Wireless network access scheme
First Claim
1. A wireless data network, comprising:
- a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio signal of a predetermined frequency over a predetermined range;
a broadcast station capable of transmitting over a predetermined service area to said mobile wireless stations; and
a plurality of base stations distributed over said predetermined service area, each base station including a radio signal transceiver and serving a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station.
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Accused Products
Abstract
A network access scheme enhances channel utilization under the ALOHA protocol by making use of the FM capture effect. The resulting network access scheme allows a transmitter to transmit a message simultaneously with other transmitters to a receiver without the need for retransmission when the message reaches the receiver with sufficient strength over the strengths of the other transmissions. In one embodiment, the network access scheme is applied to a wireless data network, which includes support to a two-way paging application. Another network access scheme combines the high channel utilization of the carrier sensing multi-access (CSMA) protocol with the FM capture effect to provide even higher expected channel utilization. The resulting network access scheme uses a channel access protocol ("CSMA/AT") which provides an adaptive threshold. An RF transmitter determines, using the adaptive threshold, whether or not to transmit its message. Under CSMA/AT, if the sensed power of other transmissions (RSSI) in the channel is below the adaptive threshold, the transmitter transmits; otherwise, the transmitter backs off.
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Citations
40 Claims
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1. A wireless data network, comprising:
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a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio signal of a predetermined frequency over a predetermined range; a broadcast station capable of transmitting over a predetermined service area to said mobile wireless stations; and a plurality of base stations distributed over said predetermined service area, each base station including a radio signal transceiver and serving a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A wireless data network comprising:
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a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio signal of a predetermined frequency over a predetermined range, each of said wireless terminals transmits said FM modulated radio signal in accordance with a carrier-sensing multiple-access (CSMA) protocol; and a plurality of base stations distributed over a predetermined service area, each base station including a radio signal transceiver and serving a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station, wherein said wireless terminals each include a circuit for sensing the received signal strength of radio transmissions at said predetermined frequency, said CSMA protocol including a threshold power value, such that when said circuit of one of said wireless terminals senses said received signal strength to exceed said threshold power value, said wireless terminal refrains from transmitting. - View Dependent Claims (15, 16, 17)
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18. A wireless data network comprising:
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a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio signal of a predetermined frequency over a predetermined range; and a plurality of base stations distributed over a predetermined service area, each base station including a radio signal transceiver and serving a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station, wherein said wireless data network includes two-way paging as an application.
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19. A wireless data network comprising:
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a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio signal of a predetermined frequency over a predetermined range; and a plurality of base stations distributed over a predetermined service area, each base station including a radio signal transceiver and serving a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station, wherein when one of said base stations receives a data packet encoded in said FM modulated radio signal from one of said wireless terminals, said base station sends an acknowledgement packet after a delay, and wherein said base station receives packets from other base stations, said base station aborting sending said acknowledgement packet, when said base station receives a control packet being an acknowledgement packet acknowledging said data packet prior to said delay expires.
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20. A wireless data network comprising:
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a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio sisal of a predetermined frequency over a predetermined range; a broadcast station capable of transmitting over a predetermined service area to said mobile wireless stations; and a plurality of base stations distributed over said predetermined service area, each base station including a radio signal transceiver and serving a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station wherein when one of said base stations receives a data packet encoded in said FM modulated radio signal from one of said wireless terminals, said base station sends an acknowledgment packet after a delay, said delay being randomly selected.
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21. A method in a wireless data network, comprising the steps of:
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providing a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio signal of a predetermined frequency over a predetermined range; providing a broadcast station capable of transmitting over a predetermined service area to said mobile wireless terminals; and distributing over said predetermined service area a plurality of base stations, each including a radio signal transceiver, each base station being adapted to serve a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A method in a wireless data network, comprising the steps of:
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providing a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio signal of a predetermined frequency over a predetermined range, said wireless terminals transmitting said FM modulated radio signal in accordance with a carrier-sensing multiple-access (CSMA) protocol; and distributing over a predetermined service area a plurality of base stations, each including a radio signal transceiver, each base station being adapted to serve a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station, wherein said wireless terminals each sense the received signal strength of radio transmissions at said predetermined frequency, said CSMA protocol including a threshold power value, such that when said circuit of one of said wireless terminals senses said received signal strength to exceed said threshold power value, said wireless terminal refrains from transmitting. - View Dependent Claims (35, 36, 37)
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38. A method in a wireless data network, comprising the steps of:
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providing a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio signal of a predetermined frequency over a predetermined range; and distributing over a predetermined service area a plurality of base stations, each including a radio signal transceiver, each base station being adapted to serve a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station, wherein said wireless data network includes two-way paging as an application.
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39. A method in a wireless data network, comprising the steps of:
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providing a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio signal of a predetermined frequency over a predetermined range; and distributing over a predetermined service area a plurality of base stations, each including a radio signal transceiver, each base station being adapted to serve a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station, wherein when one of said base stations receive a data packet from one of said wireless terminals, said base station sends an acknowledgement packet after a delay, and wherein said base station receives packets from other base stations, said base station aborting sending said acknowledgement packet, when said base station receives a control packet being an acknowledgement packet acknowledging said data packet prior to said delay expires.
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40. A method comprising the steps of:
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providing a plurality of mobile wireless terminals, each wireless terminal capable of transmitting a FM modulated radio signal of a predetermined frequency over a predetermined range; providing a broadcast station capable of transmitting over a predetermined service area to said mobile wireless terminals; and distributing over said predetermined service area a plurality of base stations, each including a radio signal transceiver, each base station being adapted to serve a local service area within said predetermined range, such that when two of said wireless terminals transmit simultaneously within the local service area of one of said base stations, a FM capture effect operates such that the radio signal of the closer one of said two wireless terminals to said base station is received by said base station when one of said base stations receive a data packet from one of said wireless terminals, sending from said base station an acknowledgment packet after a delay, said delay being randomly selected.
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Specification