12.07.2015 Views

Wireless Ad Hoc and Sensor Networks

Wireless Ad Hoc and Sensor Networks

Wireless Ad Hoc and Sensor Networks

SHOW MORE
SHOW LESS
  • No tags were found...

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

14 <strong>Wireless</strong> <strong>Ad</strong> <strong>Hoc</strong> <strong>and</strong> <strong>Sensor</strong> <strong>Networks</strong>rate of up to 57.6 kbps to individual users. GPRS <strong>and</strong> IS-136 st<strong>and</strong>ard wasable to achieve data rates to the tune of 171.2 kbps. EDGE, the st<strong>and</strong>ardfor 2.5GSM <strong>and</strong> IS-136, uses 8-PSK digital modulation in addition to theGSM’s st<strong>and</strong>ard Global Mobile shift keying (GMSK) modulation, withoutany error protection. All 8 time slots of a GSM radio channel are dedicatedto a single user <strong>and</strong> a raw peak throughput data rate of 547.2 kbps canbe provided. By combining the capacity of different radio channels(e.g., using multicarrier transmissions), EDGE can provide up to severalmegabits per second of data throughput to the individual data user.Third-generation (3G) wireless networks: Third-generation st<strong>and</strong>ardsfor wireless cellular networks promise unparalleled wirelessaccess, multimegabit Internet access, communications usingVoIP, voice-activated calls, <strong>and</strong> ubiquitous “always-on” access<strong>and</strong> many other distinguishable wireless access features. Several3G st<strong>and</strong>ards, many of which provide backward compatibility,are being followed around the world. The various upgrade pathsfor the 2G technologies to the 3G st<strong>and</strong>ards are shown in Figure 1.1.Among the available 3G st<strong>and</strong>ards the following cellular st<strong>and</strong>ardshave gained greater acceptance.3GCDMA2000-1xRTTCDMA2000-1xev,DV,DOCDMA2000-3xRTT3GPP2EDGEW-CDMATD-SCDMA3GPP2.5GIS-95BHSCSDGPRSEDGE2GIS-95GSMIS-136 & PDCFIGURE 1.1Upgrade paths for 2G technologies. (From Rappaport, T.S., <strong>Wireless</strong> Communications: Principles<strong>and</strong> Practice, Prentice Hall, Upper Saddle River, NJ, 1999. With permission.)

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!