Reliable Link Quality Estimation in Low-power Wireless Networks and its impact on Tree-routing
Ref: CISTER-TR-150208 Publication Date: Apr 2015
Reliable Link Quality Estimation in Low-power Wireless Networks and its impact on Tree-routing
Ref: CISTER-TR-150208 Publication Date: Apr 2015Abstract:
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 testbeds
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%
Published in Ad Hoc Networks, Elsevier, Volume 27, pp 1-25.
DOI:10.1016/j.adhoc.2014.11.011.
ISSN: 1570-8705.
Record Date: 13, Feb, 2015