Development of IEEE 802.15.4 Multi-Hop Calling System

• Main Authors: Kun-Chang Wu, 吳坤璋
• Other Authors: 趙亮琳
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/66166177857060712076

碩士 === 聖約翰科技大學 === 電子工程系碩士班 === 98 === In this lab, real-time speech signal is transmitted through IEEE 802.15.4 frames. The system consists of a PAN coordinator, some coordinators, and some end devices. A simple routing protocol is implemented. The sampling and reconstruction of speech signal are processed by an ADPCM codec with sampling frequency 8.23 kHz. Each speech sample is compressed into four bits, and thus each transmitted data byte contains two samples. The experimental results show that the transmission delay of the first hop is about 20 ms, and the extra delay for every hop is about 3.8 ms.