Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Multihop Medium Access Control for WSNs: An Energy Analysis Model | EURASIP Journal on Wireless Communications and Networking 2005 4 523-540 2005 Jussi Haapola et al. Multihop Medium Access Control for WSNs An Energy Analysis Model Jussi Haapola Centre for Wireless Communications CWC University of Oulu . Box 4500 90014 Oulu Finland Email jhaapola@ Zach Shelby Centre for Wireless Communications CWC University of Oulu . Box 4500 90014 Oulu Finland Email zdshelby@ Carlos Pomalaza-Raez Centre for Wireless Communications CWC University of Oulu . Box 4500 90014 Oulu Finland Email carlos@ Petri Mahonen Institute of Wireless Networks RWTH Aachen University Kackertstrafie 9 52072 Aachen Germany Email pma@ Received 30 November 2004 Revised 30 March 2005 We present an energy analysis technique applicable to medium access control MAC and multihop communications. Furthermore the technique s application gives insight on using multihop forwarding instead of single-hop communications. Using the technique we perform an energy analysis of carrier-sense-multiple-access CSMA- based MAC protocols with sleeping schemes. Power constraints set by battery operation raise energy efficiency as the prime factor for wireless sensor networks. A detailed energy expenditure analysis of the physical the link and the network layers together can provide a basis for developing new energy-efficient wireless sensor networks. The presented technique provides a set of analytical tools for accomplishing this. With those tools the energy impact of radio MAC and topology parameters on the network can be investigated. From the analysis we extract key parameters of selected MAC protocols and show that some traditional mechanisms such as binary exponential backoff have inherent problems. Keywords and phrases energy efficiency wireless sensor networks medium access control multihop communications. 1. INTRODUCTION Sensor network applications have recently become of significant interest due to cheap single-chip .
