JPH0654367A - Exchange system for mobile communication - Google Patents

Abstract

PURPOSE:To realize an exchange system for a mobile communication whose affinity with a conventional wire system interface can be improved, and whose constitution is simple by sufficiently preventing a hit when a cordless terminal is moved across radio base stations. CONSTITUTION:A cordless switch 20 is interposed between a base station interface part 71 which operates an interface between a radio base station 50 and a switchboard main body, and transformer coders 72 and 73 which exchange encoded data on a radio line with the encoded data in the switchboard. The cordless switch 20 is the device for tracing a movement whose path is switched by a cordless controller when a cordless terminal 60 is moved across the radio base stations.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exchange system for mobile communication, and is particularly suitable for application to an exchange system accommodating a digital cordless telephone.

[0002]

2. Description of the Related Art In recent years, for example, in offices and the like, an increasing number of cases are being provided with an extension telephone set housed in a private branch exchange or the like for each employee in order to improve work efficiency. As described above, a cordless telephone with excellent portability is also being considered as a telephone to be supplied to each employee, and a private branch exchange system that is compatible with the cordless telephone is being developed. Here, it is considered to employ a digital transmission method, which has better confidentiality than the analog transmission method and enables the cordless telephone to be smaller and lighter, and to perform transmission between the digital cordless telephone and the wireless base station. TDMA (Time
Division Multiple Access) has been proposed.

In a private branch exchange system for mobile communication adopting the TDMA system, it is desired to synchronize radio base stations. When a cordless telephone moves from the service zone of one radio base station to the service zone of another radio base station, the T
If the DMA frame is not synchronized, it is necessary to start the communication after the movement-destination wireless base station performs the synchronization operation, and the existence of such synchronization establishment time causes a momentary interruption in the communication. is there. In the case of a private branch exchange system accommodating a digital cordless telephone, the zone radius covered by the radio base station is narrowed (microcell) in order to improve the efficiency of frequency reuse in the office with high traffic density. Therefore, the wireless base stations are frequently switched during communication, and the problem of instantaneous interruption is great.

[0004] Document "Japanese Patent Application No. 3-097402 specification and drawings" proposes a method of synchronizing radio base stations.

[0005]

However, the instantaneous interruption cannot be sufficiently prevented only by synchronizing the radio base stations. That is, a momentary interruption occurs due to the operation of the switch that switches (tracks) the wireless base stations accommodating the digital cordless telephones that are in communication with the movement.
Therefore, the configuration of the switch for tracking the movement becomes a problem, but the digital cordless telephone is currently under active development, and no reference to such a switch for tracking the movement is found.

By the way, in a digital cordless telephone, a high-efficiency voice coding system having a low bit rate is used, unlike a conventional wired communication network, in order to maximize the frequency utilization efficiency on a wireless line. On the other hand, the voice coding system in the exchange in Japan is the μ-law PCM of 64 kb / s. Therefore, in an exchange that accommodates both a wired telephone and a mobile telephone, or an exchange that accommodates a mobile telephone but is connected to an exchange with another wired system, high-efficiency voice coded data on the wireless line and 64 kb / s μ-law P
A transcoder that performs code conversion with CM data is required. Therefore, the existence of this transcoder must be taken into consideration even when configuring the switch for mobile tracking.

The present invention has been made in consideration of the above points, and is capable of sufficiently preventing a momentary interruption even when a cordless terminal moves between wireless base stations, and has a conventional wired interface. It is intended to provide a mobile communication switching system having a simple structure and having a high affinity with.

[0008]

In order to solve the above problems, according to the present invention, in a mobile communication switching system comprising a digital cordless terminal, a wireless base station and a switch body, the switch body is a wireless base station and a switch. The cordless terminal moved between the radio base stations between the base station interface section that interfaces with the main unit and the transcoder that converts the encoded data on the wireless line and the encoded data in the exchange. It is characterized by interposing a cordless switch for movement tracking whose path is sometimes switched by a cordless controller.

Here, two cordless switches are provided: a cordless switch unit in the downward direction from the main switch to the cordless terminal, an upward cordless switch unit in the opposite direction, and an upward cordless switch unit. It is configured with a mix circuit that mixes the information channels of the above and re-inputs them to the cordless switch unit in the upstream direction, and at least before and after the cordless terminal crosses between the wireless base stations, sets a path that passes through the mix circuit to make the cordless It is preferable to track the movement of the terminal.

