| 1. |
- Perez-Ramirez, Daniel F., et al.
(författare)
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DeepGANTT: A Scalable Deep Learning Scheduler for Backscatter Networks
- 2023
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Ingår i: IPSN '23: Proceedings of the 22nd International Conference on Information Processing in Sensor Networks. - New York, NY, United States : Association for Computing Machinery (ACM). - 9798400701184 ; , s. 163-
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Konferensbidrag (refereegranskat)abstract
- Novel backscatter communication techniques enable battery-free sensor tags to interoperate with unmodified standard IoT devices, extending a sensor network’s capabilities in a scalable manner. Without requiring additional dedicated infrastructure, the battery-free tags harvest energy from the environment, while the IoT devices provide them with the unmodulated carrier they need to communicate. A schedule coordinates the provision of carriers for the communications of battery-free devices with IoT nodes. Optimal carrier scheduling is an NP-hard problem that limits the scalability of network deployments. Thus, existing solutions waste energy and other valuable resources by scheduling the carriers suboptimally. We present DeepGANTT, a deep learning scheduler that leverages graph neural networks to efficiently provide near-optimal carrier scheduling. We train our scheduler with optimal schedules of relatively small networks obtained from a constraint optimization solver, achieving a performance within 3% of the optimum. Without the need to retrain, our scheduler generalizes to networks 6 × larger in the number of nodes and 10 × larger in the number of tags than those used for training. DeepGANTT breaks the scalability limitations of the optimal scheduler and reduces carrier utilization by up to compared to the state-of-the-art heuristic. As a consequence, our scheduler efficiently reduces energy and spectrum utilization in backscatter networks.
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| 2. |
- Asan, Noor Badariah, et al.
(författare)
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Data Packet Transmission through Fat Tissue for Wireless Intra-Body Networks
- 2017
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Ingår i: IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology. - : Institute of Electrical and Electronics Engineers (IEEE). - 2469-7249 .- 2469-7257. ; 1:2, s. 43-51
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Tidskriftsartikel (refereegranskat)abstract
- This work explores high data rate microwave communication through fat tissue in order to address the wide bandwidth requirements of intra-body area networks. We have designed and carried out experiments on an IEEE 802.15.4 based WBAN prototype by measuring the performance of the fat tissue channel in terms of data packet reception with respect to tissue length and power transmission. This paper proposes and demonstrates a high data rate communication channel through fat tissue using phantom and ex-vivo environments. Here, we achieve a data packet reception of approximately 96 % in both environments. The results also show that the received signal strength drops by ~1 dBm per 10 mm in phantom and ~2 dBm per 10 mm in ex-vivo. The phantom and ex-vivo experimentations validated our approach for high data rate communication through fat tissue for intrabody network applications. The proposed method opens up new opportunities for further research in fat channel communication. This study will contribute to the successful development of high bandwidth wireless intra-body networks that support high data rate implanted, ingested, injected, or worn devices
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| 3. |
- Carlos, Perez Penichet, et al.
(författare)
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Augmenting IoT networks with backscatter-enabled passive sensor tags
- 2016
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Ingår i: Proceedings of the 3rd Workshop on Hot Topics in Wireless. - New York, NY, USA : ACM. - 9781450342513 ; , s. 23-27
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Konferensbidrag (refereegranskat)abstract
- The sensing modalities available in an Internet-of-Things (IoT) network are usually fixed before deployment, when the operator selects a suitable IoT platform. Retrofitting a deployment with additional sensors can be cumbersome, because it requires either modifying the deployed hardware or adding new devices that then have to be maintained. In this paper, we present our vision and work towards passive sensor tags: battery-free devices that allow to augment existing IoT deployments with additional sensing capabilities without the need to modify the existing deployment. Our passive sensor tags use backscatter transmissions to communicate with the deployed network. Crucially, they do this in a way that is compatible with the deployed network's radio protocol, and without the need for additional infrastructure. We present an FPGA-based prototype of a passive sensor tag that can communicate with unmodified 802.15.4 IoT devices. Our initial experiments with the prototype support the feasibility of our approach. We also lay out the next steps towards fully realizing the vision of passive sensor tags.
