Zero Generation (0G) 26 

The mobile phone was originally designed to add functionality to fixed telephones or landlines simply as an extension of basic voice services. Modern-day mobile phones

are descendants of the Mobile radio telephone system, also known as zero generation

(0G) mobile phones. Analogue in nature, the radio phone was part of the regular

public switched telephone network (PSTN), and the transceivers or user terminals

were mounted in cars with power supplied from the car battery to power the systems. The first commercially available mobile telephone system (MTS) was operated by Motorola in conjunction with the Bell System in 1946 in the United States of America. MTS was automated by the Bell System in 1962 into what was known as the Improved Mobile Telephone Service (IMTS), which offered automatic dialing to

and from the mobile receiver terminal. This was followed by Televerket Norway by

27 Germany in 1972. The only service provided by these systems was a not-so-good quality analogue voice call, prone to interference and occupied large portions of the limited radio spectrum2.

2.1.2 First Generation (1G)

The next generation of mobile phones, known as 1G or first generation, only emerged

in the early 70s. Although they were analogue in nature, they employed digital signaling in the network, particularly at the radio towers. The first generation of mobile systems was developed principally for voice services almost simultaneously in

different countries, each with its own standard. The United Kingdom developed TACS

(Total Access Communications System), while the Nordic countries developed the

NMT (Nordic Mobile Telephone) which was used in these countries, and also

Switzerland, the Netherlands, Eastern Europe and Russia. The Germans developed the

C-450 system which was also used in Portugal. The French used Radiocom 2000, and the Italians developed the RTMI (Radio Telefono Mobile Integrato). In Japan, the

TZ-801, TZ-802, TZ-803 and the JTACS (Japan Total Access Communications System) standard systems were developed. Across the Atlantic, the Americans developed the AMPS (Advanced Mobile Phone System). This range of standards was a major hitch for the 1G as the different systems could not cross-function. Cross- functionality is a major characteristic of successful technologies of the modern age. It is estimated that 1G-technologies accounted for about 20 million subscribers in 1990. With poor speech quality and low reliability, marred by the low interoperability between the numerous systems and the growing number of subscribers which the 1G system could not support, it was upgraded to 2G.

2 _{Radio Spectrum is the common transmission medium for all wireless communication, and forms part of the}  electromagnetic wave which extends from approximately 10 kHz to 300 GHz. 

28

2.1.3 Second Generation (2G)

The second generation of mobile phones (2G) saw a more coordinated development

of standards enabling roaming3, although diverse fronts were still prevalent. 2G voice

services are more consistent and reliable thanks to advanced modulation techniques which have increased capacity and spectrum efficiency, enabling easier implementation of advanced voice services, Short Messaging Service (SMS), fax and basic data services. The 1G standard also suffered from inadequate security and fraud prevention was minimal, but security has been greatly enhanced in 2G mobile systems. 2G technologies gravitate around two multiplexing technologies, with one based on time division called TDMA (Time Division Multiple Access) and the other on code division known as CDMA (Code Division Multiple Access). Both technologies employ digital techniques in the entire network, unlike in the analogue 1G-systems where only the signaling paths were digitalized. TDMA technology is based on four main standards; GSM (Global System for Mobiles), iDEN (Integrated Digital Enhanced Network), IS – 136 called D-AMPS (Advanced Mobile Phone Service) and PDC (Pacific Digital Cellular). One main CDMA-based standard known

as IS-95 or cdmaOne eventually emerged (Table 2.1)

Technology  Standard    Place of  origin  Main services  characteristicsRadio   

TDMA  GSM  Europe  Voice & SMS  Digital 

iDEN  Nextel in the USA and 

Telus in Canada 

Digital 

PDC  Japan Digital

(IS‐136, IS‐54) D‐AMPS USA Digital/Analogue

CDMA  (IS‐95) cdmaOne USA Voice, SMS & 

some data up 

to 64Kbps 

Digital

3 _{Roaming is a service whereby subscribers of one mobile phone network can use their phones on the network of other}  operators in many parts of the world to access services. 

29

2.1.3.1 GSM

GSM (Global System for Mobile communications), originally known as Groupe

Spécial Mobile, is actually the name of the study group created in 1982 by the Conference of European Posts and Telegraphs (CEPT) to develop a pan-European mobile telephone system. GSM quickly imposed itself as the leading mobile communication standard within all the 2G systems. Approximately 82 percent of all mobile connections in the world are based on the GSM standard (Fig. 2.1).