In this embodiment, further, the cordless switch unit in the down direction and the cordless switch unit in the up direction are constituted by time division switches, and a mix circuit is provided, and an information channel from the cordless terminal is inputted to one input terminal. It is preferable to use a two-input OR circuit or an AND circuit in which an idle pattern of all 0s or all 1s is input to the other input terminal.

Further, in an embodiment of a mobile communication switching system having a cordless switch and a mix circuit,
It is preferable to always set a path that passes through the mix circuit during the call connection period.

In the mobile communication switching system of the present invention, it is preferable that a plurality of base station interface units and a plurality of transcoders are mounted on the same cordless subscriber circuit board on which a cordless switch is not mounted.

[0013]

[Function] Although the main body of the exchange may accommodate only the digital cordless terminal, the encoding system in the exchange is determined in consideration of communication with other exchanges,
This may be different from the coding method on the wireless line, and the present invention is premised on such a switching system.

In the case of such an exchange system, a transcoder for converting the encoding system is provided in the exchange main body. By the way, in the case of a switching system accommodating a cordless terminal, it is necessary to switch the path in the main body of the exchange according to the movement of the cordless terminal, but if the path is switched with the main switch, the central processing that controls the entire main body of the exchange The load on the module increases. Therefore, it is preferable to provide a cordless switch for tracking movement of the cordless terminal, which is different from the main switch.

The base station interface section for interfacing the radio base station with the main body of the exchange and the above-mentioned transcoder generally constitute a cordless subscriber circuit which is a unit to be attached to and detached from the main body of the exchange. A cordless switch may be provided between the cordless subscriber circuit and the main switch.

[0016] However, when provided in such a position, the cordless switch switches the information channel according to the encoding system in the exchange to set the path, and the problem on the wireless line is encoded by the wired system. This will be handled at each stage, and the configuration of the cordless switch, transcoder, etc. will be complicated. For example, one of the two radio base stations before and after the movement outputs information channel data (for example, all 0) related to non-reception, but it is made clear that it is certainly non-reception even through the transcoder. The information channel data must be output, which complicates the configuration of the transcoder. Alternatively, the cordless switch is configured so that it can respond even if the information channel data relating to non-reception is code-converted, and in this case, the cordless switch becomes complicated.

Therefore, in the present invention, between the base station interface section and the transcoder, there is provided a cordless switch for movement tracking in which a path is switched by a cordless controller when a cordless terminal moves between radio base stations. I decided to intervene.

The cordless switch naturally comprises a cordless switch unit in the downward direction from the main switch to the cordless terminal and an cordless switch unit in the upward direction, which is the opposite direction, but is accompanied by switching without strict timing control. It is preferable that the wireless base station includes at least a cordless terminal that mixes two information channels from the upstream cordless switch unit and re-inputs them into the upstream cordless switch unit so as to eliminate instantaneous interruption. It is preferable to set a path passing through the mix circuit to track the movement of the cordless terminal before and after the passage.

In this case, the cordless switch unit in the down direction and the cordless switch unit in the up direction are constituted by time division switches, and the mix circuit is connected to one of the input terminals with the information channel from the cordless terminal and the other. It is preferable to use a two-input OR circuit or an AND circuit in which an all 0 or all 1 idle pattern is input to the input terminal. By doing so, the configuration of the mix circuit can be simplified.

When setting the path passing through the mix circuit only before and after the cordless terminal crosses between the radio base stations, do not pass through the mix circuit when switching to pass through the mix circuit. There is a momentary interruption or loss of information when returning to. Therefore, in a mobile communication switching system having a mix circuit in a cordless switch, it is preferable to set a path that always passes through the mix circuit not only before and after a cordless terminal crosses between wireless base stations but also during a call connection period.

In the mobile communication switching system of the present invention as described above, a cordless switch is used to connect a plurality of base station interface units and a plurality of transcoders in consideration of easily adapting to the addition of radio base stations and the like. It is preferable to mount the same cordless subscriber circuit board that is not mounted. When a plurality of base station interface units and a plurality of transcoders are mounted on different boards, the process of attaching and detaching boards according to the addition of radio base stations becomes complicated.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a private branch exchange system will be described in detail below with reference to the drawings.

(A) Overall Exchange System FIG. 2 shows the overall configuration of the private branch exchange system according to this embodiment. First, the entire private branch exchange system will be described with reference to FIG.

