A radio device for requesting and receiving a radio network service from at least one cellular radio network, the cellular radio network comprising a first radio network domain and a second radio network domain, the radio device comprising: - a multi-domain subscription unit, which is configured to provide at its output respective subscription information enabling access to a requested radio network domain from a set of radio network domains defined by a multi-domain service subscription, wherein each radio network domain comprises a cellular network infrastructure with a plurality of network cells in the same geographical area; - a multi-domain access-control unit, which is connected with the multi-domain subscription unit and configured to obtain the respective subscription information and to obtain access, using the respective subscription information, and maintain access to not more than one of the radio network domains at a given time, for requesting and receiving a requested radio network service; - a multi-domain monitoring unit, which is configured to determine, while access to a first one of the radio network domains is maintained, first availability information regarding the requested radio network service from the first radio network domain and second availability information regarding the requested radio network service from at least one second radio network domain of the set of radio network domains, and provide at its output, at least upon determination that the first availability information indicates non-availability of the requested radio network service from the first radio network domain, an availability output indicative at least of those second radio network domains with determined current availability of the requested radio network service, wherein the first radio network domain is reserved for machine-to-machine radio network services only. - a multi-domain subscription unit, which is configured to provide at its output respective subscription information enabling access to a requested radio network domain from a set of radio network domains defined by a multi-domain service subscription, wherein each radio network domain comprises a cellular network infrastructure with a plurality of network cells in the same geographical area; - a multi-domain access-control unit, which is connected with the multi-domain subscription unit and configured to obtain the respective subscription information and to obtain access, using the respective subscription information, and maintain access to not more than one of the radio network domains at a given time, for requesting and receiving a requested radio network service; - a multi-domain monitoring unit, which is configured to determine, while access to a first one of the radio network domains is maintained, first availability information regarding the requested radio network service from the first radio network domain and second availability information regarding the requested radio network service from at least one second radio network domain of the set of radio network domains, and provide at its output, at least upon determination that the first availability information indicates non-availability of the requested radio network service from the first radio network domain, an availability output indicative at least of those second radio network domains with determined current availability of the requested radio network service, wherein the first radio network domain is reserved for machine-to-machine radio network services only. to determine, while access to a first one of the radio network domains is maintained, first availability information regarding the requested radio network service from the first radio network domain and second availability information regarding the requested radio network service from at least one second radio network domain of the set of radio network domains, and provide at its output, at least upon determination that the first availability information indicates non-availability of the requested radio network service from the first radio network domain, an availability output indicative at least of those second radio network domains with determined current availability of the requested radio network service, wherein the first radio network domain is reserved for machine-to-machine radio network services only.