Time division multiplexing for telex signals

Abstract

Abstract The disclosed multiplexer responds to data appearing on separate channels at different signalling speeds or bit rates. At least two sampling rates are selected. One of the sampling rates is a base rate equal to or higher than the lowest signalling speed and the other sampling rate is a multiple of the base rate equal to or higher than the fastest signalling speed. The lowest speed signals are sampled at the base rate and the higher speed signals with the higher rate. The resulting sampled data is then interleaved. The lowest bit rate occupies the normal number of slots and the higher bit rate occupies a multiple number of the low rate slots. The interleaved signals are then transmitted. To accommodate telex call-establishing signals, which may occur in the same channel at rates different from the data rate, the existence of such call-establishing signals is determined and the sampling times are adjusted. The sampled signals are regenerated into bits which are multiples of the data rate. These bits are interleaved as data. Within the multiplexer distortion is removed by regenerating the signals in each channel on the basis of the condition of the center of each bit. This is comparable to a repeater. The bit center is located by high speed sampling techniques which count to the center of each bit on the basis of predetermined programs which are preset in accordance with the expected bit rate in each channel.

Inventors

• 👤 P Cohen
• 👤 P Ackerman

Bibliographic Details