KR20000056078A - Wireless private branch exchange - Google Patents

Abstract

PURPOSE: A radio private exchange is provided to implement hand-over of subscribers in the system, by building many radio private exchanges based on a Code Division Multiple Access(CDMA) system in normal private exchanges, to match synchronization of each card line in a burst type of controllers, when admitting many subscribers. CONSTITUTION: A radio private exchange comprises base stations(40), line drivers(51), a burst type of controllers(53), an oscillator(71), and a clock buffer controller(72). The line drivers(51) drive the base stations. The burst type of controllers(53) control the base stations via the line drivers. The oscillator(71) supplies a synchronization clock with the controllers. The clock buffer controller(72) buffers the synchronization clock. The radio private exchange supplies the synchronization clock with a rest burst type of controllers from the controllers, by setting a burst type of controller among the many controllers as a master burst type of a controller.

Description

Wireless private branch exchange

TECHNICAL FIELD The present invention relates to a wireless private exchange system, and more particularly, to a wireless private exchange system that is suitable for implementing handover of subscribers in a wireless private exchange system by matching synchronization between wireless private exchange subscribers.

The national exchange is the central nerve of the national telecommunication, which is installed to provide the convenience of the whole nation, and the user is intended for the national. The private exchange or the application communication system serves the subscribers of the single station, the lowest station of the public telecommunication network. .

Private exchanges are used mainly in places where there are many inter-extension business contacts such as hotels, department stores, government offices, and large corporations.

Private exchanges provide automatic call distribution, conference calls, nightly transmissions of emergency calls, data services, and mail services in addition to the normal switched access functions.

As described above, a private exchange is used to exchange and connect a subscriber so that mutual call between subscribers is possible.

In addition, private exchanges are provided to support wired telecommunications services in the premises, and provide wired and mobile communication (wireless) services in the premises, and handover such as Digital European Cordless Telecommunication (DECT) and the like. There is a wireless private switching system to support digital enhanced cordless telecommunications with the addition of automatic roaming.

The wireless private switching system to support conventional digital enhanced cordless telecommunications is a digital cordless telephone standard that the European Telecommunications Standards Organization published specifications in 1992 and is promoting standardization. To improve handover and automatic roaming, making it a flexible, low-cost system standard, especially for telepoint or personal cellular communications (PCS) functions in crowded urban areas. to be.

The conventional digital enhanced cordless telecommunications is characterized by being widely used for home use, but there is no interface technology between digital enhanced codeless telecommunications (DECT) because it is installed separately and a wireless private exchange system is used for home use.

Hereinafter, a conventional wireless private exchange system will be described with reference to the accompanying drawings.

1 is a block diagram illustrating a conventional wireless private exchange system.

In the conventional wireless private exchange system, as shown in FIG. 1, one common control fixed part (hereinafter abbreviated as CCFP) 8 and a plurality of line cards 5a and 5b are provided. (5n).

At this time, one line card 5 is composed of a plurality of base stations 11, one base station can accommodate eight base stations 4, eight base stations can accommodate 12 subscribers.

The line card 5 is a burst type control unit 12 for demodulation, encryption, and cyclic redundancy check (CRC) for time division multiple access frames based on time division multiple access (TDMA) / time division multiplexing (TDM). A prediction encoder 13 having a transmission rate of 32 Kbps, an echo canceller 15 for eliminating echo components that may occur when the distance between the base station 11 and the line driver 14 is 600 m or more; And first and second erasable program logic units 16 and 17 for interfacing the pulse code modulated signal and the high level data link control procedure, and a control unit 18 for controlling the operation of the line card 5. do.

In addition, the CCFP 8 includes a conference & switching module unit 20 for switching a common highway 19 of each line card 5 and a high level for signaling of each line card 5. Trunk module 23 for interfacing with data link control procedure adjustment section 21, echo cancellation section 22 for canceling echo components, and digital enhanced codeless telecommunications (DECT) private exchange 30. And a central processing unit 24 for controlling the line card interface module unit 8.

In this case, reference numeral 25 denotes a pulse code modulation synchronization unit, because synchronization is required for handover between base stations 11 belonging to each of the line cards 5a, 5b, and 5n. to be.

And, the data link control procedure adjustment unit 21 is connected with the wired subscriber line (2).

In the conventional wireless private exchange system having such a configuration, when a plurality of line cards 5 for enabling communication with a wireless subscriber are provided in the existing DECT private exchange 30, a plurality of DECT private exchange 30 and A CCFP 8 is provided between the line cards 5 to interface between the DECT private exchange 30 and the line card 5 to send and receive wireless subscribers through the base station 11 belonging to each line card 5. When you want to handle the call, you go through the CCFP (8).

First, when a call is input through the private exchange 30, the trunk < RTI ID = 0.0 > 23 < / RTI > is input to the conference & switching module unit 20, and the conference & switching module unit 20 performs a wired / wireless subscriber switching process. If the call goes to the subscriber, the call is switched to the wired subscriber line 2, and if the call goes to the wireless subscriber, the call is switched to the line card 5. At this time, the pulse code modulation synchronization unit 25 generates a synchronization signal for processing the handover of the base stations 11 belonging to different line cards 5.

In addition, the wireless subscribers belonging to all the base stations 11 can make an extension call through the trunk < RTI ID = 0.0 > 20 < / RTI >

The plurality of line cards 5 may be mounted on a subscriber board (not shown) of the private exchange system 30. That is, it may be mounted in any slot of each shelf, and the remaining slots allow the subscriber line board to be mounted.

