JP2007059955A - Premise mobile communication system and premise base station device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively utilize resources, such as signal transmission paths, flexibly corresponding to a change in the biasing of traffic following the progress of the alternation of generations related to a communication system. <P>SOLUTION: In a premise base station device of a premise mobile communication system, an origination detection means detects an origination request from a mobile communication terminal in a premise to a public network, based on a signal transferred by a plurality of subscriber interfaces. A setting means sets a communication path for connecting the subscriber interface corresponding to an origination source and a base station interface by switches according to the detection of an origination request. A request relay means acts for an origination request to the public network via the base station interface corresponding to a communication system selected for connection to an outside line according to the detection of the origination request. A signal conversion means mutually converts a signal transferred via switches according to a voice coding method employed in a communication method corresponding to the subscriber interface corresponding to the origination source and the base station interface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention mediates mobile communication services between subscribers inside a building such as a tenant building, office building, department store or hotel, and an underground shopping center, and communication between subscribers staying inside and outside subscribers. The present invention relates to a local mobile communication system for providing a mobile communication service and a local base station apparatus provided in the local mobile communication system.
Mobile communication services using mobile phones and PHS have made remarkable progress as services for subscribers outdoors, and subscriber terminals for these mobile communication services are already widely used. With the spread of mobile communication, provision of communication services via mobile communication terminals has been demanded even in premises where fixed telephones have been mainly used in the past.

  In response to the demand for such services, for example, whether the mobile communication terminal carried by the subscriber is an extension telephone on the premises, such as IMCS (Inbuilding Mobile Communication System) provided by NTT DoCoMo. In-house mobile communication systems that are handled in this way have been put into practical use.

FIG. 9 shows a configuration example of a general private mobile communication system.
In the on-premises mobile communication system shown in FIG. 9, the on-site base station apparatus (BTS) 401 uses an antenna 402 and a transceiver unit 403 provided on each floor of the on-site to move a subscriber who is staying at the on-site. An external line connection service is realized by exchanging radio signals with a communication terminal and relaying the radio signals to a radio base station 405 of a public network via a dedicated line.

  In such a private mobile communication system, if the subscriber's mobile communication terminal is compatible with the communication method (for example, PDC: Personal Digital Cellular method) used for the service of this private mobile communication system, the mobile communication terminal Can be used on the premises just as it is used outdoors. Further, by providing the local base station apparatus 401 with the PBX function, it is possible to realize a call between subscribers staying on the local area without intervention of the public network.

  Of course, as shown in FIG. 9, in addition to the local base station apparatus 401 and the antenna 402 corresponding to the PDC system, the local base station apparatus 411 and the antenna 412 corresponding to the PHS system can be installed in the local area. Then, if these local base station apparatuses 411 and the radio base stations 413 corresponding to the respective communication systems are connected by a dedicated line, subscriber terminals of various communication systems can be found inside the building shown in FIG. It can be used (see Non-Patent Document 1).

  Similarly, a local mobile communication system is also proposed in which a mobile communication terminal compatible with IMT-2000, which is a third-generation mobile phone communication system, can be used. For example, the applicant of the present application has applied to the IMT-2000 system in Japanese Patent Application No. 2003-080548 (filed on Mar. 24, 2003, unpublished) “Extension Extension Device and Network System Using Extension Extension Device”. A joint mobile communication system that allows communication terminals to be used on the premises is jointly proposed with Fujitsu Network Solutions Co., Ltd. and NTT Docomo.

In addition, a simple on-site mobile communication system as shown in FIG. 10 has been proposed for a relatively small store.
In FIG. 10, a relay amplifier 431 is wirelessly connected to a radio base station 433 of a public network (for example, a PDC network) via an outdoor antenna 432 installed outdoors, and transmits and receives signals transmitted and received via an indoor antenna 434. Relay to / from station 433.

In such a simple on-site mobile communication system, it is not necessary to lay a dedicated line with the wireless base station of the public network, so that the system can be introduced at a relatively low cost (see Non-Patent Document 2). ).
By the way, with the start of practical use of communication methods (IMT-DS, etc.) compliant with IMT-2000, the service area has been gradually expanded, but at present, mobile communication terminals conforming to IMT-2000 are not available. Dissemination has only just begun. For this reason, the number of mobile communication terminals conforming to IMT-2000 is not far from the number of second-generation mobile terminals that have reached the peak of popularization.

