KR20000032904A - 6-channel card unit in wireless subscriber network - Google Patents

Abstract

PURPOSE: A 6 channel card unit in wireless subscriber network is provided to decrease a size of a board by processing 6 channels using a WLL modem for supporting an E1 trunk interface. CONSTITUTION: A time switch(1) transmits data inserted into a time slot of an E1 trunk or transmits data transmitted from a base station controller(30) to a modem. A CDCA unit(2) receives the signal switched by the time switch(1) and demodulates a modem transmitted from a subscriber. A digital adder(4) adds signals of the CDCA unit(2) for transmitting data of 6 channels. A first low pass filter(6) passes a uniform band signal among an analog signal of a D/A converter(5). An amplifier(7) amplifies the signal of the first low pass filter(6) as a certain level and outputs an output signal to a subscriber matching device(10). An amplifier(8) amplifies a signal inputted from the subscriber matching device(10) as a certain level. A second low pass filter(9) passes a uniform band signal among the signal amplified in the amplifier(8). An HDLC(high level data link control procedure) unit(11) inserts a D channel into the CDCA unit(2) or extracts the D channel among a 2B+D signal transmitted from the subscriber matching device(10).

Description

6 channel card unit of wireless subscriber network base station

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless subscriber network (WLL) system, and more particularly, to processing a microprocessor on one board using a WLL modem in which a channel card unit (CCU) supports an E1 trunk interface in a base station of a W-WLL system. The present invention relates to a six-channel card unit of a wireless subscriber station base station capable of processing six channels while reducing a load.

In general, the CCU of the WLL system is a module supporting an interface with a radio interface unit (RIU) in a base station, and is responsible for transmitting and receiving channel information and traffic to and from an RF module and a system.

The CCU is located in the channel self of the base station-digital rack and processes calls within the cell. It consists of 30 boards in 3 cells based on 3 sectors, which can handle a total of 180 channels. Has capacity.

In order to do this, it is interfaced with ACSU of RF stage through analog front end to send and receive sample analog signal, RCP and IPC communication through ALCU and LCU through parallel bus controller to send and receive call setup or CCU initial and control information. It is made to be.

Voice data or digital data is transmitted to the base station controller via the RCP and E1-RPC (Radio Port Controller) via the system highway interface.

However, in the prior art as described above, there is a problem that a high-speed processor must be used without using the E1 trunk interface, and since the peripheral logic must be used separately, the cost increases and the size of the board increases.

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 six-channel card unit of a wireless subscriber network base station that can reduce the processing load of a microprocessor by processing six channels through an E1 trunk interface. To provide.

1 is a view showing the overall configuration of a typical wireless subscriber network

2 is a block diagram of a six-channel card unit of the present invention wireless subscriber network base station

<Explanation of symbols for main parts of drawing>

1: Time switch 2: CDCA part

3: clock supply section 4: digital adder

5: D / A Converter 6: First Low Pass Filter

7, 8: amplifier 9: second low pass filter

10: A / D converter 11: HDLC part

In order to achieve the above object, the present invention provides a subscriber matching device which is located in the middle between a base station and a terminal to provide a wireless connection between the base station and the terminal, and wirelessly transmits and receives signals of the subscriber matching device to the CCU, RCP, and E1-. A base station including an RPC, a base station controller and an exchanger for controlling the base station, comprising a time switch, a modem, a digital adder, a converter, a low pass filter, and the like, in the CCU of the base station, for 6-channel information and traffic. Characterized in that configured to process the.

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

1 is a diagram illustrating a path of ISDN (Integrated Service Digital Network) traffic data, and is located in the middle between a base station and a terminal and a subscriber matching device 10 providing a wireless connection between the base station and the terminal and And a base station 20 for transmitting and receiving a signal of the subscriber matching device 10 wirelessly, including a CCU 21, an RCP 22, and an E1 RPC 23, and a base station controller for controlling the base station 20 ( 30) and exchanger (40).

FIG. 2 is a detailed configuration diagram of the CCU 21 in FIG. 1, and transmits data carried in the time slot of the E1 trunk from each modem to the base station controller 30 or transmits data transmitted from the base station controller 30 to the modem. A time switch 1 for transmission, a CDCA unit 2 which is a modem for demodulating a modem transmitted from a subscriber by receiving a signal switched by the time switch 1, and demodulating or demodulating modem data E1 trunk The clock supply unit 3 distributes 20ms, 32.768 MHz, and Even Sec to the channel card to accurately load the WLL modem data on the channel card, and the signals of the CDCA unit 2 are digitally transmitted to transmit 6 channels of data. A digital adder 4 to be summed in phase, a D / A converter 5 for converting the digital data of the digital adder 4 into an analog signal for transmission to the subscriber matching device 10, and the D / A converter 5 A) of The first low pass filter 6 which passes only a signal of a predetermined band from the analog output signal, and amplifies the signal of the first low pass filter 6 to a predetermined level to output the signal to the subscriber matching device 10. Amplified by the amplifier 7, the amplifier 8 which amplifies the signal RX input from the subscriber matching device 10 to a predetermined level, and a signal of a predetermined band in the signal amplified by the amplifier 8; A second low pass filter 9 for passing only, an A / D converter 10 for converting an analog signal of the second low pass filter 9 into a digital signal and outputting the digital signal to the CDCA unit 2; Insert the D channel having the ISDN call processing signal among the ISDN signals transmitted from the time switch to the CDCA unit 2 for the ISDN subscriber service in the CDCA unit 2 or the D 2B + D signal transmitted from the subscriber matching device 10. It consists of HDLC (High Level Data Link Control Procedure) part 11 to extract only channels It is.

