160 likes | 264 Views
BTS – Communications II. Requirements and Technologies. BTS Communication. Requirements Redundant links for robustness Terrain and distance dependent Compatible/non-interfering with existing systems Technologies Satellite RF, Microwave Fiber-optic
E N D
BTS – Communications II Requirements and Technologies CSE 8394
BTS Communication • Requirements • Redundant links for robustness • Terrain and distance dependent • Compatible/non-interfering with existing systems • Technologies • Satellite • RF, Microwave • Fiber-optic • Commercial phones (land lines and wireless • IP Links CSE 8394
Satellite Orbits • Low Earth Orbit (LOE) • 200- 1000 Miles Above Ground Level • .03 Second Roundtrip Latency for Upload and Download • Used by military satellites • Middle Earth Orbits (MEO) • 6250 - 13000 Miles Above Ground Level • .06 to .14 Second Roundtrip Latency • Geo-synchronous Orbit • 22,300 Miles Above Ground Level • .24 Second Roundtrip Latency • Used by most commercial satellites CSE 8394
Satellite Remote Sensing • Optical • Radar • Insensitive to weather • Sensitive to ground conditions CSE 8394
Microwave Links • Benefits: • No need to dig • Only option over inhospitable terrain or congested areas • Despite low cost, broadcast level video quality • COFDM (Coded Orthogonal Frequency Division Multiplex) helps in the noisy urban areas • Excellent for ad hoc deployment • Specs • Single channel (To collecting points) • Multi-channel CSE 8394
Typical Setup CSE 8394
Microwave Repeaters CSE 8394
COFDM Advantages CSE 8394
Advanced Microwave Setup CSE 8394
Advanced Microwave Setup (Relay) CSE 8394
New Technologies Courtesy: ParcelCall CSE 8394
Generations of Wireless Technologies • 1G: 1979-1992 analog wireless technology • 2G: current digital wireless technology • TDMA (GSM: Global Systems of Mobile Communication) • CDMA • 2.5G: interim technology accommodates graphics • 3G: non-IP based technology (2001-2005) supports rich media (video clips) • 4G: fully IP-based network (2006-2010) • GPRS: General Packet Radio Services • WCDMA: Wideband CDMA CSE 8394
Wireless Technologies (Cont’d) • GPS: Satellite-based Global Positioning System • SMS: Short Message Service (e-mail, up to 160 characters) • EMS: Enhanced Messaging Service • Extension of SMS; simple animation, tiny picture, short melody • MMS: Multimedia Messaging Service • Rich media of next generation • UMTS: Universal Mobile Telecommunications System for 3G mobile standard • WAP: Wireless Application Protocol for Internet Browsing CSE 8394
Automated Vehicle Location (AVL) • GPS to track vehicles • Already more than a million vehicles in the US with AVL • $3 billion business by 2007 • In line with the new vision for BTS CSE 8394
New Interesting Proposals • Airships • Comparison with UAVs, Satellites CSE 8394