Motorola Corporation

Mark Charles Miner

Michael Jaimie Cooper

John L Moran, Iii

John A Perreault

John Dinatale

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.

Spectrum management method for a cable data system

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., off-hook signal) by the RIU's associated communication device to communicate in the system. The secondary downstream channel utilizes a substantially slower transmission speed (e.g., a lower order modulation) than does the primary downstream channel, thereby enabling the RIU to consume substantially less power when in standby mode than when in active mode, without adversely impacting the throughput rate of the primary downstream channel.

Low-powered communication system and method of operation

An apparatus (101, 110) and method for channel acquisition in a communication system (100) provides for selecting a channel, from a multiplicity of available channels (205), and determining whether the selected channel is the properly assigned channel for data and other information to be received by the apparatus (101, 110). The selected channel is monitored for a predetermined or adaptive energy level (210), a predetermined modulation mode (215), for a protocol signal, and for a protocol signal having an identification specifying the particular apparatus (225), such as a protocol frame containing a serial number corresponding to the apparatus. When a protocol signal having an identification specifying the particular apparatus (225) is received, the selected channel is acquired (250) for reception of data and other information. Channels are selected on the basis of searching first for those channels most likely to be assigned to the particular apparatus, such as previously assigned channels (305, 320, 325), followed by a focused search initially in the vicinity of a central channel under a particular channel plan (345, 355). The process may also be repeated utilizing a variety of channel or frequency plans (375).

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Foxboro, MA, United States of America

Mark Charles Miner