In FIG. 2, the private branch exchange system according to this embodiment is a radio base station 50 which performs communication between a digital cordless terminal (hereinafter, simply referred to as a cordless terminal) 60 and the cordless terminal 60 according to the TDMA system.
And a private branch exchange 1 that accommodates the wireless base station 50 and performs exchange processing so that communication can be performed between the cordless terminals 60 or between the cordless terminal 60 and a wired telephone (not shown).

The radio base station 50 is a base station for exchanging voice signals and control signals by a multi-carrier TDMA with a cordless terminal 60 which is a digital mobile communication terminal located in a micro zone assigned to itself.
A cordless subscriber circuit 16 (16-) of the exchange 1 described later.
, ..., 16-n). Wireless base station 50
Are arranged at predetermined intervals so that communication can be performed even when the cordless terminal 60 moves between zones during communication. As a result, even when the cordless terminal 60 moves across the zones of the plurality of wireless base stations 50 during communication, the wireless base station switching processing is executed and continuous call can be performed. .

Note that 32 Kb / s ADPCM data is exchanged between the cordless terminal 60 and the radio base station 50,
32 Kb / s AD between wireless base station 50 and private branch exchange 1
PCM data is exchanged.

Private branch exchange 1 is a multi-carrier TDMA
2 is an exchange that realizes digital mobile communication by
As shown in FIG.
0-m, a time divisional switch 30 which is a main switch, and a central processing module 40.

Line trunk module 10 (10-1)
10-n) are line accommodating units in which interface circuits such as wired or wireless subscriber terminals or various trunks are arranged as necessary. As shown in the line trunk module 10-1, each line trunk module 10 has n universal slots 12 (12-
, ..., 12-n), a cordless controller 18 common to each cordless subscriber circuit 16, a cordless switch (movement tracking switch) 20 common to each cordless subscriber circuit 16, and a highway interface controller 22. Has been done. Each universal slot 12 (12-1, ..., 12-n) is a highway 100.
, And the wired interface circuit 14 (14-1, ..., 14-n) for interfacing with the control bus 102 and the cordless subscriber circuit 16 (16-1, ...) For interfacing the cordless control bus 110, the cordless highway 112 and the highway 100. , 16-n).

The wired interface circuit 14 includes a general analog telephone, a multi-function telephone, an office line interface circuit such as an analog data terminal or an ISDN line, a conference trunk, a paging trunk, a voice guidance trunk, or a service trunk serving as an interface. Are accommodated. Each wired interface circuit 14 is connected to the time-division switch 30 via the highway 100, which is a time-division multiplex path having a transmission capacity of 2 Mbits.
It is also connected to the highway interface controller 22 via the control bus 102.

The cordless subscriber circuit 16 accommodates the radio base station 50 and serves as an interface between the radio base station 50 and the time division switch 30. FIG. 1 shows a detailed configuration of the cordless subscriber circuit 16, and its specific function will be described later.

The cordless controller 18 mainly manages the movement of the cordless terminal 60, and controls the cordless switch 20 in response to a request for switching a channel during a call from the cordless terminal 60 across the wireless base stations 50. That is, the cordless controller 18 is connected to the central processing module 40 via the highway interface controller 22, terminates the control information from the central processing module 40 and transmits it to the cordless subscriber circuit 16, and at the same time, the cordless subscriber circuit 16, It controls and manages the radio base station 50 and the cordless terminal 60. The cordless controller 18 also includes a cordless subscriber circuit 16
Wireless base station 50 or cordless terminal 6 received via
The control information from 0 is terminated, and control is autonomously performed according to a predetermined processing procedure. As a result, the process of switching the in-call channel between the wireless base stations 50 accommodated in the line trunk module 10 is performed. The cordless controller 18 further transfers the control information associated with the exchange processing to the central processing module 40 via the highway interface controller 22, and when the cordless terminal 60 moves to the zone of the radio base station 50 of the different line trunk module 10. Central processing module 40 so that the communication channel can be switched to continue the call.
To exchange control information.

Cordless switch (movement tracking switch)
Reference numeral 20 denotes the wireless base station 5 as the wireless base station 50 moves from one zone to another while the cordless terminal 60 accommodated therein is talking.
This is a switch for switching 0. FIG. 1 also shows a detailed configuration of the cordless switch 20, and its specific function will be described later.

It should be noted that it is not preferable to perform movement tracking by the main time divisional switch 30 because the burden on the central processing module 40 is too heavy.

