World Library  
Flag as Inappropriate
Email this Article

E-utran

Article Id: WHEBN0022406416
Reproduction Date:

Title: E-utran  
Author: World Heritage Encyclopedia
Language: English
Subject: Radio access network, LTE (telecommunication)
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

E-utran

e-UTRA is the air interface of 3GPP's Long Term Evolution (LTE) upgrade path for mobile networks. It is the abbreviation for evolved UMTS Terrestrial Radio Access, also referred to as the 3GPP work item on the Long Term Evolution (LTE)[1] also known as the Evolved Universal Terrestrial Radio Access (E-UTRA) in early drafts of the 3GPP LTE specification.[1] E-UTRAN is the initialism of Envolved UMTS Terrestrial Radio Access Network and is the combination of E-UTRA, UE's and EnodeB's.

It is a radio access network standard meant to be a replacement of the UMTS, HSDPA and 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:

  • Peak download rates of 299.6 Mbit/s for 4x4 antennas, and 150.8 Mbit/s for 2x2 antennas with 20 MHz of spectrum. LTE Advanced supports 8x8 antenna configurations with peak download rates of 2998.6 Mbit/s in an aggregated 100 MHz channel.[2]
  • Peak upload rates of 75.4 Mbit/s for a 20 MHz channel in the LTE standard, with up to 1497.8 Mbit/s in an LTE Advanced 100 MHz carrier.[2]
  • Low data transfer latencies (sub-5ms latency for small IP packets in optimal conditions), lower latencies for handover and connection setup time.
  • Support for terminals moving at up to 350 km/h or 500 km/h depending on the frequency band.
  • Support for both FDD and TDD duplexes as well as half-duplex FDD with the same radio access technology
  • Support for all frequency bands currently used by IMT systems by ITU-R.
  • Flexible bandwidth: 1.4 MHz, 3 MHz, 5 MHz, 15 MHz and 20 MHz are standardized. By comparison, W-CDMA uses fixed size 5 MHz chunks of spectrum.
  • Increased spectral efficiency at 2-5 times more than in 3GPP (HSPA) release 6
  • Support of cell sizes from tens of meters of radius (femto and picocells) up to over 100 km radius macrocells
  • Simplified architecture: The network side of EUTRAN is composed only by the enodeBs
  • Support for inter-operation with other systems (e.g. GSM/EDGE, UMTS, CDMA2000, WiMAX...)
  • Packet switched radio interface.

Rationale for E-UTRA

Although UMTS, with HSDPA and HSUPA and their evolution, deliver high data transfer rates, wireless data usage is expected to continue increasing significantly over the next years due to the increased offering and demand of services and content on-the-move and the continued reduction of costs for the final user. This increase is expected to require not only faster networks and radio interfaces but also higher cost-efficiency than what is possible by the evolution of the current standards. Thus the 3GPP consortium set the requirements for a new radio interface (EUTRAN) and core network evolution (System Architecture Evolution SAE) that would fulfill this need.

This improvements in performance allow wireless operators to offer quadruple play services - voice, high-speed interactive applications including large data transfer and feature-rich IPTV with full mobility.

Starting with the 3GPP Release 8, e-UTRA is designed to provide a single evolution path for the GSM/EDGE, UMTS/HSPA, CDMA2000/EV-DO and TD-SCDMA radio interfaces, providing increases in data speeds, and spectral efficiency, and allowing the provision of more functionality.

Architecture[3]

EUTRAN consists only of enodeBs on the network side. The enodeB performs tasks similar to those performed by the nodeBs and RNC (radio network controller) together in UTRAN. The aim of this simplification is to reduce the latency of all radio interface operations. eNodeBs are connected to each other via the X2 interface, and they connect to the packet switched (PS) core network via the S1 interface.

EUTRAN protocol stack


The EUTRAN protocol stack consist of:[3]

  • Physical layer:[4] Carries all information from the MAC transport channels over the air interface. Takes care of the link adaptation (AMC), power control, cell search (for initial synchronization and handover purposes) and other measurements (inside the LTE system and between systems) for the RRC layer.
  • MAC:[5] The MAC sublayer offers a set of logical channels to the RLC sublayer that it multiplexes into the physical layer transport channels. It also manages the HARQ error correction, handles the prioritization of the logical channels for the same UE and the dynamic scheduling between UEs, etc..
  • RLC:[6] It transports the PDCP's PDUs. It can work in 3 different modes depending on the reliability provided. Depending on this mode it can provide: ARQ error correction, segmentation/concatenation of PDUs, reordering for in-sequence delivery, duplicate detection, etc...
  • PDCP:[7] For the RRC layer it provides transport of its data with ciphering and integrity protection. And for the IP layer transport of the IP packets, with ROHC header compression, ciphering, and depending on the RLC mode in-sequence delivery, duplicate detection and retransmission of its own SDUs during handover.
  • RRC:[8] Between others it takes care of: the broadcast system information related to the access stratum and transport of the non-access stratum (NAS) messages, paging, establishment and release of the RRC connection, security key management, handover, UE measurements related to inter-system (inter-RAT) mobibility, QoS, etc..

