1,720,963 research outputs found
Opportunistic Routing Stack for Intermittently Powered Devices using the INET Framework
No full textCode supporting the paper Longman, Edward, Mohammed El-Hajjar, and Geoff Merrett "Intermittent Opportunistic Routing Components for the INET Framework". 8th OMNeT++ Community Summit 2021.</span
Dataset for: Wake-up Radio-enabled Intermittently-powered Devices for Mesh Networking: A Power Analysis
No full textDataset supports: Longman, E., Cetinkaya, O., El Hajjar, M., & Merrett, G. (2020). Wake-up Radio-enabled Intermittently-powered Devices for Mesh Networking: A Power Analysis. Paper presented at IEEE Consumer Communications and Networking Conference, .</span
Dataset for: Multihop Networking for Intermittent Devices
No full textData and simulation code to support conference paper: Multihop Networking for Intermittent Devices
10th International Workshop on Energy Harvesting & Energy-Neutral Sensing Systems (ENSsys 2022)
Containing complete simulation outputs from OMNeT++ simulations, categorised by the experiments explained in the paper.</span
Dataset for: Mesh Networking for Intermittently-powered Devices: Architecture and Challenges
No full textRadio performance data of selected 868/900MHz radios and associated matlab files used to generate plot in article titled "Mesh Networking for Intermittently-powered Devices: Architecture and Challenges " published in IEEE Network. </span
Multihop wireless networking with RF wake-up enabled intermittently-powered nodes
No full textWireless sensors and devices already form an integral part of modern society, but they are constrained by their battery life and the need to be recharged and replaced. To remove the need for batteries and the associated problems of recharging, energy harvesting (EH) can provide power from ambient energy in the environment, meaning large storage is not required as energy is continually replenished. However, the very low harvesting power of small harvesters means it is challenging to operate these devices. Existing work can split computation tasks in conditions where the power supply is intermittent, however, communication in these conditions has only been demonstrated with a nearby high capability device to communicate with. Alternatively, research has demonstrated that EH can power peer-to-peer mesh networked devices, but requiring higher capacity storage and fails with intermittent EH sources. Therefore, in this thesis I demonstrate how to achieve mesh networked communication of intermittently-powered devices. First the specific challenges of intermittent devices are looked at and why these conditions make communication difficult. In order to communicate in spite of this, I examine how wake-up receivers (WuRxs), rectifying antennas (rectennas) and industrial, scientific and medical (ISM) Band transceivers can be used to achieve point-to-point links. Resulting from this, higher power communications from 10 dBm to 15 dBm are shown to generally achieve better performance, due to greater transmitter efficiency and enabling lower power WuRx to effectively extend listening time. Once nodes are deployed, optimal real time operation is important in order to maximize the utility from the harvested energy, where wasteful transmitting or listening leads to suboptimal performance. I generalize the energy consumption for an EH node, including the consumption from each radio wake-up, in an analytical and simulated model to see how different parameters affect the resultant goodput, a measure of throughput. Consequently, splitting the energy equally between transmitting and receiving is shown to maximize performance, but the wake-ups reduce throughput and affects the optimum energy split. Whilst the theoretical analysis is helpful for shaping initial decisions, simulation is required for analysing network behaviour over multiple hops. Therefore, new routing methods for low duty cycle networks are implemented and measured in an intermittent scenario. Specifically, the existing protocol, routing protocol for low power and lossy networks (RPL), is analysed iv under scarce EH conditions, where the intermittency caused by insufficient EH results in a collapse in multihop routing capability. Comparably, an alternative protocol opportunistic RPL (ORPL), can utilise the network without specifying potentially unavailable forwarders and instead dynamically utilizing available forwarders. This allows it to operate over multiple hops in spite of intermittency. Finally, combining both the benefits of ORPL and WuRx leads demonstration of multihop routing in intermittent networks with minimal EH requirements. By modelling several configurations of WuRx, the experiments investigate the trade-off between neighbour count and neighbour availability, as well as the number of hops to reach the destination. The highest range shows the greatest performance when considering routing to a fully powered root node. However, when the root node is intermittent, or when routing data to other intermittent destinations, the cost of the high power radio leads to lower delivery rates. Instead a balance is found, to reach sufficient forwarders to ensure packet delivery, but without compromising the duty cycle too much
