Selected papers from Chinacom'06

The special issue consists of four papers addressing recent state-of-the-art research of wireless communication and networking technologies, which is timely and valuable for future analysis, implementation and experiments. The first two papers propose efficient and secure routing algorithms for wireless sensor networks. In the first paper ‘‘A Dynamic-Clustering Reactive Routing Algorithm for Wireless Sensor Networks,’’ Bin Guo and Zhe Li define a node model based on the structure and transmission principle of neuron and propose a dynamic clustering reactive routing algorithm for large-scale wireless sensor networks. Two accumulation schemes are also designed to further improve the efficiency of data collection. In the paper ‘‘Proactive mitigation of impact of wormholes and sinkholes on routing security in energy-efficient wireless sensor networks’’, Huzaifa Al Nahas, et al., propose a novel routing approach, Secure-Path Routing (SPR), to mitigate the impact of undetected compromised nodes on routing by increasing traffic flow over legitimate routes. Two SPR algorithms are developed to balance risk with energy consumption, using different attack models. SPR can be used for sensitive message delivery to extend the lifetime of low-risk nodes. Next generation WLAN is expected to enable various broadband multimedia services. In the third paper ‘‘Supporting Voice and Video Applications over IEEE 802.11n WLANs’’, Lin X. Cai, et al., develop an analytical model for the performance study of an IEEE 802.11n WLAN, considering the enhanced MAC mechanisms, i.e., frame aggregation and bidirectional transmission. The enhancements can effectively improve the network capacity by not only reducing the protocol overheads, but also smoothing the AP-bottleneck effect in an infrastructurebased WLAN. In the fourth paper ‘‘Time-Frequency Hopping Sequences with Three No Hit Zones’’, Xianyang Jiang, et al., propose new sequences with Three No Hit Zones (TNHZ) in Time-Frequency Hopping (TFH) systems, based on the idea of No Hit Zone (NHZ) in Frequency Hopping (FH) systems. The T-NHZ sequences efficiently reduce or eliminate multipath interference in TFH-CDMA systems and achieve much better bit error performance than traditional frequency hopping sequences and NHZ sequences. In closing, the guest editors would like to acknowledge the contribution of many experts who participated in the review process and provided helpful suggestions to the authors on improving the content and presentation of the articles. The advice and support from Editor-in-Chief, Dr. Imrich Chlamtac, and the Editorial Assistant, Karen Decker, are greatly appreciated. Guest Editors Xuemin (Sherman) Shen Andreas F. Molisch Zhisheng Niu Honggang Zhang Xuemin (Sherman) Shen (&) Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, Canada N2L 3G1 e-mail: [email protected]