Frame transmission system
AssigneeNEC Corporation
InventorNaohiro Shimada
Life of this patent
Estimating the term…
Abstract
In a frame transmission system for transmitting multi-frames of a DS3.C-bit parity frame system as prescribed in American National Standard and also in Proposed Contribution to CCITT (ITU-T), C1-bits assigned to the prior art DS3.C-bit parity frame, i.e., 3.times.3=9 C-bits (fixed bits) for the 2nd, 6th and 7th channels, are used as control bits of DS2 level signal for intrinsic purposes. These bits may be processed in their entirely in the same manner as with the prior art control bits.
Claims12
A transmitter for transmitting DS3 frames each having a plurality of channels, first, second, and third channels among said plurality of channels each including three control bits, said transmitter comprising:
- a first stuff circuit for accommodating a DS2 level signal in the first channel;
- means for superimposing stuff information of the first stuff circuit on the control bits of the first channel;
- a second stuff circuit for accommodating a different DS2 signal in an externally assigned channel other than the first channel;
- means for superimposing the stuff information of the second stuff circuit on the control bits of the second channel;
- and
- means for superimposing channel assignment information indicative of the externally assigned channel on the control bits of the third channel.
A DS3 frame transmitter/receiver comprising:
- means for receiving a DS3 level signal having a plurality of channels;
- means for extracting channel assignment information from control bits stored in a channel among said plurality of channels;
- means for extracting first and second stuff information respectively from control bits stored in two other channels among said plurality of channels;
- a first de-stuff circuit for de-stuffing a channel assigned by the channel assignment information according to the first stuff information;
- and
- a second de-stuff circuit for de-stuffing another channel according to the second stuff information.
Dependencies are inferred from the claim text.