| 1. |
- Al Nahas, Beshr, 1985, et al.
(författare)
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Competition: Aggressive synchronous transmissions with in-network processing for dependable all-to-all communication
- 2018
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Ingår i: International Conference on Embedded Wireless Systems and Networks. - 2562-2331. ; , s. 209-210
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Konferensbidrag (refereegranskat)abstract
- Low-power wireless networking needs to survive interference in order to accommodate the requirements of serious applications of the Internet of Things. Synchronous transmission techniques like Glossy and Chaos perform well under normal operating conditions. However, their data delivery latency suffers under interference even when extended to use channel hopping. In this paper, we discuss our techniques to enhance the robustness of synchronous flooding while keeping the latency and power consumption minimal and how to collect data from multiple sources to multiple destinations.
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| 2. |
- Al Nahas, Beshr, 1985, et al.
(författare)
-
Competition: Towards Low-Latency, Low-Power Wireless Networking Under Interference
- 2016
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Ingår i: International Conference on Embedded Wireless Systems and Networks. - 2562-2331. ; 2016, s. 287-288
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Konferensbidrag (refereegranskat)abstract
- Low latency reliable data delivery is a key challenge for mission critical applications in the Industrial Internet of Things. Chaos was shown to perform well under normal operating conditions. In this paper we discuss some techniques to enhance its robustness under strong interference.
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| 3. |
- Al Nahas, Beshr, 1985, et al.
(författare)
-
Competition: Towards Low-Power Wireless Networking that Survives Interference with Minimal Latency
- 2017
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Ingår i: International Conference on Embedded Wireless Systems and Networks. - 2562-2331. ; 2017, s. 268-269
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Konferensbidrag (refereegranskat)abstract
- Low-power wireless networking needs to survive interference in order to accommodate the requirements of serious applications of Internet of Things. Synchronous transmission techniques like Glossy and Chaos perform well under normal operating conditions. However, their data delivery latency suffers under interference even when extended to use channel hopping. In this paper we discuss our techniques to enhance the robustness of synchronous flooding while keeping the latency and power consumption minimal.
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| 4. |
- Al Nahas, Beshr, 1985, et al.
(författare)
-
Concurrent Transmissions for Multi-hop Bluetooth 5
- 2019
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Ingår i: International Conference on Embedded Wireless Systems and Networks. - 2562-2331. ; , s. 130-141
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Konferensbidrag (refereegranskat)abstract
- Bluetooth is an omnipresent communication technology, available on billions of connected devices today. While it has been traditionally limited to peer-to-peer and star network topology, the recent Bluetooth 5 standard introduces new operating modes to allow for increased reliability and Bluetooth Mesh supports multi-hop networking based on message flooding. In this paper, we present BlueFlood. It adapts concurrent transmissions, as introduced by Glossy, to Bluetooth. The result is fast and efficient network-wide data dissemination in multi-hop Bluetooth networks. Moreover, we show that BlueFlood floods can be reliably received by off-the-shelf Bluetooth devices such as smart phones, opening new applications of concurrent transmissions and seamless integration with existing technologies. We present an in-depth experimental feasibility study of concurrent transmissions over Bluetooth PHY in a controlled environment. Further, we build a small-scale testbed where we evaluate BlueFlood in real-world settings of a residential environment. We show that BlueFlood achieves 99% end-to-end delivery ratio in multi-hop networks with a duty cycle of 0.13% for 1-second intervals.
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| 5. |
- Al Nahas, Beshr, et al.
(författare)
-
Network Bootstrapping and Leader Election in Low-power Wireless Networks
- 2017
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Ingår i: Proceedings of the International Conference on Embedded Networked Sensor Systems (ACM SenSys 2017), November 5-8, 2017, Delft, The Netherlands. - New York, NY, USA : ACM Press.
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Konferensbidrag (refereegranskat)abstract
- Many protocols in low-power wireless networks require a leader to bootstrap and maintain their operation. For example, Chaos and Glossy networks need an initiator to synchronize and initiate the communication rounds. Commonly, these protocols use a fixed, compile-time defined node as the leader. In this work, we tackle the challenge of dynamically bootstrapping the network and electing a leader in low-power wireless scenarios.
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| 6. |
- Al Nahas, Beshr, 1985, et al.
