KR20010057299A - Serve channel control apparatus and method between base station and base station controller for ATM system - Google Patents

Abstract

PURPOSE: An apparatus for controlling a subchannel between a base station of an asynchronous transmission mode system and control station of the base station is provided to increase transmission efficiency between an RP and an RPC in a WLL(Wireless Local Loop) system as well as facilitate maintenance and expandability of the system by reducing installation cost and time of an E1 link. CONSTITUTION: When a system is turned on, a PBA is initiated and an E1 frame is inputted through an E1 line interface transformer. An HDLC(High-level Data Link Control Procedure) array detects a D-channel and an E1 RP/RPC CPU extracts a payload and sends to an RMCU(RPC Main Control Unit). The RMCU analyzes the information for processing a call and sends a subchannel switching command. Then, the input subchannel is compared with the predetermined channel. If the input subchannel is not identical with the predetermined channel, the E1 RP/RPC CPU sends an 8bits channel switching command to a time switch. Subsequently, in case that the RMCU switches to an IWF(Inter Working Function), the IWF connects to the Internet. Otherwise, the E1 RP/RPC CPU sends the subchannel switching command to a time switch. Then, the E1 RP/RPC time switch assigns an 8bits channel per one data of an ADPCM and sends to a main switch. The RMCU sends the input data to an ECTU, processes the data by a transcoder, and transmits the data processed by a vocoder to an exchanger.

Description

{Serve channel control apparatus and method between base station and base station controller for ATM system}

The present invention relates to a WLL system, and more particularly, to an apparatus and method for controlling a subchannel between a base station and a base station control station in an asynchronous transmission mode system for improving E1 link transmission efficiency between an RP and an RPC in a WLL system.

In general, the WRP system's RP and RPC are matched with E1 / LAPD, and their physical connection method is implemented using equipment such as E1 dedicated line or HDSL.

These leased lines are installed and provided by WLL service providers. The number of E1 leased lines is determined by the switch capacity of the WLL RP.

The E1 dedicated line basically provides 32 PCM channels, and channel 0 is used as a synchronization channel and channel 16 is used as a dedicated channel for the LAPD protocol, so only 30 channels can be provided.

The OMNI base station of the WLL system provides 30-40 channels by default, but three E1 dedicated lines are needed because 1FA 3 sectors must accommodate 90-120 channels.

This E1 leased line has a disadvantage of high initial installation cost, so it is necessary to design the base station capacity increase well later, but it is difficult to accurately estimate the service growth rate according to the region, and it is very difficult to establish one E1 link when the capacity of the E1 link is exceeded. It takes a lot of time and money.

Conventionally, there is a method of maximizing the limited E1 link between RP and RPC as a means to solve this problem.

That is, 64 Kbps PCM voice information between RP and RPC is modulated and transmitted by 32 Kbps ADPCM, and only 4 bits are filled in one voice channel.

FIG. 1 is a basic conceptual diagram of subchannel switching between RP and RPC of a WLL system, and (A) is a conceptual diagram illustrating a state in which voice-modulated ADPCM data is transmitted and received on one 8-bit channel in a conventional system.

(B) is a conceptual diagram for performing subchannel switching between RP and RPC, and is a conceptual diagram illustrating a state of transmitting and receiving two 4-bit ADPCM data on one 8-bit channel.

FIG. 2 is a block diagram of an E1 RP / RPC matching board unit when implemented in an E1 matching unit among various methods for performing subchannel switching between RP and RPC, and FIG. 3 is a CCU / ECRU for performing subchannel switching. A block diagram of the unit.

Such subchannel switching methods are performed in the RMCU (RPC Main Control Unit) and RCP (RP Control Processor) where the main switch is located, and the CCU (Cannel Control Unit) and ETU that directly handle each 4-bit ADPCM data. There is a way to do it in (Echo Canceller & Trancoding Unit).

However, since the conventional RMCU / RCP is implemented in the main switch, the system configuration has a simple advantage, but it requires a large capacity switch, which requires a lot of software load.

In addition, since the method implemented in the CCU / ETU currently handles subchannels in each part, a separate hardware implementation is unnecessary, but there is a disadvantage in that full capacity subchannel switching for a corresponding base station cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a switching device for a subchannel that increases the transmission efficiency of an E1 link between an RP and an RPC in a WLL system, thereby providing system maintenance and scalability. The present invention provides a subchannel control apparatus and method between a base station and a base station control station in an asynchronous transmission mode system to facilitate this.

1 is a conceptual diagram of subchannel switching

2 is a block diagram of an E1RP / RPC unit performing subchannels

3 is a block diagram of a CCU / ECTU unit performing subchannel switching

4 is a block diagram of an E1RP / RPC unit performing subchannel switching of the present invention.

5 is an operation flowchart of an E1RP / RPC unit performing subchannel switching according to the present invention.

<Explanation of symbols for main parts of drawing>

10: E1 line interface transformer 11: E1 framer and transformer

12: Clock synchronous 13: HDAL array

14: Time switch 15: Parallel bus controller

16: CPU 17: EPLD Interrupt Handler

18: Romans 19: Ram

20: Fresh rom 21: SIO

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a detailed block diagram of an E1 RP / RPC unit performing subchannel switching, and transmits and receives an E1 frame interface 10 and an E1 line interface transformer 10 that matches the characteristics of E1, a physical connection method between a base station and a control station. And an E1 framer and transceiver 11 for checking and recovering an error of the input E1 frame and synchronizing the clock; and a clock synchronizing unit 12 for supplying a clock synchronization signal to the E1 framer and transceiver 11, and an E1 frame. As a controller for LAPD processing, an HDLC array 13 for extracting a high-level Data Link Control Precedure (HDLC) frame from a channel assigned to each channel in an input E1 frame, and a parallel bus controller (15) inside a matching device. The time switch 14, the parallel bus controller 15, and each unit for analyzing the information of the input data and sending the sub-switching information to the upper control unit through CPU 16 for controlling the CPU, an EPLD 17 for dealing with various clocks and decoders / interrupts used therein, a ROM 18 having software for starting a board on-board, and application software. When the program of the ROM 18 is driven and the software recorded therein is loaded into the RAM 19, the fresh ROM 20 is driven and the application software is loaded and used to store variables for various calculations. RAM 19 is used, and a serial input SIO (Serial Input-Output) 21 which serves to help communicate with the internal through RS-232.

