1,720,996 research outputs found
Visita di Stefano Basagni (Northeastern University)
No full textprogettazione, valutazione e test di protocolli per reti di sensori.01/01/201
Advanced Lectures on Networking, Lecture Notes in Computer Science, N. 2497, Novembre 2002, Springer.
No full textA Performance Comparison of Scatternet Formation Protocols for Networks of Bluetooth Devices
No full textEnabling the mobile IoT: Wake-up unmanned aerial systems for long-lived data collection
No full textNetworking and robotics are increasingly coming together to meet the requirements of applications that only advances in both fields can enable. This paper explores one of these joint applications, namely, using a robotic platform such as an Unmanned Aerial System (UAS) to wirelessly retrieve data produced by the devices of a sensor network. For energy conservation purposes devices operate according to a set duty cycle, or are endowed with wake-up radio transceivers allowing them to transmit and receive data only when needed. We define two simple UAS-aided data collection strategies depending on whether the devices use duty cycling or can be woken up by the visiting UAS. The performance of the two strategies is evaluated by using GreenCastalia, an open source simulator extended to model duty cycles, wake-up radio capabilities and the mobility of the UAS. We compare the two strategies with respect to the amount of data the UAS can collect in its visit, the energy consumption of the devices and the corresponding network lifetime. Our results show the key role of low-cost, low-energy consumption wake-up receivers in providing ways of collecting all data from the sensing devices while consuming a negligible fraction of the energy required to devices operating with a duty cycle. As a result, the lifetime of wake-up radio-based networks is orders of magnitude higher than that afforded to networks with duty cycling: Many decades vs. the very few years of networks with extremely low duty cycles
On the Effectiveness of Semantic Addressing for Wake-up Radio-enabled Wireless Sensor Networks
No full textThis paper investigates various ways of minimizing energy consumption in Wireless Sensor Networks (WSNs). We are interested in those methods and technologies that allow network nodes to drastically decrease energy consumption by turning off their primary communication circuitry (main radio), arguably the main culprit of energy depletion. We consider WSNs whose nodes operate according to pre-set duty cycles and WSNs with nodes featuring very low-power wake-up radio devices. In these scenarios we evaluate the performance of an energy-aware routing protocol, showing that when nodes wake up their neighbors based on their suitability to forward data packets (semantic addressing), energy consumption and network lifetime are remarkably better than when all of a sender neighbors are awoken indistinctly (broadcast addressing) and than when nodes duty cycle. Protocols using semantic addressing achieve network lifetimes that are 10x higher than when broadcast addressing is used and three orders of magnitude better than in duty cycle-based networks. We also observe that semantic addressing keeps data latency at bay, achieving end-to-end latency similar to that in networks with nodes with the radio always on
Performance Evaluation of a New Scatternet Formation Protocol for Multi-hop Bluetooth Networks
No full textMultiplexing data and control channels in random access underwater networks
No full textWe address random access networks with MAC protocols that use control packets such as RTS/CTS. These protocols reduce or eliminate collisions between data packets, but they typically remain prone to collisions between control and data packets. To avoid this type of collision, the data and control channels can be separated by multiplexing in the frequency domain. A small reduction in bandwidth is thus sacrificed in exchange for a reduced number of re-transmissions. This technique is investigated in conjunction with the distance-aware collision avoidance protocol (DACAP). Simulation results show that multiplexing offers some benefits to both throughput efficiency and energy consumption. ©2009 MTS
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