A Prototyping Environment for Wireless Multihop Networks Fehmi Ben Abdesslem 1 , Luigi Iannone 2 , Marcelo Dias de Amorim 1 , Katia Obraczka 3 , Ignacio Solis 4 , and Serge Fdida 1 1 Universit´ e Pierre et Marie Curie – Paris 6 2 Universit´ e Catholique de Louvain 3 University of California at Santa Cruz 4 Palo Alto Research Center Abstract. Relative to the impressive number of proposals addressing the multitude of challenges raised by IEEE 802.11-based wireless net- works, few have known real implementation. In wireless networks, due especially to the unpredictable nature of the wireless channel, bridging theory and practice is far from trivial. In this paper, we advocate includ- ing prototyping in the design process of wireless protocols. The goal is to speed up the design process and to help validating novel solutions un- der real conditions. To this end, we introduce Prawn, a tool that allows rapid prototyping of wireless network protocols. The basic idea behind Prawn is to provide a set of basic building blocks that implement common functionalities needed by a wide range of wireless protocols (e.g., neigh- bor discovery, link quality assessment, message transmission and recep- tion). Besides these ready-to-use blocks, Prawn also provides a standard API that allows protocol designers easy access to the Prawn primitives. Through a number of examples, we showcase Prawn as a simple, yet powerful tool for fast prototyping of wireless network protocols. 1 Introduction Designing protocols for wireless networks poses countless technical challenges due to a variety of factors such as node mobility, node heterogeneity, and power limitations. Furthermore, the characteristics of the wireless channel are non- deterministic and can be highly variable in space and time. This implies that testing and evaluating such protocols under real operating conditions is crucial to ensure adequate functionality and performance. In fact, the networking research community has already acknowledged the importance of testing and evaluating wireless protocol proposals under real- world conditions. As a result, over the last few years, a number of testbeds, such as Orbit [1], Roofnet [2], and MiNT-m [3], as well as implementation tools, such as Click [4] and XORP [5], have been developed to support the deployment and evaluation of wireless protocols under realistic scenarios. When designing communication systems, and before the final version, there are mainly three evaluation methodologies commonly used, namely mathemat- ical analysis, simulation, and emulation, all of them using a synthetic virtual