Synchronous digital multiplexer for on-frame multi plexing for multipath communication

Abstract

The frame structure is a rectangle structure: 64 rows / frame, 34 columns, 139264 kb / s. the first and second columns are the overhead. 3th-34th columns are affluent information. Under control of synchronous clock, each affluent is queuing. First row of first frame is written into 256 bits of first frame of first affluent, and second row of first frame is written into 256 bits of first frame of second affluent and so on. In multiple connection procedure, with decoded to NRZ code, under control of main clock, each affluent is written to own buffer register. Then, under control of synchronous multiple connection clock, the procedure is continued to enter each queue equipment, mixer and encoder to output codes. The method overcomes the shortcomings of PDH and is better than SDH, providing features of less investment, good compatibility and lower technical difficulties.

Description

(1) Technical field [0001] The invention belongs to the technical field of multiplexing communication, and relates to a synchronizing device in a time division multiplexing system, in particular to a synchronous digital multiplexer for frame-based multiplexing of multiplexed communications. (2) Background technology [0002] The asynchronous multiplexer (PDH) is widely used on the existing multiplexed communication transmission lines, and this multiplexer adopts the method of "multiplexing by bit" (that is, multiplexing by bit). For example, the patent application number is 93106839 "Synchronous Multiplexing Method and Device for Adjusting Frame Structure Using Positive (or Negative) Code Rate". The bitwise (bit) multiplexing method is shown in Figure 1①. When multiplexing, first write the first bit of the first tributary, then write the first bit of the second tributary, ... and finally write the first bit of the last tributary; then write The 2nd bit of the 1st tributary,...

AI Technical Summary

Problems solved by technology

PDH has three major disadvantages: (1) There are multiple multiplexing systems in the world (such as 1.544Mb / s in North America, 2.048Mb / s in Europe, 1.544Mb / s in Japan, etc.), and devices with different multiplexing systems are not compatible; (2) The amount of equipment is large, and the up and down channels are complicated; (3) There are not enough overhead bytes, and the network management capability is poor, and the equipment of various manufacturers cannot be uniformly monitored

In order to overcome the three major shortcomings of PDH, SDH not only adopts code rate adjustment technology, but also adopts high-tech technologies such as positioning mapping and pointer management, and inserts a large number of bytes (overhead) for management, which makes SDH equipment not only technically difficult , the multiplexing efficiency is low, and when the PDH equipment is updated, all the equipment (including microwave and fiber channel equipment) of the original PDH system must be completely eliminated

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