Abstract: Apparatus and method for synchronizing two code streams in a digital commcation network. A locally generated code stream is stored in a precessing delay line and correlated with a received code stream using both static and dynamic techniques.

Abstract: A telephone conferencing system in which all input signals are twice applied to a circulating signal loop firstly in real time and secondly delayed by an interval equal to the delay of the circulating loop. The delayed signal cancels the first applied signal after circulation of the first applied signal to all other subscribers but before its return to the originating subscriber. The telephone conferencing system includes a network having a plurality of input/output line appearances which apply and receive signals to the network. The network consists of a signal circulating loop in which the signal circulates in a predetermined loop direction from line appearance to line appearance. At each line appearance signals are added to, received from, and deleted from the loop to provide a single circulation of each signal applied to the loop by each line appearance.

Abstract: A communication system operative on a time-shared basis on a single frequency between a plurality of mobile vehicles such as trucks and buses and one or more central base stations and associated dispatcher offices. The communication system provides a data link between the vehicles and the dispatcher for vehicle status information and commands as well as a priority interrupt voice channel on the same frequency for occasions requiring voice communication.