In this paper, we propose a sensor-cloud environmentwhich incorporates remotely located physical sensor devicesin the generic resource family along with other resources likeCPU, memory etc. The environment enables ubiquitous andon-demand access to virtual sensors which are abstractions ofphysical devices with enhanced capabilities. An architecture ofthe sensor-cloud environment is discussed in this paper thatspans multiple infrastructures hosting local and remote resources. Responsibilities of each of the components in the sensor-cloudarchitecture are defined and algorithms for provisioning thesecomponents are discussed along with some proposed enhancementswith respect to our earlier work. As forwarding datatraffic is an important task, a high performance I/O redirectionalgorithm is also proposed to deliver sensed traffic to multipleinstances of virtual sensors that is accumulated from one ormultiple physical sensors. Performance of the I/O redirectionalgorithm is observed and the experimental results are presentedin this paper.