A method and apparatus to configure a resource pool for a plurality of user equipment configured with contention based transmission; configure a resource allocation within the resource pool for a contention based transmission by a user equipment of the plurality of user equipment configured for contention based transmissions, wherein the resource allocation is configured with more than one predefined or preconfigured sets of resource allocation granularities; and send information including the resource allocation towards the user equipment, wherein the information includes an indication of a set of the predefined or preconfigured sets of the resource allocation granularities that the user equipment is to use for the contention based transmission.