JP2007295349A - Communication relay system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a reception state in the outdoors by inexpensive equipment and to seamlessly continue communication in the outdoors and communication in a room, in mobile communication. <P>SOLUTION: A communication relay system comprises: a mobile terminal 1 for performing communication through a wireless line; a radio base station 6 for performing communication with the mobile terminal 1 through a wireless line; a PLC modem 3 capable of performing communication through a wire circuit 53 and communication through a power line 74 for power supply; a small-sized portable base station 2 capable of performing communication with the PLC modem 3 through the power line 74 and communication with the mobile terminal 1 through a wireless line; and a call controller 4 which has a management database 4a wherein the PLC modem 3 and the small-sized portable base station 2 are stored and held in association with information relating to the position of the mobile terminal 1, and performs switching between communication through the radio base station 6 and communication through the PLC modem 3 and the small-sized portable base station 2 by collation with the management database 4a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a communication relay system and a communication relay method for improving radio wave reception conditions such as indoors in mobile communication.

  Conventionally, in mobile communication, as a means of distributing radio waves to general houses, condominium buildings, or underground shopping streets, for example, by increasing the transmission power from a large portable base station covering a wide area, There are passive measures that expect a penetration effect into the room and active measures such as installing a device that relays radio waves (RF repeaters) in the window of a house or installing a small antenna indoors.

On the other hand, in recent years, power line communication (PLC) using a power line as a communication line has been proposed. In this power line carrier communication, it is said that data communication of several Mbps to several hundred Mbps is possible by installing a communication adapter (PLC modem) in a power line outlet and connecting a communication device such as a personal computer. The technology using this PLC is a home phone equipped with a master unit and a slave unit. The charger of the slave unit is provided with the PLC function described above, and wired communication (optical communication is performed via a power line to which the charger is connected. (For example, refer to Patent Document 1) that switches between wireless communication through a master unit and wired communication through a charger.
Japanese Patent Laid-Open No. 2003-229790

  However, with the above passive measures, there is a problem that it is difficult to obtain sufficient indoor cover and cost effectiveness is low although excessive costs are required to increase the transmission power from the radio base station. is there.

  In addition, with the above active measures, there are restrictions on the installation positions of RF repeaters and small antennas, and sufficient indoor covers cannot be obtained depending on the conditions of the installation location. It is necessary to lay an optical cable or an antenna feeder from a large-sized mobile base station installed in a place where reception is possible to an indoor antenna, and the optical cable or antenna length is limited. In particular, in the case of each room of a general house or a condominium, it is difficult to take measures with an RF repeater or a small antenna, and in reality, only the above-mentioned passive measures are actually being taken.

  Furthermore, in the technique disclosed in Patent Document 1 described above, it is possible to easily install a slave unit as a repeater in a general household or each apartment room, but there is a relationship between the master unit and the slave unit. Since the system is premised, there is a limit to the range that can be used, such as outdoor communication and indoor communication must be separated.

  Therefore, the present invention has been made in view of the above points, and in mobile communication, it is possible to improve the indoor reception state with inexpensive equipment and to continuously continue outdoor communication and indoor communication. It is an object of the present invention to provide a communication relay system and a communication relay method.

  In order to solve the above-described problems, a wireless relay system and method of the present invention are capable of communication through a wireless line, a portable mobile terminal, a wireless base station that communicates with the mobile terminal through the wireless line, and a wired line. A PLC modem capable of communication via the power line and a power supply power line, a small wireless base station capable of communicating with the PLC modem via the power line, and a mobile terminal via the wireless line, It has a management database that stores and holds information related to the location of a mobile terminal in association with a PLC modem and a small radio base station, collates the management database, and communicates via the radio base station, and the PLC modem and small radio base station A call control device that switches communication through a station is used.

And in the present invention,
(1) A mobile terminal, a PLC modem, and a small radio base station are associated and stored in advance in a management database,
(2) The mobile terminal monitors whether or not communication with the mobile terminal is possible, and according to the monitoring result, makes a location registration request from the mobile terminal to the call control device,
(3) In response to the location registration request, in the call control device, by updating the information on the location of the mobile terminal on the management database, and sending a connection switching request to the small radio base station or the radio base station, It switches between communication via a radio base station and communication via a PLC modem and a small radio base station.

  In the above (2) and (3), the small radio base station monitors whether or not communication with the mobile terminal is possible and responds to a control signal from the communication link monitoring unit and a connection switching request from the call control device. Preferably, communication with the mobile terminal is established or disconnected.

