EP0475681A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Antenna control for a wireless local area network station
Assignee: Nokia of America Corp
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Filing: 1991-09-05
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Granted: —
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Expires: 2011-09-05
Abstract
Abstract A local area network station (12) includes a transceiver (20) adapted to transmit and receive signals using electromagnetic radiation on a wireless communications link. The station (12) utilizes a CSMA/CD communications controller (22) in a CSMA/CA (collision avoidance) technique wherein deferred data frames are transmitted after a random number of backoff slot periods. A plurality of antennas (14,16) are employed, with the antenna having the best receive conditions being selected for reception of a data frame. The antennas have a slotting control (200) which is synchronized with the backoff slotting to provide a short carrier detect time and hence high throughput.
Inventors
- 👤 Adriaan Kamerman
- 👤 Hans Van Driest
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 10:04
CPC Classifications
H; H04; H04W; H04W74/00; H04W74/08; H04W74/0833; H04W74/0841; H04W74/085; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0802; H04B7/0805
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
138 words
A method of operating a local area network including a plurality of local area network stations (12), each station (12) including transceiver means (20) adapted to operate on a wireless transmission channel and a plurality of antennas (14,16), characterized by the steps of: determining, in each station (12), if said transmission channel is active and, if so, deferring transmission of a data frame by that station (12) for a random number of equal duration backoff slot time periods after said transmission channel has become inactive; providing, in each station (12), switching means (204) adapted to connect said antennas (14,16) in turn to said transceiver means (20), each for an antenna slot time period equal to one of said backoff slot time periods; and synchronizing said antenna slot time periods for all of said stations (12) in said network.
Claim 2
Dependent Claim
30 words
A method according to claim 1, characterized in that said step of deferring transmission is effected by using a LAN controller device (22) which is adapted to a CSMA/CD protocol.
Claim 3
Dependent Claim
128 words
A local area network station, characterized by transceiver means (20) adapted to operate on a wireless electromagnetic wave transmission channel, plurality of antennas (14,16), communication control means (22) adapted, if said transmission channel is active, to defer the transmission of a data frame for a random number of backoff slot time periods after the transmission channel has become inactive, antenna switch means (204) adapted to select one of said plurality of antennas (14,16) for operative connection to said transceiver means (20), and synchronizing means (200,240) adapted to control said antenna switch means (204) to provide antenna slot time periods having durations equal to said backoff slot time periods, and further adapted to synchronize the start of data frame transmissions with the start of said antenna slot time periods.
Claim 4
Dependent Claim
42 words
A local area network station according to claim 3, characterized in that said synchronizing means (200,240) is adapted to be resynchronized in response to the transmission of a data frame and the reception of a data frame by said transceiver means (20).
Claim 5
Dependent Claim
41 words
A local area network station according to claim 4, characterized in that said synchronizing means includes slot sync control means (240) adapted to provide slot control pulses to antenna slot control means (200) adapted to control said antenna switch means (204).
Claim 6
Dependent Claim
93 words
A local area network station according to claim 5, characterized in that said sync control means (240) includes cyclic counter means (350) adapted to count clock pulses (CLK) and to provide a count output pulse in response to each counting of a predetermined number of said clock pulses (CLK), blocking means (354) adapted to receive the count output pulses provided by said cyclic counter means (350) and having an output line (242) on which are provided said slot control pulses, and reset control means (360) adapted to reset said cyclic counter means (350).
Claim 7
Dependent Claim
64 words
A local area network station according to claim 6 characterized in that said reset control means (360) is adapted to receive said clock pulses (CLK) and is effective to provide a resetting signal to said cyclic counter means after a first or a second predetermined time interval in dependence on whether said transceiver means (20) is in a transmit mode or a receive mode.
Claim 8
Dependent Claim
59 words
A local area network station according to claim 7, characterized in that said blocking means (354) is enabled, thereby blocking said count output pulses, in response to the detection by said transceiver means (20) of the termination of a data frame, and is disabled, thereby passing said count output pulses, in response to the generation of said resetting signal.
Claim 9
Dependent Claim
142 words
A local area network station according to claim 7, characterized in that said communication controller means (22) is adapted to defer transmission of a data frame in response to a first control signal (CRS) applied thereto and is further effective, in response to a second control signal (CDT) applied thereto, to commence the transmission of the deferred data frame after said random number of backoff slot time periods; and in that signal generating means (40) is provided, coupled to said communication controller means (22) and adapted, in response to the outputting by said communication controller means (22) of a third control signal (RTSA) requesting transmission of a deferred data frame, to generate said second control signal (CDT) thereby causing said communication controller means (22) to inhibit transmission of the deferred data frame until after said random number of backoff slot time periods.
Claim 10
Dependent Claim
76 words
A local network station according to claim 8, characterized in that said signal generator means (40) is adapted to generate a fourth control signal (RTSB), requesting transmission of a data frame, said fourth control signal (RTSB) being applied to said antenna slot control means (200), which is adapted in response to provide a sixth control signal (RTSC) adapted to initiate data frame transmission in synchronism with the initiation of one of said antenna slot time periods.
References Cited (Backward Citations)
No citation records indexed.
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