Interfacing layers to the EUTRAN protocol stack:

  • NAS:[9] Protocol between the UE and the MME on the network side (outside of EUTRAN). Between others performs authentication of the UE, security control and generates part of the paging messages.
  • IP

Physical layer (L1) design

E-UTRA uses orthogonal frequency-division multiplexing (OFDM), multiple-input multiple-output (MIMO) antenna technology depending on the terminal category and can use as well beamforming for the downlink to support more users, higher data rates and lower processing power required on each handset.[10]

In the uplink LTE uses both OFDMA and a precoded version of OFDM called Single-Carrier Frequency-Division Multiple Access (SC-FDMA) depending on the channel. This is to compensate for a drawback with normal OFDM, which has a very high peak-to-average power ratio (PAPR). High PAPR requires more expensive and inefficient power amplifiers with high requirements on linearity, which increases the cost of the terminal and drains the battery faster. For the uplink, in release 8 and 9 multi user MIMO / Spatial division multiple access (SDMA) is supported; release 10 introduces also SU-MIMO.

In both OFDM and SC-FDMA transmission modes a cyclic prefix is appended to the transmitted symbols. Two different lengths of the cyclic prefix are available to support different channel spreads due to the cell size and propagation environment. These are a normal cyclic prefix of 4.7µs, and an extended cyclic prefix of 16.6µs.

LTE supports both Frequency-division duplex (FDD) and Time-division duplex (TDD) modes. While FDD makes use of paired spectra for UL and DL transmission separated by a duplex frequency gap, TDD splits one frequency carrier into alternating time periods for transmission from the base station to the terminal and viceversa. Both modes have their own frame structure within LTE and these are aligned with each other meaning that similar hardware can be used in the base stations and terminals to allow for economy of scale. The TDD mode in LTE is aligned with TD-SCDMA as well allowing for coexistence. These days, a single chipset can support both TDD-LTE and FDD-LTE operating modes.

The LTE transmission is structured in the time domain in radio frames. Each of these radio frames is 10 ms long and consists of 10 sub frames of 1 ms each. For non-MBMS subframes the OFDM subcarrier spacing in the frequency domain is 15 kHz. Twelve of these subcarriers together are called a resource block. A LTE terminal can be allocated in the downlink or uplink a minimum of 1 resource block during 1 subframe.

All L1 transport data is encoded using turbo coding and a contention-free quadratic permutation polynomial (QPP) turbo code internal interleaver.[11] L1 HARQ with 8 (FDD) or up to 15 (TDD) processes is used for the downlink and up to 8 processes for the UL

EUTRAN physical channels and signals

Downlink (DL)

In the downlink there are several physical channels:[12]

  • The Physical Downlink Control Channel (PDCCH) carries between others the downlink allocation information, uplink allocation grants for the terminal.
  • The Physical Control Format Indicator Channel (PCFICH) used to signal the length of the PDCCH.
  • The Physical Hybrid ARQ Indicator Channel (PHICH) used to carry the acknowledges from the uplink transmissions.
  • The Physical Downlink Shared Channel (PDSCH) is used for L1 transport data transmission. Supported modulation formats on the PDSCH are QPSK, 16QAM and 64QAM.
  • The Physical Multicast Channel (PMCH) is used for broadcast transmission using a Single Frequency Network
  • The Physical Broadcast Channel (PBCH) is used to broadcast the basic system information within the cell

And the following signals:

  • The synchronization signals (PSS and SSS) are meant for the UE to discover the LTE cell and do the initial synchronization.
  • The reference signals (cell specific, MBSFN, and UE specific) are used by the UE to estimate the DL channel.
  • Positioning reference signals (PRS), added in release 9, meant to be used by the UE for OTDOA positioning (a type of multilateration)

Uplink (UL)

In the uplink there are three physical channels:

  • Physical Random Access Channel (PRACH) is used for initial access and when the UE losses its uplink synchronization,[13]
  • Physical Uplink Shared Channel (PUSCH) carries the L1 UL transport data together with control information. Supported modulation formats on the PUSCH are QPSK, 16QAM and depending on the user equipment category 64QAM. PUSCH is the only channel, which because of its greater BW, uses SC-FDMA
  • Physical Uplink Control Channel (PUCCH) carries control information. Note that the Uplink control information consists only on DL acknowledges as well as CQI related reports as all the UL coding and allocation parameters are known by the network side and signaled to the UE in the PDCCH.

