ELEKTRONIKA IR ELEKTROTECHNIKA, ISSN 1392-1215, VOL. 19, NO. 9, 2013 Abstract—The present paper introduces an adaptive channel selection algorithm that can be integrated in a ZigBee network performing in an environment that is highly affected by IEEE 802.11 interferences. The algorithm can be implemented when a tree network topology is used. The interferences are detected by means of an ACK/NACK type algorithm. When interference is detected, each node of the network contributes to the selection of the optimum channel performance. A series of tests have been conducted in order to validate the performance of the suggested algorithm. Even when the RF environment is congested, the coordinator is able to make the optimum selection of the operating channel for the entire network. Index Terms—IEEE 802.15.4, channel selection algorithm, street lighting control, ZigBee. I. INTRODUCTION Wireless networks are becoming more widespread, thus causing the congestion of the radio frequency environment. The scientific literature includes a series of papers that approach the allocation of the optimum performance channel within an IEEE 802.15.4 ZigBee sensor network that operates in an environment that is highly affected by interferences – mostly of the IEEE 802.11 type [1]–[9]. None of these papers approaches the issue of determining the optimal operating channel that can be applied in a street lighting monitoring and control system. In the implementation of a lighting control system by employing the IEEE 802.15.4 standard which also includes the ZigBee communication protocol, each lamp is integrated in a network and thus becomes a node [10]. As presented in a related paper [11], the tree type network topology ensures a high performance level in terms of end-to-end application delay, throughput, number of hops and the possibility to integrate a large number of nodes. Thus, the tree topology is recommended when a monitoring and control street lighting system is implemented. This system it is of the long-thin Manuscript received December 17, 2012; accepted May 30, 2013. This paper was supported by the project "Improvement of the doctoral studies quality in engineering science for development of the knowledge based society-QDOC” contract no. POSDRU/107/1.5/S/78534, project co- funded by the European Social Fund through the Sectorial Operational Program Human Resources 2007-2013. type and it can incorporate more than a few hundred nodes [11]. The aim of this paper is to propose a novel adaptive channel selection algorithm that can be integrated in a street lighting control architecture operating in an environment that is highly affected by interferences. The algorithm can be used when employing a tree network topology. II. CHANNEL ALLOCATION This section presents, an analysis of the channel allocation for the IEEE 802.11 standard and IEEE 802.15.4. The communication channels provided in the 802.11g standard have a bandwidth of 20MHz, as shown in Fig. 1. Fig. 1. Channel overlapping IEEE 802.1 and IEEE 802.15.4. The bandwidth of an IEEE 802.15.4 channel is about 2 MHz, just as the frequency guard interval and therefore the channels that do not overlap are very few (for example channels 1, 5, 9 and 13 for IEEE 802.11g EU zone). As shown in Fig. 1, the selection of the optimal channel for the IEEE 802.15.4 network when the RF environment is congested is still a highly debated issue [12]. III. ADAPTIVE CHANNEL SELECTION ALGORITHM The coexistence of the IEEE 802.15.4 and the IEEE 802.11 networks, as well as the channel allocation, can be addressed by assessing the interferences from an AP (Access Point) IEEE 802.11 to an IEEE 802.15.4 network [13]. Thus, an algorithm is suggested for the adaptive channel selection in an environment that is highly disturbed by interferences. In [14] is presented an adaption system for interferences in order to obtain a high level of performance in an IEEE 802.15.4 network that uses a mesh topology. The disadvantages of the suggested algorithm are that it assumes Adaptive Channel Selection Algorithm for a Large Scale Street Lighting Control ZigBee Network A. Lavric 1 , V. Popa 1 , S. Sfichi 1 1 Department of Computers, Electronics and Automation, Stefan cel Mare University, Universitatii St. 13, RO–720229 Suceava, Romania lavric@eed.usv.ro http://dx.doi.org/10.5755/j01.eee.19.9.5659 105