Conference Paper

Assert: A wireless networking testbed

DOI: 10.1007/978-3-642-17851-1_17 Conference: Testbeds and Research Infrastructures. Development of Networks and Communities - 6th International ICST Conference, TridentCom 2010, Berlin, Germany, May 18-20, 2010, Revised Selected Papers
Source: DBLP


As wireless networks become a critical part of home, business and industrial infrastructure, researchers will meet these demands by providing new networking technologies. However, these technologies must be tested before they can be released for mainstream use. We identify the key design considerations for a wireless networking testbed as a) accuracy b) controllability c) mobility d) repeatability e) cost effectiveness f) data collection g) resource sharing h) multi-nodal capability i) scalability. In this paper we portray how we have used coaxial cables and our custom hardware of RF switches and programmable attenuators to create Advanced wireleSS Environment Research Testbed (assert), addressing the above requirements. assert supports various types of wireless devices, providing researchers in academia and industry with the necessary experimentation tools to validate their designed protocols and devices.

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Available from: Neeraj Mittal,
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    • "We can find wireless testbeds from very different nature: number of nodes, communication standards, physical environment and configuration. Among them exist EmuLab [1], ORBIT [2], CREW project, ASSERT [11]. It is possible to distinguish these environments depending on the level of control over the physical medium. "
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    ABSTRACT: In the field of Networking and Telecommunications, researchers have often the choice between several environments (real, experimental, emulated or simulated) to validate their results. Each facet of our work, from the study of network behavior, to protocol improvements, including the characterization of specific phenomena, can be related to different environments more or less realistic. We are thus confronted to a trade-off mixing the level of abstraction, bias of measurement, and implementation complexity (in term of cost and time). Nevertheless, because simulations are often regarded as quicker, easier to use and simpler environments than real testbeds, they are mostly used despite their accuracy limits. This is particularly true when simulating wireless communication, where cross-layer effects and physical medium are complex to isolate and understand.While some effort have been made to improve simulators, their comparison with real environments are still in progress and requires experimental equipments, especially for wireless networks. In this context, we built a controlled test-bed environment to calibrate wireless simulators. This paper compares the results obtained for scenarii respectively played within this environment and the Ns3 platform. Our analysis method is based on network traces comparison using classification trees. On a first basis the construction of the tree is supervised, but later, it could be unsupervised and feed the need for a comparison tool of different network environments.
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    • "The following is a general overview of assert in terms of the software and hardware design choices that we made during the " functionality centric " phase. For more details of the design phase please refer to [1] "
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    ABSTRACT: This article discusses lessons learned from use of our publicly available wireless networking testbed, assert[1]. In [1] we discussed the design and implementation phase of a testbed based on a set of propositions. By opening the testbed to users not familiar with underlying architecture of assert, we put these propositions to the test. While fidelity of the testbed is a major challenge for developers, users assume the fidelity as a given and look for ease of use comparable with a simulator. We list the main demands by users of our testbed and the way we addressed these demands during an enhancement phase.
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    ABSTRACT: Field experiments are an important part of research in wireless networks. Since the wireless channel varies with location and time, the results vary for the same field experiment at a different place and time. Assumptions about the wireless environment can lead to biased results. It is necessary to shield wireless transmission from uncontrolled interference in order to make the experiment repeatable. This paper describes $\underline{A}$ dvanced wirele $\underline{SS}$ $\underline{E}$ nvironment $\underline{R}$ esearch $\underline{T}$ estbed (ASSERT) which uses shielded co-axial cables as the communication media for radio signals to conduct reliable, scalable and accurate wireless experiments. Shielding the transmission also protects the signal from random burst of noise introduced by the environment. The paper describes how the combination of programmable attenuators and RF splitters/combiners, which are part of ASSERT, helps in emulating complex and varying environments including those in which multipath interference plays a significant role. Our experimental results indicate that (1) tweaking the MAC layer and retransmissions at the application layer neutralize, to an extent, the impact of multipath effects when the received signal strength is extremely good, and (2) when the received signal strength falls below a certain threshold multipath interference plays a significant role.
    Wireless Networks 05/2012; 18(4). DOI:10.1007/s11276-011-0411-2 · 0.96 Impact Factor
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