Abstract: This disclosure concerns a communications network information system, and ovides apparatus and a method for efficiently providing survivable communications capability to every surviving node in the communications network from every other surviving node. The types of information provided can include high priority message between users of the communications system, or perhaps of even greater importance, very frequently updated status information about the communications network nodes and their interconnecting links for use in optimally utilizing the surviving resources of a heavily damaged network. With this capability every surviving node in the network will be automatically and efficiently provided with the status of every node and interconnecting link.

Abstract: When one time reference distribution node is referenced to another time reference distribution node through a repeater, the same delays are put into signals transmitted from the repeater that are in signals received by the repeater. This is accomplished by introducing variable storage buffers into the paths of signals transmitted from the repeater, and by providing for their control. Since the same delays are added to signals transmitted to a node that are in the signals received from that node, the difference in signal transit times in the two directions of transmission on a duplex transmission path is minimized. Accordingly, the transit time in both directions of transmission between any pair of nodes, which are communicating through the repeater, is essentially the same, and high accuracy is maintained for time reference distribution among the nodes of an electronic network.

Abstract: A method and apparatus for distributing an accurate time reference to numus locations, such as to the nodes of a digital communications network which can also be used to synchronize the network, which method and apparatus entails the functions of measurement of the local clock's time error, assignment of weighting factors to the paths over which the time reference is distributed through the network, and correction of the time error of the local clock, wherein the first two functions are not affected by the correction of the clock error at any other mode and wherein the time reference distribution system does not contain any closed (reentrant) distribution paths.

Abstract: An electronic short range communication system which allows communication between two or more parties who are fairly close to each other and which allows communication between parties having the communication equipment without interfering with those who do not have communication equipment. The equipment has a definite range limit so as to prevent undesirable interference with other similar systems located beyond a reasonable distance. This system also permits communication from the nearest units of the system so as to override communication originating from more remote units.