The main driving force behind GSM’s success is the GSMA (GSM Association). The GSMA ‘is the global trade association representing the interests of over 850 GSM mobile phone operators and over 180 manufacturers and suppliers worldwide, encompassing technical, commercial and public policy initiatives. [It] focuses on ensuring wireless services work globally’ (GSMA, 2008). GSMA has been particularly effective in facilitating the interoperability of mobile phones across networks which has brought about international roaming whereby subscribers of one

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 2000 2002 2004 2006 2007 2008 2009 2010 2011 2012 B illi on s

Global connections per bearer technology

cdmaOne CDMA2000 1X CDMA2000 1xEV-DO

CDMA2000 1xEV-DO Rev. A GSM WCDMA

WCDMA HSPA TD-SCDMA TDMA

PDC iDEN

Fig. 2.1:Evolution of Mobile Standards (Bearer Technology) In Terms of Connection (Global)

30

network can use their phones in many parts of the world. Also advances in radio

spectrum management techniques have facilitated the growth of 2G mobile phones particularly as the GSM standard permits the optimal use of the radio spectrum by employing Time division multiplexing. One of the key features of GSM is the

Subscriber Identity Module (SIM), commonly known as a SIM card. It contains the

user's subscription information and phonebook and allows the user to retain his or her information after switching off the handset. It permits the handset to be used on other mobile phone networks by simply inserting in a new SIM.

2.1.3.2 cdmaOne.

The cdmaOne, also known as IS-95, created in 1993, employs code division multiplexing technology known as CDMA. The IS-95 A (Interim Standard – 95), which is the original standard, was designed mainly for digital voice services with limited data capability (14.4kbps), although they have more capacity than GSM due to their ability to spread a mobile call signal over a wide spectrum(from 9.6Kbps to 1.23Mbps. It was later revised in 1995 to IS-95B with enhanced data capabilities offering file transfers services of up to 64kbps, fax, SMS and supplementary services. IS-95B has comparative functionality with 2.5G and a subscriber base of nearly 420 million worldwide.

2.1.3.3 PDC

The PDC (Pacific Digital Cellular) system is a TDMA-based mobile phone system deployed mainly in Japan. The main benefits offered by the technology is its ability to use much smaller cells than GSM or CDMA, maximising the reuse of frequency via a

31 process called mobile assisted handoff (MAHO). By the close of 2008, PDC accounted for about 5.9 million subscribers worldwide.

2.1.3.4 iDEN (Integrated Digital Enhanced Network):

iDEN is a proprietary standard for Motorola released in 1994. Modern iDEN handsets use SIM cards like GSM and are also compatible with GSM. Its interconnection side even uses GSM signalling for call setup and mobility management. It is a fully digital system used commonly on the 800MHz frequency band in the United States of America, Canada, South America and Israel, and on 1.5GHz in Japan. It has the capability to integrate other wireless systems, and provides mobile telephony services,

2-way radio systems like the Walkie-Talkie, and also handles data services, fax and

the internet. By the close of 2008, iDEN accounted for about 21.4 million subscribers worldwide.

2.1.3.5 (IS-136, IS-54) AMPS (Advanced Mobile Phone Service):

This system operates in the 800MHz frequency range and employs the IS-45 network standard developed by the Telecommunications Industry Association (TIA) of the USA. It is the predominant system in use across most of the USA. It provides mobile telephony services with a reduced set of diversion and call-barring features.

2.1.4 2.5 G and 2.75G

2.5G refers to the enhancement of 2G systems to accommodate more data at higher speeds. For 2G-GSM, the cellular system is enhanced by combining the system with a

General Packet Radio Service (GPRS). 2G systems are designed specifically for voice and SMS services. The increasing customer demand for data enabled the system

32

to be upgraded to 2.5G. This was achieved by adding a mobile data service GPRS,

which is a packet-based air interface as an overlay over existing 2G circuit switched networks. GPRS is capable of increasing data transmission rates from 14.4 Kbps in a normal 2G channel to about 171.2 Kbps per GPRS channel. Data transmitted over GPRS are typically charged per kilobyte of data transferred, contrary to circuit switched data (2G), which are charged per second of connection whether data is successfully transmitted or not. GPRS can be combined with Wireless Application

Protocol 4(WAP) access and XML5 (Extended Markup Language) to provide the user

with limited Internet communication services, Short Message Service (SMS), Multimedia Messaging Service (MMS), and e-mails with small attachments.

In 2003, it became possible to further enhance 2.5G or GPRS to achieve higher data transmission rates and improved data transmission reliability. This further

enhancement is known as Enhanced Data rates for GSM Evolution (EDGE) or

Enhanced GPRS (EGPRS). Theoretically, data rates of 476Kbps can be achieved with EDGE, although they are typically between 75Kbps and 135 Kbps. EDGE is generally classified as the unofficial 2.75G standard. It can be used for any packet switched application, such as text and image-based web browsing, very slow file transfers (500-Kb file loads in about 30 seconds), limited internet-based phone known as VoIP6, short video clips and limited corporate applications.

