03-10-2012, 04:58 PM
3G and 4G Wireless – Advances and Challenges
3G and 4G.ppt (Size: 2.12 MB / Downloads: 174)
Where are We?
Classic Wireline MaBell Public Switched Telephone Network (PSTN)
US Universal coverage achieved early 1980’s
“Wireless” First Generation Analog Systems
Speech
AMPS, TACS
Second Generation Digital Systems
Enhanced Capacity
CDMA, D-AMPS, TDMA, GSM, DECT, PDC
2.5 Generation Systems
Low Speed Data
GPRS, EDGE
Third Generation Systems
“INTERNET” on Wireless
WiFi/HyperLAN <-> WiMAX/HyperWAN <-> CDMA2000/WCDMA
Evolution to All IP Network including VoIP
Representative Wireless Standards
GSM/TDMA
Time Division Multiplexing based access
CDMA
Code Division Multiplexing based access
OFDM
Orthogonal Frequency Division Multiplexing
Orthogonal Frequency Division Multiplexing (OFDM)
Successor to Frequency Hopping and Direct Sequence CDMA
Capability to cancel multipath distortion in a spectrally efficient manner without requiring multiple local oscillators (802.11a and 802.16)
Based on use of IFFT and FFT
Frequency orthogonality as compared to code orthogonality in CDMA using Walsh Code
Key Mobility Services
Multimedia Messaging Services (MMS)
Text, sounds, images, and video
Transition from Short Message Service (SMS)
Open Internet standards for messaging
Web Applications
Information portals
Wireless Markup Language (WML) with signals using Wireless Application Protocol (WAP)
Location Communications Services
Location Awareness Based
Personalization of information presentation format
Service capability negotiations (MExE environment)
Customized Application for Mobile Enhanced Logic (CAMEL)
CAMEL = IN + Service portability (incl mobility and roaming)
Virtual Private Network (VPN)
Mobile user <-> ISP <-> corporate server
Mobility, Security, Capacity and quality
Prepaid, Usage Limitations, Advanced Routing Services
Virtual Home Environment (VHE)
Subscriber profile, charging information, Service information, numbering information
Integration of array of services, content conversion to heterogeneous services, network user profile, location aware services