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

First, in order to demodulate and demodulate modem data from the clock supply unit 3 or to accurately load WLL modem data on the E1 trunk, 20 ms, 32,768 MHz, and Even Sec are supplied to the channel card.

In this state, the data carried in the time slot of the E1 trunk from each modem is transmitted to the base station controller 30 via the system highway via the time switch 1, or vice versa, the data transmitted from the base station controller 30 is stored in the system. It is transmitted to the modem via the time switch 1 via the highway, where the data transmission speed is converted to 4.096 MHz by the time switch 1.

Normally, the 2.048MHz E1 trunk consists of 32 time slots. Time slots 1 and 16 are used for signal transmission to synchronize and control the E1 trunk. Each time slot consists of 8 bits. Data can be transmitted at a data rate of 32 Kbps per packet.

In addition, the modem supports data rates of up to 144Kbps, requiring three time slots per modem and can carry up to 10 subscriber data on an E1 trunk at 2.048MHz.

In the present invention, the CCU 21 is interfaced with the ACSU to transmit and receive analog sample signals. As shown in FIG. 1, the CCU 21 is interfaced to the RCP 22 and the E1RPC 23 through a system highway to provide voice encoded data and traffic related information. Give and take

Here, the CCU 21 includes a CDCA unit 2 which is a sub-board on which a modem chip and a Viterbi chip are mounted. The CDCA unit 2 can be equipped with six CDCAs and one CDCA processes one channel. There is one modem chip and one Viterbi chip.

The CDCA unit 2 needs a 32.768 MHz system clock supplied from the clock supply unit 3 and needs a clock of 20 ms and Even sec to synchronize.

Traffic data and voice coded data are switched by the time switch 1 via the system highway and interfaced to the CDCA unit 2.

Therefore, the CDECA unit 2 reads the data contained in the 2.048 MHz time slot transmitted from the time switch 1 and modulates the data. The modulated six-channel data is a digital adder for combining signals with other boards. 4) and then converted into digital data through the A / D converter 5, and then a signal of a predetermined level is passed through the first low pass filter 6, amplified by the amplifier 7, and then converted into RF. It is output to the matching device 10.

In this case, the digital adder 4 combines the respective signals in digital form to transmit six channels of data.

In contrast to the above, when a signal is wirelessly input from the subscriber matching device 10, the amplifier 8 amplifies the input signal to a predetermined level, filters it through the second low pass filter 9, and then A / D converter ( 10) converts the input signal into a digital signal.

The digital signal thus converted is demodulated through the CDCA unit 2, which is a modem, and the demodulated data is carried in a time slot of an E1 trunk of 2.048 MHz.

At this time, the HDLC unit 11 inputs the D-channel having the ISDN call processing signal among the ISDN signals transmitted from the time switch to the CDCA modem for the ISDN subscriber service to the CDCA unit 2 or from the subscriber matching device 10. It plays a role to extract only D channel among 2B + D signals transmitted.

As described above, since the present invention uses the E1 trunk interface, a low speed processor may be used, and thus, since the peripheral logic does not need to be used for the E1 trunk interface as in the related art, cost reduction and board size are reduced. It can be effective.

Claims (1)

The subscriber matching device 10 is located between the base station and the terminal to provide a wireless connection between the base station and the terminal, and wirelessly transmits and receives signals of the subscriber matching device 10 and the CCU 21 and the RCP 22 and the E1RPC. A base station 20 including 23, a base station controller 30 and a switch 40 for controlling the base station 20, A time switch 1 for transmitting data carried in the time slot of the E1 trunk from each modem to the base station controller 30 or transmitting data transmitted from the base station controller 30 to the modem; A CDCA unit 2 which is a modem for demodulating a modem transmitted from a subscriber by receiving the signal switched by the time switch 1; A clock supply unit (3) for distributing 20 ms, 32.768 MHz, and even sec to the channel card in order to demodulate and demodulate modem data or to accurately load WLL modem data on an E1 trunk; A digital adder (4) for digitally adding the signals of each of the CDCA units (2) to transmit six channels of data; A D / A converter 5 for converting the digital data of the digital adder 4 into an analog signal for transmission to the subscriber matching device 10; A first low pass filter 6 for passing only signals of a predetermined band from the analog output signal of the D / A converter 5; An amplifier 7 for amplifying the signal of the first low pass filter 6 to a predetermined level and outputting the signal to the subscriber matching device 10; An amplifier 8 for amplifying the signal RX input from the subscriber matching device 10 to a predetermined level; A second low pass filter 9 for passing only signals of a predetermined band in the signal amplified by the amplifier 8, An A / D converter 10 for converting the analog signal of the second low pass filter 9 into a digital signal and outputting the digital signal to the CDCA unit 2; 2B transmitted from the subscriber matching device 10 or inserting the D-channel having the ISDN call processing signal among the ISDN signals transmitted from the time switch 1 to the CDCA unit 2 for the ISDN subscriber service to the CDCA unit 2; And a HDLC unit (11) for extracting only D channels of the + D signals.