Method and system for carrier sense multiple access with collision avoidance (csma/ca) with directional transmission

Abstract

Aspects of a method and system for carrier sense multiple access with collision avoidance (CSMA/CA) with directional transmission are presented. Aspects of the system may include a communicating device (DEV), which transmits a portion of a PDU utilizing omnidirectionally transmitted signals and a subsequent portion of the PDU utilizing directionally transmitted signals. In an exemplary system the communicating DEV may transmit a frame, which represents a physical layer PDU. The frame may comprise a physical layer convergence procedure (PLCP) preamble that is transmitting utilizing omnidirectionally transmitted signals (omni preamble), a PLCP header that is transmitted utilizing omnidirectionally transmitted signals (omni header), a PLCP preamble that is transmitted utilizing directionally transmitted signals (directional preamble) and a physical layer service data unit (PSDU) field, or data, field, which is transmitted utilizing directionally transmitted signals (directional data). In another exemplary system, the communicating DEV may transmit PDUs utilizing directional signal transmission.

1 - 20 . (canceled) 
     
     
         21 . A method for communicating data, comprising:
 transmitting, by circuitry and using a plurality of antennas, a preamble field of a protocol data unit (PDU) via omnidirectional transmission to a plurality of destination communication devices;   determining, with the circuitry, a location of one of the plurality of destination communication devices base on a signal received from the one of the plurality of destination devices in response to transmission of the preamble field; and   transmitting, with the circuitry and using the plurality of antennas, the PDU, which includes the preamble field and a payload, in a direction of the one of the plurality of destination communication devices via directional transmission.   
     
     
         22 . The method according to  claim 21 , further comprising:
 transmitting, with the circuitry, a header field of the PDU via omnidirectional transmission, the header field comprising a network allocation vector (NAV) value.   
     
     
         23 . The method according to  claim 22 , wherein the NAV value specifies a time duration for another one of the plurality of destination communication devices to refrain from transmitting. 
     
     
         24 . The method according to  claim 21 , further comprising:
 transmitting, with the circuitry, the preamble field of the PDU within an omnidirectional coverage area; and   transmitting, with the circuitry, the PDU including the preamble field and the payload within a directional coverage area which includes a portion of the omnidirectional coverage area.   
     
     
         25 . The method according to  claim 21 , further comprising:
 determining, with the circuitry, a direction for the directional transmission based on the determined location.   
     
     
         26 . The method according to  claim 21 , further comprising:
 determining, with circuitry, whether an acknowledgment has been received in response to the transmitted preamble field and/or in response to the transmitted PDU including the preamble field and the payload.   
     
     
         27 . The method according to  claim 26 , further comprising:
 computing, with the circuitry, a back-off interframe spacing (BaIFS) value when determining that the acknowledgement has not been received.   
     
     
         28 . A system for communicating data, comprising:
 circuitry configured to   transmit, using a plurality of antennas, a preamble field of a protocol data unit (PDU) via omnidirectional transmission to a plurality of destination communication devices;   determine a location of one of the plurality of destination communication devices base on a signal received from the one of the plurality of destination devices in response to transmission of the preamble field; and   transmit, using the plurality of antennas, the PDU, which includes the preamble field and a payload, in a direction of the one of the plurality of destination communication devices via directional transmission.   
     
     
         29 . The system according to  claim 28 , wherein the circuitry is further configured to transmit a header field of the PDU via omnidirectional transmission, the header field including a network allocation vector (NAV) value. 
     
     
         30 . The system according to  claim 28 , wherein the circuitry is further configured to:
 transmit the preamble field of the PDU within an omnidirectional coverage area; and   transmit the PDU including the preamble field and the payload within a directional coverage area that includes a portion of the omnidirectional coverage area.   
     
     
         31 . The system according to  claim 28 , wherein the circuitry is further configured to:
 compute a channel estimate to determine a coherence bandwidth; and   select frequency carriers for the directional transmission according to the coherence bandwidth.   
     
     
         32 . The system according to  claim 28 , wherein the circuitry is further configured to determine a direction for the directional transmission based on the determined location. 
     
     
         33 . The system according to  claim 28 , wherein the circuitry is configured to determine whether acknowledgement has been received in response to the transmitted preamble field and/or the transmitted PDU including the preamble field and the payload. 
     
     
         34 . The system according to  claim 33 , wherein the circuitry is further configured to compute a back-off interframe spacing (BaIFS) value when determining that the acknowledgement has not been received. 
     
     
         35 . The system according to  claim 28 , wherein the circuitry is further configured to transmit the preamble field and payload of the PDU using a plurality of orthogonal frequency division multiplexing (OFDM) carriers between 57 GHz and 66 GHz. 
     
     
         36 . The system according to  claim 35 , wherein the circuitry is further configured to:
 select a first plurality of the OFDM carriers for transmitting the preamble field via omnidirectional transmission; and   select a second plurality of the OFDM carriers for transmitting the PDU including the preamble field and the payload via directional transmission.   
     
     
         37 . The system according to  claim 28 , wherein the circuitry is further configured to:
 simultaneously transmit omnidirectional signals and directional signals.   
     
     
         38 . A non-transitory computer-readable medium encoded with computer-readable instructions that, when executed by circuitry, cause the circuitry to perform a method comprising:
 transmitting, using a plurality of antennas, a preamble field of a protocol data unit (PDU) via omnidirectional transmission to a plurality of destination communication devices;   determining a location of one of the plurality of destination communication devices base on a signal received from the one of the plurality of destination devices in response to transmission of the preamble field; and   transmitting, using the plurality of antennas, the PDU, which includes the preamble field and a payload, in a direction of the one of the plurality of destination communication devices via directional transmission.