First Generation Analog Wireless Systems
- The First generation of wireless telecommunication
technology is known as 1G was introduced in 1980.
- The main difference between then existing systems and 1G
was invent of cellular technology and hence it is also known as First
generation of analog cellular telephone.
- In 1G or First generation of wireless telecommunication
technology the network contains many cells (Land area was divided
into small sectors, each sector is known as cell, a cell is covered by a
radio network with one transceiver) and so same frequency can be reused
many times which results in great spectrum usage and thus increased the
system capacity i.e. large number of users could be accommodated easily.
- The First generation of wireless telecommunication
technology used analog transmission techniques which were basically used
for transmitting voice signals.
- 1G or first generation of wireless
telecommunication technology also consist of various standards among which
most popular were Advance Mobile Phone Service (AMPS), Nordic Mobile
Telephone (NMT), Total Access Communication System (TACS).
- All of the standards in 1G use frequency modulation
techniques for voice signals and all the handover decisions were taken at
the Base Stations (BS).
- The spectrum within cell was divided into number of
channels and every call is allotted a dedicated pair of channels. Data
transmission between the wire part of connection and PSTN (Packet Switched
Telephone Network) was done using packet-switched network.
Second
Generation Digital Wireless
Systems
- Second-generation (2G) digital
cellular systems constitute the majority of cellular communication
infrastructures deployed today.
- 2G systems such as Global System
for Mobile communication(GSM), whose rollout started in 1987, signaled a
major shift in the way mobile communications is used worldwide.
- In part they helped fuel the
transition of a mobile phone from luxury to necessity and helped to drive
subscriber costs down by more efficient utilization of air interface and
volume deployment of infrastructure components and handsets.
Third
Generation Wireless Systems
- 3rd Generation Mobile Telecommunications (3G), is a set
of standards that came about as a result of the International
Telecommunication Union’s (ITU) initiative known as IMT-2000 (International
Mobile Telecommunications-2000).
- 3G systems are expected to deliver quality
multimedia to mobile devices by way of faster and easier wireless
communications as well as “anytime, anywhere” services.
This term is also known as 3rd generation mobile telecommunications.
Written
By A.Devasena
Associate
Professor/ ECE Dept.
