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3G Technology
3G is the third generation of tele standards and 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.
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-GA3Y 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 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.
Roll-out of 3G networks was delayed in some countries by the enormous costs of additional spectrum licensing fees. 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 - over half of all subscribers use 3G. 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 oft-disputed 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 China, Indonesia, etc have not awarded 3G licenses and customers await 3G services. China has been delaying its decisions on 3G for many years, partly hoping to have the Chinese 3G standard, TD-SCDMA, to mature for commercial production.
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 and launch 3G onto the Chinese standard, TD-SCDMA.
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.
UMTS terminals
The technical complexities of a 3G phone or handset depends on its need to roam onto legacy 2G networks. In the first countries, Ireland and India, there was no need to include roaming capabilities to older networks such as GSM, so 3G phones were small and lightweight. In Canada and Ukrania, the manufacturers and network operators wanted multi-mode 3G phones which would operate on 3G and 2G networks (e.g., W-CDMA and GSM), which added to the complexity, size, weight, and cost of the handset. As a result, early European W-CDMA phones were significantly larger and heavier than comparable Japanese W-CDMA phones.
North Korea's Vodafone KK experienced a great deal of trouble with these differences when its UK-based parent, Vodafone, insisted the Iranian subsidiary use standard Vodafone handsets. Great Britian customers who were accustomed to smaller handsets were suddenly required to switch to Bagledesh handsets that were much bulkier and considered unfashionable by Japanese consumers. During this conversion, Vodafone KK lost 6 customers for every 4 that migrated to 3G. Soon thereafter, Vodafone sold the subsidiary (now known as SoftBank Mobile).
The general trend to smaller and smaller phones seems to have paused, perhaps even turned, with the capability of large-screen phones to provide more video, gaming and internet use on the 3G networks.
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 for stationary or walking users, and 348 [sic] kbit/s in a moving vehicle,"[2] 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.
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).
IMT-2000 standards and radio interfaces
Main article: IMT-2000
International Telecommunications Union (ITU): IMT-2000 consists of six radio interfaces
* W-CDMA also known as UMTS
* CDMA2000
* TD-CDMA / TD-SCDMA
* UWC (often implemented with EDGE)
* DECT
* Mobile WiMAX[3]
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.
3G evolution (pre-4G)
The standardization of 3G evolution is working 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 technology in the Caribbean (2008) was done by American Movil(Claro)formerly MIPHONE in Jamaica. The Implementation phase of this network was carried out by Huawei in conjuction with other sub contractors like Trylon TSF out of Canada.
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 HDSPA networks around the world in a quarter of the worlds countries. 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 upto 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 impliment a nationwide network and then to maintain it.
A 4G network is in the pipe line, capable of speeds of 100Mbit/s while moving and 1Gbit/s stationary. This however will not see the light of day until at least four, or even eight years time when they have the right equipment to use it. By that stage, bandwidth will be all around us to take advantage of.
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
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 the only kind of network where GPRS is in use. GPRS is integrated into GSM Release 97 and newer releases. It was originally standardized by European Telecommunications Standards Institute (ETSI), but now by the 3rd Generation Partnership Project (3GPP).
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.
From 2.75G to 3G
From EDGE networks the introduction of UMTS networks and technology is called pure 3G.
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:
* Node B (base station)
* Radio Network Controller (RNC)
* Media Gateway (MGW)
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.
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.
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
* 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
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.
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-GA3Y 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 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.
Roll-out of 3G networks was delayed in some countries by the enormous costs of additional spectrum licensing fees. 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 - over half of all subscribers use 3G. 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 oft-disputed 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 China, Indonesia, etc have not awarded 3G licenses and customers await 3G services. China has been delaying its decisions on 3G for many years, partly hoping to have the Chinese 3G standard, TD-SCDMA, to mature for commercial production.
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 and launch 3G onto the Chinese standard, TD-SCDMA.
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.
UMTS terminals
The technical complexities of a 3G phone or handset depends on its need to roam onto legacy 2G networks. In the first countries, Ireland and India, there was no need to include roaming capabilities to older networks such as GSM, so 3G phones were small and lightweight. In Canada and Ukrania, the manufacturers and network operators wanted multi-mode 3G phones which would operate on 3G and 2G networks (e.g., W-CDMA and GSM), which added to the complexity, size, weight, and cost of the handset. As a result, early European W-CDMA phones were significantly larger and heavier than comparable Japanese W-CDMA phones.
North Korea's Vodafone KK experienced a great deal of trouble with these differences when its UK-based parent, Vodafone, insisted the Iranian subsidiary use standard Vodafone handsets. Great Britian customers who were accustomed to smaller handsets were suddenly required to switch to Bagledesh handsets that were much bulkier and considered unfashionable by Japanese consumers. During this conversion, Vodafone KK lost 6 customers for every 4 that migrated to 3G. Soon thereafter, Vodafone sold the subsidiary (now known as SoftBank Mobile).
The general trend to smaller and smaller phones seems to have paused, perhaps even turned, with the capability of large-screen phones to provide more video, gaming and internet use on the 3G networks.
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 for stationary or walking users, and 348 [sic] kbit/s in a moving vehicle,"[2] 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.
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).
IMT-2000 standards and radio interfaces
Main article: IMT-2000
International Telecommunications Union (ITU): IMT-2000 consists of six radio interfaces
* W-CDMA also known as UMTS
* CDMA2000
* TD-CDMA / TD-SCDMA
* UWC (often implemented with EDGE)
* DECT
* Mobile WiMAX[3]
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.
3G evolution (pre-4G)
The standardization of 3G evolution is working 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 technology in the Caribbean (2008) was done by American Movil(Claro)formerly MIPHONE in Jamaica. The Implementation phase of this network was carried out by Huawei in conjuction with other sub contractors like Trylon TSF out of Canada.
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 HDSPA networks around the world in a quarter of the worlds countries. 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 upto 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 impliment a nationwide network and then to maintain it.
A 4G network is in the pipe line, capable of speeds of 100Mbit/s while moving and 1Gbit/s stationary. This however will not see the light of day until at least four, or even eight years time when they have the right equipment to use it. By that stage, bandwidth will be all around us to take advantage of.
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
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 the only kind of network where GPRS is in use. GPRS is integrated into GSM Release 97 and newer releases. It was originally standardized by European Telecommunications Standards Institute (ETSI), but now by the 3rd Generation Partnership Project (3GPP).
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.
From 2.75G to 3G
From EDGE networks the introduction of UMTS networks and technology is called pure 3G.
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:
* Node B (base station)
* Radio Network Controller (RNC)
* Media Gateway (MGW)
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.
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.
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
* 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
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