HSCSD (High-Speed Circuit-Switched Data) is another 2.5G technology integrated with the 2G GSM system. It is capable of transmitting data at up to 56.6Kbps, which

4 _{Wireless Application Protocol (WAP) is a standard which enables access to the internet via mobile phones and other}  handheld devices. 

5 _{Extended Markup Language (XML) is a technical language used for encoding documents and serialising data to ease the} 

sharing of information between different kinds of mobile telephony access devices, computers and applications. 

6 _{Voice over Internet Protocol (VoIP) is general a term used to describe a family of technologies which makes it possible to} 

33 is about four times the speed of a normal 2G GSM system, thanks to its ability to provide access to four channels simultaneously per transmission.

2.1.5 Third Generation (3G)

3G is the third generation of mobile phone standards and technology, built particularly to increase the ability to use data applications on the move. It represents the point of real convergence between computing and telecommunications, enabling the transmission of e-mails with full attachments, multimedia messaging services with audio and video, full web browsing with a 100-Kb page taking just about 2 seconds to load, and data speeds estimated to reach 2Mbps. It also supports file transfers of up to 500-Kb in 10 seconds. 3G fully supports corporate applications and location-based services like navigation.

3G technologies 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 and

broadband wireless data. 3G networks are wide area cellular telephone networks that

have evolved to incorporate internet access and video telephony, providing extremely high-speed data transmission with services speeds of 5-10 Mb per second. 3G networks support greater numbers of voice and data customers at lower incremental cost than 2G, which makes it a viable option for network operators. The 3G family of technologies is defined by the International Telecommunications Union (ITU), and is called IMT-2000. The IMT-2000 defines the requirements of a mobile communication system capable of supporting Internet Protocol (IP) based applications and multimedia services. The system was conceptualised to ensure quality of service control and

34 bandwidth on demand, and was also recommended to be built on a single technology as a global standard. While ITU-2000 has been very successful in achieving its objectives, it has not succeeded in ensuring delivery of 3G services via one common technology. 3G currently runs on three technologies: UMTS (Universal Mobile Telecommunications System), cdma2001 (Code Division Multiple Access 2000) and TD-SCDMA (Time Division Synchronous CDMA), which consists of six radio interfaces:

•IMT- Direct Spread (IMT_DS) deployed as W-CDMA (Wide Code Division

Multiple Access)

•IMT – Multicarrier (IMT-MC) deployed as CDMA2000 (Code Division

Multiple Access 2000)

•IMT – Time Code (IMT – TC) deployed as TD-CDMA / TD-SCDMA (Time

Division CDMA/ Time Division Synchronous CDMA)

•IMT – Single Carrier) deployed as UWC (Universal Wireless Communication)

and often implemented with EDGE.

•IMT – Frequency Time (IMT – FT) deployed as DECT (Digital Enhanced

Cordless technology).

•OFDMA (Orthogonal Frequency-Division Multiplexing): deployed as 802.16

– WiMAX (Wireless Interoperability for Microwave Access). It is being defined by the IEEE (Institute of Electrical and Electronic Engineers)

2.1.5.1 UMTS

(Universal Mobile Telecommunications System) is the 3G system which has been proposed for Europe. The definition of UMTS standard is being handled by the Third Generation Partnership Project (3GPP). UMTS is built on a WCDMA (Wideband

35 Code Division Multiple Access) platform. It is one of the most diffused of 3G technologies, with close to 224.6 million users worldwide. UMTS delivers data speeds of between 384kbps to 2Mbps.

2.1.5.2 cdma2000:

It is mostly being defined by standardising bodies in the United States of America. It is an evolution of the cdmaOne standard (2G) employing WCDMA like the UMTS, although the two do not use the same protocols, making the two incompatible. The evolution of cdma2000 is being assured by a study group called 3GPP2. The first functional cdma2000 technology is the cdma2000 1xEV-DO, which is capable of delivering data rate of between 384kbps and 2.4 Mps and supports a wide range of services including videoconferencing, full internet and MP3 transfers. The second most evolved CDMA technology is the cdma2000 1xEV-DV, which is capable of delivering data speeds of up to 3.1 Mbps. 1x implies that it uses a single carrier just like the cdmaOne, while EV-DO stands for Evolution Data Only and EV-DV for Evolution Data and Voice. CDMA developers have obtained approval from the ITU for a faster 3G CDMA technology called CDMA 2000-3x, which will operate in the 5MHz frequency range providing data speeds of 2-4 Mbps.

