 4, “terminal (unregistered)” indicates an unregistered terminal, and “terminal (registered / unregistered)” is an operation common to the registered terminal and the unregistered terminal. It shows that. FIG. 5 shows a flowchart when a non-registered terminal hands off from a macro cell to a femto cell based on the conventional CDMA2000 1xEV-DO protocol. Hereinafter, the handoff based on the conventional protocol will be described with reference to FIGS.

  First, as shown in FIG. 4A, the terminal (registered / unregistered) AT1 enters the cover area of the femtocell FAP from the cover area of the base station (macrocell) AN, and the femtocell FAP from the base station (macrocell) AN. To the base station (macrocell) AN (steps T11 and T12 in FIG. 5). Next, the terminal (registration / non-registration) AT1 requests the femtocell FAP to make a UATI (Unicast Access Terminal Identifier) update assignment (step T13). Then, as shown in FIG. 4B, the UATI of the own terminal is updated to the UATI transmitted from the femtocell FAP (steps T31 and T14). Further, the terminal (registered / unregistered) AT1 disconnects the previous Point-to-Point Protocol (PPP) with the base station (macrocell) AN and releases the EV-DO session (Step T15). Thereafter, the femtocell FAP requests the terminal (registered / unregistered) AT1 to transmit an ESN (Electric Serial Number) that is a terminal-specific number (terminal identifier) of the terminal (step T32). That is, the femtocell FAP determines whether or not the terminal requesting handoff is a terminal that is registered as a user with the own station. In response to this request, the terminal (registered / unregistered) AT1 responds by transmitting its own ESN (steps T16 and T33). At this time, an EV-DO session is established between the femtocell FAP and the terminal (registered / unregistered) AT1 (steps T17 and T34). Up to this point, the same processing is performed on the registered terminal and the unregistered terminal.

  After the EV-DO session is established, the terminal AT1 requests the femtocell FAP to start communication in order to establish PPP with the femtocell FAP (step T18). At this time, if it is a registered terminal, communication with the femtocell FAP is started and PPP is established. However, if it is an unregistered terminal, communication to the femtocell FAP is rejected as shown in FIG. 4C (steps T19 and T36).

JP 2008-113158 A

  As described above, an unregistered terminal that has not registered for use with the femtocell FAP is refused to communicate with the femtocell FAP, and therefore stops handoff to the femtocell FAP and attempts to connect to a neighboring macro cell. It will be. That is, as shown in FIG. 4C, the unregistered terminal must perform UATI update, EV-DO session, and PPP establishment again from a search for neighboring macro cells (steps T20 to T25). In this case, it is not always possible to re-establish PPP with the macro cell before handoff. In addition, since the unregistered terminal cannot establish the PPP with the femtocell FAP, it has disconnected the PPP with the base station (macrocell) AN before handoff after the UATI is allocated from the femtocell FAP. Streaming and downloading data that was performed at the time of handoff is interrupted. In this case, the unregistered terminal has to redo data download from the beginning, and lacks usability.

  Accordingly, an object of the present invention is to provide a technique (base station, base station) that prevents a connection with a macro cell before handoff from being disconnected when an unregistered terminal that is not registered for use with the own station attempts a handoff to the own station. Control method).

In order to solve the above-described problems, the base station according to the present invention provides:
A registration unit for registering a mobile station unique number (ESN) of a mobile station that uses the local station;
When the mobile communication system receives from the mobile device an assignment request for the identifier (UATI) of the mobile device assigned to the mobile device, a request unit that requests the mobile device to transmit a number unique to the mobile device;
Neighboring base station based on the mobile station specific number received from the mobile station in response to the request from the request section and the mobile station specific number of the mobile station using the local station registered in the registration section A control unit that creates information (neighbor list) and controls the created neighboring base station information to be transmitted to the mobile device ;
In the control unit, the mobile unit specific number received from the mobile unit in response to the request from the request unit matches the mobile unit specific number of the mobile unit using the local station registered in the registration unit. If not, the identifier of the mobile device is not updated, the neighboring base station information not including the information of the own station is created, and the created neighboring base station information is controlled to be transmitted to the mobile device .

