US 6,075,972 AGranted

CATV network and cable modem system having a wireless return path

AssigneeCOM21, Inc.

InventorsMark Laubach, Paul Baran

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Abstract

A two-way CATV network having a radio return path. A cable headend controller is used to control downstream as well as upstream communications over the two-way CATV network. Downstream signals are sent to subscribers' cable modems through conventional coaxial cables. On the upstream side, a signal generated at a first frequency by an interactive cable modem. This signal is then sent to a transmitter applique, which converts the signal to a second frequency. The signal is then transmitted through a wireless segment at this second frequency to a receiver applique. The receiver applique converts the transmitted signal into a third frequency. In some cases, the third frequency is the same as the third frequency. Eventually, the upstream signal is sent to the headend controller. Throughout the entire upstream transmission process, the same signal is maintained; only its frequency is changed. In the various embodiments, the first, second, and third frequencies are the same; the first frequency is the same as the third frequency but not the second frequency; and the first channel can be the same as the third channel but is not the same as the second channel.

Claims5

Dependent claims

A method for wireless communication of digital signal transmission between a source and a plurality of receivers, comprising the steps of:

sending a first digital upstream signal by a cable modem on a first upstream channel;
converting the first digital upstream signal on the first upstream channel to a second digital upstream signal on a second channel;
transmitting the second digital upstream signal on the second channel over the air, wherein only upstream signals are transmitted over the air while downstream signals are transmitted from a head end controller through a cable medium to the cable modem without any wireless segment;
receiving the transmitted first digital signal on the first upstream channel by a receiver from a plurality of cable modems including a cable modem which share a same second upstream channel according to time domain multiplexing;
processing a bitstream signal on a third upstream channel selected from a set of channels in a third channel group, wherein multiple received second upstream channels may be processed simultaneously;
generating a third upstream digital signal from the second digital upstream signal on the third upstream channel selected from the set of channels in the third channel group, wherein there is a one to one correspondence between each channel in a second upstream channel group with each channel contained in the third upstream channel group;
receiving the third upstream digital signal by a head end controller via the third upstream channel assigned to the receivers.

4 more elements

Dependencies are inferred from the claim text.