US 7,321,580 B1
Directional carrier sense medium access for wireless nodes
Subramanian Ramanathan, Concord, Mass. (US); and Cesar A. Santivanez, Boston, Mass. (US)
Assigned to BBN Technologies Corp., Cambridge, Mass. (US)
Filed on Oct. 18, 2002, as Appl. No. 10/273,748.
Int. Cl. H04Q 7/00 (2006.01)
U.S. Cl. 370—339  [370/752; 370/329; 455/456.4] 51 Claims
OG exemplary drawing
 
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.