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Concentrating Low Speed Lines into a High Speed Link

IP.com Disclosure Number: IPCOM000085256D
Original Publication Date: 1976-Mar-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 3 page(s) / 33K

Publishing Venue

IBM

Related People

Blanc, A: AUTHOR [+2]

Abstract

Two basic techniques are used for concentrating a plurality of low-speed lines into a high-speed line using time-division multiplexing.

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Concentrating Low Speed Lines into a High Speed Link

Two basic techniques are used for concentrating a plurality of low-speed lines into a high-speed line using time-division multiplexing.

Assuming v and V are the bit rates of each of the low-speed lines and of the high-speed line, respectively, the first technique permits the concentration of N low-speed lines, N being defined by Nv=V. This technique has good performances but is costly. According to the second technique, each low-speed line is sampled at v1>v, and each sample is transmitted. v1 is chosen according to distortion D:

v1 = v/D

This technique permits the concentration of Nl low-speed lines:

N1v1 = V

This second technique is not costly but has poor performances.

For example, assuming v = 200 bps and V = 64 Kbps, the first technique permits 320 lines to be concentrated, while only 16 lines with maximum distortion D = 5 % can be concentrated by using the second technique.

Described is a third technique which permits greater concentration at a low- cost, more lines than the second technique does.

Each low-speed (v) input line is sampled at rate v2=pv. The sequence S1 of samples is fed to an adapter in which a second sequence of samples S2 is derived therefrom by selecting one every q samples. The other intermediate samples of S1 are stored in the adapter. In sequence S2 p/q successive samples have the same binary value. A third sequence of samples S3 is transmitted to the multiplexer, which sequence S3 i...