48 research outputs found
Cooja TimeLine: A Power Visualizer for Sensor Network Simulation
Power consumption is one of the most important factors
in wireless sensor network research, but most simulators do
not provide support for visualizing the power consumption
of an entire sensor network. This makes it hard to develop,
debug, and understand mechanisms and protocols based on
power-saving mechanisms. We present Cooja TimeLine, an
extension to Contiki’s Cooja network simulator, that visualizes
radio traffic and radio usage of sensor networks. Cooja
TimeLine makes is possible to visually see the behavior of
low-power protocols and mechanisms thereby increasing the
understanding of the behavior of sensor networks. We see
this as an important tool for the field moving forward
Poster Abstract: Modeling an Electronically Switchable Directional Antenna for Low-power Wireless Networks
WISENET (NES
Cross-level sensor network simulation with COOJA
Simulators for wireless sensor networks are a valuable tool for
system development. However, current simulators
can only simulate a single level of a system at once. This makes
system development and evolution difficult since developers
cannot use the same simulator for both high-level algorithm
development and low-level development such as device-driver implementations.
We propose cross-level simulation, a novel type of wireless
sensor network simulation that enables holistic simultaneous
simulation at different levels. We present an implementation of such a
simulator, COOJA, a simulator for the Contiki sensor node operating
system. COOJA allows for simultaneous simulation at the
network level, the operating system level, and the machine code
instruction set level. With COOJA, we show the feasibility of the
cross-level simulation approach
Hidden Terminal-Aware Contention Resolution with an Optimal Distribution
Achieving low-power operation in wireless sensor networks with high data load or bursty traffic is challenging. The hidden terminal problem is aggravated with increased amounts of data in which traditional backoff-based contention resolution mechanisms fail or induce high latency and energy costs. We analyze and optimize Strawman, a receiver-initiated contention resolution mechanism that copes with hidden terminals. We propose new techniques to boost the performance of Strawman while keeping the resolution overhead small. We finally validate our improved mechanism via experiments
Electronically-switched Directional Antennas for Low-power Wireless Networks: A Prototype-driven Evaluation
We study the benefits of electronically-switched directional antennas in low-power wireless networks. This antenna technology may improve energy efficiency by increasing the communication range and by alleviating contention in directions other than the destination, but in principle requires a dedicated network stack. Unlike most existing works, we start by characterizing a real-world antenna prototype, and apply this to an existing low-power wireless stack, which we adapt with minimal changes. Our results show that: i) the combination of a low-cost directional antenna and a conventional network stack already brings significant performance improvements, e.g., nearly halving the radio-on time per delivered packet; ii) the margin of improvement available to alternative clean-slate protocol designs is similarly large and concentrated in the control rather than the data plane; iii) by artificially modifying our antenna's link-layer model, we can point at further potential benefits opened by different antenna designs