And the following signals:

  • Reference signals (RS) used by the enodeB to estimate the uplink channel to decode the terminal uplink transmission.
  • Sounding reference signals (SRS) used by the enodeB to estimate the uplink channel conditions for each user to decide the best uplink scheduling.

User Equipment (UE) categories

3GPP Release 8 defines five LTE user equipment categories depending on maximum peak data rate and MIMO capabilities support. With 3GPP Release 10, which is referred to as LTE Advanced, three new categories have been introduced.[2]

3GPP Release User Equipment Category Maximum L1 datarate Downlink Maximum number of DL MIMO layers Maximum L1 datarate Uplink
Release 8 Category 1 10.3 Mbit/s 1 5.2 Mbit/s
Release 8 Category 2 51.0 Mbit/s 2 25.5 Mbit/s
Release 8 Category 3 102.0 Mbit/s 2 51.0 Mbit/s
Release 8 Category 4 150.8 Mbit/s 2 51.0 Mbit/s
Release 8 Category 5 299.6 Mbit/s 4 75.4 Mbit/s
Release 10 Category 6 301.5 Mbit/s 2 or 4 51.0 Mbit/s
Release 10 Category 7 301.5 Mbit/s 2 or 4 102.0 Mbit/s
Release 10 Category 8 2998.6 Mbit/s 8 1497.8 Mbit/s

Note: These are L1 transport data rates not including the different protocol layers overhead. Depending on cell BW, cell load, network configuration, the performance of the UE used, propagation conditions, etc. practical data rates will vary.

Note: The 3.0 Gbit/s / 1.5 Gbit/s data rate specified as Category 8 is near the peak aggregate data rate for a base station sector. A more realistic maximum data rate for a single user is 1.2 Gbit/s (downlink) and 600 Mbit/s (uplink).[14] Nokia Siemens Networks has demonstrated downlink speeds of 1.4 Gbit/s using 100 MHz of aggregated spectrum.[15]

EUTRAN releases

As the rest of the 3GPP standard parts E-UTRA is structured in releases.

  • Release 8, frozen in 2008, specified the first LTE standard
  • Release 9, frozen in 2009, included some additions to the physical layer like dual layer (MIMO) beamforming transmission or positioning support
  • Release 10, frozen in 2011, introduces to the standard several LTE Advanced features like carrier aggregation, uplink SU-MIMO or relays, aiming to a considerable L1 peak data rate increase.

All LTE releases have been designed so far keeping backward compatibility in mind. That is, a release 8 compliant terminal will work in a release 10 network, while release 10 terminals would be able to use its extra functionality.

Frequency bands and channel bandwidths

From Tables 5.5-1 "E-UTRA Operating Bands" and 5.6.1-1 "E-UTRA Channel Bandwidth" of 3GPP TS 36.101,[16][17] the following table lists the specified frequency bands of LTE and the channel bandwidths each listed band supports:

E-UTRA
Operating
Band
Uplink (UL)
BS Receive
UE Transmit (MHz)
Downlink (DL)
BS Transmit
UE Receive (MHz)
Duplex
Mode
Channel
Bandwidths
(MHz)
Common Name Frequency
band
(MHz)
1 1920 - 1980 2110 - 2170 FDD 5, 10, 15, 20 IMT 2100
2 1850 - 1910 1930 - 1990 FDD 1.4, 3, 5, 10, 15, 20 PCS 1900
3 1710 - 1785 1805 - 1880 FDD 1.4, 3, 5, 10, 15, 20 DCS 1800
4 1710 - 1755 2110 - 2155 FDD 1.4, 3, 5, 10, 15, 20 AWS 1700
5 824 - 849 869 - 894 FDD 1.4, 3, 5, 10 CLR 850
6 830 - 840 875 - 885 FDD 5, 10 UMTS 800
(not applicable, replaced by band 19)
800
7 2500 - 2570 2620 - 2690 FDD 5, 10, 15, 20 IMT-E 2600
8 880 - 915 925 - 960 FDD 1.4, 3, 5, 10 E-GSM 900
9 1749.9 - 1784.9 1844.9 - 1879.9 FDD 5, 10, 15, 20 UMTS 1700 1700
10 1710 - 1770 2110 - 2170 FDD 5, 10, 15, 20 Extended AWS
(superset of band 4)
1700
11 1427.9 - 1447.9 1475.9 - 1495.9 FDD 5, 10 Lower PDC 1500
12 699 - 716 729 - 746 FDD 1.4, 3, 5, 10 Lower SMH blocks A/B/C 700
13 777 - 787 746 - 756 FDD 5, 10 Upper SMH block C 700
14 788 - 798 758 - 768 FDD 5, 10 Upper SMH block D 700
15 1900 - 1920 2600 - 2620 FDD 5, 10 Reserved
16 2010 - 2025 2585 - 2600 FDD 5, 10, 15 Reserved
17 704 - 716 734 - 746 FDD 5, 10 Lower SMH blocks B/C
(subset of band 12)
700
18 815 - 830 860 - 875 FDD 5, 10, 15 Japan lower 800 850
19 830 - 845 875 - 890 FDD 5, 10, 15 Japan upper 800
(superset of band 6)
850
20 832 - 862 791 - 821 FDD 5, 10, 15, 20 EU Digital Dividend 800
21 1447.9 - 1462.9 1495.9 - 1510.9 FDD 5, 10, 15 Upper PDC 1500
22 3410 - 3490 3510 - 3590 FDD 5, 10, 15, 20 3500
23 2000 - 2020 2180 - 2200 FDD 1.4, 3, 5, 10 S-Band
(a/k/a AWS-4)
2000
24 1626.5 - 1660.5 1525 - 1559 FDD 5, 10 L-Band 1600
25 1850 - 1915 1930 - 1995 FDD 1.4, 3, 5, 10, 15, 20 Extended PCS
(superset of band 2)
1900
26 814 - 849 859 - 894 FDD 1.4, 3, 5, 10, 15 Extended CLR
(superset of bands 5, 6, 18 and 19)
850
27 807 - 824 852 - 869 FDD 1.4, 3, 5, 10, 15 SMR 800
28 703 - 748 758 - 803 FDD 5, 10, 15, 20 APAC 700
29 N/A 716 - 728 FDD 5, 10 Lower SMH blocks D/E
(additional DL via Carrier Aggregation)
700
30 2305 - 2315 2350 - 2360 FDD 5, 10 WCS blocks A/B 2300
33 1900 - 1920 TDD 5, 10, 15, 20 IMT 2100
34 2010 - 2025 TDD 5, 10, 15 IMT 2100
35 1850 - 1910 TDD 1.4, 3, 5, 10, 15, 20 PCS (Uplink) 1900
36 1930 - 1990 TDD 1.4, 3, 5, 10, 15, 20 PCS (Downlink) 1900
37 1910 - 1930 TDD 5, 10, 15, 20 PCS (Duplex spacing) 1900
38 2570 - 2620 TDD 5, 10, 15, 20 IMT-E 2600
39 1880 - 1920 TDD 5, 10, 15, 20 1900
40 2300 - 2400 TDD 5, 10, 15, 20 2300
41 2496 - 2690 TDD 5, 10, 15, 20 BRS / EBS 2500
42 3400 - 3600 TDD 5, 10, 15, 20 3500
43 3600 - 3800 TDD 5, 10, 15, 20 3700
44 703 - 803 TDD 5, 10, 15, 20 APAC 700

Deployments by region

The following table shows the standardized LTE bands and their regional use. The main LTE bands are in bold print.