In addition, the base station according to an embodiment of the present invention,
The controller is
When the mobile station specific number received from the mobile station in response to the request from the request section matches the mobile station specific number of the mobile station that uses the local station registered in the registration section, The base station information including the above information is created, and control is performed so as to transmit the created neighbor base station information to the mobile device.

  As described above, the solution of the present invention has been described as an apparatus. However, the present invention can be realized as a method, a program, and a storage medium storing the program, which are substantially equivalent thereto, and the scope of the present invention. It should be understood that these are also included. Note that each step of the method and program uses an arithmetic processing unit such as a CPU or DSP as necessary in data processing, and the input data, processed / generated data, etc. are stored in HDD, memory, etc. Is stored in the storage device.

For example, a communication method by a base station of a mobile communication system that implements the present invention as a method is:
Registering a mobile station unique number (ESN) of a mobile station using its own station;
When the mobile communication system receives an update assignment request for the identifier (UATI) of the mobile device assigned to the mobile device from the mobile device, the mobile device requests the mobile device to transmit a number unique to the mobile device;
Based on the mobile station specific number received from the mobile station according to the requesting step and the mobile station specific number of the mobile station that uses the local station registered in the registering step create a station information (neighbor list), it viewed including the steps of a neighbor base station information the created control to transmit to the mobile station,
In the controlling step, the unique number of the mobile device received from the mobile device in response to the request of the requesting step is unique to the mobile device of the mobile device using the local station registered in the registering step. If the number does not match, the identifier of the mobile device is not updated, the neighboring base station information not including the information of the own station is created, and the created neighboring base station information is controlled to be transmitted to the mobile device It is characterized by .

  According to the present invention, when a non-registered terminal that is not registered for use in the local station attempts a handoff to the local station, a technique for preventing disconnection from the macro cell before the handoff (control of the base station and the base station). Method).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, CDMA2000 1xEV-DO is assumed as the mobile communication system.

  FIG. 1 is a block diagram of a femtocell (base station) according to an embodiment of the present invention. As shown in the figure, the femtocell FAP is connected to the Internet INET through an ADSL (Asymmetric Digital Subscriber Line) or a broadband line (general line) such as an optical fiber installed in a general household. The Internet INET is connected to the mobile communication network CNET via the femto gateway FGW. The mobile communication network CNET is a mobile communication network including a PDSN (Packet Data Serving Node, packet data service node), a PCF (Packet Control Function, packet controller), etc. (not shown).

  As shown in the figure, the femtocell FAP includes a radio unit 110, a femtocell control unit 120, a storage unit 130, a LAN connection unit 140, and an antenna ANT. The radio unit 110 communicates with the mobile device via the antenna ANT. The storage unit 130 stores various setting information and information on neighboring base stations (macro cell, femto cell) located in the vicinity of the own station (details will be described later). The LAN connection unit 140 is connected to the Internet INET via a blow band line. The femtocell control unit 120 controls the entire apparatus, and includes a registration unit 122, a request unit 124, a creation unit 126, and a determination unit 128. The registration unit 122 registers a mobile device specific number (identification information such as ESN, mobile phone number, terminal ID, etc.) of the mobile device that uses the femtocell FAP through a wireless or broadband line, and stores it in the storage unit 130. The femtocell control unit 120 performs control such that communication is permitted only to a mobile device having a mobile device specific number registered in the registration unit 122. Upon receiving from the mobile device an update assignment request for the mobile device identifier (UATI) assigned to the mobile device by the mobile communication system, the request unit 124 requests the mobile device to transmit a number unique to the mobile device. The determination unit 128 determines whether or not the mobile unit specific number transmitted from the mobile unit in response to the request from the request unit 124 is registered by the registration unit 122. The creation unit 126 creates neighboring base station information (neighbor list) under the control of the femtocell control unit 120 that has received the determination result of the determination unit 128. The femtocell control unit 120 transmits the neighbor base station information (neighbor list) created by the creation unit 126 to the mobile device that has requested the update assignment request for the identifier (UATI) of the mobile device. The femtocell control unit 120, when the mobile unit specific number received from the mobile unit matches the mobile unit specific number of the mobile unit that uses the local station registered by the registration unit 122, The creation unit 126 is controlled so as to create the neighboring base station information (neighbor list) including it. On the other hand, when the mobile station specific number received from the mobile station does not match the mobile station specific number of the mobile station that uses the local station registered by the registration unit 122, the femtocell control unit 120 The creation unit 126 is controlled to create neighboring base station information (neighbor list) that does not include station information.