(författare)
-
Network-wide Consensus Utilizing the Capture Effect in Low-power Wireless Networks
- 2017
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Ingår i: Proceedings of the Conference on Embedded Networked Sensor Systems (ACM SenSys). - New York, NY, USA : ACM. - 9781450354592
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Konferensbidrag (refereegranskat)abstract
- In low-power wireless networking, new applications such as cooperative robots or industrial closed-loop control demand for network-wide agreement at low-latency and high reliability. Distributed consensus protocols is a mature field of research in a wired context, but has received little attention in low-power wireless settings. In this paper, we present A2: Agreement in the Air, a system that brings distributed consensus to low-power multi-hop networks. We introduce Synchrotron, a synchronous transmissions kernel that builds a robust mesh by exploiting the capture effect, frequency hopping with parallel channels, and link-layer security. We build A2 on top of this reliable base layer, and enable the two- and three-phase commit protocols, as well as network services such as joining, hopping sequence distribution and re-keying.We evaluate A2 on four public testbeds with different deployment densities and sizes. A2 requires only 475 ms to complete a two-phase commit over 180 nodes. The resulting duty cycle is 0.5 percent for 1-minute intervals. We show that A2 achieves zero losses end-to-end over long experiments, representing millions of data points.When further adding controlled failures, we show that two-phase commit ensures transaction consistency in A2 while three-phase commit provides liveness at the expense of inconsistency under specific failure scenarios.
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| 7. |
- Al Nahas, Beshr, 1985, et al.
(författare)
-
Poster abstract : Network bootstrapping and leader election utilizing the capture effect in low-power wireless networks
- 2017
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Ingår i: SenSys 2017 - Proceedings of the 15th ACM Conference on Embedded Networked Sensor Systems. - New York, NY, USA : Association for Computing Machinery, Inc. - 9781450354592
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Konferensbidrag (refereegranskat)abstract
- Many protocols in low-power wireless networks require a leader to bootstrap and maintain their operation. For example, Chaos and Glossy networks need an initiator to synchronize and initiate the communication rounds. Commonly, these protocols use a fixed, compile-time defined node as the leader. In this work, we tackle the challenge of dynamically bootstrapping the network and electing a leader in low-power wireless scenarios.
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| 8. |
- Alizai, Muhammad Hamad, et al.
(författare)
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Exploiting the Burstiness of Intermediate-Quality Wireless Links
- 2012
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Ingår i: International Journal of Distributed Sensor Networks. - : SAGE Publications. - 1550-1329 .- 1550-1477. ; , s. 826702-
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Tidskriftsartikel (refereegranskat)abstract
- We address the challenge of link estimation and routing over highly dynamic links, thats is, bursty links that rapidly shift between reliable and unreliable periods of transmissions. Based on significant empirical evidence of over 100,000 transmissions over each link in 802.15.4 and 802.11 testbeds, we propose two metrics, expected future transmissions (EFT) and MAC(3), for runtime estimation of bursty wireless links. We introduce a bursty link estimator (BLE) that based on these two metrics, accurately estimates bursty links in the network rendering them available for data transmissions. Finally, we present bursty routing extensions (BRE): an adaptive routing strategy that uses BLE for forwarding packets over bursty links if they offer better routing progress than long-term stable links. Our evaluation, comprising experimental data from widely used IEEE 802.15.4-based testbeds, reveals an average of 19% and a maximum of 42% reduction in the number of transmissions when routing over long-range bursty links typically ignored by routing protocols. Additionally, we show that both BLE and BRE are not tied to any specific routing protocol and integrate seamlessly with existing routing protocols and link estimators.
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| 9. |
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| 10. |
- António, Gonga, et al.
(författare)
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Multi-channel communication vs. adaptive routing for reliable communication in WSNs
- 2012
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Ingår i: IPSN'12 - ACM/IEEE Proceedings of the 11th International Conference on Information Processing in Sensor Networks, (Beijing;16 - 20 April 2012). - New York, NY, USA : ACM. - 9781450312271 ; , s. 125-126
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Konferensbidrag (refereegranskat)abstract
- Interference and link dynamics constitute great concerns for stability and performance of protocols in WSNs. In this paper we evaluate the impact of channel hopping and adaptive routing on delay and reliability focusing on delay critical applications.
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