  According to the present invention, by installing an inexpensive and small portable base station, it is possible to expand indoor covers such as ordinary houses and apartment rooms at low cost. In other words, an additional cable is installed to install a PLC modem connected to a wired line such as a single FTTH or ADSL line, and to connect this PLC modem to a relay device in a general house or apartment room via an existing power line. There is no need for installation. In addition, the relay device has a function of executing a handover with an outdoor radio base station by control from a call control device installed on the communication network, so that communication is not interrupted and the outdoor device And move indoors.

  As described above, according to the present invention, in mobile communication, it is possible to improve indoor reception by inexpensive equipment and to continue outdoor communication and indoor communication seamlessly by handover. it can.

(System configuration)
Embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a case where the relay system of the present invention is applied to each floor of a two-story general house will be described as an example. FIG. 1 is an explanatory diagram showing a schematic configuration of the relay system according to the present embodiment.

  As shown in the figure, in this embodiment, a mobile terminal 1 used by a user, a PLC modem 3 and a small mobile base station 2 (2a and 2b) installed in a general house 10, and a backbone network 5 The call control device 4 and the radio base station 6 are roughly configured.

  The mobile terminal 1 is a portable telephone using wireless communication, and wirelessly communicates with a relay point such as the wireless base station 6 and can receive a communication service such as a call or data communication while moving. Examples of the communication system of the cellular phone include an FDMA system, a TDMA system, a CDMA system, a W-CDMA, a PHS (Personal Handyphone System) system, and the like. In addition, this mobile phone is equipped with functions such as a digital camera function, an application software execution function, or a GPS function, and a function as a personal digital assistant (PDA) can be added.

  The call control device 4 is a device that establishes a communication channel (communication link) between users by exchanging incoming telephone number information between a telephone and a subscriber exchange, between a subscriber exchange and a relay exchange, etc., according to a predetermined call control protocol. As the call control protocol, a function for ringing a ring tone of a telephone set for communication or specifying a call partner based on a telephone number is realized. The call control device 4 is a module that transmits and receives control signals and controls communication with the mobile terminal 1. In response to a control signal from the communication link monitoring unit 25 and a connection switching request from the call control device 4. The communication with the mobile terminal 1 is established or disconnected. In particular, the call control device 4 according to the present embodiment has a management database 4a that stores and holds information relating to the position of each mobile terminal in association with each small mobile base station. It has a function of switching between wireless communication via a base station and communication via a PLC modem and a small mobile base station.

  The radio base station 6 is a relay point that communicates with the mobile terminal 1 through a radio line. The radio base station 6 is installed on a utility pole, a building roof, a telephone box, a ceiling of a subway platform, etc., and connected to the backbone network 5 through a gateway 51. Yes. The radio base station 6 executes communication connection with a terminal located in the communicable area A1 according to the control from the call control device 4.

  The PLC modem 3 is a device that superimposes and separates power and communication signals.In the general house 10, the PLC modem 3 is a parent device, and the small mobile base stations 2a and 2b are child devices. Power line carrier communication via the power line 74 is performed. Specifically, as shown in FIG. 2, the PLC modem 3 includes a communication unit 32, a storage unit 31, a connection management unit 35, a signal processing unit 33, and a power line carrier communication unit 34.

The communication unit 32 is a module that performs wired communication to the backbone network 5 via a wired line 53 such as FTTH or ADSL, and has a function of performing connection and disconnection of communication according to control from the wireless link processing unit 26. ing. In the present embodiment, a wired line 53 connected to the PLC modem 3 and the backbone network 5, the present invention is not limited thereto, for example, as shown in FIG. 4, instead of the wire line 53 A wireless communication line may be used. In this case, a small wireless base station 53b having the same configuration as that of the wireless base station 6 is installed, and the small wireless base station 53a is wired to the PLC modem 3 outside the general house 10 or on the roof of an apartment. It is installed so as to be connected, and wireless communication is performed between these small wireless base stations 53a and 53b.

  The connection management unit 35 is a module that manages the connection between the communication by the communication unit 32 and the communication by the power line carrier communication unit 34, and started or disconnected communication by wireless link processing on the small mobile base station 2 side. Is detected and the connection processing to the backbone network 5 and the power line carrier communication are controlled.

  The signal processing unit 33 is a module that mutually converts a signal related to power line carrier communication and a signal related to wired communication such as FTTH and ADSL. The storage unit 31 is a module that stores and holds data related to signal processing by the signal processing unit 33.

