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ARP was the first commercially operated public mobile phone network in Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

. The technology is zero-generation (0G
0G
0G or 0-G may refer to:*0G, the mobile telephony standard for Mobile radio telephone*0-G, or Zero-gravity, also called Weightlessness*Zero G, absence of g-force**Zero-g roll, one of the common Roller coaster elements*Zero Gravity Corporation...

), 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
The term base station can be used in the context of land surveying and wireless communications.- Land surveying :In the context of external land surveying, a base station is a GPS receiver at an accurately-known fixed location which is used to derive correction information for nearby portable GPS...

s. The ARP network was closed at the end of 2000 along with NMT-900
Nordic Mobile Telephone
NMT is the first fully automatic cellular phone system...

.

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
Nordic Mobile Telephone
NMT is the first fully automatic cellular phone system...

 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 (communications)
In telecommunications and computer networking, a communication channel, or channel, refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel...

 on 147.9 - 154.875 MHz band). Transmission power ranged from 1 watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...

 to 5 watts. It first used only half-duplex
Duplex (telecommunications)
A duplex communication system is a system composed of two connected parties or devices that can communicate with one another in both directions. The term multiplexing is used when describing communication between more than two parties or devices....

 transmission, meaning that receiving and transmitting voice could not happen at the same time. Later, full-duplex car phones were introduced. Being analog
Analog signal
An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...

, it had no encryption
Encryption
In cryptography, encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information...

 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.
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