Service-Oriented Architecture (SOA) is a software architectural design pattern for constructing and deploying application functionality based on loosely coupled components. Web services is a much-used technology for implementing applications following SOA principles, and achieving interoperability between different systems. Web services are usually realized on computer systems where processing resources and network bandwidth are not a limitation, and haven't been widely employed to mobile systems that are characterized by less computational resources (e.g., small computing devices and limited power), and wireless networks characteristics (e.g., low bandwidth, often ad hoc and unreliable). Even though computing power and memory capacities of mobile devices are constantly improving, the dependency on battery power and wireless networks calls for improved solutions when implementing SOA on wireless systems. In this paper we focus on supporting SOAP on the Android platform in an efficient manner. By efficient, we mean maximizing battery life while minimizing network use. We explore and compare different transport protocols and compression techniques in order to achieve these goals. This work was performed in context of the NATO IST-118 "SOA recommendations for disadvantaged grids in the tactical domain" group.