2.1.5.3 TD-SCDMA:

This is developed and promoted by the China Wireless Telecommunication Standard group (CWTS). It was approved by the ITU in 1999 and is compatible with UMTS. The main benefit of TD-SCDMA is that it uses the GSM core network and, as such, minimises the cost of upgrading current 2G GSM networks to 3G.It not yet

36 operational but it is expected that by the first quarter of 2009, half a million people mostly in China should access 3G services via TD-SCDMA.

2.1.5.4 UWCC:

It was launched in 1995 to promote deployment of TDMA – IS-136 and IS-41 WIN.

2.1.5.5 DECT:

This is mostly intended for unlicensed spectrum bands with low-power operation and is mainly destined to serve short distance cordless phones in residences, businesses and public environments. DECT can support both voice and data traffic, making it a viable technology for Internet Access and Local area data communications, with a high degree of secure communications. DECT is TDM- based, capable of supporting

up to 100,000 users per KM2 within a business environment.

2.1.6 3.5 G

As mentioned earlier, the desire of the International Telecommunications Union (ITU) in defining the specifications for a third generation global network was to have just one standard. However, this has not been possible and, at the moment, there are three main standard bodies working on three different but similar standards: the EV-DO Revision C, the IEEE 802.20 and the 3G-LTE. The three standards are promoted by the 3GPP2, IEEE and the 3GPP working committees respectively. These standards are considered as the 3G standards and offer higher speed services.

The 3GPP2 is supplying 3.5G services under the 1xEV-DO and 1xEV-DV, which were defined earlier in Section 2.1.5. EVDO–C is the upgraded standard for EV-DO,

37 which is aimed at achieving data speeds of between 150 – 200Mbps. It employs a mix of CDMA and OFDMA carriers in the uplink and OFDMA only in the downlink.

3GPP defines the radio access network systems which are beyond 3G, as Long-Term

Evolution (LTE), and the corresponding network architecture as System Architecture Evolution (SAE). 3GPP is currently deploying 3.5G services under the HSPDA (High- Speed Downlink Packet Access) technology with data speeds expected to reach 100Mbps for the downlink and 50 Mbps for the uplink within a 20MHz spectrum. LTE services are expected to support full mobility at speeds of up to 350km/h and possibly 500km/h. By the close of 2008, HSPA accounted for about 89 million subscribers worldwide.

The IEEE 802.16e standard, known as WiMAX (Worldwide Inter-operability for Microwave Access), is an emerging technology promoted mainly by Intel and Qualcomm companies. Data speeds are expected to reach 130 Mbps for a 20 MHz channel. They are increasing deployed mobile telephone networks to backhaul traffic to switching centres.

2.1.7 Fourth Generation (4G)

Beyond 3.5G, it is expected at least by the ITU that the three competing 3G standards (3GPP, 3GPP2 and IEEE 802.20) will fully converge into a single standard, giving users seamless mobility with broadband services everywhere every time.

38 3G‐LTE EVDO‐C  802.20  Broa dban d Da ta op timis ation (8 -8 0Mb ps) 3. 5G W‐CDMA HSDPA Cdma2000   3G1x GSM/GPRS GSM/GPRS/EDGE  EVDO‐0 EVDO‐A TD‐SCDMA 802.16d 802.16e HSUPA   4G  D‐AMPS GSM (IS‐95)  _cdmaOne iDEN PDC 3GPP2   3GPP   IEEE   Cdma2000   1x RTMI C­450 system NMT  TZ­801 Radiocom 2000 TZ­803 JTACS TZ­802 AMPS TACS IMTS (1962) B‐Netz (1972) MTS (1946) Televerket (1966) Autoradiopuhelin (1971) 3G 2. 5G 2 G 1G 0G 2015 1946 2005 2010 2000 1980 1972 T rue Conve rgen ce (up to 100M bp s (IP B as ed) D at a o pt im is ati on ( 384K bp s – 2 .4M bp s) (Mult im ed ia , pa ck et s w it ched ) S pe ec h o pt im is at ion (9. 6K bps – 14 4K bp s) (So m e Mu lt im ed ia , ci rcuit /pack et s w it ch ed ) An alog ue, s im ple spe ech ( no d ata) (Mu lt imed ia , pa ck et swi tch ed)

39 The unified standard or point of convergence is known as 4G, where broadcasting technologies and traditional computer networks like LAN (Local Area Network), MAN (Metropolitan Area Network) and WAN (Wide Area Networks) are expected to converge with mobile technologies into a single network with data and broadband speeds expected to reach 1 Gbps.