From Wikipedia, the free encyclopedia

Jump to: navigation, search

3G is the third generation of telecommunication hardware standards and general technology for mobile networking, superseding 2.5G. It is based on the International Telecommunication Union (ITU) family of standards under the IMT-2000.[1]

3G networks enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include wide-area wireless voice telephony, video calls, and broadband wireless data, all in a mobile environment. Additional features also include HSPA data transmission capabilities able to deliver speeds up to 14.4 Mbit/s on the downlink and 5.8 Mbit/s on the uplink.

Unlike IEEE 802.11 networks, which are commonly called Wi-Fi or WLAN networks, 3G networks are wide-area cellular telephone networks that evolved to incorporate high-speed Internet access and video telephony. IEEE 802.11 networks are short range, high-bandwidth networks primarily developed for data.


[edit] Implementation and history

The first pre-commercial 3G network was launched by NTT DoCoMo in Japan branded FOMA, in May 2001 on a pre-release of W-CDMA technology. The first commercial launch of 3G was also by NTT DoCoMo in Japan on October 1, 2001. The second network to go commercially live was by SK Telecom in South Korea on the 1xEV-DO technology in January 2002. By May 2002 the second South Korean 3G network was by KTF on EV-DO and thus the Koreans were the first to see competition among 3G operators.

The first European pre-commercial network was at the Isle of Man by Manx Telecom, the operator then owned by British Telecom, and the first commercial network in Europe was opened for business by Telenor in December 2001 with no commercial handsets and thus no paying customers. These were both on the W-CDMA technology.

The first commercial United States 3G network was by Monet Mobile Networks, on CDMA2000 1x EV-DO technology, but this network provider later shut down operations. The second 3G network operator in the USA was Verizon Wireless in October 2003 also on CDMA2000 1x EV-DO, and this network has grown strongly since then.

The first pre-commercial demonstration network in the southern hemisphere was built in Adelaide, South Australia by m.Net Corporation in February 2002 using UMTS on 2100 MHz. This was a demonstration network for the 2002 IT World Congress. The first commercial 3G network was launched by Hutchison Telecommunications branded as Three in April 2003.

In December 2007, 190 3G networks were operating in 40 countries and 154 HSDPA networks were operating in 71 countries, according to the Global Mobile Suppliers Association (GSA). In Asia, Europe, Canada and the USA, telecommunication companies use W-CDMA technology with the support of around 100 terminal designs to operate 3G mobile networks.

In Europe, mass market commercial 3G services were introduced starting in March 2003 by 3 (Part of Hutchison Whampoa) in the UK and Italy. The European Union Council suggested that the 3G operators should cover 80% of the European national populations by the end of 2005.

Roll-out of 3G networks was delayed in some countries by the enormous costs of additional spectrum licensing fees. (See Telecoms crash.) In many countries, 3G networks do not use the same radio frequencies as 2G, so mobile operators must build entirely new networks and license entirely new frequencies; an exception is the United States where carriers operate 3G service in the same frequencies as other services. The license fees in some European countries were particularly high, bolstered by government auctions of a limited number of licenses and sealed bid auctions, and initial excitement over 3G's potential. Other delays were due to the expenses of upgrading equipment for the new systems.

By June 2007 the 200 millionth 3G subscriber had been connected. Out of 3 billion mobile phone subscriptions worldwide this is only 6.7%. In the countries where 3G was launched first - Japan and South Korea - 3G penetration is over 70%[2]. In Europe the leading country is Italy with a third of its subscribers migrated to 3G. Other leading countries by 3G migration include UK, Austria, Australia and Singapore at the 20% migration level. A confusing statistic is counting CDMA 2000 1x RTT customers as if they were 3G customers. If using this definition, then the total 3G subscriber base would be 475 million at June 2007 and 15.8% of all subscribers worldwide.

Still several major countries such as Indonesia have not awarded 3G licenses and customers await 3G services. China delayed its decisions on 3G for many years. China announced in May 2008, that the telecoms sector was re-organized and three 3G networks would be allocated so that the largest mobile operator, China Mobile, would retain its GSM customer base. China Unicom would retain its GSM customer base but relinquish its CDMA2000 customer base, and launch 3G on the globally leading WCDMA (UMTS) standard. The CDMA2000 customers of China Unicom would go to China Telecom, which would then launch 3G on the CDMA 1x EV-DO standard. This meant that China would have all three main cellular technology 3G standards in commercial use. Finally in January 2009, Ministry of industry and Information Technology of China has awarded licenses of all three standards,TD-SCDMA to China Mobile, WCDMA to China Unicom and CDMA2000 to China Telecom.

