System and method for secondary communications with directional transmission
First Claim
1. A method for transmitting information, the method comprising:
- (1) setting a directional antenna of a transmitter of a cognitive radio system to a first transmission direction;
(2) determining whether a state of a spectrum band in the first transmission direction is idle or busy;
(3) transmitting the information in the first transmission direction to a receiver of the cognitive radio system when the spectrum band state is idle and the receiver lies within a coverage area of the transmitter;
(4) transmitting the information in the first transmission direction to a first relay when the spectrum band state is idle and the receiver lies without the coverage area of the transmitter; and
when the spectrum band state is busy;
(5) determining whether a group of untested transmission directions of the directional antenna is empty or not empty,(6) selecting an untested transmission direction from the group of untested transmission directions when the group of untested transmission directions is not empty,(7) determining whether the state of the spectrum band in the untested transmission direction is idle or busy,(8) transmitting the information in the untested transmission direction to the receiver when the spectrum band state is idle and the receiver lies within a coverage area of the transmitter, and(9) transmitting the information in the untested transmission direction to a second relay when the spectrum band state is idle and the receiver lies without the coverage area of the transmitter; and
(10) when the group of untested transmission directions is empty,(11) buffering the information.
1 Assignment
0 Petitions
Accused Products
Abstract
System and method for exploiting spatial spectrum holes (SSH) in the time/spectrum/location of wireless resources. A method comprises setting a directional antenna to a first transmission direction, determining a state of a spectrum band in the first transmission direction, transmitting information in the first transmission direction to the receiver in response to determining that the spectrum band state is idle and that the receiver lies within a coverage area of a transmitter, and transmitting the information in the first transmission direction to a first relay in response to determining that the spectrum band state is idle and that the receiver lies without the coverage area of the transmitter.
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Citations
21 Claims
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1. A method for transmitting information, the method comprising:
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(1) setting a directional antenna of a transmitter of a cognitive radio system to a first transmission direction; (2) determining whether a state of a spectrum band in the first transmission direction is idle or busy; (3) transmitting the information in the first transmission direction to a receiver of the cognitive radio system when the spectrum band state is idle and the receiver lies within a coverage area of the transmitter; (4) transmitting the information in the first transmission direction to a first relay when the spectrum band state is idle and the receiver lies without the coverage area of the transmitter; and when the spectrum band state is busy; (5) determining whether a group of untested transmission directions of the directional antenna is empty or not empty, (6) selecting an untested transmission direction from the group of untested transmission directions when the group of untested transmission directions is not empty, (7) determining whether the state of the spectrum band in the untested transmission direction is idle or busy, (8) transmitting the information in the untested transmission direction to the receiver when the spectrum band state is idle and the receiver lies within a coverage area of the transmitter, and (9) transmitting the information in the untested transmission direction to a second relay when the spectrum band state is idle and the receiver lies without the coverage area of the transmitter; and (10) when the group of untested transmission directions is empty, (11) buffering the information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for transmitting information, the method comprising:
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setting a directional antenna of a transmitter of a cognitive radio system to a first transmission direction; determining whether a state of a spectrum band in the first transmission direction is idle or busy, comprising filtering a received signal to attenuate signals outside of the spectrum band; measuring a received energy of the filtered received signal within the spectrum band; accumulating the measured received energy for a time interval; and deciding the state of the spectrum band based on a comparison of the accumulated received energy and a threshold; transmitting the information in the first transmission direction to a receiver of the cognitive radio system when the spectrum band state is idle and the receiver lies within a coverage area of the transmitter; and transmitting the information in the first transmission direction to a first relay when the spectrum band state is idle and the receiver lies without the coverage area of the transmitter.
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11. A method for transmitting information, the method comprising:
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setting a directional antenna of a transmitter of a cognitive radio system to a first transmission direction; determining whether a state of a spectrum band in the first transmission direction is idle or busy;
wherein a transmission containing the information is assigned a priority class k, and wherein the determining the state of the spectrum band comprises;determining that the state of the spectrum band is idle when no active transmission is taking place; determining that the state of the spectrum band is idle when an active transmission is taking place, the active transmission having a priority class j, wherein priority class j is lower in priority than priority class k; and determining that the state of the spectrum band is busy when an active transmission is taking place, the active transmission having a priority class i, wherein priority class i is greater than or equal in priority to priority class k; transmitting the information in the first transmission direction to a receiver of the cognitive radio system when the spectrum band state is idle and the receiver lies within a coverage area of the transmitter; and transmitting the information in the first transmission direction to a first relay when the spectrum band state is idle and the receiver lies without the coverage area of the transmitter.
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12. A method for relaying a transmission, the method comprising:
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determining, by a communications relay having a directional antenna, a receiver from the transmission; determining whether the communications relay is capable of relaying the transmission to the receiver or not, if the communications relay is capable of relaying the transmission to the receiver, setting the directional antenna to a first transmission direction, determining whether spectrum band availability in the first transmission direction is idle or busy, relaying a corresponding transmission directly to the receiver when the spectrum band is idle and the receiver lies within a coverage area of the communications relay, and relaying the corresponding transmission to a second communications relay when the spectrum band is idle and the receiver lies without the coverage area of the communications relay; and discarding the transmission when the communications relay is not capable of relaying the transmission to the receiver. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A communications node comprising:
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a receiver coupled to an antenna, the receiver configured to receive signals detected by the antenna; a transmitter coupled to a directional antenna, the transmitter configured to directionally transmit signals using the directional antenna; and a processor coupled to the receiver and to the transmitter, wherein the processor comprises; a spectrum sensing unit configured to sense a state of the spectrum band over which signals are transmitted and received; a message relay unit coupled to the spectrum sensing unit, the message relay unit configured to determine if the intended receiver is within a coverage area of a directional transmission of the transmitter by accessing the database, and to select a relay node of a cognitive radio system capable of relaying the received transmission to the intended receiver if the intended receiver is without the coverage area by accessing the database, and configured to relay a received transmission to the received transmission'"'"'s intended receiver or to the relay node; and a database generator coupled to the message relay unit, the database generator configured to generate a database containing transmission relaying information based on responses to messages transmitted by the communications node, the database arranged based on a directional transmission of the transmitter. - View Dependent Claims (19, 20, 21)
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Specification