Startup protocol for high throughput communications systems

Abstract

A startup protocol is provided for use in a communications system having a communications line with a master transceiver at a first end and a slave transceiver at a second end, each transceiver having a noise reduction system, a timing recovery system and at least one equalizer all converging at startup of the system. The operation of the startup protocol is partitioned into stages. The first stage includes the step of converging the equalizer and the timing recovery system of the slave while converging the noise reduction system of the master. Upon completion of the first stage the protocol enters a second stage which includes the step of converging the equalizer and the timing recovery system of the master, converging the noise reduction system of the slave, freezing the timing recovery system of the slave, and resetting the noise reduction system of the master. Upon completion of the second stage, the protocol enters a third stage which includes the step of reconverging the noise reduction system of the master. The protocol then enters a fourth stage in which the master transceiver and the slave transceiver are ready to communicate with each other.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]This invention relates to methods of enabling the transmission and reception of signals through unshielded twisted pairs of wires within a communications system. The invention particularly relates to a startup protocol for initiating normal transmission between transceivers within a high throughput communications system. A “high throughput” as used within the context of this disclosure may include, but is not limited to, one gigabit (GB) per second.[0003]2. Description of Related Art[0004]A basic communications system is illustrated in FIG. 1. The system includes a hub and a plurality of computers serviced by the hub in a local area network (LAN). Four computers are shown by way of illustration but a different number of computers may be contained within the system. Each of the computers is usually displaced from the hub by a distance which may be as great as approximately one hundred meters (100 m.). The computers are a...

AI Technical Summary

Benefits of technology

"The invention relates to a method for improving the reliability and synchronization of signals in a high throughput communications system. The method involves separating the convergence of different adaptation and acquisition algorithms in the transceivers to reduce interaction among them and improve the reliability of the synchronization process. The method includes a startup protocol with three stages, each designed to improve the performance of the system. The first stage focuses on the timing recovery system and the equalizer of the master transceiver, while the second and third stages focus on the noise reduction system of the master and the equalizer of the slave transceiver, respectively. The method also includes the use of a master-slave configuration to improve the synchronization process. Overall, the invention provides a more reliable and synchronized communication system."

Problems solved by technology

A common problem associated with communications systems employing multiple unshielded twisted pairs and multiple transceivers is the introduction of crosstalk and echo noise or impairment signals into the transmission signals.

However, the effects of these impairment signals are magnified in Gigabit Ethernet.

As a result of these impairment signals the performance of the transceivers, particularly the receiver portion, is degraded.

Each of the receivers in the system encounter the same effect and accordingly the signals passing through the receivers experience signal distortion due to the echo impairment signal.

Far-end crosstalk (FEXT) is an impairment that results from capacitive coupling of the signal from the far-end transmitters to the input of the receivers.

A disadvantage of such a startup is that there is a high level of interaction among the various adaptation and acquisition algorithms within the transceiver.

This high level of interaction reduces the reliability of the convergence and synchronization operations which occur during startup.

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