Diagnosing the weakest link in WSN testbeds: A reliability and cost analysis of the USB backchannel

This paper highlights and characterizes the main obstacle to deploying a robust wireless sensor network testbed: the USB connections that link each of the nodes via ethernet gateways to the central server. Unfortunately, these connections are also the components that, when properly installed, can reduce testbed costs by attaching multiple nodes per gateway. After illustrating how unreliable current solutions can become (regardless of the used sensor nodes, USB cabling, or gateway setup), a set of experiments led to a list of dos and don´ts in testbed deployment. Furthermore, a simple and cost-effective suggestion is presented that allows to bypass current USB backchannel issues, leading to a more robust testbed that avoids manual maintenance of individual nodes.