Mobile Technologies

Many different mobile technologies are available in various mobile solutions and in mobile communication networks.  The paradigm of mobile computing can be described in a situation, in which users carrying portable devices have access to a shared infrastructure independent of their physical location. Mobile computing provides flexible communication between people and continuous access to networked services. The realization of this paradigm depends on two factors: the reduced size of computing devices and the increased capability of transporting digital data wirelessly.

Wireless technologies advance rapidly in the recent time. The major initiative is the realization of the third generation (3G) wireless network that provides high bandwidth wireless access to digital data on the Internet. Moreover, recent improvements in computer and embedded systems have enabled portable power-aware devices with sufficiently high computing capability. The combination of these advances triggered the notion of mobile computing, which integrates high bandwidth wireless network infrastructures with portable computing clients to enable varieties of new digital services such as email, web access, video conferencing, etc.

1^st Generation (1G)

The first generation (1G) system is a mixed of analog voice channels and digital control channels. In addition to voice communication capability, such system was actually able to send a very limited digital data. Services such as short messaging were available but very limited to slow data rate. Thus, the 1G system can be considered as analog only.

The earliest commercial 1G analog cellular system was established by Nippon Telephone and Telegraph (NTT) in Tokyo on December 1979. Motorola introduced the first truly portable, hand held phone. These systems (NIT, AMPS, SACS, RT MI, C-Net, and Radio com 2000) later became known as first generation (1G) mobile phones.

2^nd Generation (2G)

In the 1990s, 'second generation' (2G) mobile phone systems such as GSM, IS-136 ("TDMA"), iDEN and IS-95 ("CDMA") began to be introduced and they improves on its predecessor by using digital radio channels for both voice and control channels. Purely digital system is beneficial because limited frequency spectrum used by cellular design can further expanded to provide more user capacity by having logical channels. Moreover, digital features such as short messaging can now decently provided. 2G phone systems were characterized by digital circuit switched transmission and the introduction of advanced and fast phone to network signaling.

In 1991 the first GSM network (Radiolinja) opened in Finland. The second generation introduced a new variant to communication, as SMS text messaging became possible, initially on GSM networks and eventually on all digital networks. The first machine-generated SMS message was sent in the UK in 1991. The first person-to-person SMS text message was sent in Finland in 1993. All 2G, 2.5G, and 2.75G are considered to be in this generation.

3^rd Generation (3G)

The third generation (3G) system came into being due to the demand of new features and more efficient services desired by the highly successful 2G cellular phone markets in the early 1990s. 3G systems are also called universal mobile telecommunications system (UMTS). The first pre-commercial trial network with 3G was launched by NTT DoCoMo in Japan in the Tokyo region in May 2001. As improvements from the 2G systems, 3G systems provide high-speed (broadband) data services, multimedia support (simultaneous voice and data), increased system efficiency (cost reduction), and backward compatibility with 2G systems. The most intriguing enhancement is the capability of having simultaneous data transfers on a higher data rate (maximum of 2Mbps) with controlled quality of service, which enables 3G phones to do multiple tasks at the same time, such as having video conferencing while downloading music files from the Internet.

By the end of 2007 there were 295 Million subscribers on 3G networks worldwide, which reflected 9% of the total worldwide subscriber base. About two thirds of these are on the WCDMA standard and one third on the EV-DO standard.

Features of three generations of cellular systems

Comparison of 2G, 2.5G, and 3G systems

Mobile Phone as a Mobile Computing Device

The current popular device that is widely used and has incorporated these mobile computing features is a mobile phone. Thus, it is of significant interest to assess the society’s perspective on mobile phone in order to better understand its role as a computing and communication device. Historically, the wireless phone industry can be divided into three generations, based on the standard cellular technology used at the time.

Mobile phones, which used to be a conventional device used only for wireless voice communication, now have begun to transform into mobile computing devices. Features such as emails and web browsing available in 2G and 2.5G systems clearly represent the notion of mobile computing, in which was defined as users carrying portable devices that enable information sharing, independent of their location.

From the computing perspective, we can see embedded processors, such as ARM, being widely used in the mobile phone market [29]. Moreover, we can also see a breed of new devices that integrate PDA and mobile phone starting to appear in the market. An example is the TMobile Pocket PC Phone Edition [2], which uses 20 MHz Intel Strong Arm CPU, 32MB of ROM and RAM, and weigh 6.8 ounces.

Wireless Internet and Mobile Internet - Is There a Difference?

The breakthrough occurred with the introduction of digital mobile cellular systems (2G) in the early 1990s - just like the Internet after the introduction of the World Wide Web (WWW, or the Web). New services come with new enabling functions - like mobility, personalization, and localization capabilities - which are the characteristics of 3G mobile systems. This is the motivation for the industry to evolve the wireline Internet to a mobile Internet with new capabilities and applications. Key enabling functions for the mobile Internet are as follows:

IP-transparency - All elements involved in the end-to-end communications path have to support IP, both in the fixed and in the mobile parts of the network.

Mobility management - It has to function in a globally networked environment for roaming.

Addressing - It must allow every user a unique address capability, which is independent from the userís location.

Personalization of information and positioning - There must be means to provide such functionality.

Positioning - The individual must be positioned to enable location dependent services.

Security - It has to be provided end-to-end for fixed and mobile users.