Multihop Networking for Intermittent Devices
No full textEnergy harvesting (EH) devices without batteries can enable the Internet of Things (IoT) to reach new and challenging scenarios. Multihop routing is needed to extend the range but, when low EH causes intermittency, it has been overlooked and is not possible with existing protocols. Also, whilst wake-up receivers (WuRxs) have been used to enable star networks, the cost of another EH node sending wake-ups, required for multihop communication, has not been considered. This paper adapts the opportunistic RPL (ORPL) protocol to make possible multihop routing between intermittently-powered devices. Furthermore, the benefit of usingWuRx to enable networks is measured, considering different sensitivity devices and associated range. Comparing ORPL to RPL, we show that opportunistic routing enables multihop communication where RPL cannot. If WuRx are used for routing towards a central hub, the more sensitive WuRx perform better, but routing cross-network benefits from lower sensitivity, lower power WuRx
Intermittent opportunistic routing components for the INET framework
No full textIntermittently-powered wireless sensor networks (WSNs) use energy harvesting and small energy storage to remove the need for battery replacement and to extend the operational lifetime. However, an intermittently-powered forwarder regularly turns on or off, which requires alternative networking solutions. Opportunistic routing (OR) is a potential cross-layer solution for this novel application, but due to the interaction with the energy storage, the operation of these protocols is highly dynamic. To compare protocols and components in like-for-like scenarios we propose module interfaces for MAC, routing and discovery protocols, that enable clear separation of concerns and good interchangeability. We also suggest some candidates for each of the protocols based on our own implementation and research
Mesh networking for intermittently-powered devices: Architecture and challenges
No full textRecent advances in low-power computing enable energy harvesting-powered devices, even in energy scarce conditions. This reduces the reliance on batteries in Internet of Things devices, reducing the cost and enabling new application domains. However, energy scarcity requires devices to operate intermittently, with minimal stored energy and where high-cost radio frequency (RF) communication dominates the power consumption, so transceivers are disabled most of the time. For deployment in challenging environments without high capability neighboring devices, a peer-to-peer topology for intermittently powered devices is required. To remove the requirement for high capability devices, we categorize four receiver types harnessing RF power transfer for a wake-up from other intermittently powered devices. This mesh networking of homogeneous nodes could enable applications where high power coordinators are undesirable or impossible. In this article, we identify the cross-layer challenges of mesh networking with intermittently powered devices and we describe the node receiver hardware required for peer-to-peer networking with intermittently powered devices. We conclude with a case study of transceiver power consumption in this context
Wake-up radio-enabled intermittently-powered devices for mesh networking: A power analysis
No full textThis paper analyzes the successful communication probability between two intermittently-powered nodes in a homogeneous energy harvesting (EH) mesh network. Powering devices using EH can enable networks to operate indefinitely; however, with limited energy storage and in scarce EH conditions, nodes may only be intermittently-powered. This reduces the effectiveness of conventional networking techniques, where listening modes of radios deplete the storage too quickly, rendering nodes useless. This is particularly problematic in the deployment of mesh networks, where there is no provision of a high-power coordinator. To counter this, wake-up receivers (WuRxs) provide extended listening time without the need for a high power conventional radio, but with a cost to sensitivity. Therefore, listening time must be balanced with transmission and wake-to-receive cost, where if all the harvested energy is spent listening none remains to transmit, and vice versa. From stochastic analysis and simulation of the energy usage in mesh nodes, we obtain the optimum transmission load to maximize goodput, which is the rate of successful communications. We include the cost of each wake-up based on the network size in our goodput analysis. Simulations for a fixed number of homogeneous nodes verify this. Furthermore, we model and evaluate the energy consumption trade-off between transmit power and WuRx sensitivity to enable the maximum goodput
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