KR970002705B1 - Frame mapping/demapping for n-isdn - Google Patents

Abstract

An imframe mapping/demapping device for the N-ISDN where matches with the subscriber connection/terminal device having the passive optical network (PON) structure in the CATV. The said device consist of the first group multiplex matching means, one PCM control means at the least, one frame arrangement means at the least, clock division means, a signal detection and reset means.

Description

Frame Mapping / Demapping Unit for N-ISDN

1 is a block diagram of an optical cable and a CATV network to which the present invention is applied;

2 is a block diagram of a frame mapping / demapping apparatus according to the present invention;

3 is a frame mapping diagram from a primary group multiplexed signal V4RX to a mapper transmission signal 2MTX,

4 is a diagram of frame decoupling from a mapper received signal 2MRX to a first group multiplexed signal V4TX,

5 is an operation flowchart of a central processing unit.

* Explanation of symbols for main parts of the drawings

20: primary group multiple matching unit 21: PCM control unit,

22: frame alignment unit 23: central processing unit,

25: clock divider 26: signal detection and reset unit.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame mapping / demapping apparatus for narrowband integrated telecommunication networks that matches subscriber access / terminal apparatus having a PON (Passive Optical Network) structure in an optical cable.

Conventional frame mapping / demapping apparatus for narrowband integrated telecommunication networks is matched with a subscriber access device having a 1: 1 structure in a distribution center to map / demap a frame containing 12 basic accesses in a primary group multiplex signal. .

Accordingly, there is a problem in that subscriber access / terminal devices having a phone structure of 1: 3 downlink and 1: 1 uplink between a distribution center and a subscriber in an optical CATV network cannot be matched.

The present invention devised to solve the problems of the prior art, the 12 basic access to match the subscriber access / terminal device having a PON (Passive Optical Network) structure connected 1: down, 1: 1 down 12 basic accesses are multiplexed by extracting 2B + D and C (Cv1) channels from 12 subscribers' mapper received signals from the first group multiplexed signal An object of the present invention is to provide a frame mapping / demapping apparatus for a narrowband general information communication network that outputs a primary group multiplexed signal.

In order to achieve the above object, the present invention receives the primary group multiplexed signal (V4RX) from the outside, aligns the frame and outputs after absorbing the jitter components, and receives the primary group multiplexed signal and matches the primary group multiplexed signal. Primary group multiple matching means for outputting to the outside; A mapper received signal (2MRX) that receives the output of the first group multiple matching means, maps the time slot of the first group multiple signal frame, outputs a plurality of reconstructed frames, and reads the channel Cv4 for frame alignment and maintenance. At least one PCM control means for receiving a plurality of inputs and demapping them into the primary group multiplexing signals and outputting the primary group multiplexing means; Receives one of a plurality of reconstructed frames from the PCM control means, inserts a channel Cv4 for frame alignment and maintenance, generates a mapper transmission signal 2MTX, and outputs it to the outside, and receives a mapper received signal from the outside ( At least one frame alignment means for receiving 2MRX) and reading the channel Cv4 for frame alignment and maintenance and outputting the same to the PCM control means; Central processing means connected to said PCM control means for reading the contents of time slot 0 (Cv4 channel) of a frame and detecting and outputting information on frame loss and frame synchronization loss; Clock distribution means for receiving a clock from the outside and supplying a clock to the first group multiple matching means, the PCM control means, and the frame alignment means; When the clock is lost by detecting an external clock (4.096 MHz), a reset signal is supplied to the primary group multiple matching means, the central processing means, the PCM control means, and the frame alignment means, and the power is turned on. And detecting means for detecting a power supply Vcc and generating a reset signal when the power supply Vcc is turned off.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram of an optical cable, T. V network to which the present invention is applied.

In order to transmit 2B + D and subscriber control signals of subscriber and exchange period when receiving ISDN service in subscriber device of optical CATV network, it should be composed of frames applicable to digitalization and optical CATV network. Looking at the signaling state for the ISDN basic access from the exchange side to the subscriber side, the central station (CO) interfaces with the primary group multiple devices to transmit and receive the primary group multiplexed 2.048Mb / s digital signal multiplexed with 12 basic accesses. The ISDN service data transmission from the central station to the distribution center is composed of a CEPT (Conference of European Post and Telecommunication Adminstration) frame with a feeder signal of 2.048 Mb / s. Transfer to distribution center.

