Mobile Computing

What is Mobile Computing ?

Mobile computing refers to the creation of an information management platform, independent of spatial and temporal constraints. This independence permits accessing and processing of information from any location across the globe. The user's state (whether static or mobile) has no impact on the information management ability of the mobile platform.

Meaning of Mobile Computing

A user is able to access and alter the data as per her/his requirement from any location like while traveling plane, in car or on a ship. Therefore, it creates an illusion that the desired data and processing power is in the hands of the user but in reality, the original data location is far away from user.

The ability to use computing capability in the absence of a pre-defined location and/or connection to a network for access to information is termed as mobile computing. The information travels between processing units via wireless channels in the mobile computing platform.

Mobile computing is also referred to wireless mobile computing as this combination assists in a real-time connection between a mobile device and other computing environments like the internet or intranet.

Elements of Mobile Computing

The various elements of mobile computing system are described below :

1) Data Source : 
This can be analog or digital which is transmitted from one side to another. Any change in the state of data will effect a modulation in the message frame on a RF carrier wave. The frame format is given below :

Data Source

2) Radio Frequency Generating Section : 
An RF source (oscillator or synthesizer), a modulator and an amplifier are parts of radio frequency generating section. All of the three functions may be present in a single circuit of one transistor in simple short-range devices.

3) RF Conduction and Radiation : 
The short-range devices have built-in antennas and their transmission lines are also short and simple. In higher frequencies, the lengths include a high percentage of wavelengths. This influences the transmission efficiency of the transmitter.

4) Radio Channel : 
For short-range applications, the radio channel is short and the equipment is mostly used indoors. The permitted radio frequency is fairly low and is regulated by the telecommunications department.

5) Receivers : 
These are analogous to transmitters but the operation is reversed. For their operation they use oscillators and have an antenna, transmission line and RF amplifiers. Receivers convert the data source back to its original form.

6) Power Supplies : 
When size is small, battery size and energy also become limited Changing of batteries becomes expensive and inconvenient and acts as a hindrance to large scale use of radio in place of wires. Therefore, low-current consumption is an important aspect while designing wireless devices.

Mobile Computing Framework

Mobile computing is developing in four dimensions : 

1) Wireless Delivery Technology and Switching Methods : 
This concerns the fast spreading delivery technology of cellular, radio, paging. satellite and wireless LAN communications which assure to provide information to mobile users anywhere at any time.

2) Mobile Information Access Devices : 
Just like the changing delivery technology, there has been a sudden increase in the choice of access equipment's ranging from large units like laptops, notebooks and other portable computers with large memories and powerful processors to hand held or palmtops like personal digital assistants or personal communicators. The smaller equipment's run on AA batteries and usually have no memory storage capacity.

3) Mobile Data Inter-Networking Standards and Equipment : 
Initially, the voice oriented cellular systems were designed only for voice calls and not data. Even then, it has faced hindrances like weak connections, frequent noise and momentary dropouts when users move from one cell tower to another and face physical barriers like bridges and tunnels. These same disturbances may occur for data calls; also there are low numbers of frequencies available. In order to solve this problem, work has been undertaken in the area of digital cellular standards which help in data communications over cellular lines.

4) Mobile Computing-Based Business Applications : 
Mobility and portability have been responsible for creating new class of applications and new markets which combine personal computing and consumer electronics. Vehicle dispatch and routing, inventory and package tracking and retail point of sale are examples of already existing vertical, niche applications of mobile computing. Mail-enabled applications and information or data services to mobile users are two examples of organisational applications in use (yet less used).

Advantages of Mobile Computing

The Importance of mobile computing are explained below :

1) Locational Flexibility : 
The most significant feature of mobile computing is one does not need to be fixed at a particular location in order to communicate with other people located anywhere, globally. This is an important feature which affects the economy of the country as well as the world. Mobile computing helps users to be mobile about their location and yet perform computing activities.

2) Saves Time : 
With the help of this technology, transit time can be used very effectively.

