Methods and apparatus of spectrum sharing for cellular-controlled offloading using unlicensed band

Abstract

There are provided measures for spectrum sharing for cellular-controlled offloading using an unlicensed band. Such measures exemplarily comprise initiating an offloading of traffic from a cellular link on a cellular band to an unlicensed link on an unlicensed band, wherein the unlicensed link is synchronized with the cellular link, and sensing a channel on the unlicensed band in a symbol-synchronized sensing duration of at least one symbol length at the beginning of a predetermined subframe of the unlicensed band.

1 . A system comprising
 circuitry configured to
 initiate an offloading of traffic from a cellular link on a cellular band to an unlicensed link on an unlicensed band, wherein the unlicensed link is synchronized with the cellular link; and 
 sense a channel on the unlicensed band by sensing one or more symbols at the beginning of a predetermined frame of the unlicensed band. 
   
     
     
         2 . The system of  claim 1 , wherein
 the circuitry is configured to sense the channel on the unlicensed band in a symbol-synchronized sensing duration of a length of at least one of the one or more symbols at a beginning of the predetermined frame of the unlicensed band.   
     
     
         3 . The system of  claim 1 , wherein
 the circuitry is configured to sense at least one of an occupancy state and an interference level of the channel of the unlicensed band based on the sensed one or more symbols.   
     
     
         4 . The system of  claim 3 , wherein
 the circuitry is configured to determine that the channel on the unlicensed band is usable for the initiated traffic offloading based on the at least one of the sensed occupancy state and the sensed interference level of the channel.   
     
     
         5 . The system of  claim 1 , wherein
 the circuitry is configured to determine whether the channel of the unlicensed band is usable for the initiated traffic offloading.   
     
     
         6 . The system of  claim 5 , wherein
 the circuitry is configured to transmit the offloaded traffic on the channel of the unlicensed band when it is determined that the channel of the unlicensed band is usable for the initiated traffic offloading   
     
     
         7 . The system of  claim 5 , wherein
 the circuitry is configured to discard transmission of the offloading traffic on the channel of the unlicensed band when it is determined that the channel of the unlicensed band is not usable for the initiated traffic offloading.   
     
     
         8 . The system of  claim 1 , wherein
 the system is a terminal serving as a master of a cluster of paired terminals residing in a cell controlled by a base station.   
     
     
         9 . The system of  claim 8 , wherein
 the predetermined frame of the unlicensed band is a beacon sub frame.   
     
     
         10 . The system of  claim 9 , wherein the circuitry is configured to:
 schedule traffic resource blocks on the unlicensed band for the offloading traffic of the paired terminals of the cluster; and   transfer the scheduled traffic resource blocks to the paired terminals of the cluster on the unlicensed band.   
     
     
         11 . The system of  claim 8 , wherein the circuitry is configured to:
 detect proximity of another cluster of paired terminals; and   informing the base station of a delay time of occupancy of the sensed channel by the another cluster.   
     
     
         12 . The system of  claim 8 , wherein the circuitry is configured to:
 receive an unlicensed band sharing notification including a parameter of channel sharing from the base station;   schedule traffic resource blocks on the unlicensed band for the offloading traffic of the paired terminals of the cluster on the basis of the received parameter of channel sharing; and   transfer the scheduled traffic resource blocks to the paired terminals of the cluster on the unlicensed band.   
     
     
         13 . The system of  claim 1 , wherein the circuitry is configured to:
 transmit a dummy signal for occupying the sensed channel within the predetermined frame after elapse of a predetermined delay time since the sensing of the channel is completed.   
     
     
         14 . The system of  claim 13 , wherein
 the system is a terminal serving as a master of a cluster of paired terminals residing in a cell controlled by a base station, and   the predetermined delay time is random or fixedly preconfigured by the base station.   
     
     
         15 . The system of  claim 8 , wherein
 the predetermined frame of the unlicensed band is a scheduled transmission subframe on a scheduled transmission bandwidth of the terminal.   
     
     
         16 . The system of  claim 15 , wherein
 the scheduled transmission subframe and the scheduled transmission bandwidth of the terminal are received as a scheduled transmission resource block a master of the cluster.   
     
     
         17 . A method comprising:
 initiating an offloading of traffic from a cellular link on a cellular band to an unlicensed link on an unlicensed band, wherein the unlicensed link is synchronized with the cellular link; and   sensing a channel on the unlicensed band by sensing one or more symbols at the beginning of a predetermined frame of the unlicensed band.   sense a channel on the unlicensed band by sensing one or mot e symbols at the beginning of a predetermined frame of the unlicensed band   
     
     
         18 . An apparatus comprising:
 circuitry configured to
 configure an offloading of traffic from a cellular link on a cellular band to an unlicensed link on an unlicensed band, wherein the unlicensed link is synchronized with the cellular link; 
 send a configured parameter of traffic offloading to a terminal; and 
 configure a sensing duration to be used by the terminal for sensing a channel on the unlicensed band by sensing one or more symbols at the beginning of a predetermined frame of the unlicensed band. 
   
     
     
         19 . The apparatus according to  claim 18 , wherein
 the apparatus is a base station.   
     
     
         20 . The apparatus of  claim 18 , wherein
 the terminal serves as a master of a cluster of paired terminals residing in a cell controlled by the base station.