  • Networks on LTE-bands 1, 3, 7, 28 (FDD-LTE) or 38, 40 (TDD-LTE) are suitable for future global roaming in ITU Regions 1, 2 and 3.
  • Networks on LTE-band 8 (FDD-LTE) may allow global roaming in the future (ITU Regions 1, 2 and 3) (Long-term perspective).
  • Networks on LTE-band 20 (FDD-LTE) are suitable for roaming in ITU Region 1 (EMEA) only.
  • Networks on LTE-bands 2 and 4 (FDD-LTE) are suitable for roaming in ITU Region 2 (Americas) only.
Operating band Frequency band Common name North America Latin America Europe Asia Africa Oceania
01 2100 IMT No No Sweden (3) Yes Angola (Unitel), South Africa (Cell C) (no deployments)
02 1900 PCS A-F USA (C Spire) Dominican Republic (Tricom), Paraguay (Personal) No No No No
03 1800 DCS No Dominican Republic (Orange), Venezuela (Digitel GSM) Yes Yes Yes Yes
04 1700 AWS A-F USA (AT&T, T-Mobile, BendBroadband, Big River Broadband, C Spire, Leap, Verizon), Canada (Bell, Eastlink, MTS, Rogers, Telus, SaskTel) Argentina (Movistar) (in Trial), Mexico (Telcel), Paraguay (Copaco), Peru (Movistar) (in Trial), Uruguay (Ancel) No No No No
05 850 CLR (no deployments) (no deployments) No South Korea (LG U+, SK Telecom) No (no deployments)
06 800 No No No replaced by band 19 No No
07 2600 IMT-E Canada (Bell, Rogers) Brazil (Claro, Oi, TIM, Vivo), Chile (Claro), Colombia (Une-EPM), Costa Rica (ICE Celular) Yes Yes (no deployments) Australia, New Zealand
(no deployments)
08 900 E-GSM No No Sweden (Net4Mobility) South Korea (KT) (no deployments) Australia (Telstra) (in Trial)
09 1700 No No No Japan (EMOBILE)
(to be replaced by band 3)
No No
10 1700 EAWS A-G (no deployments) (no deployments) No No No No
11 1500 LPDC No No No Japan (au) No No
12 700 LSMH A/B/C USA (Regional) No No No No No
13 700 USMH C USA (Verizon) Bolivia (Entel Bolivia) No Uzbekistan (UCell) No No
14 700 USMH D USA (Public Safety) No No No No No
15 No No Reserved No No No
16 No No Reserved No No No
17 700 LSMH B/C USA (AT&T) No No No No No
18 800 No No No Japan (au)
(to be replaced by band 26)
No No
19 800 No No No Japan (NTT Docomo)
(to be replaced by band 26)
No No
20 800 EUDD No No Yes Qatar (ooredoo) Tanzania (Smile), Uganda (Orange, Smile) No
21 1500 UPDC No No No Japan (NTT Docomo) No No
22 3500 No No (no deployments) No No No
23 2000 S-Band USA
(no deployments)
No No No No No
24 1600 L-Band USA
(no deployments)
No No No No No
25 1900 EPCS A-G USA (Sprint) (no deployments) No No No No
26 850 ECLR (no deployments) (no deployments) No (no deployments) No (no deployments)
27 800 SMR USA
(no deployments)
No No No No No
28 700 APAC (no deployments) (no deployments) No (no deployments) No (no deployments)
29 800 LSMH D/E USA (AT&T)
(no deployments)
No No No No No
30 2300 WCS USA (AT&T)
(no deployments)
No No No No No
31 Reserved Reserved Reserved Reserved Reserved Reserved
32 Reserved Reserved Reserved Reserved Reserved Reserved
33 TDD 2100 IMT No No (no deployments) Sri Lanka, Singapore, Malaysia
(no deployments)
No Australia
(no deployments)
34 TDD 2100 IMT No No (no deployments) China, Japan
(no deployments)
No No
35 TDD 1900 PCS (no deployments) (no deployments) No No No No
36 TDD 1900 PCS (no deployments) (no deployments) No No No No
37 TDD 1900 PCS (no deployments) (no deployments) No No No No
38 TDD 2600 IMT-E No Brazil (On Telecom, SKY Brasil) Poland (Aero2), Russia (MegaFon, MTS), Spain (COTA) (in Trial), Sweden (3) Saudi Arabia (Mobily, Zain), China (China Mobile) (in Trial) Uganda (MTN) No
39 TDD 1900 No No No China (China Mobile) (in Trial) No No
40 TDD 2300 No (no deployments) Russia (Vainah Telecom) China (China Mobile) (in Trial), Hong Kong (China Mobile), India (Airtel), Oman (Omantel), Saudi Arabia (STC), Sri Lanka (Dialog) South Africa, Uganda
(no deployments)
Australia (NBN Co, Optus)
41 TDD 2500 BRS/EBS USA (Sprint, nTelos (in Trial)) No No Japan (SoftBank (WCP)) No No
42 TDD 3500 No Chile (Entel) (in Trial) United Kingdom (UK Broadband) No No No
43 TDD 3700 No No United Kingdom (UK Broadband) No No No
44 TDD 700 APAC No No No China
(no deployments)
No No

Technology demos

  • In September 2007, NTT Docomo demonstrated e-UTRA data rates of 200 Mbit/s with power consumption below 100 mW during the test.[18]
  • In April 2008, LG and Nortel demonstrated e-UTRA data rates of 50 Mbit/s while travelling at 110 km/h.[19]
  • February 15, 2008 - Skyworks Solutions has released a front-end module for e-UTRAN.[20][21][22]

See also

References

External links

  • 3GPP Long Term Evolution page
  • LTE 3GPP Encyclopedia
  • 3G Americas - UMTS/HSPA Speeds Up the Wireless Technology Roadmap. 3G Americas Publishes White Paper on 3GPP Release 7 to Release 8. Bellevue, WA, July 10, 2007

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.