Abstract: Methods (600, 700), an access controller (350), and a communication system (300) for optimizing utilization of a wireless communication link in a limited bandwidth communication system or network are provided. Statistical multiplexing is achieved by partitioning a wireless communication link (240) into multiple communication channels (250) and assigning communication sources (220) to communicate information over an air interface for a predetermined time interval, where the number of communication sources (220) assigned to the communication channels (250) during a particular time interval exceeds the number of available communication channels (250). The methods (600, 700), access controller (350), and communication system (300) disclosed also allow a system operator to provide varying levels of quality of service (QoS) guarantees in a communication system or network using statistical multiplexing by designating varying levels of QoS among the communication channels (250).

Abstract: A transmitter system (18) which transmits a communication signal (14) through a phased-array antenna (10) uses a signal processor (26) and a multiplicity of direct modulators (30). Each direct modulator (30) drives a single element (12) of the antenna (10). Each direct modulator (30) receives a digital baseband phase point data signal (62) from a digital data stream (28). The digital data stream (28) also conveys digital beam formation data (60). Each direct modulator (30) digitally combines the baseband phase point data (62) with the beam formation data (60) to produce digital streams that modulate an RF carrier signal (34). The digital data stream (28) is generated by a phased-array signal processor (26) which processes user data bits (86) received from any number of input signals (22) and processes beam signals (24). In one embodiment, the signal processor (26) calculates phase point data (62) representative of all input signals (22).

Abstract: A laser transmitter (200, 300) includes a femptosecond pulse forming circuit (214, 308) and an ultra high-speed optical switch (218, 304) which enable the transmitter (200, 300) to generate a modulated pulse stream having pulses with widths of under 200 femptoseconds. The transmitted pulse stream is processed by a laser detector (500), including a wideband optical detector (504) and pulse stretching circuit (506), that regenerates information included in the modulated pulse stream.

Abstract: A cellular communication system (10) forms cells (18) from low earth orbit satellites (12). The system (10) uses an off-line process (24) to identify cells (18) that fall within various reuse distances of other cells (18) and to save system usage statistics. An on-line process (42) associates a demand with each cell (18), and the demand is predicted from the system usage statistics. Need factors assigned in response to the cells' demands are ranked and processed by an inner loop that assigns the various ones of the cells (18) to one channel (22) at a time and an outer loop that performs the inner loop for many different channels (22). The inner loop assigns cells (18) to a selected channel (22) in accordance with the need factor ranking.

Abstract: A telecommunication network (10) includes satellites (12) in which cellular base station switches (42) are located. Each switch (42) is hardware configured to require the use of relatively few interconnection segments but would suffer a significant amount of call blocking if operated in a conventional manner. A new call setup process (96) is performed whenever a request to setup a new call is received at the switch (42). The process (96) defines new connections through switch 42 for ongoing calls while simultaneously defining a new connection for the new call. In addition, the process (96) forces the new connections to use only those interconnection segments that are reasonably required to implement the new connections. Segments that are not required are deactivated (128) to reduce power consumption.

Abstract: In a satellite cellular communication system (10), a phased array antenna (41) includes a dynamic beamformer (50) that provides individual antenna beams (35) within which communications with subscriber units (26) take place. The satellites (12) are located in several orbits (14). As the satellites move with respect to Earth's surface, each of the antenna beams is stepped backward (104) to compensate for the satellites movement. After each satellite travels a distance equal to a predetermined portion of the satellites' spacing in the orbit, each satellite's antenna beams are stepped forward (116) to replace the previous satellite's footprint. Accordingly, cell-to-cell hand-off is not required for subscriber units communicating within an antenna beam.