In this paper a combination of routing and power management within the context of wireless ad-hoc sensor networks is considered. Using lower layer information (e.g. collision that is considered in MAC layer) is another novel concern which is used in routing decisions. More specifically in this paper we introduce a cross-layer design in which each node dynamically chooses the number of its neighbors and adjusts its power just enough to reach its farthest determined neighbor. In this algorithm the power of transmission and collision are used as metrics for routing and the number of neighbors in which the total energy consumption in data transmission will be the minimum is selected.