  The power line carrier communication unit 34 is a module for transmitting and receiving data to and from the small mobile base station 2 by indoor power line carrier communication via the power line 74 for supplying power. Is connected to the power line 74 of the outdoor, and the communication signal transmitted and received through the wired line 53 of the backbone network 5 is superimposed or separated on the power drawn indoors from the transformer 73 provided on the outdoor power pole through the power lead-in line 72 To do. The signal superimposed by the power line carrier communication unit 34 is acquired from the communication unit 32 through the signal processing unit 33, while the signal separated from the power line carrier communication unit 34 is input to the communication unit 32 through the signal processing unit 33. The

  The small mobile base station 2 (2a and 2b) is a slave device that performs power line carrier communication with the PLC modem 3 through the power line 74, and is a relay device that can communicate with the mobile terminal 1 through a wireless line.・ Obtain a cover area A2 covering each room in the apartment. That is, the small mobile base station 2 has a smaller output radio wave than the wide-area radio base station 6, and the radius of the cover area A2 is about several tens of meters, which is about one room or one floor of a general house.

  Specifically, as shown in FIG. 3, the small mobile base station 2 includes a radio communication unit 22, a storage unit 21, a communication link monitoring unit 25, a radio link processing unit 26, a signal processing unit 23, and a power carrier. And a communication unit 24.

  The wireless communication unit 22 is a module that communicates with the mobile terminal 1 via wireless communication, and may perform wireless communication using the same protocol as the wireless base station 6, for example, a wireless base such as a wireless LAN or a Buluetooth Wireless communication with a protocol different from the protocol used for communication with the station 6 may be performed.

  The communication link monitoring unit 25 is a module that monitors whether communication with a mobile terminal is possible.

  The signal processing unit 23 is a module that mutually converts a signal related to power line carrier communication and a signal related to wired communication such as FTTH and ADSL. The storage unit 21 is a module that stores and holds data related to signal processing by the signal processing unit 33.

  The power carrier communication unit 24 is a module that transmits and receives data to and from the PLC modem 3 by indoor power line carrier communication via the power supply power line 74.

(Communication relay method)
By operating the communication relay system having the above configuration, the communication relay method of the present invention can be implemented. Below, an example of the system operation | movement in this embodiment is demonstrated. The present invention is not limited to the following operation, and a known handover process (communication link process) can be applied.

  For example, if the mobile terminal 1 that is communicating wirelessly through the wireless base station 6 enters the general house 10 outdoors, the location of the mobile terminal 1 is detected by the mobile terminal 1 or the small mobile base station 2 . This location detection can be performed by, for example, receiving a signal (pilot signal) periodically transmitted from the small mobile base station 2 by the mobile terminal 1.

  Then, in response to the detection of the small mobile base station 2, the call control device 4 is requested to start the handover process through the radio base station 6 currently communicating. This request includes a terminal identifier for identifying the mobile terminal 1 and a base station identifier for identifying the detected small mobile base station 2 (or PLC modem 3).

  In response to this request, the call control device 4 searches for the gateway specified by the base station identifier, sends a call (Invite) to the detected gateway (52 in this case), and calls the called gateway. 52 calls the PLC modem 3 through a wired line 53 such as FTTH or ADSL. The called PLC modem 3 starts PLC connection to the corresponding small mobile base station 2. In response to this PLC connection, the small mobile base station 2 searches for a communication link to establish a communication link with the mobile terminal 1 located in the area A2. This search for the communication link is performed by transmitting “Invite” to the mobile terminal 1 that should be in the vicinity and receiving “ACK” in response thereto.

  The mobile terminal 1 that has received “Invite” in step S109 transmits the “ACK” to the small mobile base station 2 and transmits a location registration request (Register) to the call control device 4. In response to this location registration request, the call control device 4 updates the data on the management database 4a and registers the current location of the mobile terminal 1, the detected small mobile base station 2 and the PLC modem 3.

  Next, when the registration of the mobile terminal 1 is completed on the call control device 4 side, “OK” is transmitted to the mobile terminal 1 and reception of “ACK” is received. In response to reception of this ACK, the call control device 4 transmits a connection switching request to the small mobile base station 2 and the radio base station 6. In response to the connection switching request, the radio base station 6 disconnects the radio communication with the mobile terminal 1, and the gateway 52 starts communication with the PLC 3 to complete the handover process.

  On the other hand, in the indoor area A2, if the mobile terminal 1 that is communicating through the small mobile base station 2 and the PLC modem 3 goes outside (area A1), the mobile terminal 1 or the radio base station 6 A location is detected. This location detection can be performed, for example, by receiving a signal (pilot signal) periodically transmitted from the radio base station 6 on the mobile terminal 1 side.

  Then, in response to the detection of the radio base station 6, the call control device 4 is requested to start the handover process through the small mobile base station 2 currently communicating. This request includes a terminal identifier for identifying the mobile terminal 1 and a base station identifier for identifying the detected radio base station 6.