Highway interface controller 2
Reference numeral 2 is a control circuit that relays control information in each component in the line trunk module 10. That is, the controller 22 is connected to the wired interface circuit 14 via the control bus 102 and the cordless subscriber circuit 16 via the cordless controller 18, and these circuits and the central processing module 40 are connected.
It relays control information between them.

The time divisional switch 30 is the line trunk 1
It is a main switch that forms a communication path between terminals or trunks accommodated in 0 or between line trunks 10. The time-division switch 30 is connected to the central processing module 40, and performs switching processing by the time-division multiplexing method according to a connection control instruction from the module 40.

The central processing module 40 is a main control unit for controlling each component of the exchange 1, and has a function of executing connection control according to a call processing program.

(B) Detailed Configurations of Cordless Subscriber Circuit and Cordless Switch Next, detailed configurations of the cordless subscriber circuit 16 and the cordless switch 20, which are characteristic parts of this embodiment, will be described with reference to FIG. . Although only one cordless subscriber circuit 16 is shown in FIG. 1, a plurality of cordless subscriber circuits 16 are actually connected to the cordless switch 20.

The cordless subscriber circuit 16 includes base station interface units 71 (71-1 to 71-x) connected to the wireless base station 50 by wire, and a transcoder 72 that interfaces with the main time division switch 30. (72
-1 to 72-x), 73 (73-1 to 73-x), and a control processor 74.

The transcoder 72 is a low bit rate voice coded data (ADPCM: 32 kb / characteristic) peculiar to mobile communication.
s) is standard voice coded data (μ-law PC in the switch)
M: 64 kb / s), and the transcoder 73 converts standard voice coded data in the exchange into low bit rate voice coded data peculiar to mobile communication, and forms a pair. ing. Transcoder 7
2, 73 interface with the main time divisional switch 30 and the cordless switch 20 (81, 82). The transcoders 72 and 73 are positioned similarly to the CODEC (analog voice μ-law PCM) of the analog subscriber line interface in the conventional wired interface when viewed from the time division switch 30 side. In practice, if 16 lines are assigned to one universal slot, the transcoders 72 and 73 will have a maximum of 16 lines.
Up to a set can be installed.

The base station interface unit 71 is an interface that is connected to the radio base station 50 by wire and transmits / receives information channels to / from the radio base station 50.

The control processor 74 intervenes in the exchange of control information between the cordless controller 18 and the radio base station 50, and controls the cordless subscriber circuit 16 as a whole.

In FIG. 1, only the signal lines having a strong relationship with the features of this embodiment are shown, and the other control information signal lines and the like are omitted.

One feature of this embodiment is that the base station interface section 71 and the transcoders 72 and 73 are mounted on the same board, for example, but are not directly connected (electrically separated). Point). That is, the base station interface unit 71 and the transcoder 7
2, 73 are connected via a cordless switch 20 for movement tracking.

The cordless switch 20 is composed of three blocks of a downward cordless switch section 81, an upward cordless switch section 82 and a mix circuit 83.

The downlink cordless switch section 81 is realized by a time divisional switch routed by the cordless controller 18. The down direction cordless switch unit 81 includes the main time division switch 30.
The down highway 100B (112F1) from is connected to the input side via the transcoder 73. The outgoing side of the downlink cordless switch section 81 is connected to the downlink information channel processing section of the base station interface section 71 via the downlink highway 112B2.

The upstream cordless switch section 82 is realized by a time division switch routed by the cordless controller 18. An upstream highway 112F2 extending from the upstream information channel processing unit of the base station interface unit 71 and an upstream highway 112F3 extending from the output of the mix circuit 83 are provided on the input side of the upstream cordless switch unit 82. Connected. The output side is connected to the upstream highway 100F of the main time division switch 30 via the upstream highway 112B1 and the transcoder 72, and is also connected to the input side of the mix circuit 83 via the upstream highway 112B3. There is.

FIG. 3 shows the input / output timing of each cordless switch section (time division switch) 81, 82. Each cordless switch (time division switch)
Reference numerals 81 and 82 are for switching operation in synchronization with the highway synchronization clock and the highway frame pulse, and are synchronized with the valid edge of the highway synchronization clock generated when the highway frame pulse is significant and the first information of the frame. The channel is output, and then the information channel replaced in synchronization with the highway synchronization clock is output, and the information channel from the input side highway is taken in and latched and switched in synchronization with the highway synchronization clock.

