System for transmitting data in wireless sensor network based on virtual backbone

A system for transmitting data in a wireless sensor network based on a virtual backbone is provided to minimize problems like a network delay, energy consumption or overhearing in an existing MAC(Media Access Control) protocol, to support a low duty cycle and to enable real time data to be transmitted. A system for transmitting data includes plural branch nodes(110a-110d) and plural sensor nodes(130a-130i). The branch nodes have star configuration which is composed of upper level nodes and lower level nodes and make the lower level nodes transmit data to the upper level nodes. The sensor nodes are arranged in correspondence with the branch nodes, and generate sensing data via embedded sensors. The sensing data generated by the sensor nodes is transmitted to a corresponding branch node by a competition base with other sensor nodes within the corresponding branch node.