  Under such circumstances, at present, the capability of a mobile communication system that provides an IMT-2000 public network is more than that of actual traffic, while providing a PDC public network. The capacity of a mobile communication system is full and has little capacity to handle current traffic. In this way, at the time when the generation change of the mobile communication system is in progress, traffic is biased toward the communication system that occupies the mainstream, so the capacity that can be provided by the network system of the mainstream communication system at that time and While the demand for transmission capability is tight, the capability of a new generation of mobile communication systems pre-arranged in order to acquire new customers is indebted. Such a phenomenon is not limited to the generation change time from the second generation to the third generation, but is considered to occur similarly in the subsequent generation change time.

On the other hand, depending on the location, there may be a traffic bias between the PDC method and the PHS method. It is well known that when there is such a bias, better communication quality can be obtained by using a communication method with a sufficient processing capacity. For example, a mobile communication terminal (so-called dual terminal) that has a function of sending a call request to a base station of a communication method that supports both the PDC method and the PHS method on the mobile communication terminal side and can expect better communication quality. It has been proposed (see Patent Document 1).
JP 2000-209644 (paragraphs [0018] to [0030], FIG. 4) “IMCS: System using IMCS”, “Use Cases for Corporate Services Tab” [online], N.C. Tee. Tee. Docomo Hokkaido, [03/10/20], Internet <URL: http://www.nttdocomo-h.co.jp/houjin/houjin.css> "Simple IMCS", Simple IMCS device configuration section on the product / service tab, [online], DOCOMO Engineering Co., Ltd. [03/10/20], Internet <URL: http // www.nttdocomo.co.jp / goods / imcs / gaiyou.html>

In the conventional local mobile communication system shown in FIG. 9, for example, the local base station apparatus 401 connected to the PDC network and the local base station apparatus 411 connected to the PHS network are completely independent.
Therefore, if mobile communication terminals of the same communication method are used, extension calls can be made with each other by the PBX function provided in each of the local base station devices 401 and 411. An extension call cannot be realized between a terminal and a PHS mobile communication terminal even though each subscriber is on the premises. In this case, a communication path is formed connecting the PDC system base station apparatus 401 and the PHS system base station apparatus 411 via the corresponding dedicated line and public network radio base stations 405 and 415, respectively. Will be.

  Another problem is the cost required to install and maintain a dedicated line. For example, at the present time when the transition to the third generation is expected, the third generation mobile communication terminal can be expected to become a major target in the future, so a dedicated line for connecting to the IMT-2000 network is prepared and the local mobile communication system It is considered advantageous to construct However, at the present time when the number of mobile communication terminals conforming to the IMT-2000 system is small, the cost required to install and maintain a dedicated line in anticipation of future increase in demand is seen as an advantage obtained by the operation of the private mobile communication system. There may be cases where it does not fit. Further, it is obvious that users of PDC mobile communication terminals that have been excluded from the service targets of the private mobile communication system feel dissatisfied. Nonetheless, considering the situation where the generation change of the mobile communication system has already started, a private mobile communication system targeting a PDC mobile communication terminal is added to the private mobile communication system for the IMT-2000 system, Furthermore, it may be a wasteful investment to newly install a dedicated line between the PDC mobile communication system and the PDC network. This is because when the generation change to the third generation mobile communication system is completed, the private mobile communication system for the PDC system and the dedicated line connecting this to the PDC network may become useless. is there.

  The present invention relates to a local base station apparatus and a local base station apparatus that can flexibly cope with a change in traffic bias associated with the progress of generation change relating to a communication method, and can effectively use resources such as signal transmission paths. An object is to provide an applied private mobile communication system.

A local mobile communication system according to the present invention includes an antenna and a local base station apparatus. The local base station apparatus includes a plurality of subscriber interfaces, a base station interface, a transmission detection unit, a switch, and a setting unit. And request relay means and signal conversion means.
The principle of the local mobile communication system according to the present invention is as follows.

  Terminals that exchange radio signals with mobile communication terminals that exist on the premises via antennas installed on the premises, and that are connected to each other and between the mobile communication terminals that exist on the premises and to the public network In a private base station device of a private mobile communication system for realizing a communication service with a device, a plurality of subscriber interfaces are connected to mobile communication terminals existing on the campus via an antenna installed on the campus. Send and receive radio signals according to different communication methods. The base station interface exchanges wired or wireless signals with a public network base station that operates according to a communication method selected from a plurality of communication methods. The transmission detection means detects a transmission request from the mobile communication terminal existing on the premises to the public network based on signals exchanged by a plurality of subscriber interfaces. The switch forms a speech path for exchanging signals between a plurality of subscriber interfaces and base station interfaces. The setting means sets a communication path connecting the subscriber interface corresponding to the source mobile communication terminal and the base station interface by the switch in response to the call request detected by the call detection means. The request relay unit relays the transmission request by proxying the transmission request to the public network via the base station interface in response to the detection of the transmission request by the transmission detection unit. The signal conversion means converts the signals transferred through the switch to each other according to the voice coding method applied in the communication method corresponding to the subscriber interface and the base station interface connected by the communication path formed in the switch. To do.