3G has also been declined in Europe since organizations do not want to pay the high license fee and people do not want to pay more than what they need.

In November 2008, Turkey has auctioned four IMT 2000/UMTS standard 3G licenses with 45, 40, 35 and 25 MHz top frequencies. Turkcell has won the 45MHz band with its €358 million offer followed by Vodafone and Avea leasing the 40 and 35MHz frequencies respectively for 20 years. The 25MHz top frequency license remains to be auctioned.

The first African use of 3G technology was a 3G videocall made in Johannesburg on the Vodacom network in November 2004. The first commercial launch of 3G in Africa was by EMTEL in Mauritius on the W-CDMA standard. In north African Morocco in late March 2006, a 3G service was provided by the new company Wana.

Rogers Wireless began implementing 3G HSDPA services in eastern Canada early 2007 in the form of Rogers Vision. Fido Solutions and Rogers Wireless now offer 3G service in most urban centres.

[edit] Speed

The ITU has not provided a clear definition of the speeds users can expect from 3G equipment or providers. Thus users sold 3G service may not be able to point to a standard and say that the speeds it specifies are not being met. While stating in commentary that "it is expected that IMT-2000 will provide higher transmission rates: a minimum speed of 2Mbit/s and maximum of 14.4Mbit/s for stationary users, and 348 kbit/s in a moving vehicle,"[3] the ITU does not actually clearly specify minimum or average speeds or what modes of the interfaces qualify as 3G, so various speeds are sold as 3G intended to meet customers expectations of broadband speed. It is often suggested by industry sources that 3G can be expected to provide 384 kbit/s at or below pedestrian speeds, but only 128 kbit/s in a moving car. While EDGE is part of the 3G standard, some phones report EDGE and 3G network availability as separate things.

[edit] Network standardization

The International Telecommunication Union (ITU) defined the demands for 3G mobile networks with the IMT-2000 standard. An organization called 3rd Generation Partnership Project (3GPP) has continued that work by defining a mobile system that fulfills the IMT-2000 standard. This system is called Universal Mobile Telecommunications System (UMTS).

[edit] IMT-2000 standards and radio interfaces

International Telecommunications Union (ITU): IMT-2000 consists of six radio interfaces

[edit] Advantages of a layered network architecture

Unlike GSM, UMTS is based on layered services. At the top is the services layer, which provides fast deployment of services and centralized location. In the middle is the control layer, which helps upgrading procedures and allows the capacity of the network to be dynamically allocated. At the bottom is the connectivity layer where any transmission technology can be used and the voice traffic will transfer over ATM/AAL2 or IP/RTP.

[edit] 3G evolution (pre-4G)

The standardization of 3G evolution is progressing in both 3GPP and 3GPP2. The corresponding specifications of 3GPP and 3GPP2 evolutions are named as LTE and UMB, respectively. Development on UMB has been cancelled by Qualcomm as of November 2008. 3G evolution uses partly beyond 3G technologies to enhance the performance and to make a smooth migration path.

There are several different paths from 2G to 3G. In Europe the main path starts from GSM when GPRS is added to a system. From this point it is possible to go to the UMTS system. In North America the system evolution will start from Time division multiple access (TDMA), change to Enhanced Data Rates for GSM Evolution (EDGE) and then to UMTS.

In Japan, two 3G standards are used: W-CDMA used by NTT DoCoMo (FOMA, compatible with UMTS) and SoftBank Mobile (UMTS), and CDMA2000, used by KDDI. Transition for market purposes to 3G was completed in Japan in 2006.

The first introduction of 3G (UMTS/HSDPA) technology in the Caribbean (2007) was done by SETAR in Aruba in December 2007. The Implementation phase of this network was carried out by Alcatel-Lucent. SETAR had also implemented a 3G network based on CDMA 1X EV-DO in April 2007.

Not just broadband internet can be exploted from multi megabit speeds. Video calling and VOIP. HSDPA (High Speed Data Packet Access) has capabilities of bringing 14.4 Mbit/s downstream, this is faster than most standard lines, and even some in cities in well developed areas. Not to mention capabilities of 5.8Mbit/s uplink that is more than ten times standard ADSL, And almost seven times the leading cable provider; Virgin Media.