3) Enhanced Productivity : 
With increased work flexibility, better work productivity arises. The fact that one can work from anywhere without taking the trouble in getting access to computing facility, makes people do more work with greater case. Due to this reason various companies offer work from home facilities today. 
For example, in case of a national emergency or natural calamity and closure of offices, employees may be still continuing work from their respective hornes. 

4) Ease of Research : 
The flexibility offered by mobile computing allows students and professionals to conduct research on any topic or subject from anywhere.

5) Entertainment : 
There are many entertainment options such as games, movies, music, videos, etc. available on mobile computing devices now a-days.

Disadvantages of Mobile Computing

Mobile computing systems also have their limitations when compared to static systems. These disadvantages are inherent to mobility and not just the current technology. The Limitations of Mobile Computing are as mentioned below :

1) Mobile Elements are Resource-Poor Relative to Static Elements : 
Given any level of expenditure and technology, mobile elements are computationally less capable when compared to their static counterparts in terms of weight, power, size and ergonomics. In absolute ability, mobile elements perform better but will always be at a disadvantage compared to static elements.

2) Mobile Elements are More Prone to Loss, Destruction, and Subversion than Static Elements : 
A Wall Street stockbroker has higher chances of getting robbed on the streets of Manhattan and have his laptop stolen than if it were in her/his office. Though security is not an issue, then also portable computers are more prone to loss or damage.

3) Mobile Elements must Operate under a Much Broader Range of Networking Conditions : 
A desktop connection relies on LAN and WAN connectivity whereas a laptop has modem or ISDN connectivity. A laptop with a cellular modem gets intermittent connectivity whenever it is close to the nearest mobile tower.

Applications of Mobile Computing

There are various applications benefiting from wireless networks and mobile communications such as :

1) Vehicles : 
Several wireless communication systems and mobility aware applications are categorized under vehicles. At any location, wireless system is used to transmit music, news, weather reports and other broadcast information.

2) Emergencies : 
If an ambulance has a high quality wireless connection to the hospital, then crucial information about the condition of the patient can be sent to the hospital which can make necessary preparations before the patient reaches the hospital and help in early diagnosis. In case of natural disasters like cyclones or earthquakes, only wireless networks can be used as means of communication.

3) Business :
Sales professionals who need to travel frequently require instant access to the company's database to keep them updated about the company's current state and this conversely helps. the company keep track of its travelling employees. With wireless access, the laptop gets converted to a mobile office and efficient synchronization mechanism ensures data consistency.

4) Infotainment : 
A wireless network can provide updated information about anything at an appropriate location. Like a travel guide might provide information about the history of a building through GPS, local base station contact or triangulation. It may also provide information about evening concert that is to be held in the building.

5) Location Dependent Services : 
Many times, the applications should have knowledge about location or else the user might require location information for conducting her/his activities. The following services require actual location information :

i) Follow-on Services : 
Call forwarding to current user location is a known function from the traditional telephone system. Irrespective of one's location, if the temporary phone number is transmitted to one's phone, all incoming calls get redirected. 
For example, by using mobile computers, a follow-on service can be offered which helps in accessing the same desktop environment by the user from any location. In this, all e-mails will be automatically forwarded and all changes in desktop and documents will get stored in the central storage location of the company.

ii) Location Aware Services : 
For example, if one wanted to print a document from her/his laptop sitting in a hotel lobby, ac print-out would be at the office printer unless the correct printer option is chosen since the office printer is the default configuration set in the laptop. In such case, additional information is required for configuring other printers to the laptop.

iii) Privacy : 
There might be times when one might not want to receive certain services at specific locations as they are disturbing. In such a case, one might want to use available location dependent services but not want that location to know about one's identity.

iv) Information Services : 
While walking through a city, one can use the wireless travel guide to get information about a service. 
For example, location of the nearest beverage store.

v) Support Services :
To support a mobile device, additional mechanisms are integrated. Intermediate results of calculations, state information or cache contents can be stored and follow the mobile node via fixed network. Once the node gets reconnected every information is available to be accessed. This feature reduces access time delay and the network traffic.
The memory space is inadequate in desktop systems which restricts the caching of data in a mobile device. As an alternative, a central location is used for storing user information and user access information over a large network as is prevalent today.