The operation of the private mobile communication system configured as described above is as follows.
The request relay means is a mobile communication terminal (for example, PDC type mobile communication) that exists on the premises regardless of whether the call detection means detects a call request from transmission / reception of a signal via a subscriber interface corresponding to any communication method. The call request from the terminal) is transmitted through the base station interface corresponding to the communication method (for example, IMT-2000 method) selected by the local mobile communication system for connection to the outside to the public network (for example, The above transmission request is sent to the IMT-2000 public network. At this time, the setting means sets, in the switch, a communication path that connects the subscriber interface where the call request is detected and the above-described base station interface. Then, in the process of transferring the voice signal through the communication path, the signal conversion means performs appropriate signal conversion similar to the above-described extension call. In this way, using the base station interface prepared in the local base station apparatus of the local mobile communication system, it is possible to realize an external line connection service for other types of mobile communication terminals existing in the local area.

A first local base station apparatus according to the present invention comprises a subscriber interface, a base station interface, transmission detection means, setting means, request relay means, signal transfer means, and signal conversion means. .
The principle of the first local base station apparatus according to the present invention is as follows.
Terminals that exchange radio signals with mobile communication terminals that exist on the premises via antennas installed on the premises, and that are connected to each other and between the mobile communication terminals that exist on the premises and to the public network In the local base station apparatus of the local mobile communication system that mediates communication with the apparatus, the subscriber interface exchanges radio signals according to the first communication method with the mobile communication terminal existing on the local area. The base station interface exchanges wired or wireless signals with a public network base station that operates according to another second communication method. The transmission detection means detects a transmission request from the mobile communication terminal of the first communication method to the public network based on a signal exchanged by the subscriber interface. The setting means sets a communication path that connects the subscriber interface and the base station interface in response to the call request detected by the call detection means. The request relay unit relays the transmission request by acting as a proxy for a transmission request to the public network of the second communication system via the base station interface in response to detection of the transmission request by the transmission detection unit. The signal transfer means transfers the signal between the subscriber interface and the base station interface according to the communication path set by the setting means. The signal conversion means converts the signal transferred by the signal transfer means between the voice coding scheme applied in the first communication scheme and the voice coding scheme applied in the second communication scheme.

The operation of the first local base station apparatus configured as described above is as follows.
When a request for outgoing call from the mobile communication terminal a of the first communication method (for example, PDC method) existing on the premises is detected by the request detection means, the request relay means Regardless of the communication method, the above-described transmission request is relayed by proxying the transmission request to the corresponding public network via the base station interface corresponding to the second communication method (for example, IMT-2000 method). At this time, the setting means sets a communication path connecting the subscriber interface and the base station interface. In the process in which the signal transfer means transfers the signal through this communication path, the signal conversion means converts the voice signal from the mobile communication terminal on the premises received by the subscriber interface into a voice encoding adapted to the second communication method. After being converted according to the system, it is sent to the base station interface, and the base station interface converts the voice signal received via the public network according to the voice coding system suitable for the first communication system, and then to the subscriber interface. Send it out.

In this way, for example, a local mobile communication system service for a PDC mobile communication terminal can be realized by a local base station apparatus having a base station interface compatible with the IMT-2000 system.
A second local base station apparatus according to the present invention includes a plurality of subscriber interfaces, a plurality of base station interfaces, a switch, an estimation unit, an outside line detection unit, a selection unit, a relay unit, and a setting unit. And signal conversion means.

The principle of the second local base station apparatus according to the present invention is as follows.
The plurality of subscriber interfaces exchange radio signals according to different communication schemes with mobile communication terminals existing on the premises via antennas installed on the premises. The plurality of base station interfaces exchange wired or wireless signals with a plurality of public network base stations that operate according to a plurality of different communication methods. The switch forms a communication path for transferring signals between the plurality of subscriber interfaces and the plurality of base station interfaces. The estimation means estimates the communication quality that can be expected when a transmission path is set through the plurality of base station interfaces, based on signals transmitted and received by the plurality of base station interfaces. The outside line detecting means detects a call request from the mobile communication terminal existing on the premises to the public network based on a signal exchanged by the subscriber interface. The selecting means selects a base station interface to be used for outside line transmission from a plurality of base station interfaces based on the estimation result by the estimating means in response to the transmission request detected by the outside line detecting means. The relay means acts as a proxy for a call request to the corresponding public network via the base station interface selected by the selection means in response to detection of the call request by the outside line detection means. The setting means sets, in the switch, a communication path that connects the subscriber interface corresponding to the source mobile communication terminal and the base station interface selected by the selection means in response to the detection of the transmission request by the outside line detection means. The signal conversion means includes a voice coding method applied to a communication method corresponding to a selected base station interface and a voice coding method applied to a communication method of a source mobile communication terminal for a signal transferred via a switch. Convert to and from each other.

