(ARP; ) was the first commercially operated public mobile phone network in

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

. 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, BS) is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a " land station in the land mobile service." A base station is called '' node B'' in 3G, '' eNB'' in L ...

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 on 147.9 - 154.875 MHz band). Transmission power ranged from 1

watt The watt (symbol: W) is the unit of Power (physics), 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 quantification (science), quantify the rate of Work ...

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, it had no

encryption In Cryptography law, cryptography, encryption (more specifically, Code, encoding) is the process of transforming information in a way that, ideally, only authorized parties can decode. This process converts the original representation of the inf ...

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 In cellular telecommunications, handover, or handoff, is the process of transferring an ongoing call or data session from one channel connected to the core network to another channel. In satellite communications it is the process of transf ...

, 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.

References

{{Authority control 1971 establishments in Finland 2000 disestablishments in Finland Mobile radio telephone systems Telecommunications in Finland