  When a non-registered terminal that has not performed user registration with respect to the femtocell FAP performs a handoff from the base station (macrocell) AN to the femtocell FAP according to a conventional protocol, the unregistered terminal performs a handoff to the femtocell FAP. The communication with the femtocell FAP is rejected only when the communication start request is made to the femtocell FAP. Since the PPP or EV-DO session with the base station (macrocell) AN before the handoff has already been released when the communication is rejected, the data that was being communicated with the base station (macrocell) AN before the handoff Will be disconnected from streaming or downloading. The processing when the femtocell FAP according to the present invention that solves this problem is requested for handoff from the base station (macrocell) AN by the mobile device (unregistered terminal or registered terminal) will be described with reference to FIGS. explain. FIG. 2 is a flowchart when the mobile device (registered terminal and unregistered terminal) AT performs handoff from the base station (macrocell) AN to the femtocell FAP according to an embodiment of the present invention.

  First, a terminal (non-registration / registration) that establishes PPP with a base station (macro cell) and communicates enters the coverage area of the femtocell FAP and captures the femtocell FAP (steps S11 and S31). Thereafter, the terminal (unregistered / registered) requests the base station (macrocell) AN to perform a handoff from the base station (macrocell) AN to the femtocell FAP (steps S12 and S32). Further, the terminal (unregistered / registered) requests the femtocell FAP to update the UATI allocated from the mobile communication system for communication with the base station (macrocell) before handoff (step) S13, S33). On the other hand, the femtocell FAP requests the terminal (unregistered / registered) to transmit an ESN (step S21). The terminal (unregistered / registered) responds with the ESN of its own terminal to the ESN transmission request of the femtocell FAP (steps S14 and S34). The determination unit 128 of the femtocell FAP determines whether or not the ESN received from the terminal (non-registration / registration) matches the ESN registered by the registration unit 122 as an ESN that uses the local station (step S22). ). That is, the femtocell FAP determines whether or not the terminal that has transmitted the UATI update allocation request to the own station is the registered terminal of the own station. In this way, in response to the UATI update allocation request from the terminal, according to the conventional protocol, a response is made by allocating UATI. In the present invention, the terminal requests transmission of ESN prior to UATI allocation, and the terminal It is determined whether it is a registered terminal.

  If it is determined in step S22 that the ESN received from the terminal matches the ESN registered by the registration unit 122 (when the received ESN belongs to the registered terminal), the femtocell FAP creation unit 126 Creates neighboring base station information (neighbor list) including various information such as frequency band, band class, and PN code used by the own station (step S24). Then, the femtocell FAP responds with a UATI in response to the UATI update allocation request from the registered terminal (step S25). The registered terminal that has acquired the UATI updates its own UATI (step S35), and releases the PPP and EV-DO sessions with the base station (macro cell) (step S36). Note that the order of step S24 and step S25 may be reversed.

  In step S22, when it is determined that the ESN received from the terminal does not match the ESN registered in the own station (when the received ESN belongs to a non-registered terminal), the femtocell FAP creation unit 126 creates neighbor base station information (neighbor list) that does not include various information such as frequency band, band class, and PN code used by the own station (step S23). That is, a neighbor list including only the various information of neighboring base stations located in the vicinity of the own station is created to assist detection of pilot signals of neighboring base stations when an unregistered terminal hands off.

