Abstract: Cable TV providers have an infrastructure which is well suited for providing additional services such as telephone and data connections to their subscribers. Techniques are disclosed for improving the error detection, masking, and avoidance capabilities of such a system. Because the system can distinguish telephony from data traffic, alternate error masking techniques can be employed for each type of traffic. An erroneous telephony packet, for example, can be replaced by silence, because the ear is relatively insensitive to short voids. Additionally, the links to the data or telephony provider can be maintained by the cable provider during interim noise periods. Because the network is structured as a multiple access network, and the likelihood of simultaneous upstream messages from all subscribers is low, error monitoring can be implemented on underutilized equipment to effect error avoidance, both as a preventive measure as well as a corrective measure.

Abstract: An improved method for Time Division Multiple Access (TDMA) communications particularly applicable to a network comprising transmitters having significantly different transmission paths to a common receiver. The common receiver measures the response time from each transmitter, relative to a common time reference, then instructs each transmitter to delay all subsequent responses by an amount specific to each transmitter, as determined from these measured response times. This imposed delay results in a more time efficient TDMA protocol, improved error detection capability, and improved security capabilities. This invention is particularly applicable to bi-directional communications to and from a provider of Cable TV, Telephony, and Data Services.