As shown in the figure, the central station 1 of the optical CATV network receives the primary group multiplexed signal V4 multiplexed with 12 basic accesses through the primary group multiple matcher of the switch 2, and the 45M multiple device 3 and 600M. When transmitting to the distribution center 5 through the transmission device 4, the distribution center 5 receives the primary group multiplexing signal by demultiplexing the 600M transmission device 6 in the distribution center 5 and the primary group multiple signal V4 in the 45M multiple device 7. The signal V4RX is matched with the frame mapping / demapping device 8 and then transmitted to the subscriber 13 side via the 155M multiple device 9. Conversely, the primary group transmission signal (V4TX) matched with the frame mapping / demapping device (8) is multiplied by the 45M multiple device (7), 600M transmission device and transmitted to the central station (1). Through the multiple device 3 it is demultiplexed into the primary group multiple signal V4 to match with the switch 2.

The frame mapping / demapping apparatus 8 provides 2.048Mb / s frames of 3B subscribers from the primary group multiplexed signal (V4RX) for 2B + D and C (Cv1) channels for ISDN basic access to the subscriber down side. Mapper transmission signal 1.2.3 (2MTX1.2.3), mapper transmission signal 4.5.6 (2MTX4.5.6), mapper transmission signal 7.8.9 (2MTX7.8.9), mapper transmission signal 10, 11, 12 (MTX10. 11.12), which is converted into an optical signal in the 155M multiple device 9 and transmitted to the subscriber 13 via the power splitter 11 and then through the 155M demultiplexer 14 and the subscriber device 15 through the narrowband ISDN. It provides a connection function.

In the case of the upstream side from the subscriber, the narrowband ISDN signal 2B + D, Cv1 received through the subscriber device 15 is converted into an optical signal in the uplink multiplexer 16 and then through the power coupler 12. It is transmitted to the distribution center 5, and recovered from the uplink signal demultiplexer 10 of the distribution center 5 to the mapper received signal 1 2MRX1 to match the frame mapping / demapping apparatus 8.

The frame mapping / demapping device 8 receives the clock (4.096 MHz) and the data primary group multiplexed signal i [V4RXi (i = 1 to12) from the uplink signal demultiplexer 10, after the data and clock are disconnected. When restored, it is configured to operate stably by operating the reset circuit.

2 is a configuration diagram of a frame mapping / demapping apparatus according to the present invention, as shown in the drawing, a first group multiple matching unit 20, a central processing unit 23, a clock distribution unit 25, a clock detection and reset unit 26, an alarm display and transmission unit 24, a PCM control unit 21, and frame alignment 22 are provided.

The primary group multiple matcher 20 uses a high density bipolar triad (HDB3) of 2.048 Mb / s European Similar Synchronous Signaling (CEPT) frame of the primary group of multiple devices of the exchanger (2) via a 45M multiple device (7). It is a part that matches high-density bipolar 3 code signal, and it has a frame alignment function and a two-frame elastic buffer to absorb 190 UI (Unit Interval) jitter.

The Pulse Code Modulation (PCM) control unit 21 is connected to the primary group multiple matching unit 20, the frame aligning unit 22, the clock divider 25, the clock detection and reset unit 26, and the central processing unit 23. do. The side where one PCM control unit 21 matches with the frame alignment unit 22 is capable of inputting and outputting four signals, and controlling 12B subscribers by switching 2B + D and Cv1 signals of the first group multiple signals into four frames. In order to accommodate, three PCM control parts 21 are required. Referring to the down-side operation, the PCM control unit 21 receives narrowband ISDN B + D channel and C (Cv1) channel information for three subscribers from the first group multiple signals of 12 subscribers received from the primary group multiple matching unit 20. Time slot 1,… Mapper transmission signal 1.2.3 (2MTX1.2.3), mapper transmission signal 4.5.6 (2MTX4.5.6), mapper transmission signal 7.8.9 (2MTX7.8.9) through the frame alignment unit 22, Generate a mapper transmission signal 10.11.12 (2MTX10.11.12). On the other hand, the PCM control unit 21 which receives 12 mapper received signals i [2MRX (i = 1 to 12] through the frame aligning unit 22 which contains 2 subscribers' 2B + D Cv1 channels upwards After the primary group multiple signal is made, the primary group multiple matching unit 20 converts the HDB3 linear signal.

The frame aligning unit 22 inserts a channel Cv4 for frame alignment and maintenance into time slot 0 of the reconstructed frame through the time slot control in the PCM control unit 21 to form a CEPT frame. Alignment and the upstream operation read out the channel Cv4.

The clock distributor 25 receives a clock of 4.096 MHz from the uplink signal demultiplexer 10 to make and supply a clock required for each part.

The signal detecting and resetting unit 26 receives a clock (4.096 MHz) from the uplink signal demultiplexing unit 10, and when the data and the clock are recovered after disconnection, the phase of the data and the clock do not coincide with each other, resulting in loss of data. When the clock is detected and the clock is recovered after the loss, the reset circuit is operated to supply the reset signal to the first group multiple matching unit 20, the central processing unit 23, the PCM control unit 21, and the frame alignment unit 22. In this case, the phase of the data and the clock coincide with each other. When the power is turned on / off, the power supply Vcc is detected to generate a reset signal.