The operation of the second local base station apparatus configured as described above is as follows.
The call request detected by the outside line detection means is the base station interface selected according to the expected value of the communication quality estimated by the estimation means, for example, the highest communication, regardless of the communication method of the mobile communication terminal that is the source. It is relayed to a corresponding public network via a base station interface corresponding to a communication method in which quality can be expected. At this time, the setting means forms a communication path in the switch that connects the subscriber interface corresponding to the communication method of the source mobile communication terminal and the selected base station interface, and the voice is transmitted through this communication path. In the process of transmitting the signal, the signal conversion means performs appropriate conversion for the speech coding scheme. As a result, the voice signal from the source mobile communication terminal is converted in accordance with a voice encoding method compatible with the selected base station interface and sent to the corresponding public network, and the base station interface selected from the public network Can be converted in accordance with a voice encoding method compatible with the subscriber interface corresponding to the source mobile communication terminal and sent to the source mobile communication terminal. In this way, regardless of the communication method supported by the originating mobile communication terminal, an outside line call can be realized using a communication method that can expect the highest communication quality at that time.

  According to the private mobile communication system and the private base station apparatus of the present invention, a mechanism for connecting to a public network via a base station interface having a communication method different from a communication method applied in a subscriber interface corresponding to a subscriber on the private campus. Therefore, it is possible to unify the communication system when connecting to an external public network, while targeting a plurality of mobile communication terminals that exist in a mixed manner on the premises.

  For example, using a base station interface that supports a new generation of communication systems, where the number of terminals is expected to increase in the future, together with a new generation of mobile communication terminals, a mobile communication terminal with a communication system that is currently at the peak of the penetration rate Can also provide local mobile communication services. As a result, it is possible to maintain the service to the majority of existing subscribers while introducing equipment suitable for the coming generation shift, so that both the efficiency of capital investment and customer satisfaction can be achieved. .

Furthermore, by providing a mechanism for selecting the one that can expect the highest communication quality from a plurality of base station interfaces connected to an external public network, it is possible to flexibly cope with changes in traffic bias accompanying the generation change of mobile communication terminals. Can respond.
In other words, while the penetration rate of the new generation mobile communication terminal is low, outgoing requests from the old generation mobile communication terminal can be made by using the surplus transmission capability of the public network corresponding to the new generation communication system. Relay to the public network via the base station interface corresponding to the communication system. On the other hand, when the transmission capacity of the public network corresponding to the new generation communication system is reduced, Expected surplus transmission capability can be utilized. In this way, it is possible to level out the traffic bias accompanying the progress of generation change, and to effectively use the equipment corresponding to the existing old generation communication method even after the generation change is almost completed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 shows an embodiment of a local mobile communication system according to the present invention.
The on-premises mobile communication system shown in FIG. 1 is an on-premises communication system that implements an internal telephone call between the mobile communication terminals on the campus and an external line call using an external base station via antennas installed at various locations within the campus. The base station apparatus 210 is comprised.

  In the on-premises base station apparatus 210 shown in FIG. 1, the PDC modem 211 transmits and receives radio signals to and from the PDC terminals existing on the premises via the antenna described above, while the IMT-2000 modem 212 is described above. A radio signal is exchanged with an IMT-2000 terminal existing on the premises via an antenna. Further, the IMT-2000 base station (BTS) interface 213 shown in FIG. 1 is wirelessly connected to the IMT-2000 base station 201 connected to the IMT-2000 network 202 which is a public network. Of course, a dedicated line may be laid between the IMT-2000 BTS interface 213 and the IMT-2000 base station 201 for wired connection.

