MOBILE COMPUTING COMPILED BY DR. A.

A OMONORI
Mobile computer with wireless network is current trend in human-computer interaction technology
as well as the social lifestyle. The smart-phone is the first mobile computer and smart pad comes
next replacing the notebook which is replacing the desk top computer. Mobile computing is
composed of mobile communication, mobile hardware, and mobile software. Communication
issues include ad hoc and infrastructure networks as well as communication properties, protocols,
data formats and concrete technologies. Hardware includes mobile devices or device components.
Mobile software deals with the characteristics and requirements of mobile applications.
The rapidly expanding technology of cellular communication, wireless LANs, and satellite
services will make information accessible anywhere and at any time. Mobility is the most
important feature of a wireless cellular communication system. Usually, continuous service is
achieved by supporting handoff (or handover) from one cell to another. Handoff is the process of
changing the channel (frequency, time slot, spreading code, or combination of them) associated
with the current connection while a call is in progress. It is often initiated either by crossing a cell
boundary or by a deterioration in quality of the signal in the current channel. Mobile phones have
been popular; powerful smartphones are now a regular choice for consumers. Today, the mobile
phone technology is mature enough to enable us to effectively interact with mobile phones using
our three major senses namely, vision, hearing and touch. Similar to the camera, which adds
interest and utility to mobile experience, the vibration motor in a mobile phone could give us a
new possibility to improve interactivity and usability of mobile phones.
Mobile computing is the discipline for creating an information management platform, which is
free from spatial and temporal constraints. The freedom from these constraints allows its users to
access and process desired information from anywhere in the space.
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.
Main Concepts of Mobile Computing are;

▪ Mobile communication

The mobile communication in this case, refers to the infrastructure put in place to ensure that
seamless and reliable communication goes on. These would include devices such as protocols,
services, bandwidth, and portals necessary to facilitate and support the stated services. The data
format is also defined at this stage. This ensures that there is no collision with other existing
systems which offer the same service.

Since the media is unguided/unbounded, the overlaying infrastructure is basically radio wave-
oriented. That is, the signals are carried over the air to intended devices that are capable of
receiving and sending similar kinds of signals.
 ▪ Mobile Hardware

Mobile hardware includes mobile devices or device components that receive or access the service
of mobility. They would range from portable laptops, smartphones, tablet Pc's, Personal Digital
Assistants.

These devices will have a receptor medium that is capable of sensing and receiving signals. These
devices are configured to operate in full- duplex, whereby they are capable of sending and
receiving signals at the same time. They don't have to wait until one device has finished
communicating for the other device to initiate communications.

▪ Mobile software

Mobile software is the actual program that runs on the mobile hardware. It deals with the
characteristics and requirements of mobile applications. This is the engine of the mobile device.
In other terms, it is the operating system of the appliance. It's the essential component that operates
the mobile device.

Since portability is the main factor, this type of computing ensures that users are not tied or pinned
to a single physical location, but are able to operate from anywhere. It incorporates all aspects of
wireless communications.

CLASSIFICATION OF MOBILE COMPUTING

Mobile computing is not only limited to mobile phones, but there are various gadgets available in
the market that are built on a platform to support mobile computing. They are usually classified in
the following categories;

Personal Digital Assistant (PDA)

The main purpose of this device is to act as an electronic organizer or day planner that is portable,
easy to use and capable of sharing information with your computer systems.

PDA is an extension of the PC, not a replacement. These systems are capable of sharing
information with a computer system through a process or service known as synchronization. Both
devices will access each other to check for changes or updates in the individual devices. The use
of infrared and Bluetooth connections enables these devices to always be synchronized.

With PDA devices, a user can browse the internet, listen to audio clips, watch video clips, edit and
modify office documents, and many more services. The device has a stylus and a touch sensitive
screen for input and output purposes.
Smartphones

This kind of phone combines the features of a PDA with that of a mobile phone or camera phone.
It has a superior edge over other kinds of mobile phones.

Smartphones have the capability to run multiple programs concurrently. These phones include
high-resolution touch screens, web browsers that can access and properly display standard web
pages rather than just mobile-optimized sites, and high-speed data access via Wi-Fi and high speed
cellular broadband.

The most common mobile Operating Systems (OS) used by modern smartphones include Google's
Android, Apple's iOS, Nokia's Symbian, RIM's BlackBerry OS, Samsung's Bada, Microsoft's
Windows Phone, and embedded Linux distributions such as Maemo and MeeGo. Such operating
systems can be installed on different phone models, and typically each device can receive multiple
OS software updates over its lifetime.

Tablet PC and iPads

This mobile device is larger than a mobile phone or a PDA and integrates into a touch screen and
is operated using touch sensitive motions on the screen. They are often controlled by a pen or by
the touch of a finger. They are usually in slate form and are light in weight. Examples would
include ipads, Galaxy Tabs, Amazon Playbooks etc.

They offer the same functionality as portable computers. They support mobile computing in a far
superior way and have enormous processing horsepower. Users can edit and modify document
files, access high speed internet, stream video and audio data, receive and send e-mails, attend/give
lectures and presentations among its very many other functions. They have excellent screen
resolution and clarity.

Principles of Mobile Computing

• Portability: Devices/nodes connected within the mobile computing system should

facilitate mobility. These devices may have limited device capabilities and limited power
supply, but should have a sufficient processing capability and physical portability to
operate in a movable environment.
• Connectivity: This defines the Quality of Service (QoS) of the network connectivity. In a
mobile computing system, the network availability is expected to be maintained at a high
level with the minimal amount of lag/downtime without being affected by the mobility of
the connected nodes.
• Interactivity: The nodes belonging to a mobile computing system are connected with one
another to communicate and collaborate through active transactions of data.
• Individuality: A portable device or a mobile node connected to a mobile network often
denote an individual; a mobile computing system should be able to adopt the technology
to cater the individual needs and also to obtain contextual information of each node.