The mix circuit 83 is used in the cordless terminal 60.
Is provided for the purpose of eliminating a momentary interruption without performing strict timing control even when moving between base stations during a call. The information channel with the radio base station 50 is mixed. The mix circuit 83 has one or more unit mix units shown in FIG. 4 and / or FIG. 6, and is adapted to handle a case where there are a plurality of cordless terminals 50 at the same time during a call that requires base station switching.

The unit mix section shown in FIGS. 4 and 6 is a radio base station 50 in which the information channel is not received on the radio line.
However, the configuration is based on the assumption that an idle pattern fixed to all 0s is output to the upstream cordless switch unit 82 as upstream information channel data from the wireless base station 50.

In the unit mix section shown in FIG. 4, the information channel of the radio base station 50-i before switching and the information channel of the radio base station 50-j after switching are two channels from the upstream cordless switch section 82. This corresponds to the case where the output is synchronized with the highway line. The output control from the upward cordless switch unit 82 is as follows.
The cordless controller 18 performs this. As shown in FIG. 5, the unit mix section shown in FIG. 4 obtains a simple logical sum of these two information channels (for example, a highway of 2 Mbps) by the OR circuit 83a and outputs it as a mix output. In this case, since one information channel is all 0, the data of the other information channel is output as it is. If the highway has 32 channels, 32 channels can be mixed by one unit mix section shown in FIG.

In the unit mix section shown in FIG. 6, the information channel of the radio base station 50-i before switching and the information channel of the radio base station 50-j after switching are one channel from the upstream cordless switch section 82. This corresponds to the case where the highway line inserts the data into the slots that are adjacent to each other and outputs the data. The output control from the upward cordless switch unit 82 is performed by the cordless controller 18
Will do. As shown in FIG. 7, the unit mix unit shown in FIG. 6 has an input information channel and a shift register 83.
The OR circuit 83c obtains the logical sum of the information channels obtained by delaying it by 1 slot by b and outputs it as a mixed output. Since one of the information channels inserted in the successive slots is all 0, the data of the other information channel is output as it is. If the highway has 32 channels, 16 channels can be mixed by one unit mix section shown in FIG.

(C) Operation before and after movement between base stations Next, the operation when the cordless terminal 60 moves between the radio base stations 50 in the private branch exchange system of the present embodiment having the above configuration will be described. Switch 20
The operation will be mainly described.

The control operation executed by the cordless controller 18 differs depending on the mixing capability of the mixing circuit 83. That is, there are a method of hunting the mix circuit 83 only before and after the movement, and a method of constantly hunting the mix circuit 83 not only before and after the movement but also during a call (during call connection) (these are different embodiments). Has become). Hereinafter, the cases will be described separately.

(C-1) Mix circuit 83 only before and after movement
First, the operation of the method of hunting the mix circuit 83 only before and after the movement will be described with reference to FIGS. 8 to 11. 8 to 11 show the flow of the information channel,
The flow of the control channel is omitted.

FIG. 8 shows a state where the cordless terminal 60 is in a call via the radio base station 50-1. The uplink information channel given from the cordless terminal 60 to the radio base station 50-1 is transmitted through the base station interface unit 71-1 accommodating the radio base station 50-1 and the uplink cordless switch unit 82 in order to a predetermined number. Given to a transcoder (for example, 72-1), this transcoder 72-1
The low bit rate voice coded data (ADPCM: 32 kb / s) peculiar to mobile communication is converted to standard voice coded data (μ-law PCM: 64 kb / s) in the exchange by the main division switch 30. To be in this way,
The mix circuit 83 is provided in the path of the uplink information channel at this time.
Is irrelevant.

The downlink information channel output from the main time division switch 30 is the transcoder 72-1 described above.
And a transcoder 73-1 for inverse conversion, which has a one-to-one correspondence with
The transcoder 73-1 converts the standard voice coded data in the exchange into low bit rate voice coded data peculiar to mobile communication, and the converted downlink information channel is converted to the downlink cordless switch unit 81. ,
It is given to the radio base station 50-1 via the base station interface unit 71-1 in order and transmitted to the cordless terminal 60.

The cordless terminal 60 monitors the accommodated radio base station and, for example, determines the accommodated radio base station based on the radio field intensity from the radio base station.
When the monitoring result that it is better to change from 0-1 to the base station 50-x is obtained, the switching to the radio base station 50-x is requested using the control channel for the radio base station 50-1. Such a switching request is given from the radio base station 50-1 to the cordless subscriber circuit 16, and its control processor 74 gives the switching request to the cordless controller 18.

