Managing transmit power for better frequency re-use in TV white space

Abstract

Certain aspects of the present disclosure provide techniques and apparatus for managing transmit power in a television white space (TVWS) network. One example method generally includes transmitting a sequence of request-to-send (RTS) messages at different transmit power levels to an apparatus and determining if a clear-to-send (CTS) message was received in response to at least one of the RTS messages corresponding to a particular one of the transmit power levels. Another example method generally includes receiving, at a first apparatus from a second apparatus, a packet that cannot be decoded by the first apparatus; determining at least one of a time or a duration corresponding to the packet; transmitting a query with an indication of the at least one of the time or the duration; and receiving a message from the second apparatus in response to the query, the message identifying the second apparatus as a source of the packet.

1 - 17 . (canceled) 
     
     
         18 . A first apparatus for wireless communications, comprising:
 a receiver configured to receive from a second apparatus a packet that cannot be decoded by the first apparatus;   a processing system configured to determine at least one of a time or a duration corresponding to the packet; and   a transmitter configured to transmit a query with an indication of the at least one of the time or the duration, wherein the receiver is configured to receive a message from the second apparatus in response to the query, the message identifying the second apparatus as a source of the packet.   
     
     
         19 . The first apparatus of  claim 18 , wherein the transmitter is configured to transmit a sequence of request-to-send (RTS) messages at different transmit power levels to the second apparatus and wherein the processing system is configured to determine if a clear-to-send (CTS) message was received in response to at least one of the RTS messages corresponding to a particular one of the transmit power levels. 
     
     
         20 . The first apparatus of  claim 19 , wherein the transmit power levels are increasing in the sequence of RTS messages. 
     
     
         21 . The first apparatus of  claim 19 , wherein the particular one of the transmit power levels comprises a minimum transmit power level for transmitting one of the RTS messages to the second apparatus and receiving the CTS message in response. 
     
     
         22 . The first apparatus of  claim 19 , wherein the transmitter is configured to transmit at least one of data, a subsequent RTS message, or a subsequent CTS message to the second apparatus based on the particular one of the transmit power levels. 
     
     
         23 . The first apparatus of  claim 18 , wherein the transmitter is configured to transmit the query via one or more channels in a television white space (TVWS). 
     
     
         24 . The first apparatus of  claim 18 , wherein the transmitter is configured to transmit to the second apparatus a request and wherein the receiver is configured to receive a response from the second apparatus indicating a link margin based on the request. 
     
     
         25 . The first apparatus of  claim 24 , wherein the transmitter is configured to transmit data to the second apparatus based on the link margin. 
     
     
         26 . The first apparatus of  claim 18 , wherein the message indicates a power used by the second apparatus to transmit the message. 
     
     
         27 . A method for wireless communications, comprising:
 at a first apparatus, receiving from a second apparatus a packet that cannot be decoded by the first apparatus;   determining at least one of a time or a duration corresponding to the packet;   transmitting a query with an indication of the at least one of the time or the duration; and   receiving a message from the second apparatus in response to the query, the message identifying the second apparatus as a source of the packet.   
     
     
         28 . The method of  claim 27 , further comprising determining if a clear-to-send (CTS) message was received, wherein the transmitting comprises transmitting a sequence of request-to-send (RTS) messages at different transmit power levels to the second apparatus and wherein determining if the CTS message was received comprises determining if the CTS message was received in response to at least one of the RTS messages corresponding to a particular one of the transmit power levels. 
     
     
         29 . The method of  claim 28 , wherein the transmit power levels are increasing in the sequence of RTS messages. 
     
     
         30 . The method of  claim 28 , wherein the particular one of the transmit power levels comprises a minimum transmit power level for transmitting one of the RTS messages to the second apparatus and receiving the CTS message in response. 
     
     
         31 . The method of  claim 28 , further comprising transmitting at least one of data, a subsequent RTS message, or a subsequent CTS message to the second apparatus based on the particular one of the transmit power levels. 
     
     
         32 . The method of  claim 27 , wherein transmitting the query comprises transmitting the query via one or more channels in a television white space (TVWS). 
     
     
         33 . The method of  claim 27 , further comprising:
 transmitting to the second apparatus a request; and   receiving a response from the second apparatus indicating a link margin based on the request.   
     
     
         34 . The method of  claim 33 , further comprising transmitting data to the second apparatus based on the link margin. 
     
     
         35 . The method of  claim 33 , wherein the message indicates a power used by the second apparatus to transmit the message. 
     
     
         36 . A first apparatus for wireless communications, comprising:
 means for receiving from a second apparatus a packet that cannot be decoded by the first apparatus;   means for determining at least one of a time or a duration corresponding to the packet; and   means for transmitting a query with an indication of the at least one of the time or the duration, wherein the means for receiving is configured to receive a message from the second apparatus in response to the query, the message identifying the second apparatus as a source of the packet.   
     
