1. A device-to-device, D2D, communication circuitry, for use in a device of a wireless communication network, the device being configured to transmit and receive device-to-device communications, the circuitry comprising:synchronization establishing circuitry to acquire radio resource synchronization and to establish a time-frequency resource grid for a D2D communication, the time-frequency resource grid having a plurality of resource units for allocation to a D2D connection;
signal metric evaluation circuitry to evaluate signal metrics of resource units of the plurality of resource units when the time-frequency resource grid has been established; and
radio resource selection circuitry to compare the signal metrics to a lower threshold value and an upper threshold value, and select a time resource of the time-frequency resource grid for allocation to the D2D communication based on said comparison of the signal metrics to the lower threshold value and the upper threshold value,
wherein the radio resource selection circuitry is to select the time resource by selecting from at least a subset of time resources of the time-frequency resource grid currently available for allocation to a new D2D transmission, the time resource being select to minimize a number of constituent resource units for which the signal metric is evaluated to lie between the lower threshold value and the upper threshold value.