In this paper, deterministic space-time block codes (STBCs) are used o design orthogonal channels to transmit the information independently in a cooperative communication-based sensor network. Two topologies of two-dimensional (2D) opportunistic networks, the ditributed grid strip and the colocated groups, having same node density are considered. Orthogonal STBCs designed for deterministic number of nodes are partially randomized with the help of indicator random vector and are used for the opportunistic multi-hop network in which the number of cooperating or decode-and-forward (DF) nodes in each hop are random. Different node geometries and the effect of increasing node number in each level are compared on the basis of one-hop success probability and network coverage at various signal-to-noise (SNR) margins. The analysis for different STBCs is made on the basis of diversity and rate it ensure at a certain required quality of service (QoS).