Technology neutral coexistence and high priority traffic in unlicensed frequency bands

Abstract

Technology neutral coexistence and high priority traffic is disclosed for use in unlicensed frequency bands. Synchronization boundaries are defined in which synchronous contention windows across all radio access technologies attempting access to a shared communication channel occur periodically. Between the synchronous contention windows, the nodes may return to asynchronous access procedures. Such synchronous access procedures may be applicable to certain power classes or deployment type nodes. Additionally, various priority schemes for the synchronous contention window may be used to ensure protection of higher priority nodes or traffic, such as ultra-reliable low latency communication (URLLC) traffic. According to certain aspects, the deployment of such synchronous access methodology may be triggered via signaling from initiating devices. Additional aspects may provide for a technology neutral receiver protection mechanism by defining resources for protection signaling during receiver protection intervals between successive synchronous contention windows.

What is claimed is: 
     
         1 . A method of wireless communication performed by a wireless node, the method comprising:
 obtaining a synchronization boundary configuration for a shared communication channel, wherein the synchronization boundary configuration defines synchronous access parameters for periodic synchronous access contention by all accessing nodes of one or more radio access technologies;   attempting transmissions on the shared communication channel using a synchronous contention procedure at a next synchronous contention window determined according to the synchronous access parameters;   configuring, in response to detection of data for transmission in a buffer of the wireless node, one or more preferred contention windows between the next synchronous contention window and the subsequent synchronous contention window;   attempting access of the shared communication channel for further transmissions of the data at a next preferred contention window of the one or more preferred contention windows; and   in response to success of the access, ceasing the further transmissions at a boundary of a subsequent preferred contention window of the one or more preferred contention windows when a portion of the data remains in the buffer.   
     
     
         2 . The method of  claim 1 , wherein the synchronous access parameters further define a synchronous periodicity between the next synchronous contention window and the subsequent synchronous contention window as a multiple of a maximum channel occupancy time (MCOT) for the shared communication channel and a preferred periodicity between each of the one or more preferred contention windows as a single MCOT. 
     
     
         3 . The method of  claim 1 , further comprising:
 failing to detect the data in the buffer;   returning to asynchronous access contention for one or more asynchronous contention windows after the next synchronous contention window and prior to the subsequent synchronous contention window;   attempting other transmissions of new data in the buffer using an asynchronous contention procedure at a next asynchronous contention window of the one or more asynchronous contention windows outside of the one or more preferred contention windows; and   continuing the other transmission of the new data after success of the asynchronous contention procedure beyond a boundary of the subsequent preferred synchronous contention window when remaining data of the new data remains in the buffer at the boundary.   
     
     
         4 . The method of  claim 1 , wherein the synchronous boundary configuration establishes a size and a frequency of the next synchronous contention window. 
     
     
         5 . The method of  claim 1 , wherein attempting transmissions on the shared communication channel using the synchronous contention procedure includes identifying a location of the next synchronous contention window based on an absolute system time reference. 
     
     
         6 . The method of  claim 1 , wherein ceasing the further transmissions at the boundary of the subsequent preferred contention window includes using an enhanced channel occupancy time (eCOT). 
     
     
         7 . An apparatus configured for wireless communication, the apparatus comprising:
 at least one processor; and   a memory coupled to the at least one processor, wherein the at least one processor is configured to:   obtain a synchronization boundary configuration for a shared communication channel, wherein the synchronization boundary configuration defines synchronous access parameters for periodic synchronous access contention by all accessing nodes of one or more radio access technologies;   attempt transmissions on the shared communication channel using a synchronous contention procedure at a next synchronous contention window determined according to the synchronous access parameters;   configure, in response to detection of data for transmission in a buffer, one or more preferred contention windows between the next synchronous contention window and the subsequent synchronous contention window;   attempt access of the shared communication channel for further transmissions of the data at a next preferred contention window of the one or more preferred contention windows; and   in response to success of the access, cease the further transmissions at a boundary of a subsequent preferred contention window of the one or more preferred contention windows when a portion of the data remains in the buffer.   
     
     
         8 . The apparatus of  claim 7  wherein the synchronous access parameters further define a synchronous periodicity between the next synchronous contention window and the subsequent synchronous contention window as a multiple of a maximum channel occupancy time (MCOT) for the shared communication channel and a preferred periodicity between each of the one or more preferred contention windows as a single MCOT. 
     
     
         9 . The apparatus of  claim 7 , wherein the at least one processor is further configured to:
 fail to detect the data in the buffer;   return to asynchronous access contention for one or more asynchronous contention windows after the next synchronous contention window and prior to the subsequent synchronous contention window;   attempt other transmissions of new data in the buffer using an asynchronous contention procedure at a next asynchronous contention window of the one or more asynchronous contention windows outside of the one or more preferred contention windows; and   continue the other transmission of the new data after success of the asynchronous contention procedure beyond a boundary of the subsequent preferred synchronous contention window when remaining data of the new data remains in the buffer at the boundary.   
     
     
         10 . The apparatus of  claim 7 , wherein the synchronous boundary configuration establishes a size and a frequency of the next synchronous contention window. 
     
     
         11 . The apparatus of  claim 7 , wherein, to attempt transmissions on the shared communication channel via the synchronous contention procedure, the at least one processor is configured to identify a location of the next synchronous contention window based on an absolute system time reference. 
     
     
         12 . The apparatus of  claim 7 , wherein, to cease further transmissions at the boundary of the subsequent preferred contention window, the at least one processor is configured to use an enhanced channel occupancy time (eCOT). 
     
