ETHERNET A TRAVES DE MULTIPLEXADO POR DIVISION EN FRECUENCIA (FDM) DE MULTIPLES PORTADORAS

Procedimiento para proporcionar control automático de la frecuencia de una pluralidad de canales de frecuencia, comprendiendo dicho procedimiento las etapas siguientes: determinar un error de frecuencia medio de los canales de frecuencia; y ajustar por lo menos un oscilador para reducir el error de frecuencia media. An architecture for providing high-speed access over frequency-division multiplexed (FDM) channels allows transmission of ethernet frames and/or other data across a cable transmission network or other form of FDM transport. The architecture involves downstream and upstream FDM multiplexing techniques to allow contemporaneous, parallel communications across a plurality of frequency channels. Moreover, an automatic frequency control resolves some issues of a free-running clock in an upstream tuner of the central concentrator by performing adjustments based on the average frequency error of a number of active upstream tones. In the preferred embodiments of the present invention, the automatic frequency control (AFC) utilizes a feedback loop for at least each active upstream tone. Also, the average of the active upstream tones is determined and is utilized in providing feedback to adjust the automatic frequency control (AFC).