Resource allocation in a radio communication system

A method of using resource blocks in a communication system with a plurality of Base Stations (BSs), including assigning resource blocks to a first BS, the first BS communicating to a second BS a message comprising information about at least one resource block assigned to the first BS and not planned to be used by the first BS, and the second BS receiving the message. Optionally, the second BS using the at least one resource block. Related apparatus and methods are also described.