Further, in the local base station apparatus 210 shown in FIG. 1, the switch 214 is connected to the above-described PDC modem 211, IMT-2000 modem 212, and IMT-2000 BTS interface 213 in accordance with instructions from the call processor 215, and voice / packet signals. A communication path that connects the processing unit (SPU) 218 to each other is formed.
The call processor 215 shown in FIG. 1 terminates a call via the PDC modem 211, the IMT-2000 modem 212, and the IMT-2000 BTS interface 213 by using an area reserved for each call in the memory 217. Further, the call processor 215 refers to the local HLR 219 via the home location register (HLR) interface 216, and determines the necessity of conversion of the speech coding system based on the information accumulated in the local HLR 219. Depending on the result, the voice / packet signal processing unit 218 is instructed to perform appropriate voice code conversion processing.

  In addition, in the voice / packet signal processing unit 218 shown in FIG. 1, the signal conversion control unit 221 receives the VSELP (Vector-Sum), which is a PDC voice coding method, in response to an instruction from the call processor 215 described above. The communication path set in the switch 214 by controlling the operation of the VSELP codec 222 corresponding to the Excited Linear Predictive Coding) method and the AMR codec 223 corresponding to the AMT (Adaptive MultiRate) method which is an IMT-2000 speech coding method The encoding method of the audio signal transmitted via the is converted.

Next, the operation of the local mobile communication system according to the present invention will be described by taking as an example the case of relaying an external line transmission from a PDC terminal existing on the campus.
FIG. 2 shows a transmission sequence from the PDC terminal to the public network. FIG. 3 is a diagram for explaining an operation of transmitting from the PDC terminal to the public network.
As shown in FIG. 2, for example, a terminal connected to an external public network as a transmission radio status report and identification information indicating a call destination from a PDC terminal to a local base station apparatus (indicated as a local BTS in FIG. 2) 1 reaches the PDC modem 211 shown in FIG. 1, this message is detected by the call detection unit 224 of the call processor 215, and is sent to the relay control unit 225, as shown in FIG. Be notified.

As described above, when a SETIP message including a telephone number indicating an external terminal is detected, the relay control unit 225 refers to the local HLR 219 via the HLR interface 216, so that the destination does not exist on the local area. Therefore, relay processing for outgoing line transmission is started.
At this time, the relay control unit 225 causes the protocol conversion unit 228 shown in FIG. 3 to proceed with the PDC authentication process (see FIG. 2) with the source PDC terminal via the PDC modem 211. The IMT-2000 authentication process (see FIG. 2) is performed with the IMT-2000 public network 202 via the IMT-2000 BTS interface 213 prepared as a base station interface for external connection in the local base station apparatus 210. .

  Subsequently, the relay control unit 225 proceeds with the PDC system channel setting process (see FIG. 2) with the source PDC terminal via the protocol conversion unit 228 and the PDC modem 211, and the protocol conversion unit 228 and the IMT. The IMT-2000 channel setting process (see FIG. 2) is performed with the IMT-2000 public network 202 via the 2000BTS interface 213.

  Thus, after the radio channel between the local base station apparatus 210 and the IMT-2000 public network 202 and the radio channel between the local base station apparatus 210 and the source PDC terminal are set, relay control is performed. As shown in FIG. 3, the unit 225 controls the switch 214 via the speech path control unit 226, and establishes a communication path from the PDC modem 211 to the IMT-2000 BTS interface 213 via the voice / packet signal processing unit 218. At the same time, the voice / packet signal processing unit 218 is instructed to perform mutual voice coding conversion between the voice coding system corresponding to the PDC system and the voice coding system corresponding to the IMT-2000 system. In FIG. 3, in order to facilitate understanding of the flow of the audio signal, the communication path connecting the PDC modem 211 and the audio / packet signal processing unit 218, the IMT-2000 BTS interface 213, the audio / packet signal processing unit 218, The switch 214 is shown separately for each of the communication paths for connecting.

  After the communication path is formed by the switch 214 in this way, a signal that reaches the PDC modem 211 from the PDC terminal is once decoded by the VSELP codec 222 of the voice / packet signal processing unit 218 via the switch 214. After that, the signal conversion control unit 221 sends this signal to the ARM codec 223, encodes the ARM codec 223, and sends it again to the IMT-2000 BTS interface 213 via the switch 214, and this IMT-2000 BTS interface 213. Is transmitted to the IMT-2000 base station 201 as an IMT-2000 radio signal. Of course, a radio signal that has arrived at the IMT-2000 BTS interface 213 of the local base station apparatus 210 from the IMT-2000 public network 202 via the IMT-2000 base station 201 is subjected to speech coding conversion processing that is the reverse of the above-described path. After being applied, it is sent to the PDC modem 211, and is sent out as a PDC wireless signal by the PDC modem 211.

