Introduction & history of mobile computing

Introduction & History of Mobile Computing

by David J Livingston([email protected])

What is Mobile Computing?

Mobile Computing is a technology that allows transmission of data, voice and video via a computer or any other wireless enabled device without having to be connected to a fixed physical link.

Mobile Computing is an umbrella term used to describe technologies that enable people to access network services anyplace, anytime, and anywhere.

Define Mobility

Mobile simply describes a computing device that is not restricted to a desktop. A mobile device may be a PDA, a “smart” cell phone or Web phone, a laptop computer, a tablet PC or any one of numerous other devices that allow the user to complete computing tasks without being physically connected to a network.

Mobile computing does not necessarily require wireless communication. In fact, it may not require communication between devices at all.

Mobility of Bits and Bytes

In the last two centuries, mobility has been redefined.

Both physical and virtual objects are now mobile.

- Mobility of physical objects relate to movement of matters,

- whereas movements of virtual objects relate to movements of bits and bytes.

More Definition on Mobile Computing!

A simple definition could be:Mobile Computing is using a computer (of one kind or another) while on the move

Another definition could be:Mobile Computing is when a (work) process is moved from a normal fixed position to a more dynamic position.

A third definition could be:Mobile Computing is when a work process is carried out somewhere where it was not previously possible.

Wireless Communication

Wireless refers to the method of transferring information between a computing device, such as a personal data assistant (PDA), and a data source, such as an agency database server, without a physical connection. Not all wireless communications technologies are mobile.

For example, lasers are used in wireless data transfer between buildings, but cannot be used in mobile communications at this time.

Wired Vs. Wireless Networks

Wired Networks

- high bandwidth

- low bandwidth variability

- can listen on wire

- high power machines

- high resource machines

- need physical access(security)

- low delay

Mobile Networks

- low bandwidth

- high bandwidth variability

- hidden terminal problem

- low power machines

- low resource machines

- need proximity

- higher delay

Why Mobile Computing?

Enable anywhere/anytime connectivity

Bring computer communications to areas without pre existing infrastructure

Enable mobility

Enable new applications

An exciting new research area

Types of Wireless Devices

Laptops

Palmtops

PDAs

Cell phones

Pagers

Sensors

Computer Network

A computer network is collection of several homogeneous/heterogeneous system, commonly used for resource sharing.

Computer networks can be classified in many ways:

Area wise:

- LAN , MAN & WAN

As per medium used:

- Wired Computer Network & Wireless Computer Network

Advantage of Wireless Networks

Flexible: Radio waves can penetrate the obstacles. Sender and receiver can be placed any where.

Mobility: Data can be access from any location.

Robustness : Can survive in disaster (Earthquake, military operations)

Scalable: Can be configured in variety of topologies.

Easy Installation

Less Cost

Usage of ISM band: ISM (Industrial, Scientific and Medical) band (2.40GHz to 2.484 GHz, 5.725 GHz to 5.850 GHz) is available for use by anyone.

No Planning: Only Wireless Ad hoc not required any planning.

Disadvantage of Wireless Networks

Quality of Service: Lower Bandwidth

Lower Data Transmission Rate

High Error Rates

Interference

Higher Delay

Restrictions: License-free frequency bands are not same worldwide.

Safety and Security: Interference from other devices (e.g. Hospital.

Eavesdropping is possible).

The Beginning

Most credit Guglielmo Marconi, “the father of radio”, with the initiation of wireless technology

1894 Marconi experimented with Hertzian Waves (radio waves) to produce and detect waves over long distances

1896 Marconi established the Wireless Telegraph & Signal Company, the first radio factory

1901 St John’s, New Foundland, Marconi received the first trans-Atlantic wireless signal from Poldhu, England

Evolution of Wireless Technology

1905 the first distress signal sent using Morse Code

1919 Radio Corporation of America (RCA) was incorporated, and consumer radio broadcasts for news and entertainment soon became popular

During World War II the US Military used wireless signals with encryption to send battle plans and instructions

US Military started the shift to radio data transmission technology

The Beginning of Wireless Technology

In 1947 researchers in AT&T Bell Labs conceived the idea of cellular phones.

They realized that by using small service areas or cells they can reuse the frequency.

This in turn can enhance the traffic capacity of mobile phones.

AT&T requested the Federal Communication Commission (FCC) to allocate a large number of radio-spectrum frequencies so that widespread mobile telephone service would become feasible.

Evolution in 20th Century

On October 4, 1957 the USSR (Union of Soviet Socialist Republic now mainly Russia) launched the Sputnik. It was the first artificial earth satellite launched from Baikonur cosmodrome in Kazakhstan.

In response to this, the US formed the Advanced Research Projects Agency (ARPA) within the Department of Defense (DoD).

This laid the foundation of packet switched data networks. The important ones are TCP /IP and X.25.

Evolution of Wireless Network

The first wireless network was commissioned in Germany in 1958. It was called A-Netz and used analog technology at 160 MHz.

Only outgoing calls were possible in this network.That is to say that connection set-up was possible from the mobile station only.

This system evolved into B-Netz operating at the same 160 MHz. It was possible to receive an incoming call from a fixed telephone network, provided that location of the mobile station was known.

Evolution of Wireless (Cont.)

A-Netz was wireless but not a cellular network. Therefore, these systems (A-Netz and B-Netz) did not have any function, which permitted handover or change of base station.

In 1968, in USA, the FCC reconsidered its position on Cellular network concept.

FCC agreed to allocate a larger frequency band for more number of mobile phones provided the technology to build a better mobile service be demonstrated.

Cellular Technology

AT&T and Bell Labs proposed a cellular system to the FCC with many small, low-powered, broadcast towers, each covering a hexagonal 'cell' of a few kilometers in radius.

Collectively these cells could cover a very large area.

Each tower would use only a few of the total frequencies allocated to the system.

As the phones traveled across the area, calls would be passed from tower to tower.

Some Inventions in Wireless Technology

In April 1973, Martin Cooper of Motorola invented the first mobile phone handset and made the first call from a portable phone to Joel Engel.

By 1977, AT&T and Bell Labs constructed a prototype of a public cellular network.

In 1978, public trials of the cellular telephony system started in Chicago with over 2000 trial customers.

First Cellular Mobile Network

In 1982, FCC finally authorized commercial cellular service for the USA.

A year later in 1983, the first American commercial analog cellular service AMPS (Advanced Mobile Phone Service) was made commercially available in Chicago.

This was the first cellular mobile network in the world

Milestones in Wireless Network

TCP/IP was driven by education and defense in the USA whereas X.25 was driven by European telecommunication industry and Governments.

1971 network technologies met radio technologies when the first wireless Local Area Network (LAN) was established at the University of Hawaii during the experiment, ‘ALOHANET’

ALOHANET used a bidirectional star topology consisting of (7) computers over (4) islands

Milestones (Cont.)

1973 Dr Martin Cooper, Motorola Labs, invented the first personal mobile cellular telephone (weighed 2.5 lbs, 30 individual circuit boards, no display screen, 9”x5”x1.75”, 10 hours to charge for 35 minutes of use)

1983 marked American entry into the commercial cellular service market

1987 FCC allows and encourages cellular service providers to use alternate technologies in the 800Mhz radio spectrum to prompt use of digital transmission

IEEE Standard for Wirless Networking

1990 IEEE 802 Executive Committee established the 802.11 Working Group to create a wireless LAN standard.

1997 working group approved IEEE 802.11 as the world’s first wireless LAN standard

New standards are continuously being developed by the Institute of Electrical and Electronical Engineers