The cordless controller 18 confirms the use status of the radio base station 50-x, etc., and if it can be assigned,
Let the cordless switch 20 set the path shown in FIG.
Immediately, the control channel is used to cause the cordless terminal 60 to transmit a request confirmation response (acknowledge).

That is, in the upstream direction, the mix circuit 83 is hunted, and the information channel from the radio base station 50-1 and the information channel from 50-x (the idle pattern of all 0) are transferred to the upstream cordless switch section 8.
2 to the mix circuit 83, and the information channel mixed by the mix circuit 83 is given to the main time division switch 30 through the upstream cordless switch section 82 and the predetermined transcoder 72-1 in order. .

In the downlink direction, the downlink information channel output from the main time division switch 30 is downlinked via the transcoder 73-1 for inverse conversion, which corresponds to the above-mentioned transcoder 72-1 on a one-to-one basis. The wireless base station 50 is provided to the direction cordless switch unit 81, is multi-connected by the down direction cordless switch unit 81, and sequentially through the base station interface units 71-1 and 71-x.
Both are given to -1 and 50-x.

In this way, two synchronized paths that can be switched at any time are established. The communication with the cordless terminal 60 is continuously executed via the wireless base station 50-1.

Upon receiving the request confirmation response (acknowledge), the cordless terminal 60 sets the transmission partner to the radio base station 50-x.
And the completion of movement is notified to the exchange 1 side using the control channel.

FIG. 10 shows the pass state at this time. With the switching, communication with the cordless terminal 60 is performed by the wireless base station 50-x. The routes in the cordless subscriber circuit 16 and the cordless switch 20 are the same as those in FIG. 9, but in the case of FIG. 9, the radio base station 50-x outputs the idle pattern.
In the case of 0, the wireless base station 50-1 outputs an idle pattern.

At the time of such switching, the mix circuit 83
The transcoder 72-1 is provided with a single line, so that when viewed from the side of the main time division switch 30, the wired interface is irrespective of which radio base station is involved in transmission and reception. The same processing as for the circuit can be continued. Further, since the mix circuit 83 is interposed, it is possible to prevent the instantaneous interruption regardless of which radio base station is involved in transmission / reception. That is, the cordless controller 18 does not need to execute strict timing control for preventing instantaneous interruption.

The information indicating the completion of movement included in the control channel received by the radio base station 50-x is obtained by the control processor 7.
4 to the cordless controller 18.
At this time, the cordless controller 18 changes to the pass state shown in FIG.

That is, the mix circuit 83 is released and the path to the radio base station 50-1 is released. Therefore, only the path between the radio base station 50-x and the main time division switch 30 in FIG. 10 remains.

Similar processing is performed when the cordless terminal 60 further moves to the zone of another radio base station.

According to the method of hunting the mix circuit 83 only during the period before and after the movement to switch the accommodated radio base station as described above, there is an advantage that the configuration of the mix circuit 83 can be made small, but the mix circuit 83 is provided. However, there is a disadvantage that inconvenience such as momentary interruption occurs during hunting and releasing.

FIG. 12 is an explanatory diagram of such disadvantages. In the state where the mix circuit 83 is not hunted, the information channel from the base station interface section 16 passes through the upstream cordless switch section 82 only once and is given to the transcoder 72.
The output frame from the upstream cordless switch unit 82 to the input cord 1 is delayed by one frame from the input frame to the upstream cordless switch unit 82 for the switching operation. On the other hand, when the mix circuit 83 is hunted, the base station interface unit 16
Since the information channel from the upstream cordless switch unit 82 passes through the upstream cordless switch unit 82 only twice and is given to the transcoder 72, the output frame from the upstream cordless switch unit 82 to the transcoder 72 is output to the upstream cordless switch unit 82. 2 frames behind the frame input to Therefore, in the transition to the hunt, only one frame of data (for example, an idle pattern) other than the information channel from the cordless terminal 60 relating to the movement is transmitted, and one frame of the information channel is discarded when the hunt is released. Will be.

In this case, one frame is, for example, one.
Since it is 25 μs, the cordless terminal 60 is hardly a problem in a telephone terminal (voice terminal), but may be a serious problem in a data terminal or a FAX terminal.