There are now around 400 3G and HSDPA networks around the world in a quarter of the worlds countries. The migration of global subscribers to 3G has passed 15%, and in countries where 3G has been launched, the migration rate is over 35% by the end of 2008. Many operators have launched low cost or fixed rate data plans for 3G data use which has increased usage and lowered costs. At the launch of 3.5G HSDPA, in many markets this technology is provided as a portable "broadband" modem connection for laptop and even desktop computer users and priced at the low end of broadband pricing. 3G data is however expensive when roaming, with the average cost per megabyte is still in the £5.00/mb range. It would be hard to use many megabytes due to the undeveloped speeds that many networks provide.

In the UK the mobile network 3 (Three) boasts that 90% of the UKs population is covered with 3G, and 99% with the standard talk and text network (2G/2.5G/EDGE)

As anticipated, if stationary, or walking slowly you can expect a minimum of 2Mbit/s. but if in a car doing average city speeds, this falls to 348kbit/s. 3G networks in Britain offer a variety of packages. Going up from 1.8Mbit/s on networks such as T-Mobile and right up as far as 7.2Mbit/s; the same speed as a fixed line within a few hundred metres from its exchange is possible in urban areas of London taking the whole concept of fast easy mobile broadband up to a whole new level. The packages they offer however cannot give you that sustained 7.2Mbit/s, a typical 3GB (3072megabytes) plan costs between £15 and £20 a month. Three is offering 15GB for a record breaking £30 a month, or £15 if you have a contract with them already. Three however does not give such headline speeds as Vodafone.

3G is still in its early years, high prices are to be anticipated because of high fees for frequency licencing and the sheer cost of employing dozens and dozens of teams of engineers to implement a nationwide network and then to maintain it. Canada, for example, boasts some of the highest data access fees in the world for subscribers. Without a data contract 1KB of data is charged at $0.05, translating to $50 per megabyte used on Canada's GSM providers Rogers and Fido.

A 4g network is in the pipe line, capable of speeds of 100Mbit/s while moving and 1Gbit/s stationary.

[edit] Evolution from 2G to 3G

2G networks were built mainly for voice data and slow transmission. Due to rapid changes in user expectation, they do not meet today's wireless needs. Evolution from 2G to 3G can be sub-divided into following phases:

  • 2G to 2.5G
  • 2.5G to 2.75G
  • 2.75G to 3G

[edit] From 2G to 2.5G (GPRS)

The first major step in the evolution to 3G occurred with the introduction of General Packet Radio Service (GPRS). So the cellular services combined with GPRS became 2.5G.

GPRS could provide data rates from 56 kbit/s up to 114 kbit/s. It can be used for services such as Wireless Application Protocol (WAP) access, Short Message Service (SMS), Multimedia Messaging Service (MMS), and for Internet communication services such as email and World Wide Web access. GPRS data transfer is typically charged per megabyte of traffic transferred, while data communication via traditional circuit switching is billed per minute of connection time, independent of whether the user actually is utilizing the capacity or is in an idle state.

GPRS is a best-effort packet switched service, as opposed to circuit switching, where a certain Quality of Service (QoS) is guaranteed during the connection for non-mobile users. It provides moderate speed data transfer, by using unused Time division multiple access (TDMA) channels. Originally there was some thought to extend GPRS to cover other standards, but instead those networks are being converted to use the GSM standard, so that GSM is and newer releases. It was originally standardized by European Telecommunications Standards Institute (ETSI), but now by the 3rd Generation Partnership Project (3GPP).

[edit] From 2.5G to 2.75G

GPRS networks evolved to EDGE networks with the introduction of 8PSK encoding. Enhanced Data rates for GSM Evolution (EDGE), Enhanced GPRS (EGPRS), or IMT Single Carrier (IMT-SC) is a backward-compatible digital mobile phone technology that allows improved data transmission rates, as an extension on top of standard GSM. EDGE can be considered a 3G radio technology and is part of ITU's 3G definition, but is most frequently referred to as 2.75G. EDGE was deployed on GSM networks beginning in 2003—initially by Cingular (now AT&T) in the United States.