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| 4. |
- Carlos, Pérez-Penichet, et al.
(författare)
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Battery-Free 802.15.4 Receiver
- 2018
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Ingår i: 2018 17th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN). - : IEEE. - 9781538652985 ; , s. 164-175
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Konferensbidrag (refereegranskat)abstract
- We present the architecture of an 802.15.4 receiver that, for the first time, operates at a few hundred microwatts, enabling new battery-free applications. To reach the required micro-power consumption, the architecture diverges from that of commodity receivers in two important ways. First, it offloads the power-hungry local oscillator to an external device, much like backscatter transmitters do. Second, we avoid the energy cost of demodulating a phase-modulated signal by treating 802.15.4 as a frequency-modulated one, which allows us to receive with a simple passive detector and an energy-efficient thresholding circuit. We describe a prototype that can receive 802.15.4 frames with a power consumption of 361 μW. Our receiver prototype achieves sufficient communication range to integrate with deployed wireless sensor networks (WSNs).We illustrate this integration by pairing the prototype with an 802.15.4 backscatter transmitter and integrating it with unmodified 802.15.4 sensor nodes running the TSCH and Glossy protocols.
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| 5. |
- Di Lascio, Elena, et al.
(författare)
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Poster Abstract : LocaLight - A Battery-free PassiveLocalization System Using Visible Light
- 2016
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Konferensbidrag (refereegranskat)abstract
- Most existing indoor localization systems are battery-powered and use the changes in Radio Frequency (RF) signals to localize objects. In this paper, we present LocaLight: a battery-free indoor localization system that localizes objects using visible light by tracking the shadow they cast. By sensing a drop in the intensity of ambient light caused by the presence of a shadow, LocaLight localizes the object. Since the position of the shadow can be predicted, it is possible to localize the object in a sensitive area by carefully positioning the light sensors and the overhead lights. Our initial results suggest that LocaLight achieves an accuracy comparable to many of the state-of-the art solutions that use RF.
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| 6. |
- Luis, Yunior, et al.
(författare)
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UrbanSense: An Urban-Scale Sensing Platform for the Internet of Things
- 2016
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Ingår i: IEEE Second International Smart Cities Conference (ISC2 2016). - 9781509018451 ; , s. 763-768
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Konferensbidrag (refereegranskat)abstract
- A critical step towards smarter and safer cities is to endow them with the abilities to massively gather a wide variety of data sets and to automatically feed those data to decision support tools and applications that leverage artificial intelligence. We present UrbanSense, a platform deployed on the streets of a mid-size European city (Porto, Portugal) to collect key environmental data. The main innovations of UrbanSense are (1) design for affordability and extensibility, (2) its ability to leverage heterogeneous networks to send the data to the cloud (using both real-time and delay-tolerant communications), and (3) its Internet of Things integration to expose the data streams to smart city tools and applications. Beyond discussing the design choices, we present operational results for 6 months of operation and give a detailed account of the challenges faced by the successful deployment of urban sensing technologies in the wild.
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| 7. |
- Pérez-Penichet, Carlos, et al.
(författare)
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A Fast Carrier Scheduling Algorithm for Battery-free Sensor Tags in Commodity Wireless Networks
- 2020
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Ingår i: IEEE INFOCOM 2020 - IEEE Conference on Computer Communications. - : IEEE. - 9781728164120 ; , s. 994-1003
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Konferensbidrag (refereegranskat)abstract
- New battery-free sensor tags that interoperate with unmodified standard IoT devices and protocols can extend a sensor network’s capabilities in a scalable and cost-effective manner. The tags achieve battery-free operation through backscatter-related techniques, while the standard IoT devices avoid additional dedicated infrastructure by providing the unmodulated carrier that tags need to communicate. However, this approach requires coordination between devices transmitting, receiving and generating carrier, adds extra latency and energy consumption to already constrained devices, and increases interference and contention in the shared spectrum. We present a scheduling mechanism that optimizes the use of carrier generators, minimizing any disruptions to the regular nodes. We employ timeslots to coordinate the unmodulated carrier while minimizing latency, energy consumption and overhead radio emissions. We propose an efficient scheduling algorithm that parallelizes communications with battery-free tags when possible and shares carriers among multiple tags concurrently. In our evaluation we demonstrate the feasibility and reliability of our approach in testbed experiments. We find that we can significantly reduce the excess latency and energy consumption caused by the addition of sensor tags when compared to sequential interrogation. We show that the gains tend to improve with the network size and that our solution is close to optimal on average.
