Directional carrier sense medium access for wireless nodes
First Claim
1. In a wireless network of nodes, each of said nodes having a transceiver and a plurality of antennas in selective communication with said transceiver, a computer-based method for controlling access to a transmission medium, said method comprising:
- obtaining a packet for transmission at said transceiver of a transmitting node of said nodes, said packet including a destination identifier of a receiving node of said nodes;
selecting a transmitting antenna from said plurality of antennas in response to said destination identifier;
switching to said transmitting antenna;
determining whether said transmission medium is free in a beam direction of said transmitting antenna; and
transmitting said packet from said transmitting antenna over said transmission medium when said transmission medium is free.
7 Assignments
0 Petitions
Accused Products
Abstract
A method (508) and system (226) provide directional medium access control for wireless nodes (102) in a wireless network (100), each of the nodes (102) having a transceiver (228) and a plurality of antennas (232, 234, 236, 238, 240) in selective communication with the transceiver (228). Packets (202) are transmitted from a transmitting node (106) of the nodes (102) when a channel (104) is sensed as being free in a beam direction of a selected one of the antennas (232, 234, 236, 238, 240), and in accordance with a pre-determined transmission mode (304) for the data packet (202). The transmitting node (106) is periodically placed in a forced idle state, thereby being prevented from transmitting data packets (202), but being able to receive and respond to data packets (202) from other nodes (102).
59 Citations
51 Claims
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1. In a wireless network of nodes, each of said nodes having a transceiver and a plurality of antennas in selective communication with said transceiver, a computer-based method for controlling access to a transmission medium, said method comprising:
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obtaining a packet for transmission at said transceiver of a transmitting node of said nodes, said packet including a destination identifier of a receiving node of said nodes; selecting a transmitting antenna from said plurality of antennas in response to said destination identifier; switching to said transmitting antenna; determining whether said transmission medium is free in a beam direction of said transmitting antenna; and transmitting said packet from said transmitting antenna over said transmission medium when said transmission medium is free. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. In a node of a wireless network, a system for controlling access to a transmission medium, said node configured for communicating with other nodes in said wireless network over said transmission medium, said node including a router for providing a packet for transmission over said transmission medium, said packet including a destination identifier of a receiving node of said other nodes, said node further including a transceiver for obtaining said packet from said router, an omnidirectional antenna, directional antennas, and a switch selectively interconnecting said omnidirectional antenna and said directional antennas with said transceiver, said system comprising:
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a processor, in communication with said router and said transceiver for controlling access to said transmission medium; and a memory element, in communication with said processor, for storing a database of transmission characteristics for each of said omnidirectional and directional antennas, wherein said processor performs operations comprising; accessing said database to select one of said omnidirectional antenna and said directional antennas to be a transmitting antenna in response to said destination identifier; activating said switch to interconnect said transceiver and said transmitting antenna; performing carrier sensing on said transmitting antenna to determine whether said transmission medium is free in a beam direction of said transmitting antenna; when said transmission medium is free, initiating transmission of said packet from said transmitting antenna over said transmission medium; and when said transmission medium is busy, preventing said transmission of said packet. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42)
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43. A computer readable medium having stored thereon executable code for causing a processor of a node in a wireless network to carry out a method of controlling access to a transmission medium, wherein the node includes a router, a transceiver, a plurality of antennas, and a switch for selectively interconnecting one of said plurality of antennas with said transceiver, and the method comprises:
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a) configuring said node to transmit a packet over said transmission medium, by; obtaining said packet from said router, said packet including a destination identifier; selecting said one of said plurality of antennas in response to said destination identifier to be said transmitting antenna; activating said switch to interconnect said transceiver and said transmitting antenna; performing carrier sensing on said transmitting antenna to determine whether said transmission medium is free in a beam direction of said transmitting antenna; and transmitting said packet from said transmitting antenna over said transmission medium when said transmission medium is free; and b) configuring said node to receive a second packet at a second antenna over said communication medium, by; placing said node in an idle state following said transmitting operation; receiving a data structure from said second node when said node is in said idle state; receiving said second packet from said second node in response to said data structure; and delivering said second packet to said router. - View Dependent Claims (44, 45, 46, 47, 48)
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49. A computer readable medium having stored thereon executable code for causing a processor of a node in a wireless network to carry out a method of controlling access to a transmission medium, wherein the node includes a router, a transceiver, a plurality of antennas, and a switch for selectively interconnecting one of said plurality of antennas with said transceiver, and the method comprises:
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obtaining a packet from said router for transmission over said transmission medium, said packet including a destination identifier; selecting said one of said plurality of antennas in response to said destination identifier to be said transmitting antenna; activating said switch to interconnect said transceiver and said transmitting antenna; performing carrier sensing on said transmitting antenna to determine whether said transmission medium is free in a beam direction of said transmitting antenna; when said transmission medium is busy, said executable code further causes said processor to perform operations comprising; establishing a first forced idle period for a force idle state in response to a determination that said transmission medium is busy; and placing said node in said forced idle state for said first forced idle period; and when said transmission medium is free, said executable code further causes said processor to perform operations comprising; transmitting said packet from said transmitting antenna over said transmission medium; when an outcome of said transmitting operation is a successful transmission of said packet, said executable code further causes said processor to establish a second forced idle period for said forced idle state and place said node in said forced idle state for said second forced idle period; and when an outcome of said transmitting operation is an unsuccessful transmission of said packet, said executable code further causes said processor to establish a third forced idle period for said forced idle state and place said node in said forced idle state for said third forced idle period. - View Dependent Claims (50, 51)
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Specification