Mark C Miner

US Patent:

6690655, Feb 10, 2004

Filed:

Oct 19, 2000

Appl. No.:

09/692427

Inventors:

Mark Charles Miner - Foxboro MA
Michael Jaimie Cooper - Marietta GA

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04B 7005

US Classification:

370278, 370311, 370466, 455450

Abstract:

A communication system includes a network control facility ( ), two downstream channels ( ), at least one remote interface unit ( ), and at least one communication device ( ) associated with each remote interface unit (RIU). Each RIU operates in one of two operating modes: a low power, standby mode and a high power, active mode. One downstream channel ( ) is the primary downstream channel and is used by the network control facility to communicate user information and normal maintenance or control information to the RIU when the RIU is in the active mode. The other downstream channel ( ) is the secondary downstream channel and is used by the network control facility to communicate special control information, such as a wake-up command, to the RIU when the RIU is in standby mode. The wake-up command instructs the RIU to transition from standby mode to active mode in order to receive user or control information over the primary downstream channel. Alternatively, the RIU may transition from standby mode to active mode on its own upon detecting a desire (e. g.

US Patent:

6757253, Jun 29, 2004

Filed:

May 30, 2000

Appl. No.:

09/580804

Inventors:

Michael Jaimie Cooper - Marietta GA
Mark Miner - Foxborough MA

Assignee:

Motorola, Inc. - Schaumburg IL

International Classification:

H04J 116

US Classification:

370241, 370225, 725107, 455 62

Abstract:

In a cable modem system a method is provided for continuously monitoring the upstream channel to assess what unused upstream channels will better support data communication in the event that an active upstream channel degrades, with monitoring of the upstream path by using passive or unused channels not impacting active data transfer. In one embodiment, a single spectrum assessment receiver polls cable modems at various taps and has the selected modem retune itself to an unused channel and transmit a reference signal back to the spectrum assessment receiver. An analysis is made and an impaired active channel is identified to ascertain if it has degraded to an unacceptable level. If so, it is switched or hopped to this unused channel if by switching an improvement can be realized. Polling is accomplished by selecting the modem at the worst performing tap and ascertaining after one or more retunes which unused channel is best. The quality of all of the taps is maintained in a continuously-updated table to permit proper tap/modem selection.