EDGE is standardized by 3GPP as part of the GSM family, and it is an upgrade that provides a potential three-fold increase in capacity of GSM/GPRS networks. The specification achieves higher data-rates by switching to more sophisticated methods of coding (8PSK), within existing GSM timeslots.

EDGE can be used for any packet switched application, such as an Internet, video and other multimedia.

[edit] From 2.75G to 3G

From EDGE networks the introduction of UMTS networks and technology is called pure 3G. 3G Bandwidth 5 MHz

[edit] Migrating from GPRS to UMTS

From GPRS network, the following network elements can be reused:

  • Home location register (HLR)
  • Visitor location register (VLR)
  • Equipment identity register (EIR)
  • Mobile switching centre (MSC) (vendor dependent)
  • Authentication centre (AUC)
  • Serving GPRS Support Node (SGSN) (vendor dependent)
  • Gateway GPRS Support Node (GGSN)

From Global Service for Mobile (GSM) communication radio network, the following elements cannot be reused

  • Base station controller (BSC)
  • Base transceiver station (BTS)

They can remain in the network and be used in dual network operation where 2G and 3G networks co-exist while network migration and new 3G terminals become available for use in the network.

The UMTS network introduces new network elements that function as specified by 3GPP:

The functionality of MSC and SGSN changes when going to UMTS. In a GSM system the MSC handles all the circuit switched operations like connecting A- and B-subscriber through the network. SGSN handles all the packet switched operations and transfers all the data in the network. In UMTS the Media gateway (MGW) take care of all data transfer in both circuit and packet switched networks. MSC and SGSN control MGW operations. The nodes are renamed to MSC-server and GSN-server.

[edit] Security

3G networks offer a greater degree of security than 2G predecessors. By allowing the UE to authenticate the network it is attaching to, the user can be sure the network is the intended one and not an impersonator. 3G networks use the KASUMI block crypto instead of the older A5/1 stream cipher. However, a number of serious weaknesses in the KASUMI cipher have been identified.

In addition to the 3G network infrastructure security, end to end security is offered when application frameworks such as IMS are accessed, although this is not strictly a 3G property.

[edit] Issues

Although 3G was successfully introduced to users across the world, some issues are debated by 3G providers and users:

  • Expensive input fees for the 3G service licenses & agreements
  • Numerous differences in the licensing terms
  • Large amount of debt currently sustained by many telecommunication companies, which makes it a challenge to build the necessary infrastructure for 3G
  • Lack of member state support for financially troubled operators
  • Expense of 3G phones
  • Lack of buy-in by 2G mobile users for the new 3G wireless services
  • Lack of coverage, because it is still a new service
  • High prices of 3G mobile services in some countries, including Internet access (see flat rate)
  • Current lack of user need for 3G voice and data services in a hand-held device

[edit] See also

[edit] Further reading

  • Ahonen, M-Profits Making Money with 3G (Wiley, 2002), first business book about 3G, ISBN 978-0470847756
  • Ahonen, Kasper and Melkko, 3G Marketing (Wiley, 2004), first marketing book for 3G, ISBN 978-0470851005
  • Ahonen and Barrett (editors), Services for UMTS (Wiley, 2002) first book on the services for 3G, ISBN 978-0471485506
  • Holma and Toskala (editors), WCDMA for UMTS, (Wiley, 2000) first book dedicated to 3G technology, ISBN 978-0471720515
  • Kreher and Ruedebusch, UMTS Signaling: UMTS Interfaces, Protocols, Message Flows and Procedures Analyzed and Explained (Wiley 2007), ISBN 978-0470065334
  • Laiho, Wacker and Novosad, Radio Network Planning and Optimization for UMTS (Wiley, 2002) first book on radio network planning for 3G, ISBN 978-0470015759

[edit] References

  1. ^ Clint Smith, Daniel Collins. "3G Wireless Networks", page 136. 2000.
  2. ^ http://www.plus8star.com/?p=123 Plus 8 Star presentation, "Is 3G a Dog or a Demon - Hints from 7 years of 3G Hype in Asia"
  3. ^ "Cellular Standards for the Third Generation". ITU. 2005-12-01. http://www.itu.int/osg/spu/imt-2000/technology.html#Cellular%20Standards%20for%20the%20Third%20Generation. 
  4. ^ ITU Radiocommunication Assembly approves new developments for its 3G standards

Personal tools