摘要 |
To find a D2D channel, by example a shared channel for offload traffic from an allocated D2D channel, a cellular network access node sends a configuration message with parameters (e.g., sensing time, frequency band, sensing mechanism, cyclic shift) for a D2D device to sense spectrum. From results of this spectrum sensing is decided whether to utilize a frequency band, sensed according to the parameters, for D2D communications. In an embodiment the network selects a subframe configuration to set the sensing time, in which different subframe configurations have different-length guard periods which is the sensing time. In embodiments a first sensing is within a guard period and represents coarse sensing results and if those are not sufficient the network configures a longer sensing time (e.g., spanning multiple subframes) for finer sensing results. The network or alternatively the D2D device decides whether to use the sensed frequency band for offload traffic. |