Current telematics services platforms are tightly integrated, relatively fixed-function systems that manage the entire end-to-end infrastructure of devices, wireless communications, device management, subscriber management, and other functions. This closed nature prevents the infrastructure from being shared by other applications, which inhibits the development of new ubiquitous computing services that may not in themselves justify the cost of an entire end-to-end infrastructure. Services-oriented computing offers means to better expose the value of such infrastructures. We have developed a services-oriented, specification-based, ubiquitous computing platform called TOPAZ that abstracts common ubiquitous computing functions and makes them accessible to any application provider through Web-service interfaces. The nature of the TOPAZ services, as enabling long-running sessions between applications and remote clients, presents peculiar challenges to the generic issues of service metering and resource management. In this paper we describe these challenges and discuss the approach we have taken to them in TOPAZ. We first motivate and describe the TOPAZ application model and its service set. We then describe TOPAZ's resource management and service metering functions, and its three-party session model that forms the basis for them.