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ARP (Autoradiopuhelin, "car radio phone") was the first commercially operated public mobile phone network in Finland. The technology is zero-generation (0G), since although it had cells, moving between they were 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 stations. 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.

UMTS-TDD is a mobile data network standard built upon the UMTS 3G cellular mobile phone standard, using a TD-CDMA, TD-SCDMA, or other 3GPP-approved, air interface that uses Time Division Duplexing to duplex spectrum between the up-link and down-link. While a full implementation of UMTS, it is mainly used to provide Internet access in circumstances similar to those where WiMAX might be used. UMTS-TDD is not directly compatible with UMTS: a device designed to use one standard cannot, unless specifically designed to, work on the other, because of the difference in air interface technologies and frequencies used.

In Europe, CEPT allocated the 2010-2020MHz range for a variant of UMTS-TDD designed for unlicensed, self-provided use. Some telecom groups and jurisdictions have proposed withdrawing this service in favor of licensed UMTS-TDD, due to lack of demand, and lack of development of a UMTS TDD air interface technology suitable for deployment in this band.

Time Division-Synchronous Code Division Multiple Access, or TD-SCDMA, is a 3G mobile telecommunications standard, being pursued in the People's Republic of China by the Chinese Academy of Telecommunications Technology (CATT), Data and Siemens AG, in an attempt not to be dependent on Western technology. This is likely primarily for practical reasons; other 3G formats require the payment of patent fees to a large number of western patent holders.

TD-SCDMA is based on spread spectrum technology which makes it unlikely that it will be able to escape completely the payment of license fees to western patent holders. The launch of a national TD-SCDMA network was initially projected by 2005 but has still not been achieved; the latest stage of "commercial trials" across eight cities was launched on April 1, 2008 and will eventually include 60,000 users.

W-CDMA transmits on a pair of 5 MHz-wide radio channels, while CDMA2000 transmits on one or several pairs of 1.25 MHz radio channels. Though W-CDMA does use a direct sequence CDMA transmission technique like CDMA2000, W-CDMA is not simply a wide band version of CDMA2000. The W-CDMA system is a new design by NTT Do Como, and it differs in many aspects from CDMA2000. From an engineering point of view, W-CDMA provides a different balance of trade-offs between cost, capacity, performance, and density; it also promises to achieve a benefit of reduced cost for video phone handsets. W-CDMA may also be better suited for deployment in the very dense cities of Europe and Asia. However, hurdles remain, and cross-licensing of patents between Qualcomm and W-CDMA vendors has not eliminated possible patent issues due to the features of W-CDMA which remain covered by Qualcomm patents.

W-CDMA has been developed into a complete set of specifications, a detailed protocol that defines how a mobile phone communicates with the tower, how signals are modulated, how data grams are structured, and system interfaces are specified allowing free competition on technology elements.