We consider the problem of link quality estimation in wireless sensor networks. Existing link qua... more We consider the problem of link quality estimation in wireless sensor networks. Existing link quality estimators (e.g. PRR, ETX, Four-bit, and LQI) are only able to assess a single link property, thus providing a partial view on the link quality. It is therefore important, yet challenging, to design link quality estimators that perform holistic link characterization by considering several properties. In this poster, we propose F-LQE, a novel link quality estimator, that estimates link quality on the basis of four link quality prop-erties namely, packet delivery, asymmetry, stability, and channel quality. Combination of link properties is performed using Fuzzy Logic. We show through extensive TOSSIM simulation that F-LQE outperforms existing link quality estimators.
ABSTRACT Radio link quality estimation is essential for protocols and mechanisms such as routing,... more ABSTRACT Radio link quality estimation is essential for protocols and mechanisms such as routing, mobility management and localization, particularly for low-power wireless networks such as wireless sensor networks. Commodity Link Quality Estimators (LQEs), e.g. PRR, RNP, ETX, four-bit and RSSI, can only provide a partial characterization of links as they ignore several link properties such as channel quality and stability. In this paper, we propose F-LQE (Fuzzy Link Quality Estimator, a holistic metric that estimates link quality on the basis of four link quality properties—packet delivery, asymmetry, stability, and channel quality—that are expressed and combined using Fuzzy Logic. We demonstrate through an extensive experimental analysis that F-LQE is more reliable than existing estimators (e.g., PRR, WMEWMA, ETX, RNP, and four-bit) as it provides a finer grain link classification. It is also more stable as it has lower coefficient of variation of link estimates. Importantly, we evaluate the impact of F-LQE on the performance of tree routing, specifically the CTP (Collection Tree Protocol). For this purpose, we adapted F-LQE to build a new routing metric for CTP, which we dubbed as F-LQE/RM. Extensive experimental results obtained with state-of-the-art widely used test-beds show that F-LQE/RM improves significantly CTP routing performance over four-bit (the default LQE of CTP) and ETX (another popular LQE). F-LQE/RM improves the end-to-end packet delivery by up to 16%, reduces the number of packet retransmissions by up to 32%, reduces the Hop count by up to 4%, and improves the topology stability by up to 47%.
2014 12th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt), 2014
ABSTRACT Low power and lossy networks (LLNs) require efficient routing protocols that should meet... more ABSTRACT Low power and lossy networks (LLNs) require efficient routing protocols that should meet the requirements of the critical applications, such as real-time, reliability and high availability. RPL has been recently proposed by the ROLL working group as a tree routing protocol specifically designed for LLNs. It relies on objective functions to construct routes that optimize or constrain a routing metric on the paths. However, the working group did not specify the set of metrics and/or constraints to be used to specify the preferred path, and left it open to implementations. In this paper, we design OF-FL, a novel objective function that combines a set of metrics in order to provide a configurable routing decision based on the fuzzy parameters. OF-FL has the advantage to consider the application requirements in order to select the best paths to the destination. Our evaluation with a large-scale testbed in ContikiOS reveals that OF-FL can achieve remarkable performance of the RPL-based LLNs in comparison with the existing objective functions, and appropriately satisfy the quality of service contract of the different applications.
SpringerBriefs in Electrical and Computer Engineering, 2013
ABSTRACT Several network protocols and mechanisms rely on efficient link quality estimation to mi... more ABSTRACT Several network protocols and mechanisms rely on efficient link quality estimation to mitigate the unreliability of low-power links. A LQE can be efficient on a per-link basis, but it may lead to a poor performance when integrated in a particular protocol or mechanism. The objective of this chapter is to show how to use link quality estimation for improving higher layer protocols and mechanisms—especially routing and mobility management.
We consider the problem of link quality estimation in wireless sensor networks. Existing link qua... more We consider the problem of link quality estimation in wireless sensor networks. Existing link quality estimators (e.g. PRR, ETX, Four-bit, and LQI) are only able to assess a single link property, thus providing a partial view on the link quality. It is therefore important, yet challenging, to design link quality estimators that perform holistic link characterization by considering several properties. In this poster, we propose F-LQE, a novel link quality estimator, that estimates link quality on the basis of four link quality prop-erties namely, packet delivery, asymmetry, stability, and channel quality. Combination of link properties is performed using Fuzzy Logic. We show through extensive TOSSIM simulation that F-LQE outperforms existing link quality estimators.
ABSTRACT Radio link quality estimation is essential for protocols and mechanisms such as routing,... more ABSTRACT Radio link quality estimation is essential for protocols and mechanisms such as routing, mobility management and localization, particularly for low-power wireless networks such as wireless sensor networks. Commodity Link Quality Estimators (LQEs), e.g. PRR, RNP, ETX, four-bit and RSSI, can only provide a partial characterization of links as they ignore several link properties such as channel quality and stability. In this paper, we propose F-LQE (Fuzzy Link Quality Estimator, a holistic metric that estimates link quality on the basis of four link quality properties—packet delivery, asymmetry, stability, and channel quality—that are expressed and combined using Fuzzy Logic. We demonstrate through an extensive experimental analysis that F-LQE is more reliable than existing estimators (e.g., PRR, WMEWMA, ETX, RNP, and four-bit) as it provides a finer grain link classification. It is also more stable as it has lower coefficient of variation of link estimates. Importantly, we evaluate the impact of F-LQE on the performance of tree routing, specifically the CTP (Collection Tree Protocol). For this purpose, we adapted F-LQE to build a new routing metric for CTP, which we dubbed as F-LQE/RM. Extensive experimental results obtained with state-of-the-art widely used test-beds show that F-LQE/RM improves significantly CTP routing performance over four-bit (the default LQE of CTP) and ETX (another popular LQE). F-LQE/RM improves the end-to-end packet delivery by up to 16%, reduces the number of packet retransmissions by up to 32%, reduces the Hop count by up to 4%, and improves the topology stability by up to 47%.
2014 12th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt), 2014
ABSTRACT Low power and lossy networks (LLNs) require efficient routing protocols that should meet... more ABSTRACT Low power and lossy networks (LLNs) require efficient routing protocols that should meet the requirements of the critical applications, such as real-time, reliability and high availability. RPL has been recently proposed by the ROLL working group as a tree routing protocol specifically designed for LLNs. It relies on objective functions to construct routes that optimize or constrain a routing metric on the paths. However, the working group did not specify the set of metrics and/or constraints to be used to specify the preferred path, and left it open to implementations. In this paper, we design OF-FL, a novel objective function that combines a set of metrics in order to provide a configurable routing decision based on the fuzzy parameters. OF-FL has the advantage to consider the application requirements in order to select the best paths to the destination. Our evaluation with a large-scale testbed in ContikiOS reveals that OF-FL can achieve remarkable performance of the RPL-based LLNs in comparison with the existing objective functions, and appropriately satisfy the quality of service contract of the different applications.
SpringerBriefs in Electrical and Computer Engineering, 2013
ABSTRACT Several network protocols and mechanisms rely on efficient link quality estimation to mi... more ABSTRACT Several network protocols and mechanisms rely on efficient link quality estimation to mitigate the unreliability of low-power links. A LQE can be efficient on a per-link basis, but it may lead to a poor performance when integrated in a particular protocol or mechanism. The objective of this chapter is to show how to use link quality estimation for improving higher layer protocols and mechanisms—especially routing and mobility management.
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