Motorola Corporation

Yih Guang Jan

Kenneth M Peterson

Kadathur S Natarajan

Victor H Cutler, Jr

Mukund Narain-dhami Thapa

Amir David Foroudi

Kenneth Maynard Peterson

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.

Cellular communication system with efficient channel assignments and

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.

Adaptive switch resource allocation in a satellite communication system

A central controller (40) executes a method (100) that selects and assigns channels to serve mobile subscriber units (30) in a space-based mobile telecommunication system (10). The method (100) is based on simultaneous consideration of a number of criteria that affect overall system performance of the mobile telecommunication system. Another method (200) assigns serving cells (15-18) by matching the available channel resources with actual caller demand as a function of time. The methods (100, 200) may be used in systems where the actual demand (i.e., offered subscriber traffic) and the number of channels available in each cell (15-18) is varying over time.

Centralized dynamic channel assignment controller and methods

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.

Method and beam stepping apparatus for a satellite cellular

A method and apparatus for controlling communication channel allocation in a communication system (10) by obtaining (405) statistical system performance data, determining (415, 420) by a processor (815) an optimum number of sub-time slots (505, 615) and an optimum number of sub-subbands (605), generating (430) available signal transmission units from data describing historical communication traffic, and assigning (435) available signal transmission units by another processor (910) to dynamically control communication traffic.

Method and apparatus for signal transmission in a communication system

In a satellite cellular communication system, subscriber traffic is shared between satellites whose antenna coverage patterns overlap during some portion of their orbit. When the power consumption of one satellite exceeds a predetermined level, subscriber units are transferred to cells of a second satellite whose antenna coverage pattern overlaps that of the first satellite. After the subscriber units are transferred, channel assignments are redone to prevent interference with subscriber units in other cells.

Method and apparatus for load sharing in a satellite communication system

Orbiting satellites (12) project footprints (30) on the earth. Each footprint (30) is divided into cells (28). Footprints (30) of nearby satellites (12) overlap one another, and the overlap increases as satellites (12) approach a pole from the equator. Positions of all cells (28) generated by all satellites (12) are simulated (36) at numerous points throughout an orbit. Channel sets are assigned to cells (28) within a reference footprint (30a). This assignment is propagated throughout all footprints (30) except for those footprints (30) residing adjacent one side of a seam (16) between orbits (14) where satellites (12) travel in opposing directions. The channel sets are assigned near the seam (16) in response to previously assigned channel sets. Each satellite (12) stores channel set assignments for its cells (28) at various points throughout its orbit. All satellites (12) switch their communication parameters simultaneously in response to the channel set assignments.

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Phoenix, AZ, United States of America

Yih Guang Jan