Apparatus, and an associated method, for identifying availability of services in a radio network of a radio communication system. A system information message is generated at the radio access network that identifies the service availability of the radio network, such as by indicating the communication services supported by the network. The system information message, once generated, is communicated upon a broadcast control channel, or other appropriate channel, and delivered to a mobile node. The mobile node detects the system information message and determines the availability of services of the radio network therefrom. Selection of whether to register with the network is made responsive to whether the network supports the communication service that the mobile node intends to initiate.