JamLab: Augmenting Sensornet Testbeds with Realistic and Controlled Interference Generation

Radio interference drastically affects the performance of sensor-net communications, leading to packet loss and reduced energy-efficiency. As an increasing number of wireless devices operates on the same ISM frequencies, there is a strong need for understanding and debugging the performance of existing sensornet protocols under interference. Doing so requires a low-cost flexible testbed infrastructure that allows the repeatable generation of a wide range of interference patterns. Unfortunately, to date, existing sensornet testbeds lack such capabilities, and do not permit to study easily the coexistence problems between devices sharing the same frequencies. This paper addresses the current lack of such an infrastructure by using off-the-shelf sensor motes to record and playback interference patterns as well as to generate customizable and repeat-able interference in real-time. We propose and develop JamLab: a low-cost infrastructure to augment existing sensornet testbeds with accurate interference generation while limiting the overhead to a simple upload of the appropriate software. We explain how we tackle the hardware limitations and get an accurate measurement and regeneration of interference, and we experimentally evaluate the accuracy of JamLab with respect to time, space, and intensity. We further use JamLab to characterize the impact of interference on sensornet MAC protocols

Demo: An Interoperability Development and Performance Diagnosis Environment

Interoperability is key to widespread adoption of sensor network technology, but interoperable systems have traditionally been difficult to develop and test. We demonstrate an interoperable system development and performance diagnosis environment in which different systems, different software, and different hardware can be simulated in a single network configuration. This allows both development, verification, and performance diagnosis of interoperable systems. Estimating the performance is important since even when systems interoperate, the performance can be sub-optimal, as shown in our companion paper that has been conditionally accepted for SenSys 2011

PLC sensor IPv6 networking interoperabe with WSN

International audienceTechnology evolution have made possible to connect all kind of devices to IP network. This becomes an evident objective for sensors networks research. In this paper, we investigate the possibility of using IPv6 for sensor networks connected through powerline communication (PLC) non-wireless mediums and demonstrate possible interoperability. Our work is based on the adaptation of the IEEE 802.15.4 standard protocol. It is constrained by the low-power, lossy and low data-rate context of powerline transceiver that uses pulse modulation. Our aim is to provide interoperability features regarding others mediums with a robust and reliable communication stack for smart metering, home control or home area networks applications. This document propose the first adaptation of the IEEE 802.15.4 commons standard on PLC medium. Following this standard interface, we demonstrate the possibility to carry out data on PLC with great reliability, and low power energy requirement using our WPCTMphysical layer (standing for Watt Pulse Communication (WPC)). Relying on this adaptation, we then focus on the convergence of the IPv6 protocol at the network level, with the 6LoWPAN adaptation. We also present our initial implementation of the RPL setup and routing protocol. This allows for a full network layer stack and results in efficient routing in our low power, low data-rate and lossy network context. Thus, we finally demonstrate interoperability with a real testbed between powerline and wireless sensor networks running IEEE 802.15.4/6LoWPAN/IPv6/RPL stacks. We conclude about the interest of such interoperability for the real usage of sensor networks with a feedback from field's applications deployment and our future work

Heterogeneous Wireless Sensor Network Simulation

International audienceBased on our previous work on the development of a Wireless Sensor Network (WSN) simulation platform, we present here its ability to run simulations on heterogeneous nodes. This platform allows system-level simulations with low level accurate models, with graphical inputs and outputs to easily simulate such distributed systems. In the testbed we consider, the well known IEEE 802.15.4 standard is used, and different microcontrollers units (MCU) and radiofrequency transceivers compose the heterogeneous nodes. It is also possible to simulate complex networks or interacting networks; that is a more realistic case, as more and more hardware devices exist and standards permit their interoperability. This simulation platform can be used to explore design space in order to find the hardware devices and IEEE 802.15.4 algorithm that best fit a given application. Packet Delivery Rate (PDR) and packet latency can be evaluated, as other network simulators do. Energy consumption of sensor nodes is detailed with a very fine granularity: partitioning over and into hardware devices that compose the node is studied