22-06-2012, 04:12 PM
The Evolution of TDMA to 3G & 4G Wireless Systems
[attachment=25113]
TDMA parameters
30 KHz channels (like analog & CDPD)
20 msec speech frames
24.3 kbaud symbol rate
3 time-slots/users
7.4 kbps ACELP speech coding
1/2-rate channel coding on important bits interleaved over 2 bursts in 40 msec
Differential pi/4-QPSK modulation
Advantages of TDMA
Flexible bit rate
No frequency guard band required
No need for precise narrowband filters
Easy for mobile or base stations to initiate and execute hands off
Extended battery life
TDMA installations offer savings in base station equipment, space and maintenance
The most cost-effective technology for upgrading a current analog system to digital
4G Networks Advances
Seamless mobility (roaming)
Roam freely from one standard to another
Integrate different modes of wireless communications – indoor networks (e.g., wireless LANs and Bluetooth); cellular signals; radio and TV; satellite communications
100 Mb/se full mobility (wide area); 1 Gbit/s low mobility (local area)
IP-based communications systems for integrated voice, data, and video
IP RAN
Open unified standards
Stream Control Transmission Protocol (SCTP)
Successor to “SS7”; replacement for TCP
Maintain several data streams within a single connection
Service Location Protocol (SLP)
Automatic resource discovery
Make all networked resources dynamically configurable through IP-based service and directory agents
Summary: Key Features of 4G W-OFDM
IP packet data centric
Support for streaming, simulcasting & generic data
Peak downlink rates of 5 to 10 Mbps
Full macro-cellular/metropolitan coverage
Asymmetric with 3G uplinks (EDGE)
Variable bandwidth - 1 to 5 MHz
Adaptive modulation/coding
Smart/adaptive antennas supported
MIMO/BLAST/space-time coding modes
Frame synchronized base stations using GPS
Network assisted dynamic packet assignment
[attachment=25113]
TDMA parameters
30 KHz channels (like analog & CDPD)
20 msec speech frames
24.3 kbaud symbol rate
3 time-slots/users
7.4 kbps ACELP speech coding
1/2-rate channel coding on important bits interleaved over 2 bursts in 40 msec
Differential pi/4-QPSK modulation
Advantages of TDMA
Flexible bit rate
No frequency guard band required
No need for precise narrowband filters
Easy for mobile or base stations to initiate and execute hands off
Extended battery life
TDMA installations offer savings in base station equipment, space and maintenance
The most cost-effective technology for upgrading a current analog system to digital
4G Networks Advances
Seamless mobility (roaming)
Roam freely from one standard to another
Integrate different modes of wireless communications – indoor networks (e.g., wireless LANs and Bluetooth); cellular signals; radio and TV; satellite communications
100 Mb/se full mobility (wide area); 1 Gbit/s low mobility (local area)
IP-based communications systems for integrated voice, data, and video
IP RAN
Open unified standards
Stream Control Transmission Protocol (SCTP)
Successor to “SS7”; replacement for TCP
Maintain several data streams within a single connection
Service Location Protocol (SLP)
Automatic resource discovery
Make all networked resources dynamically configurable through IP-based service and directory agents
Summary: Key Features of 4G W-OFDM
IP packet data centric
Support for streaming, simulcasting & generic data
Peak downlink rates of 5 to 10 Mbps
Full macro-cellular/metropolitan coverage
Asymmetric with 3G uplinks (EDGE)
Variable bandwidth - 1 to 5 MHz
Adaptive modulation/coding
Smart/adaptive antennas supported
MIMO/BLAST/space-time coding modes
Frame synchronized base stations using GPS
Network assisted dynamic packet assignment