Apparatus and method for obtaining frequency agility in digital communication systems
AssigneeInternational Mobile Machines Corporation
InventorsDuane R. Bolgiano, Chumlong Deangdeelert
Life of this patent
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Abstract
In a communication system that comprises a plurality of subscriber stations in RF communication with a base station having multiple sequentially repetitive time slots, each time slot being assigned to a particular subscriber station, means to change either the frequency or the time slot configurations, or both, in the event of a deterioration of transmission quality caused by modulation change, frequency channel interference, equipment failure, or the like, or by the entrance of additional subscriber stations going on line.
Claims8
In a communication system provided with a base station that is in communication with a central office and subscriber stations that are connected to said base station by RF channels, said base station having multiple sequentially repetitive time slots and a plurality of frequency channels, said time slots and frequency channels being selectively assignable to said subscriber stations by movement of said subscriber stations to selected vacant time slots or frequency channels in accordance with a predetermined assignment schedule, said system including assignment means for selectively assigning time slots and frequency channels to any of the subscriber stations in response to either the coming on line of an additional subscriber or to a deterioration in transmission between the base station and a subscriber station in communication therewith.
In a communication system having a base station in communication with a central office and with a plurality of subscriber stations through RF channels, said base station having multiple sequentially repetitive time slots and a plurality of frequency channels, the method of assigning time slots and frequency channels to selected subscribers by assigning said subscribers to selected vacant slots in selected frequency channels in accordance with their adjacency to occupied slots in a memory matrix, said assignment being in response to stimuli occasioned by either additional subscribers going on line or by deterioration of transmissions between the base station and the subscribers.
A communication system including a base station and a plurality of subscriber stations in communication with each other and with an external communication network having a plurality of ports, comprising
- a communication circuit including
- a matrix containing a pattern of frequency channels, each frequency channel having a multiplicity of time slots, the time slots being arranged relative to each other in a pattern transverse to the pattern of frequency channels whereby a subscriber station may be selectively movable from one slot to another within a selected frequency channel or from one slot in one frequency channel to another slot in another frequency channel, said matrix enabling simultaneous communications between a plurality of the ports and a plurality of the subscriber stations;
- an exchange for connecting the communication circuit to the external communication network ports;
- and
- a remote-connection processor coupled both to the communication circuit by a base-station control channel and to the exchange, for continually monitoring the status of the time slots and for causing the communication circuit and the exchange to complete connections between selected external commication network ports and selected subscriber stations over time slots assigned in response to the monitored status of each of said time slots;
- said remote connection processor having a memory for storing said connections at each interval of time, whereby it is capable, at any time, of determining where within the matrix a transfer of time slots can be effected.
Dependencies are inferred from the claim text.