Abstract
The ZigBee wireless communication specifications forecast the use of multihop routes between nodes and define that nodes select their routes based on their costs. The specifications define how to compute a route cost from the probability of successfully transmitting on each of the routes’ links; and it is recommended that such probabilities be obtained by counting received link status messages or averaging link quality indicators from received packets. In this paper, we study the performance of these two recommended procedures, show that they can lead to degraded route selections, and propose a procedure that can improve route selections without modifications to the ZigBee protocol or frame formats. Our procedure estimates the probability of successful transmission on each link, based on information from the medium access layer during unicast packet transmissions, and includes a modification into how ZigBee nodes treat routing messages internally in order to reduce variations in the link cost estimates. Focusing on a home environment with one or two hops, our simulation results show that, in several scenarios, our procedure performs better than either of the two procedures recommended in the ZigBee specifications.
Highlights
ZigBee is a wireless communication protocol that has been successfully used in applications ranging from home automation to industrial control and consumer electronics [1,2]
When a node receives a route request (RREQ) with a new RREQ identifier (RREQ-ID), it updates its routing table even if the cumulative route cost is higher than the cost obtained from a previous RREQ period
In the link quality indicator (LQI)-based estimation procedure suggested in the ZigBee specifications (Section 3.6.3.1 of [13]), the cost cz1,z2 of a node z1 transmitting to a node z2 is estimated from the average LQI of received messages: Let Tavg be the duration of the estimation window; let NLQI be the number of transmissions from node z1 successfully received at node z2 during the last Tavg seconds; and let LQIz1,z2 ( j) be the value of the LQI at the jth received packet
Summary
ZigBee is a wireless communication protocol that has been successfully used in applications ranging from home automation to industrial control and consumer electronics [1,2]. We focus on one particular aspect that the ZigBee specifications do not fully specify: the estimation of the probability of successful transmission on a link Such an estimation is important because it is used by nodes to select multihop routes. Previous authors have shown that estimating link costs from beacons, such as ZigBee’s LS packets, is less accurate than estimating them from unicast data packets and have proposed alternative procedures to improve route selection [14–28]. These procedures are valuable and would improve link cost estimation and route selection, their implementation in ZigBee devices would require significant changes in the ZigBee specifications, protocol, and frame formats.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
