What is Mobile Radio Telephone System or 0G (Zero Generation) ?

By | July 27, 2011

OG (Zero Generation) is also known as Mobile Radio Telephone system. As this generation was invented prior to cellular system it was mentioned as pre cellular system. This system was analog in nature i.e. analog signals were used as carriers. Generally Mobile Radio Telephone system provides half duplex communications i.e. only one person will speak and other should hear. Mobile Radio Telephone system (Zero generation) consists of various technologies such as Advanced Mobile Telephone System (AMTS), Mobile Telephone System (MTS), MTD (Mobile telephony system D), OLT (Offentlig Landmobile Telefoni or Public Land Mobile Telephony), Push to Talk (PTT) and Improved Mobile Telephone Service (IMTS).These mobile telephones were placed in vehicles (truck, cars etc). The mobile telephone instrument had two main parts those were transceiver (transmitter – receiver) and head (instrument which had display and dial keys). Transceiver (transmitter – receiver) was fixed in the vehicle trunk; head was fixed near the driver seat and both head and transceiver were connected to each other with wire. The device (telephone) would connect to local telephone network only if it is in the range of 20 Kms. Each city had a central antenna tower with 25 channels. This means that mobile transceiver should have a powerful transmitter with a transmitting range of 50-70 Kms. Only few people were able to use this device as only 25 channels were available. Roaming facility was not supported in this generation of analog cellular Mobile Radio telephone system. Mobile Radio telephone system was a commercial service under public switched telephone network with unique telephone numbers. Zero generation had seen different variants of two way radio telephones. Large number of limitations in this generation led to the advent of new generation.

What is 0.5G Technology?

0.5G was the advance version of 0G (Zero Generation or Mobile Radio Telephone system). This 0.5G technology had introduced ARP (Autoradiopuhelin) as the first commercial public mobile phone network. This ARP network was launched in 1971 at Finland.  ARP was operated on 8 Channels with a frequency of 150 MHz (147.9 – 154.875 MHz band) and its transmission power was in a range of 1 to 5 watts.  ARP used half duplex system for transmission (voice signals can either be transmitted or received at a time) with manual switched system. This Network contains 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) with the cell size of 30 km.  As ARP did not support the handover, calls would get disconnected while moving from one cell to another. ARP provided 100% coverage which attracted many users towards it. ARP was successful and became very popular until the network became congested. The ARP mobile terminals were too large to be fixed in cars and were expensive too. These limitations led to invent of Autotel. Autotel are also known as PALM (Public Automated Land Mobile). Autotel is a radio telephone service which in terms of technology lies between MTS and IMTS. It used digital signals for messages like call stepup, channel assignment, ringing, etc only voice channel was analog. This system used existent high-power VHF channels instead of cellular system. It was developed in Canada and Columbia.