The significant factors that contribute to the success of the mobile service delivery are the Quality of Service (QoS) and the mobile connectivity. The mobile service infrastructure must be QoS-aware in addition to contextaware. In this paper, we propose to develop a QoS-aware mobile service infrastructure for context construction and discovery. The choice of connectivity and adaptation of application protocol parameters can be intelligently made on the basis of the available information about these offered-QoS. We implement a QoS-predictions server as a part of the QoS and context aware service infrastructure to attain the objectives. In addition, we develop a QoS aware Context Construction protocol. As per the requirements of a specific mobile host mentioned in the context definition, for a set of mobile hosts which are parts of the context defined, a cost effective routing tree is constructed and maintained dynamically. In the given context, only the hosts are employed to carry out Context-sensitive operations through a cooperative effort. By simulation results, we show that our QoS-aware architecture attains ore throughput with low delay in acquiring the service.