  As described above, according to the private mobile communication system provided with the private base station apparatus according to the present invention, the signal from the mobile communication terminal on the private station is terminated on the PDC modem side which is the subscriber interface, and appropriate signal conversion is performed. Therefore, the communication method applied to the base station interface prepared for connecting to the public network differs from the communication method of the mobile communication terminal requesting the outgoing call from the premises by relaying to the external public network. Even in this case, an outside line connection can be realized.

Further, in a private mobile communication system equipped with a private base station apparatus according to the present invention, if the above procedure is applied to extension connection, as shown in FIG. 4, extension calls can be made between mobile communication terminals of different communication methods. It can also be realized.
For example, when the SETUP message including the identification information of the IMT-2000 terminal b existing on the premises from the PDC terminal a shown in FIG. 4 reaches the PDC modem 211, the relay control unit 225 completes the appropriate authentication process. Later, a PDC wireless channel is set up with the PDC terminal a that is the transmission source via the protocol conversion unit 228 and the PDC modem 211, and the IMT-2000 via the protocol conversion unit 228 and the IMT-2000 modem 212. An IMT-2000 wireless channel is set up with the terminal b.

  Thereafter, the relay control unit 225 sets a communication path for connecting the PDC modem 211 and the IMT-2000 modem 212 via the voice / packet signal processing unit 218 via the speech path control unit 226, and By instructing the packet signal processing unit 218 to perform coding conversion processing between the VSELP scheme and the ARM scheme, it is possible to realize an extension call between the PDC terminal a and the IMT-2000 terminal b.

In this way, by applying the technology according to the present invention, while maintaining services for users of PDC terminals that currently occupy a large number, IMT-2000 is intended for the future transition to the IMT-2000 system. A private mobile communication system using a private base station apparatus having a base station interface corresponding to the system can be introduced.
(Second Embodiment)
Next, a description will be given of a method for providing a service of good communication quality to users on the premises by using the traffic bias in the public network that appears along with the generation change of the mobile communication system.

FIG. 5 shows a second embodiment of the local mobile communication system according to the present invention.
5 that are the same as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG. 1 and description thereof is omitted.
A local base station apparatus 210 shown in FIG. 5 includes a PDCBTS interface 231 and a quality information collection unit 232 in addition to the components shown in FIG.

  5 has a function of wirelessly connecting to a PDC base station 204 connected to the PDC public network 205. Further, the quality information collection unit 232 illustrated in FIG. 5 uses information related to restrictions notified from the corresponding base station via the common control channel as the information related to communication quality from the IMT-2000 BTS interface 213 and the PDCBTS interface 231 and the corresponding base. Information on the reception level of the signal from the station is collected and notified to the call processor 215.

  Also, the call processor 215 selects an external line connection method to be used when making a call request from the user on the premises to the public network based on the information notified from the quality information collection unit 231 as described later. Then, setting of the communication path connecting the subscriber interface corresponding to the mobile communication terminal of the transmission source and the base station interface corresponding to the communication method used for external line connection and processing necessary for external line connection are performed.

Hereinafter, an operation related to external line connection will be described by taking as an example a case where a transmission request from the IMT-2000 terminal to the public network is made.
FIG. 6 is a diagram for explaining the outside line transmission operation. FIG. 7 shows a transmission sequence from the IMT-2000 terminal to the PDC public network. Further, FIG. 8 is a diagram for explaining external line connection from the IMT-2000 terminal to the PDC public network.

  As shown in FIG. 6, the protocol selection unit 230 provided in the relay control unit 225 of the call processor 215 determines that the transmission request detected by the call detection unit 224 is transmitted to the public network by the extension / external line determination unit 229. When it is determined that the communication method is used, the communication method to be used for the external line connection is selected based on the information notified from the quality information collection unit 232, and the voice / packet signal processing unit 218, the speech path control unit 226, and the protocol conversion are selected. A necessary instruction is sent to the unit 228.

  At this time, the protocol selection unit 230 first determines whether any information indicating that the restriction is applied is included in any of the quality information collected for the PDCBS interface 231 and the IMT-2000 BTS interface 213. However, if the restriction is applied to one, the other communication method is preferentially selected as the communication method for external line connection. On the other hand, if no restriction is applied to either communication method, the information related to the reception level included in the quality information is compared, and the communication method that has a reception level that can be expected to have higher communication quality is connected to the outside line. Select the communication method for use. Of course, when comparing the reception levels, in order to compare the reception level of the PDC system and the reception level of the IMT-2000 system on the same basis, the communication quality that can be expected at each reception level is, for example, to human hearing. It converts into an appropriate evaluation value according to the standard based on, and compares these evaluation values with each other.