  Thereafter, the femtocell control unit 120 controls the neighbor list created by the creation unit 126 to be transmitted to the terminal (unregistered / registered) that has transmitted the UATI update allocation request to itself (step S26). . The neighbor list for the registered terminal includes various information such as the frequency band, band class, and PN code used by the femtocell FAP, and the neighbor list for the unregistered terminal is located in the vicinity of the own station. Only various information of neighboring base stations (macro cells) is included. The registered terminal that has received the neighbor list completes the handoff to the femtocell FAP based on the neighbor list (step S37). Thereafter, an EV-DO session is established between the registered terminal and the femtocell FAP (steps S27 and S38), a communication start request is transmitted from the registered terminal, and the femtocell FAP receives the communication start request ( In steps S39 and S28, communication between the femtocell FAP and the terminal (registration) AT is established (steps S49 and S29).

  The unregistered terminal that has received the neighbor list performs handoff to the base station (macrocell) AN based on the received neighbor list (step S15). Then, the macro cell is captured (step S16), and communication with the base station (macro cell) is resumed (step S17). At this time, since the PPP and EV-DO sessions before making the handoff request to the femtocell FAP are maintained, the data streaming or downloading performed at the time of the handoff request is not interrupted in the middle.

  Next, a description will be given using a sequence diagram. FIG. 3 is a sequence diagram when the mobile device (terminal) AT performs a handoff from the base station (macrocell) AN to the femtocell FAP according to an embodiment of the present invention. First, the terminal (registered / unregistered) AT has established a PPP with the base station (macrocell) AN (step P10). Thereafter, the terminal (registered / unregistered) AT requests the base station (macrocell) AN to perform a handoff from the base station (macrocell) AN to the femtocell FAP (step P11). Further, the terminal (registered / non-registered) AT requests the femtocell FAP for UATI update assignment (step P12). Unlike the conventional protocol, in the present invention, the femtocell FAP requests transmission of an ESN in response to a UATI update allocation request (step P13). The terminal (registered / unregistered) AT responds with the ESN of its own terminal to the ESN transmission request of the femtocell FAP (step P14). Based on the ESN received from the terminal (registration / non-registration) AT, the determination unit 128 of the femtocell FAP determines whether the terminal is a registered terminal of the own station (Step P15).

  If the received ESN belongs to a registered terminal, the femtocell FAP assigns a UATI to the terminal (registration) AT, and the terminal (registration) AT updates the UATI of the own terminal (step P16). The terminal (registration) AT that has updated UATI releases the PPP and EV-DO sessions with the base station (macrocell) AN (step P17). Thereafter, the femtocell FAP creation unit 126 creates a neighbor list including various information such as a frequency band, a band class, and a PN code used by the local station. The femtocell control unit 120 controls the neighbor list created by the creation unit 126 to be transmitted to the terminal (registration) AT that has transmitted the UATI update allocation request to the own station (step P18). The terminal (registered) AT that has received the neighbor list completes the handoff to the femtocell FAP based on the neighbor list (step P19). Then, when an EV-DO session is established between the femtocell FAP and the terminal (registration) AT and a communication start request is transmitted from the terminal (registration) AT (step P20), the femtocell FAP and the terminal (registration) AT are transmitted. Is established (step P21).

  In Step P15, when the determination unit 128 determines that the received ESN belongs to an unregistered terminal, the femtocell FAP creation unit 126 determines the frequency band and band class used by the own station, A neighbor list that does not include various information such as a PN code is created. The femtocell control unit 120 transmits the neighbor list created by the creation unit 126 to the terminal (unregistered) AT (step P22). The terminal (unregistered) AT performs handoff to the base station (macrocell) AN based on the received neighbor list. At this time, since the PPP before the handoff request to the femtocell FAP is maintained, the data streaming or downloading performed at the time of the handoff request is not disconnected halfway.

  In the above-described embodiment, ESN is used as the terminal identifier. However, as long as the femtocell can be acquired from the terminal AT, an identifier other than ESN may be used. For example, an IP address, a MEID (Mobile Equipment Identifier, A mobile device identifier), UIMID (User Identity Module Identifier), telephone number, IMSI (International Mobile Subscriber Identity) may be used. In addition, user information corresponding to the mobile device, for example, contractor information may be used.

  Furthermore, in the above-described embodiment, the description has been made assuming that CDMA2000 1xEV-DO is used as the mobile communication system. However, the present invention is not limited to this, and for example, a W-CDMA system (HSDPA or the like) system. Can be applied. In that case, the session establishment to the femtocell FAP and the macrocell AN is performed by a method according to the W-CDMA system, not the session establishment by the above-described UATI allocation.

