12/63
University of Electronic Science and Technology of China
Wireless Sensor Networks
Current Wireless Systems
Cellular Systems Wireless LANs Satellite Systems Bluetooth Ultra-wide band radios Zigbee radios …
Pre-Cellular Wireless
Wireless Sensor Networks
One highly-elevated antenna in a large service area
Small number of channels Very low capacity Examples: MJ and MK systems in the United
locations Co-channel interference between same color cells. Base stations/MTSOs coordinate handoff and control functions Shrinking cell size increases capacity, as well as networking
6/63
University of Electronic Science and Technology of China
Wireless Sensor Networks
Cellular - Implementation
7/63
University of Electronic Science and Technology of China
University of Electronic Science and Technology of China
Wireless Sensor Networks
Lec2 无线与移动通信发展历程
1/63
University of Electronic Science and Technology of China
8/63
University of Electronic Science and Technology of China
Wireless Sensor Networks
Reuse channels to maximize capacity
Geographic region divided into cells Frequencies/timeslots/codes reused at spatially-separated
First proposed by D. H. Ring at Bell Laboratories in 1947
5/63
University of Electronic Science and Technology of China
Wireless Sensor Networks
Cellular - Implementation
内容提要
Wireless Sensor Networks
1. The Wireless Vision 2. Technical Challenges 3. Current Wireless Systems 4. Emerging Wireless Systems 5. Spectrum Regulation 6. Standards
2/63
University of Electronic Science and Technology of China
Wireless History
Wireless Sensor Networks
First Mobile Radio Telephone 1924
3/63
University of Electronic Science and Technology of China
ectronic Science and Technology of China
Wireless Sensor Networks
Cellular Phone Networks
San Francisco
BS MTSO
BS Internet
PSTN
MTSO
11/63
burden
BASE STATION
Mobile Telephone Switching
Office
9/63
University of Electronic Science and Technology of China
Wireless Sensor Networks
GSM System Architecture
States
4/63
University of Electronic Science and Technology of China
Wireless Sensor Networks
The Cellular Concept
Basic Principles Frequency Reuse Cell Splitting
New York
BS
University of Electronic Science and Technology of China
内容提要
Wireless Sensor Networks
1. The Wireless Vision 2. Technical Challenges 3. Current Wireless Systems 4. Emerging Wireless Systems 5. Spectrum Regulation 6. Standards
内容提要
Wireless Sensor Networks
1. The Wireless Vision 2. Technical Challenges 3. Current Wireless Systems 4. Emerging Wireless Systems 5. Spectrum Regulation 6. Standards