Wireless devices now hold multiple radio interfaces, allowing to switch from one network to another according to required connectivity and related quality. Still, the selection of the best radio interface for a specific connection is under the responsibility of the end-user in most cases. Integrated multi-radio network management so as to improve the overall performance of the network(s) up to the software application layer, has led to a number of research efforts over the last few years. However, several challenges remain due to the inherent complexity of the problem. This paper specifically concentrates on the comprehensive analysis of energy-efficient multi-radio networking for pervasive computing. Building upon the service oriented architectural style, we consider pervasive networks of software services, which are deployed on the various networked nodes. The issue is then to optimize the energetic performance of the pervasive network through careful selection of the radio link over which service access should be realized for each such access. By considering the most common wireless interfaces in use today (Bluetooth, WiFi and GPRS), we introduce a formal model of service-oriented multi-radio networks. The proposed model enables characterizing the optimal network configuration in terms of energetic performance, which is shown to be a NP-hard problem and thus requires adequate approximation.