Referring to the operation of the present invention configured as described above is as follows.

The E1 line interface transformer 10 sends the E1 line framer and the transceiver 11 to the E1 line framer and the transceiver 11 according to the characteristics of the physical connection method between the base station and the control station. It checks and restores, synchronizes the synchronization input from the clock synchronization unit 12, and transmits / receives an E1 frame.

In addition, the HDLC array 13 performs control for LAPD processing between E1 frames, and the time switch 14 performs a subchannel directly in the matching device.

The CPU 16 analyzes the call processing and control information extracted from the HDLC array 13 and sends the information to the upper controller through the parallel bus controller 15. The CPU 16 analyzes the information of the input data and sub-switching information therefor. Receives and controls the time switch unit 14.

The EPLD decoder interrupt handler 17 handles various clocks and decoders / interrupts used therein, and the ROM 18 has software for starting a board when the board is powered on.

In addition, the fresh ROM 20 is a memory in which application software is embedded, and when a program of the ROM 18 is driven, the software recorded therein is loaded into the RAM 19 and driven.

In this case, when the application software of the fresh ROM 20 is loaded and used, the ROM 18 is used as a storage location of variables in various operations, and the SIO 21 is used as a serial port.

FIG. 5 is an operation flow diagram for implementing subchannel switching in the present invention. In the power-on, the PBA is initialized and an E1 frame is input through an E1 line interface transformer (S1-S3).

The HDLC array 13 detects the D channel (step S4), extracts the payload from the E1RP / RPC CPU, and transfers it to the RMCU (steps S4 and S5).

Then, the RMCU analyzes the call processing information and issues a subchannel switching command (step S6).

Accordingly, when it is determined whether the input subchannel is the same as the preset channel, the 8-bit channel switching command is issued to the time switch 14 by the E1RP / RPC CPU (step S8).

In addition, when switching from the RMCU to the data communication matching device IWF, the data communication matching device accesses the Internet (steps S9 and S10).

On the other hand, if the sub-channel input in step S7 is the same as the preset channel, the sub-channel switching command to the time switch 14 in the E1RP / RPC CPU (step S11).

Then, the E1RP / RPC time switch 14 allocates one 8-bit channel per ADPCM data to the main switch (step S12).

In addition, the RMCU transfers the input data to the ECTU and then processes the transcoder (step S13) and transmits the data processed by the vocoder to the exchange (step S14).

As described above, the present invention can increase the E1 link transmission efficiency between the RP and the RPC in the WLL system, and has an effect of facilitating system maintenance and scalability by modularizing the mounting board.

Claims (2)

A subchannel controller between a base station and a base station control station in a WLL system, An E1 line interface transformer 10 for matching the characteristics of E1, which is a physical connection method between a base station and a control station, An E1 framer and transceiver (11) for transmitting and receiving an E1 frame and checking and recovering and synchronizing an error of an input E1 frame, A clock synchronization unit 12 for supplying a clock synchronization signal to the E1 framer and the transceiver 11, HDLC array 13 which is a controller for LAPD processing between E1 frames, A time switch 14 which is sent from the matching device to the upper controller through the parallel bus controller 15 and analyzes the information of the input data and receives sub-switching information thereof; The parallel bus controller 15 sends call processing and control information extracted from the HDLC array 13 to an upper control unit; CPU 16 which controls each part, EPLD 17 which handles various clocks and decoders / interrupts used internally, The ROM 18 in which the software for starting the board at the board power-on is mounted, and the memory in which the application software is built, and when the program of the ROM 18 is driven, the software recorded therein is loaded into the RAM 19 and driven. Fresh ROM 20, RAM 19, which is used as a storage location of variables in various operations when the application software is loaded and used, Sub-channel control device between the base station and the base station control station of the asynchronous transmission mode system, characterized in that it comprises a SIO (21) used as a serial port to communicate with the internal through the RS-232. A subchannel control method between a base station and a base station control station in a WLL system, A first step of initializing the PBA upon power-on and inputting an E1 frame; Detecting a D channel in the HDLC array, extracting the payload from the E1RP / RPC CPU, and delivering the extracted channel to the RMCU; Performing a sub-channel switching command after analyzing call processing information in the RMCU to determine whether the input sub-channel is equal to a preset channel; If the sub-channel input in the third step is different from the preset channel, and the 8-bit channel switching command to the time switch in the E1RP / RPC CPU, the fourth step of switching to the data communication matching device in the RMCU and connected to the Internet; , If the subchannel input in the third step is the same as the preset channel, the subchannel switching command is issued to the time switch from the E1RP / RPC CPU, and the E1RP / RPC time switch allocates one 8-bit channel per ADPCM data to the main switch. The fifth stage of delivery, The RMCU comprises a sixth step of transmitting the input data to the ECTU, transcoder processing, and transmitting the data processed by the vocoder to the exchange to the base station and the base station control station of the asynchronous transmission mode system.