Existing routing and broadcasting protocols for ad hoc networks assume an ideal physical layer model. We apply the log normal shadow fading model to represent a realistic physical layer and use the probability p(x) for receiving a packet successfully as a function of distance x between two nodes. We define the transmission radius R as the distance at which p(R) = 0.5. We propose a MAC layer protocol where receiver node acknowledges packet to sender node u times, where u * p(x) ≈ 1. We derived

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... approximation for p(x) to reduce computation time. It can be used as the weight in the optimal shortest hop count routing scheme. We then study the optimal packet forwarding distance to minimize the hop count, and show that it is approximately 0.73R (for power attenuation degree 2). A hop count optimal, greedy, localized routing algorithm (referred as Ideal Hop Count Routing (IHCR)) for ad hoc wireless networks is then presented. Node C currently holding message will forward it to a neighbor A that minimizes the sum of expected hop count measure from C to A and the ideal hop count between A and destination D. We also present another algorithm called Expected Progress Routing with acknowledgements (referred as aEPR) for ad hoc wireless networks. Node C currently holding message will forward to a neighbor A (closer to destination than itself) that maximizes p 2 (|CA|)(|CD| − |AD|). Two variants of EP R algorithm, namely aEP R − 1 and aEP R − u are also presented. Next, we propose Projection Progress scheme, where neighbor A that maximizes p 2 (|CA|)(|CD| · |CA|), where CD · CA is the dot product of two vectors, is selected, and its two variants, 1−P rojection and u−P rojection. We then propose tR−greedy routing scheme, where packet is forwarded to neighbor closest to destination, among neighbors that are within distance tR. All described schemes are implemented, and their performances are evaluated and compared.