ARP (Autoradiopuhelin, "car radio phone") was the first commercially operated public mobile phone network in
Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bot ...
. The technology is zero-generation (
0G), since although it had cells, moving between them was not seamless. The network was proposed in 1968 and building began in 1969. It was launched in 1971, and reached 100% geographic coverage in 1978 with 140
base station
Base station (or base radio station) is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a "land station in the land mobile service."
The term is used in the context of mobile telephony, wireless c ...
s. The ARP network was closed at the end of 2000 along with
NMT-900.
ARP was a success and reached great popularity (10,800 users in the year 1977, with a peak of 35,560 in 1986), but the service eventually became too congested and was gradually replaced by the more modern
NMT technology. However, ARP was the only mobile phone network with 100% percent coverage for some time thereafter, and it remained popular in many special user groups.
ARP operated on 150 MHz frequency (80
channels
Channel, channels, channeling, etc., may refer to:
Geography
* Channel (geography), in physical geography, a landform consisting of the outline (banks) of the path of a narrow body of water.
Australia
* Channel Country, region of outback Austral ...
on 147.9 - 154.875 MHz band). Transmission power ranged from 1
watt
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James ...
to 5 watts. It first used only
half-duplex
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
transmission, meaning that receiving and transmitting voice could not happen at the same time. Later, full-duplex car phones were introduced. Being
analog
Analog or analogue may refer to:
Computing and electronics
* Analog signal, in which information is encoded in a continuous variable
** Analog device, an apparatus that operates on analog signals
*** Analog electronics, circuits which use analog ...
, it had no
encryption
In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can d ...
and calls could be listened to with scanners. It started as a manually switched service, but was fully automated in 1990; however, by that time the number of subscribers had dwindled down to 980 users. ARP did not support
handover, so calls would disconnect when moving to a new cell area. The cell size was approximately 30 km.
The first ARP mobile terminals were extremely large for the time and could only be fitted in cars' trunks, with a handset near the driver's seat. ARP was also expensive. In the 1990s, handhelds were introduced in ARP but they never became popular as more modern equipment was already available in other systems like NMT.
{{Mobile telecommunications standards
Mobile radio telephone systems