  In response to this request, the call control device 4 searches for the gateway specified by the base station identifier and calls the mobile terminal 1 through the detected gateway (51 in this case) and the radio base station 6 ( Invite), the called mobile terminal 1 transmits a location registration request (Register) to the call control device 4. In response to this location registration request, the call control device 4 updates the data on the management database 4a and registers the current location of the mobile terminal 1, the detected small mobile base station 2 and the PLC modem 3.

  Next, when the registration of the mobile terminal 1 is completed on the call control device 4 side, “OK” is transmitted to the mobile terminal 1 and reception of “ACK” is received. In response to reception of this ACK, the call control device 4 transmits a connection switching request to the small mobile base station 2 and the radio base station 6. In response to this connection switching request, the wireless base station 6 performs wireless communication with the mobile terminal 1, and the gateway 52 disconnects communication with the PLC 3 and completes the handover process.

(Action / Effect)
According to the present embodiment described above, by installing the small mobile base station 2 that is inexpensive and small, indoor covers such as ordinary houses and apartment rooms can be expanded at low cost. That is, a PLC modem 3 connected to a wired line 53 such as a single FTTH or ADSL line is installed. There is no need to install additional cables. In addition, the small mobile base station 2 has a function of executing a handover with the outdoor radio base station 6 under the control of the call control device 4 installed on the backbone network 5, so that communication is possible. It is possible to move outdoors and indoors without interruption.

It is explanatory drawing which shows schematic structure of the relay system which concerns on this embodiment. It is a block diagram which shows the internal structure of the PLC modem of the relay system which concerns on this embodiment. It is a block diagram which shows the internal structure of the small radio base station of the relay system which concerns on this embodiment. It is explanatory drawing which shows schematic structure of the relay system which concerns on the example of a change of this embodiment.

Explanation of symbols

A1, A2 ... Communicable area (cover area)
1… Mobile terminal
2. Small mobile base station
2a, 2b ... Small mobile base stations
3 ... PLC modem
4 ... Call control device
4a… Management database
5 ... Backbone network
6 ... Radio base station
10 ... General houses
21 ... Memory
22… Wireless communication part
23 ... Signal processing section
24… Power carrier communication section
25 ... Communication link monitoring unit
26 ... Radio link processor
31 ... Memory part
32 ... Communication Department
33 ... Signal processing section
34… Power line carrier communication section
35… Connection Management Department
51,52 ... Gateway
53… Wired line
53a, 53b ... Small radio base stations
71 ... distribution board
72 ... Power lead-in wire
73 ... Transformer
74 ... Power line

Claims (4)

A mobile terminal capable of communicating through a wireless line and portable;
A radio base station that communicates with the mobile terminal through a radio channel;
A PLC modem capable of communication via a wired line, and communication via a power line for power supply;
A small wireless base station capable of communicating with the PLC modem through the power line, and communicating with the mobile terminal through a wireless line;
Information relating to the location of the mobile terminal has a management database that stores and holds the PLC modem and the small radio base station in association with each other, and the communication through the radio base station by collating the management database, A call control device for switching between a PLC modem and communication via the small radio base station,
The call control device collates the management database in response to a location registration request from the mobile terminal, and performs communication via the radio base station, the PLC modem, and the small radio base station according to the collation result. A communication relay system characterized by switching between communications via a network. The small radio base station is
A communication link monitoring unit that monitors whether communication with the mobile terminal is possible;
2. A radio link processing unit that establishes or disconnects communication with the mobile terminal in response to a control signal from the communication link monitoring unit and a connection switching request from the call control device. The communication relay system described in 1. A mobile terminal capable of communicating through a wireless line and portable;
A PLC modem capable of communication via a wired line, and communication via a power line for power supply;
A small wireless base station capable of communicating with the PLC modem through the power line, and communicating with the mobile terminal through a wireless line;
Information relating to the location of the mobile terminal has a management database that stores and holds the PLC modem and the small radio base station in association with each other, and the communication through the radio base station by collating the management database, A communication relay method for performing communication using a PLC modem and a call control device that switches communication via the small radio base station,
(1) storing in advance information relating to the small radio base station in the management database;
In the mobile terminal, monitoring whether or not communication with the mobile terminal is possible, and according to the monitoring result, a step (2) of performing a location registration request from the mobile terminal to the call control device;
In response to the location registration request, the call control device updates information related to the location of the mobile terminal in the management database and transmits a connection switching request to the small radio base station or the radio base station. Switching between communication via the radio base station and communication via the PLC modem and the small radio base station (3)
A communication relay method comprising: In the step (2), the small radio base station monitors the availability of communication with the mobile terminal,
In the step (3), the small radio base station establishes or disconnects communication with the mobile terminal in response to a control signal from the communication link monitoring unit and a connection switching request from the call control device. 4. The communication relay method according to claim 3, wherein