US 6,480,511 B1 · Arrangement for synchronization of a stream of synchronous traffic delivered by an asynchronous medium

Abstract

An ATM cell constructor (100) of an ATM transmitter assembles a stream of frames of constant bit-rate traffic received on a listen TDM bus (102) into cell payloads (1104) using ATM adaptation layer 1 (AAL1). Once every eight cells, the AAL1 structured data transfer (SDT) cell constructor layer (112) introduces a one-octet SDT offset pointer (1120) into the payload. This pointer designates traffic-block (TDM frame) boundaries. The payload with an attached ATM header forms an ATM cell, and the constructor transmits a stream of the ATM cells to an ATM cell deconstructor (2100) of an ATM receiver. The deconstructor disassembles the payloads of the received ATM cells and transmits the stream of frames of constant bit-rate traffic on a talk TDM bus (102). In response to each received SDT offset pointer, the deconstructor's time slot interchanger (TSI 2108) resets to the start of frame-processing, thereby aligning frames formed by the TSI with the received frames. The deconstructor (2100:2104) detects occurrence of TDM frames on the talk TDM bus and synchronizes (aligns) transmission of the frames formed by the TSI with the TDM frames on the talk TDM bus. The listen and talk TDM buses are thereby synchronized with each other.

Claims21

Dependent claims

A method of synchronizing synchronous information received by a receiver over an asynchronous communications link with a synchronous communications medium at the receiver, comprising:

asynchronously receiving at the receiver a stream of information including the synchronous information and an indication of where in the stream of information occurred a boundary between blocks of information;
transmitting the stream of information from the receiver on the medium;
detecting at the receiver where boundaries between blocks for information occur on the medium;
and
in response to receipt of the indication;
synchronizing transmissions from the receiver on the medium of information at the boundary indicated by the indication in the stream of information with occurrence of a boundary between blocks on the medium.

3 more elements

A method of synchronizing a first synchronous communications medium at a receiver of an asynchronous communications link with a second synchronous communications medium at a transmitter of the asynchronous communications link, comprising:

detecting at the transmitter occurrence of a boundary between blocks of information in a stream of information being received from the second medium at the transmitter;
transmitting the information asynchronously from the transmitter to the receiver with a first indication of where in the stream of information the boundary occurred;
receiving the information and the first indication at the receiver;
transmitting a stream of the information from the receiver on the first medium;
detecting at the receiver where boundaries between blocks for information occur on the first medium;
in response to receipt of the first indication, synchronizing transmission from the receiver on the first medium of the information at the boundary indicated by the first indication with occurrence of a boundary between blocks on the first medium.

3 more elements

Dependencies are inferred from the claim text.

Arrangement for synchronization of a stream of synchronous traffic delivered by an asynchronous medium

Life of this patent

Arrangement for synchronization of a stream of synchronous traffic delivered by an asynchronous medium

Life of this patent

Abstract

Claims21