Wireless local area network communications system
First Claim
1. A multiple access communications system, comprisingA. one or more hub units,B. a plurality of station units associated with each of said hub units,C. link means for establishing a bidirectional communications link between each of said hub units and its associated station units, said link means including:
- i) downlink means for establishing a unidirectional downlink radio frequency signal path from each of said hub units to all of its associated station units at a first predetermined frequency,ii) uplink means for establishing a unidirectional uplink radio frequency signal path from each of said station units to its associated hub unit at a second predetermined frequency,iii) synchronization means, selectively operative in a first mode, for establishing a common slotted time frame for each of said hub units and its associated station units, said time frame defining a plurality of time slots, and for allocating subsets of said time slots to each of said associated station units, and selectively operative in a second mode, for allocating sole access to said uplink radio frequency signal path to one of said associated station units, in response to receipt of an access request signal from said one station unit in a time slot included in said subset of time slots allocated to said one station unit,verification means for verifying, within a predetermined number of said time slots the integrity of said bidirectional communications link between each of said hub units and its associated station units, wherein said predetermined number is less than the total number of slots in said time frame.
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Accused Products
Abstract
A local area network including at least one hub unit, at least one associated station unit and a wireless communication link between each hub unit and its associated station units. The communication link includes a wireless down-link channel for transferring information from each hub unit to its associated station units and a wireless up-link channel for transferring information from each station unit to its associated hub unit. Communication is conducted in accordance with a combination time division multiplexing and contention based protocol. A synchronized common slotted time frame between each hub unit and its associated station units is imposed by the hub unit.
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Citations
49 Claims
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1. A multiple access communications system, comprising
A. one or more hub units, B. a plurality of station units associated with each of said hub units, C. link means for establishing a bidirectional communications link between each of said hub units and its associated station units, said link means including: -
i) downlink means for establishing a unidirectional downlink radio frequency signal path from each of said hub units to all of its associated station units at a first predetermined frequency, ii) uplink means for establishing a unidirectional uplink radio frequency signal path from each of said station units to its associated hub unit at a second predetermined frequency, iii) synchronization means, selectively operative in a first mode, for establishing a common slotted time frame for each of said hub units and its associated station units, said time frame defining a plurality of time slots, and for allocating subsets of said time slots to each of said associated station units, and selectively operative in a second mode, for allocating sole access to said uplink radio frequency signal path to one of said associated station units, in response to receipt of an access request signal from said one station unit in a time slot included in said subset of time slots allocated to said one station unit, verification means for verifying, within a predetermined number of said time slots the integrity of said bidirectional communications link between each of said hub units and its associated station units, wherein said predetermined number is less than the total number of slots in said time frame. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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21. A multiple access communications system, comprising
A. one or more hub units B. a plurality of station units associated with each of said hub units C. link means for establishing a bidirectional communications link between each of said hub units and its associated station units, said link means including i) downlink means for establishing a unidirectional downlink radio frequency signal path from each of said hub units to all of its associated station units at a first predetermined frequency, ii) uplink means for establishing a unidirectional uplink radio frequency signal path from each of said station units to its associated hub unit at a second predetermined frequency, and iii) synchronization means, selectively operative in a first mode, for establishing a common slotted time frame for each of said hub units and its associated station units, said time frame defining a plurality of time slots, and for allocating subsets of said time slots to each of said associated station units, and selectively operative in a second mode, for allocating sole access to said uplink radio frequency signal path to one of said associated station units, in response to receipt of an access request signal from said one station unit in a time slot included in said subset of time slots allocated to said one station unit,
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22. A multiple access communications system operating over a predetermined region, comprising:
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A. one or more hub units, B. a plurality of station units associated with each of said hub units, C. link means for establishing a bidirectional wireless communications link between each of said hub units and its associated station units, said communications link supporting a data rate, R, said link means including; i) downlink means for establishing at least one wireless downlink radio frequency signal path for transferring information from each of said hub units to all of its associated station units at a first predetermined frequency, f1, ii) uplink means for establishing at least one wireless uplink radio frequency signal path for transferring information from each of said station units to its associated hub unit at a second predetermined frequency, f2, wherein f1 and f2 are frequencies at which signal reflections from local objects may exist within said region such that a plurality of said uplink and said downlink radio frequency signal paths may occur between a particular hub unit and an associated station unit, each of said signal paths having an associated signal delay for a signal passing over said path, said associated delay varying in proportion to said signal path'"'"'s deviation in length from that of a theoretical straight line path between said particular hub unit and said associated station unit, said signal path having the greatest of said deviations in length being associated with a maximum delay, Dmax, wherein Dmax is a predetermined portion of 1/R, iii) recovery means, responsive to said signals passing between said particular hub unit and said associated station unit, over said plurality of paths, for regenerating said information transferred between said hub unit and said associated station unit, and iv) synchronization means, selectively operative in a first mode, for establishing a common slotted time frame for each of said hub units and its associated station units, said time frame defining a plurality of time slots, and for allocating subsets of said time slots to each of said associated station units, and selectively operative in a second mode, for allocating sole access to said uplink radio frequency signal path to one of said associated station units, in response to receipt of an access request signal from said one station unit in a time slot included in said subset of time slots allocated to said one station unit. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48, 49)
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Specification