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| 8. |
- Pérez-Penichet, Carlos, et al.
(författare)
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Carrier Scheduling in IoT Networks with Interoperable Battery-free Backscatter Tags
- 2019
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Ingår i: IPSN '19. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450362849 ; , s. 329-330
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Konferensbidrag (refereegranskat)abstract
- New battery-free backscatter tags that integrate with unmodified standard IoT devices can extend the latter's sensing capabilities in a scalable and cost effective way. Existing IoT nodes can provide the unmodulated carrier needed by the new nodes, avoiding the need for additional infrastructure. This, however, puts extra energetic demands on constrained IoT nodes while increasing interference and contention in the network. We use a slotted MAC protocol to guarantee synchronization between transmitters, receivers and carrier generators. We then express the slot allocation problem as a Constraint Optimization Problem (COP) that parallelizes interrogations to battery-free tags when they do not collide with each other and reuses carriers for multiple tags looking to minimize the total time and the number of carrier generators needed to interrogate a set of tags. In networks with sufficient battery-free nodes we obtain a 25% reduction in the number of necessary carriers and a 50% decrease in interrogation time in most cases; leading to significant energy savings, reduced collisions and improved latency.
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| 9. |
- Perez Penichet, Carlos, et al.
(författare)
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Demo : Passive Sensor Tags
- 2016
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Ingår i: Mobicom'16. - New York, NY, USA : ACM. - 9781450342261 ; , s. 477-478
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Konferensbidrag (refereegranskat)abstract
- The sensing capabilities of an Internet-of-Things (IoT) network are usually fixed at deployment. Adding new sensing modalities is a cumbersome process because it requires altering the deployed hardware. We introduce passive sensor tags that allow to easily and seamlessly add new sensors to existing IoT deployments without requiring hardware modifications or additional energy sources. Passive sensor tags employ backscatter communication to generate transmissions that can be decoded by the radio transceivers present in today's IoT devices. Furthermore, unlike recent works, our approach does not require dedicated infrastructure to generate the unmodulated carrier used for backscatter communication. The demo showcases our prototype of a passive sensor tag collecting sensor data and delivering it to unmodified commodity IoT devices using passive 802.15.4 transmissions.
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| 10. |
- Pérez-Penichet, Carlos, et al.
(författare)
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Demo Abstract : Battery-Free 802.15.4 Receiver
- 2018
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Ingår i: 2018 17th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN). - : IEEE. - 9781538652985 ; , s. 130-131
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Konferensbidrag (refereegranskat)abstract
- We present the architecture for an 802.15.4 receiver that enables battery-free operation. To reach micro-power consumption, the architecture diverges from that of commodity receivers in the following ways: First, similar to backscatter transmitters, it offloads the power-hungry local oscillator to an external device. Second, we avoid the energy cost of demodulating a phase-modulated signal by treating 802.15.4 as a frequency-modulated one, allowing us to receive with a simple passive detector and an energy-efficient thresholding circuit. We demonstrate an off-the-shelf prototype of our receiver receives 802.15.4 from a distance of 470 cm with the carrier generator 30 cm away. This range is sufficient to integrate with deployed wireless sensor networks (WSNs). We demonstrate this integration by pairing our receiver with a 802.15.4 backscatter transmitter and integrating it with unmodified commodity sensor nodes running the TSCH protocol.
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