Abstract: A cable communication system (100) where a control unit (110) sends operation parameters to subscriber units (130) and the subscriber units (130) respond by modifying the method of communication. Also, the subscriber units (130) send messages which include information on the subscriber unit (130) and the capabilities of the subscriber unit (130). Furthermore, the control unit (110) efficiently manages the system 100 by monitoring the capabilities and instructing the subscriber units (130) on-how to communicate on the system (100). Such management allows for the migration of subscriber units (170) from one service area (140) to another (190) without the disruption of service. In addition, initialization of subscriber units (130) may be accomplished over the cable and does not require an operator at the subscriber location.

Abstract: Carriers (51) in a cable telephony system (10) are prioritized (70) according to their usability. A local access manager (LAM) (27) creates a frequency list that ranks the carriers (51) based upon their frequency. When a cable fixed access unit (CFAU) (44) requests a traffic channel, the LAM (27) selects a traffic channel based on the channel's carrier usability. The LAM (27) also selects an alternative channel based on both the channel's carrier usability and the based on the number of carriers between the traffic channel and the alternate channel in the frequency list. When either the LAM (27) or the CFAU (44) determines the traffic channel is unacceptable during a call they transmit a "Switching to Alternate Channel" message. The CFAU (44) retunes to the alternate channel and transmits a "Re-Connect" request. The LAM (27) then transmits a new alternate channel and the call continues.

Abstract: Video and two-way telephone services are provided via a cable distribution network. Video signals and one group of trunked telephone channels are coupled in the forward direction to the cable distribution network. A second group of trunked telephone channels are extracted, in the reverse direction, from the cable distribution network.

Abstract: A is a duel processor system (100) with duplicated memory (114,124) has two modes (10,11) of operation: a converged mode (10) in which one of the two processors (101,102) is active and executing all system tasks while the other processor is inactive; and a diverged mode (11) in which both processors are active and independently executing different tasks. The system automatically changes modes in response to requests such as manual and program control and certain system fault conditions. In diverged mode, the system may be in either of two states of operation (1 and 2). In one state (1) one processor (101) is designated a primary processor, and in the other state (2) the other processor (102) is designated the primary processor. In the converged mode the system may be in either of four states of operaton (3-6). In two of these states (3,4) one processor is active while the other processor is standing by ready to take up execution of tasks from the point where the one processor stoped execution.