The central processing unit 23 reads the contents of time slot 0 (Cv4 channel) of the European Similar Synchronous Signaling (CEPT) frame to detect alarms of frame loss and frame synchronization loss, and displays the alarm through the alarm display and the transmission unit 224. And transmit.

[Table 1] is a frame structure diagram of the primary group multiple signal (V4TX / V4RX), which is a group of primary group multiple signals that are transparently transmitted from the switch 2 through the 45M multiple device 3 and the 600M transmission device 4,6. Two narrowband ISDNs (2B + D and Cv1 channels) are simply multiplexed in a frame. B1, n represents a basic access n is a B1 channel, B2, n represents a B2 channel of a basic access n, C (Cv1) n represents a Cv1 channel of a basic access n, and Dn represents a D channel of a basic access n, respectively.

Table 1

Table 2 shows the bit arrangement of time slot 5 from the 45M communication channel multiple device side.

[Table 2]

FIG. 3 is a frame mapping diagram of the first group multiplexed signal (V4RX) to the mapper transmission signal (2MTX), which maps 3 subscribers' 2B + D and C (Cv1) channels into one frame corresponding to each subscriber. It shows the structure of pseudo-synchronous signaling (CEPT) frame.

4 is a frame demapping diagram from a mapper received signal (2MRX) to a primary group multiplexed signal (V4TX), wherein 2B + D and C (Cv1) from 13 subscribers transmitted from the optical CATV subscriber access unit side per subscriber. Remap to 2.048 Mb / s European pseudo-synchronous signaling (CEPT) frames that accommodate the

5 is an operation flowchart of the central processing unit.

The central processing unit 23 performs 2.048 Mb / s of 12 basic access multiplexed through the initialization of the primary multiple matching unit 20, the PCM control unit 21, and the frame aligning unit 22 to 2.048 Mb / After mapping to s frames (4 frames / 3 subscribers) (61) 2.048Mb / multiplexed 12 basic accesses by extracting 2B + D and C (Cv1) channels from 2.048Mb / s frames for 12 subscribers After demapping to s (62), the contents of time slot 0 (Vc4 channel) of the European Similar Synchronous Signaling (CEPT) frame are read to detect alarms of frame loss and frame synchronization loss (63). An alarm is displayed through 24, and a frame loss and frame synchronization loss alarm is transmitted.

As described above, the present invention can be matched to a subscriber access / terminal device having a PON structure, and when data is recovered after a clock, the data and the clock phases are aligned, and the subscribers desire the number of channels of the ISON basic access. By the software processing, the operator can easily handle the increase and decrease of the channel number of the subscriber.

Claims (3)

Primary group multiple matching signal (V4RX) received from the outside to align the frame and absorb the jitter components, and outputs, and receives the primary group multiple signal to match the primary group multiplexing signal output to the first group multiple matching means 20; Receives a mapper that receives the output of the first group multiple matching means 20 and maps it to a time slot of a first root multiplex signal frame, outputs a plurality of reconstructed frames, and reads a channel Cv4 for frame alignment and maintenance. At least one PCM control means (21) for receiving a signal (2MRX) again and de-packing it into the primary group multiplexing signal and outputting the primary group multiplexing means (20); Receives one of a plurality of reconstructed frames from the PCM control means 21, inserts a channel Cv4 for frame alignment and maintenance, generates a mapper transmission signal 2MTX, and outputs it to the outside. At least one frame alignment means (22) which receives a received signal (2MRX) and reads out the channel (Cv4) for frame alignment and maintenance and outputs it to the PCM control means (21); A central processing means (23) connected to said PCM control means (21) for reading out the contents of time slot 0 (Cv4 channel) of a frame and detecting and outputting alarms of frame loss and frame synchronization loss; Clock distribution means (25) for receiving a clock from the outside and supplying a clock to the primary group multiple matching means (20), the PCM control means (21) and the frame alignment means (22); And a first group matching unit 20, the central processing unit 23, each PCM control unit 21, and each frame alignment unit when the clock is lost by detecting an external clock (4.096 MHz). And a signal detecting and resetting means 23 for supplying a reset signal to the reset signal 22 and detecting a power supply Vcc and generating a reset signal when the power supply is turned on or off. Frame Mapping / Demapping Device. 2. The PCM control means (21) according to claim 1, characterized in that the PCM control means (21) is provided such that three PCM control means (21) are matched with respect to one primary group multiple matching means (20) to accommodate 12 subscribers. Frame mapping / demapping apparatus for narrowband Telecommunication Network. 2. The narrowing device according to claim 1, wherein the frame alignment means (22) is provided such that four frame alignment means (22) are matched with respect to one PCM control means (21) to accommodate 12 subscribers. Frame mapping / demapping apparatus for band integrated telecommunication network.