E-UTRA

e-UTRA is the air interface of 3GPP's Long Term Evolution (LTE) upgrade path for mobile networks. It is an acronym for evolved UMTS Terrestrial Radio Access, also referred to as the 3GPP work item on the Long Term Evolution (LTE) also known as the Evolved Universal Terrestrial Radio Access (E-UTRA) in early drafts of the 3GPP LTE specification. E-UTRAN is the initialism of Evolved UMTS Terrestrial Radio Access Network and is the combination of E-UTRA, UEs and EnodeBs.

It is a radio access network standard meant to be a replacement of the UMTS and HSDPA/HSUPA technologies specified in 3GPP releases 5 and beyond. Unlike HSPA, LTE's E-UTRA is an entirely new air interface system, unrelated to and incompatible with W-CDMA. It provides higher data rates, lower latency and is optimized for packet data. It uses OFDMA radio-access for the downlink and SC-FDMA on the uplink. Trials started in 2008.

Features

EUTRAN has the following features:

1447 Utra

1447 Utra, provisional designation 1938 BB, is a stony asteroid and slow rotator from the inner regions of the asteroid belt, about 13 kilometers in diameter. It was discovered by Finnish astronomer Yrjö Väisälä at Turku Observatory on 26 January 1938.

The S-type asteroid orbits the Sun at a distance of 2.4–2.6 AU once every 4.04 years (1,474 days). Its orbit shows an eccentricity of 0.04 and is tilted by 5 degrees to the plane of the ecliptic. It has a very long rotation period of 7002257000000000000♠257±30 hours and an albedo of 0.38 and 0.30, according to the results from the Akari and Wide-field Infrared Survey Explorer missions, respectively.

The minor planet was named after the northeastern Finnish town, Utra, birthplace of the discoverer.

References

External links

Universal Mobile Telecommunications System

The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the International Telecommunications Union IMT-2000 standard set and compares with the CDMA2000 standard set for networks based on the competing cdmaOne technology. UMTS uses wideband code division multiple access (W-CDMA) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators.

UMTS specifies a complete network system, which includes the radio access network (UMTS Terrestrial Radio Access Network, or UTRAN), the core network (Mobile Application Part, or MAP) and the authentication of users via SIM (subscriber identity module) cards.

The technology described in UMTS is sometimes also referred to as Freedom of Mobile Multimedia Access (FOMA) or 3GSM.

Unlike EDGE (IMT Single-Carrier, based on GSM) and CDMA2000 (IMT Multi-Carrier), UMTS requires new base stations and new frequency allocations.