Base stations of neighbor cells can coordinate with each other in allocating grant-free uplink (GUL) resources for a device-to-device (D2D) connection or channel between user equipments (UEs) across the neighbor cells. The base stations coordinate to determine a condition conducive to D2D communication between the UEs. If the condition exists, the base stations coordinate to allocate network resources for D2D communication between the UEs, and establish a D2D connection between the UEs using the allocated network resources for D2D communication.