In the conventional wireless private switching system, 96 subscribers in one line card use the same synchronization, so there is no problem in handover between each other, but CCFP controlling all line cards in the system for handover between subscribers in other line cards. In this case, since the additional CCFP must be installed in all existing wireless private exchange systems, there was a problem that the cost increased along with the installation problem.

An object of the present invention is to simply configure a plurality of wireless private exchanges in a general private exchange based on a time division multiple access system so that each burst scheme control unit synchronizes each line card when accommodating a large number of subscribers. The present invention provides a wireless private exchange system.

According to a feature of the present invention for achieving the above object, a plurality of base station, a plurality of line driver for driving the base station, a plurality of burst control unit for controlling the plurality of base stations through the plurality of line driver And a oscillator for providing a synchronous clock to the plurality of burst scheme controllers, and a clock buffer controller for buffering the synchronous clock, and setting one of the burst scheme controllers as a master burster controller. The master burst scheme controller provides a synchronization clock to the remaining burst scheme controller.

According to the present invention as described above, handover between subscribers is easy because the synchronization of the wireless private exchange system can be synchronized at a low cost.

1 is a block diagram showing a conventional wireless private exchange system

2 is a block diagram showing a wireless private exchange system of the present invention

Figure 3 is a block diagram showing in detail one line card of the wireless private switching system of the present invention

Description of the main parts of the drawing

40: base station 50: line card

51 line driver 52 logic logic

53: burst method control unit 54: predictive encoding unit

55: echo canceller 56: program logic section

57: control unit 71: oscillator

72: clock buffer control unit

Hereinafter, the configuration and operation according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a block diagram of a private exchange system of the present invention, and FIG. 3 is a block diagram showing one line card of the wireless private exchange system of the present invention in detail.

As shown in FIG. 2, the private switching system of the present invention is based on a plurality of base stations 40, a line driver 51 controlling the base stations 40, and time division multiple access (TDMA) / time division multiplexing (TDM). To remove the echo components that may occur between the burst mode control unit 53a and the base station 40 and the line driver 51a that perform modulation / demodulation, encryption, and cyclic redundancy check (CRC) for time division multiple access frames. The first to fifth program logic sections 52a ₁ , 52a ₂ , 52a ₃ , 52a ₄ , 56a for interfacing the echo canceller 55a, the pulse decoded modulation signal, and the high level data link control procedure; And a predictive encoding unit 54a for transmitting data, and a control unit 57a for controlling the operation of the line card 50a.

In this case, the first to eighth burst mode control unit _{(53a 1) (53a 2)} ··· (53a 8) the first burst mode control unit (53a ₁₎ of the master (master) and the other second to eighth burst The first burst scheme control section 53a ₁ uses the rest of the burst scheme control section 53a ₂ and 53a _{3 with the} scheme control section 53a ₂ (53a ₃ ).... 53a ₈ as a slave. (53a ₈ ).

That is, as shown in FIG. 3, an oscillator 71 which performs clock source control and sync clock buffering in each line card 50a, 50n, and a clock buffer control unit. It constitutes 72.

At this time, all of the burst mode controllers 53a receive a clock of 13.824Mhz and use it as a clock source.

However, when the chip is designed such that only the first burst mode controller 53a ₁ set as the master outputs the sync clock Sync_Clock through the sync port, the remaining burst mode controller 53a ₂ 53a is a slave. ₃ ) The sync port SYNC_PORT of 53a ₈ operates as an input pin PIN, and receives the synchronization clock Sync_Clock from the master burst mode control unit 53a ₁ to synchronize.

At this time, only the first burst mode control unit 53a ₁ , which is set as a master line card by firmware, sets the synchronization port SYNC_PORT as an output, and the remaining seven burst mode control units 53a ₂ and 53a are set. ₃ ) Burst mode control unit 53b ₁ (53b ₂ ) 53b ₃ of the second to nth line cards 50b in addition to 53a ₈ ... 53b ₈ The synchronization clock SYNC_CLOCK can also be provided to 53n ₁ 53n ₂ 53n ₃ 53n ₈ .

At this time, one of the plurality of burst mode control sections 53a of one line card 50a is set as a master and transferred to another line card 50b, 50c ... 50n without fanout. When the master or slave is set, the flag is set in software, and the fanout is performed by placing a buffer on each of the line cards 50a, 50b, and 50n.

At this time. The reference numerals are an interrupt generator 62 for generating an interrupt, a chip selector 60 for selecting a chip, a master slave selector 63 for selecting a master slave, and the like.

The present invention develops only a DECT line card when a DECT (Digital Enhanced Cordless Telecommunication) system is installed in a private exchange, so that the subscriber line circuit is not changed without changing the structure of the existing private exchange system. As long as the number of subscribers required to install the DECT line card as in the circuit), the structure of the system is simple, the price is lowered, and the operator operating it can be easily installed.

Claims (1)

A plurality of base stations; A plurality of line drivers for driving the base station; A plurality of burst scheme controllers controlling the plurality of base stations through the plurality of line drivers; An oscillator for providing a synchronization clock to the plurality of burst control units; And a clock buffer control unit configured to buffer the synchronization clock, wherein one burst control unit of the plurality of burst control units is set as a master buster control unit to provide a synchronization clock from the master burst control unit to the remaining burst control unit. Wireless private exchange system, characterized in that.