In the recent past, wireless systems are widely used in almost all fields. Many technologies make use of jet speed digital wireless systems. 4G wireless systems refer to the fourth generation of wireless standards; precursors to 4G were 2G and 3G standards.
The first generation systems were mainly used for voice communications; the second generation systems were used for voice transmission and reception while the 3G systems were designed for paging and voice services. Read on to know more about the most expected fourth generation wireless systems.
4G wireless system is a packet switched with coverage of a wide area and great throughput. It is supposed to have an infrastructure that can manage the preceding 3G systems as well as other wireless systems. 4G system is designed in such a way that it can provide high spectral efficiency; it is also cost effective. It makes use of Millimeter wireless, Ultra Wide radio Band (UWB) and Orthogonal Frequency Division Multiplexing (OFDM). Mobile speed is 200 Km/hr and data rate is 20 Mbps. The reasons for the high performance are:
- It makes use of long term channel prediction schedule amidst users in frequency as well as time.
- Smart antennas are united with power control and adaptive modulation.
- Frequency band: 2 – 8 GHz; this range enables mobile to be accessed from any part of the world .i.e. world wide roaming.
Features of 4G Wireless Systems
The salient features of $G wireless systems include:
- Supports streaming video, voice calls, internet and many more broadband services
- High levels of speed and high capacity at a lower cost leading to enhanced performance
- High spectral efficiency
- IP based mobile technology
- Improved scheduling and call admission control methods
- Multi-hop and Ad hoc networks
- Flawless network of manifold protocols
- Faultless switching
- World wide access, service portability and scalable mobile networks
- Range of services based on Quality of Service (QOS) conditions
3G systems versus 4G systems
The table given below compares few of the significant parameters of 3G and the possible 4G systems:
|Parameters||3G wireless systems||4G wireless systems|
|Bandwidth||5-20 MHz||5-20 MHz|
|Frequency Range||1.8 – 2.5 GHz||2 – 8 GHz|
|Access||Wideband CDMA||Multi-carrier – CDMA or OFDM|
|Data Rate||Up to 2Mbps||Up to 20 Mbps or more|
|Mobile high speeds||200 kmph||200 kmph|
The Bottom Line
4G is expected to be commercially available in the year 2010; as of now it is in the formative phase. The previous generation wireless systems provided maximum wide area network (WAN) coverage of 384 Kbps and restricted coverage for 2 Mbps. Thus, the main objective of 4G wireless systems is to provide broadband services. In the future, a modified internet protocol is expected to be the universal protocol with the complete network being digital and packet switched.