     
         13 . A method of wireless communication performed by a wireless node, the method comprising:
 obtaining a synchronization boundary configuration for a shared communication channel, wherein the synchronization boundary configuration defines synchronous access parameters for periodic synchronous access contention by all accessing nodes of one or more radio access technologies;   deriving a plurality of synchronizing boundaries based on the synchronous access parameters relative to an absolute timing reference, wherein the synchronous access parameters include a synchronizing boundary location and a periodicity of the plurality of synchronizing boundaries;   determining a condition at the wireless node associated with synchronous operation;   initiating, in response to the condition, a synchronous contention procedure during a current synchronization period between a last prior synchronizing boundary and a next current synchronizing boundary at an end of the current synchronization period;   participating in a communication burst in response to success of the synchronous contention procedure, wherein a length of the communication burst is set by the wireless node up to a maximum length of two times the periodicity; and   stopping the participating in the communication burst at a next synchronizing boundary after the length.   
     
     
         14 . The method of  claim 13 , wherein the communication burst includes:
 idle time during the synchronous contention procedure;   transmission time of the wireless node;   reception time of the wireless node; and   switching time between the transmission time and the reception time.   
     
     
         15 . The method of  claim 13 , wherein the length of the communication burst is defined according to a predefined percentage of the two times the periodicity. 
     
     
         16 . The method of  claim 15 , further including:
 determining an available length for the communication burst, wherein the available length includes an available transmission time between the synchronous contention procedure and the next synchronizing boundary; and   ending the communication burst at the next current synchronization boundary in response to at least one of:
 the available length exceeding the predefined percentage of the two times the periodicity, wherein the participating and the stopping are in response to the available length satisfying the predefined percentage of the two time the periodicity, and 
 the synchronous contention procedure occurs at the last prior synchronization boundary. 
   
     
     
         17 . The method of  claim 15 , wherein the synchronous access parameters further define periodic synchronizing super boundaries within the plurality of synchronizing boundaries located at a super periodicity within the plurality. 
     
     
         18 . The method of  claim 17 , further including:
 ending the communication burst at a next synchronizing super boundary without regard to the length set by the wireless node.   
     
     
         19 . The method of  claim 13 , wherein the synchronous access parameters identify a location and a frequency of a synchronous contention window. 
     
     
         20 . The method of  claim 16 , further including:
 ending the communication burst at the next current synchronization boundary in response to the available length exceeding the predefined percentage of the two times the periodicity.   
     
     
         21 . The method of  claim 16 , further including:
 ending the communication burst at the next current synchronization boundary in response to the synchronous contention procedure occurs at the last prior synchronization boundary.   
     
     
         22 . An apparatus configured for wireless communication, the apparatus comprising:
 at least one processor; and   a memory coupled to the at least one processor, wherein the at least one processor is configured to:
 obtain a synchronization boundary configuration for a shared communication channel, wherein the synchronization boundary configuration defines synchronous access parameters for periodic synchronous access contention by all accessing nodes of one or more radio access technologies; 
 derive a plurality of synchronizing boundaries based on the synchronous access parameters relative to an absolute timing reference, wherein the synchronous access parameters include a synchronizing boundary location and a periodicity of the plurality of synchronizing boundaries; 
 determine a condition at the apparatus associated with synchronous operation; 
 initiate, in response to the condition, a synchronous contention procedure during a current synchronization period between a last prior synchronizing boundary and a next current synchronizing boundary at an end of the current synchronization period; 
 participate in a communication burst in response to success of the synchronous contention procedure, wherein a length of the communication burst is set by the apparatus up to a maximum length of two times the periodicity; and 
 stop the participating in the communication burst at a next synchronizing boundary after the length. 
   
     
     
         23 . The apparatus of  claim 22 , wherein the communication burst includes:
 idle time during the synchronous contention procedure;   transmission time of the apparatus;   a reception time of the apparatus; and   switching time between the transmission time and the reception time.   
     
     
         24 . The apparatus of  claim 22 , wherein the length of the communication burst is defined according to a predefined percentage of the two times the periodicity. 
     
     
         25 . The apparatus of  claim 24 , wherein the at least one processor is further configured to:
 determine an available length for the communication burst, wherein the available length includes an available transmission time between the synchronous contention procedure and the next synchronizing boundary; and   end the communication burst at the next current synchronization boundary in response to at least one of:
 the available length exceeding the predefined percentage of the two times the periodicity, wherein the participating and the stopping are in response to the available length satisfying the predefined percentage of the two time the periodicity, and 
 the synchronous contention procedure occurs at the last prior synchronization boundary. 
   
     
     
         26 . The apparatus of  claim 24 , wherein the synchronous access parameters further define periodic synchronizing super boundaries within the plurality of synchronizing boundaries located at a super periodicity within the plurality. 
     
     
         27 . The apparatus of  claim 26 , wherein the at least one processor is further configured to:
 end the communication burst at a next synchronizing super boundary without regard to the length set by the apparatus.   
     
     
         28 . The apparatus of  claim 22 , wherein the synchronous access parameters identify a location and a frequency of a synchronous contention window. 
     
     
         29 . The apparatus of  claim 25 , wherein the at least one processor is further configured to:
 end the communication burst at the next current synchronization boundary in response to the available length exceeding the predefined percentage of the two times the periodicity.   
     
     
         30 . The apparatus of  claim 25 , wherein the at least one processor is further configured to:
 end the communication burst at the next current synchronization boundary in response to the synchronous contention procedure occurs at the last prior synchronization boundary.