Therefore, the mix circuit 83 is included in the configuration of the exchange.
If the data terminal is accommodated and the quality requirement thereof is strict, it is preferable to constantly hunt the mix circuit 83 not only during the period before and after movement but also during a call, which will be described later.

(C-2) Operation by the method of hunting the mix circuit 83 during a call Next, the operation by the method of constantly hunting the mix circuit 83 during a call will be described with reference to FIGS. 13 to 16. 13 to 16 show the flow of the information channel, and the flow of the control channel is omitted.

In FIG. 13, the call is connected and the radio base station 50-
1 shows a path state in which the cordless terminal 60 and the exchange 1 are communicating with each other via 1. In this case, the mix circuit 83 is used when the path is first set in the call connection.
And the mix circuit 83 is passed in the upward direction. At this time, the wireless base station of the moving destination is not determined, but it is sufficient to form a pair with the channel transmitting the idle pattern and input it to the mix circuit 83. Except for this point, the operation is the same as the method in which the mix circuit 83 is hunted only before and after the movement, and the description thereof will be omitted.

FIG. 14 shows how the path is set when there is a movement request, and FIG. 15 shows how the path is set when the path is switched due to the movement. The operation according to FIGS. 14 and 15 is the same as the operation in the method of hunting the mix circuit 83 only before and after the movement, and the description thereof will be omitted.

The cordless terminal 60 which has completed the movement processing notifies the new radio base station 50-x of the movement completion by using the control channel. The movement completion information included in the control channel received by the radio base station 50-x is given to the cordless controller 18 by the control processor 74. At this time, the cordless controller 18
The path state is changed to that shown in FIG.

That is, the path with the radio base station 50-1 is released without releasing the mix circuit 83.
Therefore, only the path between the radio base station 50-x and the main time division switch 30 in FIG. 15 remains. At this time, the wireless base station of the moving destination is not determined, but it is sufficient to form a pair with the channel transmitting the idle pattern and input it to the mix circuit 83. The mix circuit 8
3 is released by the disconnection processing of the call.

(D) Effect of Embodiment According to the above embodiment, the cordless switch 20 is interposed between the base station interface section 71 of the cordless subscriber circuit 16 and the transcoders 72 and 73. Cordless switch 20 and transcoder 72
The structure of can be simplified.

FIG. 17 shows an example of a switchboard in which a cordless switch is provided at a position where it can be easily considered, and is to be compared with the above-mentioned embodiment and to clarify the effect of the embodiment. is there. In addition, in FIG.
The same or corresponding portions as and are designated by the same reference numerals.
Base station interface unit 71 and transcoders 72, 7
3, the cordless subscriber circuit 16 which is a unit to be attached to and detached from the exchange main body by the addition of a radio base station is constructed. Therefore, it is easily conceivable to provide the cordless switch 20 between the transcoders 72 and 73 and the main time divisional switch 30. Therefore, the data of the uplink information channel is code-converted and then input to the mix circuit 83. At this time, one input to the mix circuit 83 does not become a fixed pattern because the data from the wireless interface unit 71 is converted even if the data is guaranteed to be a fixed idle pattern. It is not possible to apply the simple OR operation configuration as shown in (3), which becomes complicated. In order to avoid this, the transcoder 73 needs to convert the fixed idle pattern into the fixed idle pattern, and the transcoder 73 becomes complicated because there is a portion where the simple conversion rule cannot be applied.

Conversely, according to the above embodiment, the mix circuit 83 provided for preventing instantaneous interruption without requiring strict timing control can have a simple and simple structure. .

Further, according to the above-mentioned embodiment, the fact that each cordless switch section 81, 82 is composed of a time division switch is also the reason why the mix circuit 83 has a simple and simple structure. .

Further, according to the above embodiment, even if the cordless switch 20 is interposed between the base station interface unit 71 and the transcoders 72 and 73, the base station interface unit 71 and the transcoders 72 and 73 are cordless. Since it is mounted on the same board that is separate from the switch 20,
As in the conventional case, the attachment / detachment operation can be performed for each cordless subscriber circuit 16 by adding a wireless base station.

Furthermore, if the hunt of the mix circuit 83 is performed from the time of call setting as described above, the cordless terminal 6
The hunt of the mix circuit 83 due to the movement of 0 between base stations /
Since the release process is eliminated, it is possible to further prevent instantaneous interruption. In such a case, the digital cordless terminal 60
However, high quality communication can be performed even if there is a strict requirement for instantaneous interruption such as FAX.