  The advantages of the present invention will be described again. In response to a UATI update allocation request from a terminal, according to the conventional protocol, a response is made by performing a UATI update allocation. According to the present invention, the terminal is requested to transmit an ESN, and the terminal is registered. It is determined whether it is a terminal. In order to prevent the unregistered terminal from performing the UATI update assignment and not to disconnect the EV-DO session between the unregistered terminal and the base station (macro cell), No re-establishment operation or data re-downloading occurs, improving user convenience.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each unit, each step, etc. can be rearranged so that there is no logical contradiction, and a plurality of components, steps, etc. can be combined or divided into one. . It should be noted that any information for allowing a mobile station to detect a base station (macro cell) without being bound by the term neighbor list is included in the scope of the present invention. If the mobile device can be connected to a femtocell, a notebook computer, a PDA (personal digital assistance), a portable game machine, a portable audio player, a portable video player, a portable electronic dictionary, a portable electronic book viewer, etc. The present invention can be widely applied to various portable electronic devices.

1 is a block diagram of a femtocell according to one embodiment of the present invention. 4 is a flowchart when a mobile station performs handoff from a base station (macro cell) to a femto cell according to an embodiment of the present invention. FIG. 6 is a sequence diagram in a case where a mobile device performs a handoff from a base station (macro cell) to a femto cell according to an embodiment of the present invention. It is a figure which shows a mode that a mobile station (wireless communication terminal) hands off based on the protocol of the conventional CDMA2000 1xEV-DO. The flowchart in case an unregistered terminal hands off from a macro cell to a femto cell based on the protocol of the conventional CDMA2000 1xEV-DO is shown.

Explanation of symbols

FAP femtocell 110 radio unit 120 femtocell control unit 122 registration unit 124 request unit 126 creation unit 128 determination unit 130 storage unit 140 LAN connection unit ANT antenna AN base station (macro cell)
AT, AT1 terminal (mobile device)
CNET Mobile communication network INET Internet FGW Femto gateway

Claims (3)

A base station for a mobile communication system,
A registration unit for registering a unique number of a mobile device that uses the mobile station;
When the mobile communication system receives an update assignment request for the identifier of the mobile device assigned to the mobile device from the mobile device, a request unit that requests the mobile device to transmit a number unique to the mobile device;
Neighboring base station based on the mobile station specific number received from the mobile station in response to the request from the request section and the mobile station specific number of the mobile station that uses the local station registered by the registration section A control unit that creates information and controls the created neighboring base station information to be transmitted to the mobile device;
Equipped with a,
In the control unit, the mobile unit specific number received from the mobile unit in response to the request from the request unit matches the mobile unit specific number of the mobile unit using the local station registered in the registration unit. If not, update the identifier of the mobile device, create neighboring base station information that does not include the information of the own station, and control to send the created neighboring base station information to the mobile device,
A base station characterized by that . In the base station according to claim 1,
The controller is
When the mobile station specific number received from the mobile station in response to the request from the request section matches the mobile station specific number of the mobile station that uses the local station registered in the registration section, To create a neighboring base station information including the information of, and control to send the created neighboring base station information to the mobile device,
A base station characterized by that. A control method for a base station of a mobile communication system, comprising:
A step of registering a mobile device-specific number of a mobile device using the own station;
When the mobile communication system receives an update assignment request for the identifier of the mobile device assigned to the mobile device from the mobile device, the mobile device requests the mobile device to transmit a number unique to the mobile device;
Neighboring base station based on the mobile station specific number received from the mobile station according to the requesting step and the mobile station specific number of the mobile station that uses the local station registered in the registering step Generating information and controlling the generated neighboring base station information to be transmitted to the mobile device ,
In the controlling step, the unique number of the mobile device received from the mobile device in response to the request of the requesting step is unique to the mobile device of the mobile device using the local station registered in the registering step. If the number does not match, the identifier of the mobile device is not updated, the neighboring base station information not including the information of the own station is created, and the created neighboring base station information is controlled to be transmitted to the mobile device.
A control method for a base station.

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