A first wireless device receives, from a base station, configuration parameters of a resource pool of a sidelink. The configuration parameters indicate a primary zone configuration, a secondary zone configuration, and a first primary zone identifier of a first primary zone. a second primary zone identifier of a second primary zone in which the first wireless device is positioned, is determined based on a geographic location of the first wireless device using the primary zone configuration. A secondary zone identifier of a secondary zone in which the first wireless device is positioned, is determined based on the geographic location using the secondary zone configuration. The first wireless device transmits control information indicating the secondary zone identifier to second wireless device(s). The control information is transmitted via the resource pool, in response to the second primary zone identifier being the same as the first primary zone identifier.