Limiting wireless discovery range

Abstract

Systems and methods of limiting wireless discovery range are described. A method may include determining, at a first device, a discovery range threshold that limits a distance from the first device at which a second device is operative to decode a discovery message. The method may include adjusting a transmission attribute at the first device based on the discovery range threshold. The method may include sending the discovery message in accordance with the adjusted transmission attribute.

What is claimed is: 
     
         1 . A method comprising:
 determining, at a first device, a discovery range threshold that limits a distance from the first device at which a second device is operative to decode a discovery message;   adjusting a transmission attribute at the first device based on the discovery range threshold; and   sending the discovery message in accordance with the adjusted transmission attribute.   
     
     
         2 . The method of  claim 1 , wherein the transmission attribute includes a transmit power level, a modulation and coding scheme (MCS), or any combination thereof. 
     
     
         3 . The method of  claim 1 , wherein the discovery message is included in an information element of an Institute of Electrical and Electronics Engineers (IEEE) 802.11 beacon. 
     
     
         4 . The method of  claim 1 , wherein the discovery message is included in a management action frame. 
     
     
         5 . The method of  claim 1 , further comprising encoding information to be displayed by the second device into the discovery message. 
     
     
         6 . The method of  claim 1 , further comprising encoding a uniform resource locator (URL) to be navigated to by the second device into the discovery message. 
     
     
         7 . The method of  claim 1 , wherein determining the discovery range threshold at the first device includes receiving data indicating the discovery range threshold from a device other than the first device. 
     
     
         8 . An apparatus comprising:
 a processor; and   a memory storing instructions executable by the processor to:
 determine, at a first device, a discovery range threshold that limits a distance from the first device at which a second device is operative to decode a discovery message; 
 adjust a transmission attribute at the first device based on the discovery range threshold; and 
 send the discovery message in accordance with the adjusted transmission attribute. 
   
     
     
         9 . The apparatus of  claim 8 , wherein the first device comprises a wireless local area network (WLAN) device, an access point, or any combination thereof. 
     
     
         10 . The apparatus of  claim 8 , wherein the transmission attribute includes a transmit power level, a modulation and coding scheme (MCS), or any combination thereof. 
     
     
         11 . The apparatus of  claim 8 , wherein the discovery message is included in an information element of an Institute of Electrical and Electronics Engineers (IEEE) 802.11 beacon. 
     
     
         12 . The apparatus of  claim 8 , wherein the discovery message is included in a management action frame. 
     
     
         13 . The apparatus of  claim 8 , wherein the instructions are further executable by the processor to encode, into the discovery message, information to be displayed by the second device. 
     
     
         14 . The apparatus of  claim 8 , wherein the instructions are further executable by the processor to encode, into the discovery message, a uniform resource locator (URL) to be navigated to by the second device. 
     
     
         15 . A method comprising:
 receiving at a second device a discovery message from a first device;   determining a distance between the second device and the first device based on at least one attribute of the discovery message;   based on determining that the distance is within a discovery range threshold, processing the discovery message; and   based on determining that the distance is outside the discovery range threshold, discarding the discovery message.   
     
     
         16 . The method of  claim 15 , wherein the at least one attribute of the discovery message includes a received signal strength indication (RSSI). 
     
     
         17 . The method of  claim 16 , wherein determining the distance comprises searching a table that associates RSSI values with expected distances. 
     
     
         18 . The method of  claim 17 , further comprising storing the table at the second device. 
     
     
         19 . The method of  claim 15 , wherein the at least one attribute of the discovery message includes a transmit power, and wherein the discovery message includes an indicator of the transmit power. 
     
     
         20 . The method of  claim 15 , wherein the at least one attribute of the discovery message includes a modulation and coding scheme (MCS). 
     
     
         21 . The method of  claim 15 , wherein the discovery range threshold is included in the discovery message. 
     
     
         22 . The method of  claim 15 , further comprising, when the distance is within the discovery range threshold, displaying at least a portion of the processed discovery message at the second device. 
     
     
         23 . The method of  claim 15 , further comprising, when the distance is within the discovery range threshold, navigating to a uniform resource locator (URL) in the processed discovery message via an application executed at the second device. 
     
     
         24 . An apparatus comprising:
 a processor; and   a memory storing instructions executable by the processor to:
 receive at a second device a discovery message from a first device; 
 determine a distance between the second device and the first device based on at least one attribute of the discovery message; 
 based on determining that the distance is within a discovery range threshold, process the discovery message; and 
 based on determining that the distance is outside the discovery range threshold, discard the discovery message. 
   
     
     
         25 . The apparatus of  claim 24 , wherein the at least one attribute of the discovery message includes a received signal strength indication (RSSI). 
     
     
         26 . The apparatus of  claim 25 , further comprising a table that associates RSSI values with expected distances and that is stored at the second device. 
     
     
         27 . The apparatus of  claim 26 , wherein the instructions are executable by the processor to determine the distance by searching the table. 
     
     
         28 . The apparatus of  claim 24 , wherein the at least one attribute of the discovery message includes a transmit power, and wherein the discovery message includes an indicator of the transmit power. 
     
     
         29 . The apparatus of  claim 24 , wherein the discovery range threshold is included in the discovery message. 
     
     
         30 . The apparatus of  claim 24 , wherein the second device comprises a mobile telephone, a portable computing device, a tablet computing device, a personal digital assistant (PDA), a portable media player, or any combination thereof.