Abstract: A method and apparatus are disclosed for conducting broadcast, multipoint, and conference communications in a TDMA network at various data rates while simultaneously conducting point-to-point communications at other data rates, either between local ports or between geographically remote ports during time intervals within a TDMA burst, which are not necessarily predefined. The disclosed apparatus appends a direct destination address to each point-to-point port communication for transmission over a communications link, to directly address the intended destination port. The disclosed invention appends an indirect destination address to each broadcast communication transmitted over the communications link. A broadcast memory is provided at the receiving end of the communications link, for storing correlated direct addresses which are accessed by the indirect destination addresses, to directly address a plurality of intended destination ports.

Abstract: A multiple data rate digital switch for a TDMA communications controller is disclosed which can service a plurality of input/output ports having many different data rates on a time divided basis, either between ports connected to the same controller or between ports connected to different, geographically remote controllers. A transmit burst buffer and a receive burst buffer are connected between the local ports and a TDMA communication link and an intranodal buffer is connected between local ports. All three buffers are accessed by a switch control memory which stores n.sub.i control words for each of the ports which are scanned m times per TDMA frame, there being a frame rate of f frames per second. Thus, the ports are selected and their data is buffered at a rate R.sub.i which is equal to the product of n.sub.i times m times f. In this manner, ports having a variety of data rates can be serviced on a time interleaved basis with maximum connectivity.

Abstract: The position of a channel of information transmitted from a particular port is varied in response to the changing priority of that port's messages as time passes. Variable priority assignments become necessary when low speed data has been deferred in its transmission until a time just prior to the production of a second unit of data. The effect of changing the priority of deferred data messages in a TDMA burst is to change the relative position of the associated channel within the TDMA burst by means of compiling the address of that message in a higher priority threaded list.

Abstract: The transmission and reception pattern generators are synchronized for all data ports operating at the same data rate throughout an entire TDMA system. This eliminates the necessity for bit stuffing to accommodate non-integral multiple data rate data ports and yet allows data activity compression operations to be carried out.

Abstract: To make the most efficient use of the TDMA frame for a satellite communications network, the assignment of each local station's TDMA burst duration is based on a statistical assessment of the demand by local voice and data ports. Occasionally the actual voice and data port demand at a local station exceeds that station's assigned burst duration so that some of the messages which are ready for transmission cannot be transmitted and may be frozen-out. To avoid or minimize the effects of message freeze-out, the various types of messages are categorized into a hierarchy of priorities for transmission.