(E) Other Embodiments The present invention is not limited to the exchange system relating to the private branch exchange, but can be applied to the exchange system relating to the central office exchange. Further, the cordless terminal is not limited to the cordless telephone. Furthermore, the main switch and the cordless switch are not limited to the time division switch.

[0084]

As described above, according to the present invention, a base station interface section for interfacing between a radio base station and a switch body, and conversion of coded data on a radio line and coded data in the switch. Since a cordless switch for moving tracking, which is switched by a cordless controller when a cordless terminal moves between radio base stations, is interposed between the transcoder and
It is possible to realize a mobile communication switching system that can prevent instantaneous interruptions and that has a simple configuration and that is highly compatible with conventional wired interfaces.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of an embodiment.

FIG. 2 is a block diagram showing the overall configuration of the embodiment.

FIG. 3 is an explanatory diagram of input / output timing of the cordless switch unit according to the embodiment.

FIG. 4 is a unit configuration example (1) of the mix circuit of the embodiment.
It is a block diagram showing.

5 is a timing chart of each part of FIG.

FIG. 6 is a unit configuration example (2) of the mix circuit of the embodiment.
It is a block diagram showing.

FIG. 7 is a timing chart of each part of FIG.

FIG. 8 is an explanatory diagram (Part 1) of the first path setting method of the embodiment.

FIG. 9 is an explanatory diagram (Part 2) of the first path setting method of the embodiment.

FIG. 10 is an explanatory diagram (Part 3) of the first path setting method of the embodiment.

FIG. 11 is an explanatory diagram (Part 4) of the first path setting method of the embodiment.

FIG. 12 is an explanatory diagram of a defect in the first path setting method of the embodiment.

FIG. 13 is an explanatory diagram (1) of the second path setting method of the embodiment.

FIG. 14 is an explanatory diagram (No. 2) of the second path setting method of the embodiment.

FIG. 15 is an explanatory diagram (Part 3) of the second path setting method according to the embodiment.

FIG. 16 is an explanatory diagram (Part 4) of the second path setting method according to the embodiment.

FIG. 17 is a block diagram showing a configuration compared with the embodiment.

[Explanation of symbols]

1 ... Exchange (exchange main body), 16 ... Cordless subscriber circuit, 18 ... Cordless controller, 20 ... Cordless switch, 30 ... Time division switch (main switch),
40 ... Central processing module, 50 ... Wireless base station, 60 ...
Digital cordless terminal, 71 ... Base station interface unit, 72, 73 ... Transcoder, 74 ... Control processor, 81 ... Upward cordless switch unit, 82 ... Downward cordless switch unit, 83 ... Mix circuit, 83
a, 83c ... OR circuit.

Claims (5)

[Claims] 1. A mobile communication switching system comprising a digital cordless terminal, a radio base station, and a switch body, wherein the switch body has a base station interface section for interfacing between the radio base station and the switch body, and a wireless circuit. A cordless mobile tracking device in which a cordless controller switches a path between a codec on a line and a transcoder for converting coded data in a switch when a cordless terminal moves between radio base stations. A mobile communication switching system characterized by a switch. 2. The mobile communication switching system according to claim 1, wherein the cordless switch is a cordless switch unit in a downward direction from a main switch to the cordless terminal, and a cordless switch in an upward direction which is a reverse direction thereof. And a mix circuit for mixing the two information channels from the upstream cordless switch unit and re-inputting them to the upstream cordless switch unit, at least before and after the cordless terminal passes between the wireless base stations. The mobile communication switching system is characterized in that a path passing through the mix circuit is set to track the movement of the cordless terminal during the period. 3. The mobile communication switching system according to claim 2, wherein the downlink cordless switch unit and the uplink cordless switch unit are time-division switches, and the mix circuit has one input. The information channel from the cordless terminal is input to the terminal, and the other input terminal is configured by using a 2-input OR circuit or AND circuit in which an idle pattern of all 0 or all 1 is input. Communication switching system. 4. The mobile communication switching system according to claim 2, wherein a path passing through the mix circuit is set during a call connection period. 5. The mobile communication switching system according to claim 1, wherein the plurality of base station interface units and the plurality of transcoders are provided on the same cordless subscriber circuit board on which the cordless switch is not mounted. A mobile communication switching system characterized by being installed.