  When the transition to the third generation mobile communication system is almost completed in the future, there is a possibility that traffic is greatly biased to the IMT-2000 public network, and rather, there is a margin in the transmission capability of the PDC public network. is there. In such a case, as shown in FIG. 7, when a transmission request is made from an IMT-2000 terminal, for example, the quality evaluation value corresponding to the reception level collected by the quality information collection unit 232 for the PDC public network is better. Since the value is higher than the quality evaluation value corresponding to the reception level collected for the IMT-2000 public network, the above-described protocol selection unit 230 selects the PDC method as the communication method for external line connection.

In this case, in response to an instruction from the protocol selection unit 230, the protocol conversion unit 228 sets a PDC wireless channel with the PDC public network via the PDCBTS interface 231, and at the same time, an IMT-2000 modem 212. Then, an IMT-2000 wireless channel is set up with the source IMT-2000 terminal (see FIG. 7).
Thereafter, as shown in FIG. 8, the speech path control unit 226 sets a communication path for connecting the PDCBTS interface 231 and the IMT-2000 modem 212 via the voice / packet signal processing unit 218, and the voice / packet. By instructing the signal processing unit 218 to perform coding conversion processing between the VSELP system and the ARM system, the IMT-2000 terminal can be connected to the PDC public network via an external line (see FIG. 7).

Of course, in the private mobile communication system shown in FIG. 5, by performing the procedure as described in the first embodiment at a time when the PDC terminal is more dominant, the outgoing line transmission from the PDC terminal is performed by the IMT-2000 public. It can also be realized by switching to a net.
Further, even when the PDC terminal and the IMT-2000 terminal are competing with each other, for example, grasping a phenomenon in which there is a margin in the transmission capability of either the PDC public network or the IMT-2000 public network for each time zone, These communication methods can be used properly. Of course, when the PDC public network and the IMT-2000 public network are congested to the same extent, the corresponding subscriber interface and base station interface are connected via the switch 214 to connect the external line. A connection can also be realized. At this time, if the necessary conditions including matching the secret key and establishing frame synchronization are satisfied, the communication directly connecting the PDC modem 211 and the PDCBTS interface 231 and the IMT-2000 modem 212 and the IMT-2000 BTS interface 213 respectively. It is also possible to set a route.

  In this way, in the private mobile communication system according to the present invention, since the external connection is made to the public network of the communication method that can be expected to have the highest communication quality at the time of the outgoing call request regardless of the mobile communication terminal of the transmission source, It is possible to flexibly cope with the generation change, and to provide a service with higher communication quality to the user of the local mobile communication service by using the change in the bias of the traffic generated along with the generation change.

  The present invention relates to a type of mobile communication service contracted by a subscriber in a premises where a radio signal from an outdoor base station is difficult to reach, such as a building such as a tenant building, office building, department store or hotel, or an underground shopping center. Regardless of whether the mobile communication service is the same as when outdoors. In addition, since it is possible to limit the types of base station interfaces to be provided in the private mobile communication system, the cost required to provide the private mobile communication service and the need for operating this service are required. Cost can be reduced. As a result, it is possible to eliminate the cost problem that has been an obstacle to the introduction of on-premises mobile communication systems, so from facilities such as large shopping malls to relatively small shops and restaurants, The field of application of the private mobile communication system can be expanded.

  Furthermore, since the local base station apparatus according to the present invention can selectively use any one of a plurality of communication methods regardless of the communication method of the source mobile communication terminal, the mobile communication system. It is possible to improve the communication quality when a user on the premises connects to the outside line by using the transmission capacity margin in each public network that changes in accordance with the progress of the generation change.

It is a figure which shows embodiment of the local mobile communication system concerning this invention. It is a figure which shows the transmission sequence from a PDC terminal to a public network. It is a figure explaining the operation | movement which transmits to a public network from a PDC terminal. It is a figure explaining the extension call between a PDC terminal and an IMT2000 terminal. It is a figure which shows 2nd Embodiment of the local mobile communication system concerning this invention. It is a figure explaining an outside line transmission operation. It is a figure which shows the transmission sequence from an IMT2000 terminal to a PDC public network. It is a figure explaining the external line connection from an IMT2000 terminal to a PDC public network. It is a figure which shows the structural example of a general private mobile communication system. It is a figure which shows the example of a simple type local mobile communication system.