     
         37 . A computer-program product for wireless communications, comprising a computer-readable medium comprising instructions executable to:
 receive, at a first apparatus from a second apparatus, a packet that cannot be decoded by the first apparatus;   determine at least one of a time or a duration corresponding to the packet;   transmit a query with an indication of the at least one of the time or the duration; and   receive a message from the second apparatus in response to the query, the message identifying the second apparatus as a source of the packet.   
     
     
         38 . A wireless node, comprising:
 at least one antenna;   a receiver configured to receive, from an apparatus via the at least one antenna, a packet that cannot be decoded by the wireless node;   a processing system configured to determine at least one of a time or a duration corresponding to the packet; and   a transmitter configured to transmit, via the at least one antenna, a query with an indication of the at least one of the time or the duration, wherein the receiver is configured to receive a message from the apparatus in response to the query, the message identifying the apparatus as a source of the packet.   
     
     
         39 . A first apparatus for wireless communications, comprising:
 a transmitter configured to transmit a packet at a particular time with a certain duration;   a receiver configured to receive from a second apparatus a query with an indication of at least one of a query time or a query duration for the packet; and   a processing system configured to:
 store at least one of the particular time or the certain duration for the packet; and 
 determine that the at least one of the query time or the query duration substantially matches the at least one of the stored time or the stored duration, wherein the transmitter is configured to transmit a message to the second apparatus in response to the query, the message identifying the first apparatus as a source of the packet. 
   
     
     
         40 . The first apparatus of  claim 39 , wherein the receiver is configured to receive a request-to-send (RTS) message from the second apparatus and wherein the transmitter is configured to transmit a clear-to-send (CTS) message in response to the RTS message. 
     
     
         41 . The first apparatus of  claim 39 , wherein the receiver is configured to receive the query via one or more channels in a television white space (TVWS). 
     
     
         42 . The first apparatus of  claim 39 , wherein the receiver is configured to receive from the second apparatus a request and wherein the transmitter is configured to transmit a response to the second apparatus indicating a link margin based on the request. 
     
     
         43 . The first apparatus of  claim 42 , wherein the request comprises a transmit power control (TPC) request and wherein the response comprises a TPC response. 
     
     
         44 . The first apparatus of  claim 39 , wherein the message indicates a power used by the first apparatus to transmit the message. 
     
     
         45 . A method for wireless communications, comprising:
 at a first apparatus, transmitting a packet at a particular time with a certain duration;   storing at least one of the particular time or the certain duration for the packet;   receiving from a second apparatus a query with an indication of at least one of a query time or a query duration for the packet;   determining that the at least one of the query time or the query duration substantially matches the at least one of the stored time or the stored duration; and   transmitting a message to the second apparatus in response to the query, the message identifying the first apparatus as a source of the packet.   
     
     
         46 . The method of  claim 45 , further comprising:
 receiving a request-to-send (RTS) message from the second apparatus; and   transmitting a clear-to-send (CTS) message in response to the RTS message.   
     
     
         47 . The method of  claim 45 , wherein receiving the query comprises receiving the query via one or more channels in a television white space (TVWS). 
     
     
         48 . The method of  claim 45 , further comprising:
 receiving from the second apparatus a request; and   transmitting a response to the second apparatus indicating a link margin based on the request.   
     
     
         49 . The method of  claim 48 , wherein the request comprises a transmit power control (TPC) request and wherein the response comprises a TPC response. 
     
     
         50 . The method of  claim 45 , wherein the message indicates a power used by the first apparatus to transmit the message. 
     
     
         51 . A first apparatus for wireless communications, comprising:
 means for transmitting a packet at a particular time with a certain duration;   means for storing at least one of the particular time or the certain duration for the packet;   means for receiving from a second apparatus a query with an indication of at least one of a query time or a query duration for the packet; and   means for determining that the at least one of the query time or the query duration substantially matches the at least one of the stored time or the stored duration, wherein the means for transmitting is configured to transmit a message to the second apparatus in response to the query, the message identifying the first apparatus as a source of the packet.   
     
     
         52 . A computer-program product for wireless communications, comprising a computer-readable medium comprising instructions executable to:
 transmit from a first apparatus a packet at a particular time with a certain duration;   store at least one of the particular time or the certain duration for the packet;   receive from a second apparatus a query with an indication of at least one of a query time or a query duration for the packet;   determine that the at least one of the query time or the query duration substantially matches the at least one of the stored time or the stored duration; and   transmit a message to the second apparatus in response to the query, the message identifying the first apparatus as a source of the packet.   
     
     
         53 . A wireless node, comprising:
 at least one antenna;   a transmitter configured to transmit, via the at least one antenna, a packet at a particular time with a certain duration;   a receiver configured to receive, from an apparatus via the at least one antenna, a query with an indication of at least one of a query time or a query duration for the packet; and   a processing system configured to:
 store at least one of the particular time or the certain duration for the packet; and 
 determine that the at least one of the query time or the query duration substantially matches the at least one of the stored time or the stored duration, wherein the transmitter is configured to transmit a message to the apparatus in response to the query, the message identifying the wireless node as a source of the packet.