Explanation of symbols

201 IMT-2000 Base Station 202 IMT-2000 Network 204 PDC Base Station 205 PDC Public Network 210 Local Base Station 211 PDC Modem 212 IMT-2000 Modem 213 IMT-2000 Base Station (BTS) Interface 214 Switch 215 Call Processor 216 HLR Interface 217 Memory 218 Voice / packet signal processing unit 219 Local HLR
221 Signal conversion control unit 222 VSELP codec 223 AMR codec 224 Call detection unit 225 Relay control unit 226 Communication path control unit 228 Protocol conversion unit 229 Extension / outside line determination unit 230 Protocol selection unit 231 PDC base station (BTS) interface 232 Quality information collection Unit 401, 411 On-site base station device (on-premises BTS)
402, 412 Antenna 403 Transmitter / receiver handset 405, 413 Radio base station 431 Relay amplifier 432 Outdoor antenna 433 Radio base station 434 Indoor antenna

Claims (3)

Sends and receives radio signals to and from mobile communication terminals existing on the campus via an antenna installed on the campus, and connects between the mobile communication terminals existing on the campus and the mobile communication terminals and public network existing on the campus In a local mobile communication system including a local base station device that relays communication with a terminal device,
The campus base station device
A plurality of subscriber interfaces that respectively transmit and receive radio signals according to different communication schemes with mobile communication terminals existing on the premises via antennas installed on the premises;
A base station interface that exchanges wired or wireless signals with a public network base station that operates according to a communication method selected from the plurality of communication methods;
Based on signals transmitted and received by the plurality of subscriber interfaces, transmission detection means for detecting a transmission request from the mobile communication terminal existing on the premises to the public network,
A switch forming a speech path for exchanging signals between the plurality of subscriber interfaces and the base station interface;
Setting means for setting, by the switch, a communication path connecting a subscriber interface corresponding to the mobile communication terminal of the transmission source and the base station interface, in response to a transmission request detected by the transmission detection means;
Request relay means for relaying the call origination request by proxying the call origination request to the public network via the base station interface in response to detection of the call origination request by the call origination detection means;
The subscriber interface and the base station interface connected by a communication path formed in the switch mutually convert signals transferred through the switch according to a voice coding scheme applied in a corresponding communication scheme. And a signal converting means. Sends and receives radio signals to and from mobile communication terminals existing on the campus via an antenna installed on the campus, and connects between the mobile communication terminals existing on the campus and the mobile communication terminals and public network existing on the campus In the local base station device of the local mobile communication system that mediates communication with the terminal device,
A subscriber interface that exchanges radio signals according to a first communication method with mobile communication terminals existing on the premises;
A base station interface that exchanges wired or wireless signals with a public network base station that operates according to another second communication method;
Based on a signal transmitted and received by the subscriber interface, a transmission detection means for detecting a transmission request from the mobile communication terminal of the first communication method to the public network;
Setting means for setting a communication path connecting the subscriber interface and the base station interface in response to a call request detected by the call detection means;
Request relay means for relaying the call origination request by proxying the call origination request to the public network of the second communication method via the base station interface in response to detection of the call origination request by the call origination detection means;
Signal transfer means for transferring a signal between the subscriber interface and the base station interface according to a communication path set by the setting means;
Signal conversion means for converting the signal transferred by the signal transfer means between the voice encoding scheme applied in the first communication scheme and the voice encoding scheme applied in the second communication scheme; A local base station apparatus characterized by that. A plurality of subscriber interfaces for transmitting and receiving radio signals according to different communication schemes with mobile communication terminals existing on the premises via antennas installed on the premises;
A plurality of base station interfaces that respectively send and receive wired or wireless signals to and from a plurality of public network base stations that operate according to a plurality of different communication methods;
A switch forming a speech path for exchanging signals between the plurality of subscriber interfaces and the plurality of base station interfaces;
Estimating means for estimating communication quality expected when a transmission path is set through the plurality of base station interfaces based on signals transmitted and received by the plurality of base station interfaces,
Based on a signal transmitted and received by the subscriber interface, an outside line detecting means for detecting a call request to the public network from a mobile communication terminal existing on the premises,
In response to the transmission request detected by the external line detection unit, a selection unit that selects a base station interface to be used for external line transmission from the plurality of base station interfaces based on an estimation result by the estimation unit;
In response to detection of a transmission request by the external line detection unit, a relay unit that performs a transmission request to the corresponding public network via the base station interface selected by the selection unit;
Setting means for setting, in the switch, a communication path connecting a subscriber interface corresponding to the source mobile communication terminal and the base station interface selected by the selection means in response to detection of a call request by the outside line detection means. When,
For a signal transferred via the switch, a speech coding method applied in a communication method of the source mobile communication terminal and a speech coding method applied in a communication method corresponding to the selected base station interface A local base station apparatus comprising: signal conversion means for converting between each other.

Images