1
Module 1
Introduction to mobile computing, Middleware and Gateways, Application and services, Internet-
Ubiquitous networks, Architecture and three-tier architecture for Mobile Computing, Design
consideration for Mobile Computing.
1.Mobile Computing
The rapidly expanding technology of cellular communication, wireless LANs, and satellite
services will make information accessible anywhere and at any time. Regardless of size, most mobile
computers will be equipped with a wireless connection to the fixed part of the network, and, perhaps, to
other mobile computers. The resulting computing environment, which is often referred to as mobile or
nomadic computing, no longer requires users to maintain a fixed and universally known position in the
network and enables almost unrestricted mobility. Mobility and portability will create an entire new
class of applications and, possibly, new massive markets combining personal computing and consumer
electronics.
A technology that allows transmission of data, via a computer, without having to be connected
to a fixed physical link.
• Mobile voice communication is widely established throughout the world and has had a very
rapid increase in the number of subscribers to the various cellular networks over the last few years. An
extension of this technology is the ability to send and receive data across these cellular networks. This
is the principle of mobile computing.
• Mobile data communication has become a very important and rapidly evolving technology as
it allows users to transmit data from remote locations to other remote or fixed locations.
Mobile Computing is an umbrella term used to describe technologies that enable people to
access network services anyplace, anytime, and anywhere. There are 2 aspects of mobile computing
• – User mobility: users communicate “anytime, anywhere, with anyone” (example: read/write
email on web browser). User mobility refers to a user who has access to the same or similar
telecommunication services at different places, i.e.,the user can be mobile, and the services will follow
him or her.
• – Device portability: devices can be connected anytime, anywhere to the network. With
device portability, the communication device moves .Many mechanisms in the network and inside the
device have to make sure that communication is still possible while the device is moving.
Different names of Mobile Computing:-
VHE – Virtual Home Environment- VHE is defined as an environment in a foreign network such that
the mobile users can experience the same computing experience as they have in their home or corporate
computing environment.
Anywhere, anytime information- This is the generic definition of ubiquity,where the information is
available anywhere all the time.
Nomadic computing-The computing environment is nomadic and moves along with the mobile user.
Pervasive computing-It is pervasive in nature and can be made available in any environment.
Gayathry K V,SNGCE
, 2
Ubiquitous computing- Ubiquitous computing is a concept in software engineering and computer science
where computing is made to appear anytime and everywhere. In contrast to desktop computing, ubiquitous
computing can occur using any device, in any location, and in any format.
Global service portability-Making a service portable and available in every environment.
Wearable computers -Wearable computers, also known as wearables or body-borne computers, are
small computing devices (nowadays usually electronic) that are worn under, with, or on top of clothing.
The definition of 'wearable computer' may be narrow or broad, extending to smartphones or even
ordinary wristwatches.
Mobile Computing Functions
We can define a computing environment as mobile if it supports one or more of the following characteristics:
● User Mobility: The user should be able to move from one physical location to another and use
the same service. The service could be in a home or remote network. For example, a user
moves from London to New York and uses Internet to access the corporate application the
same way the user uses it in the home office.
● Network Mobility: Network mobility deals with two types of use-cases. In one use-case, the
user is moving from one network to another and uses the same service seamlessly, An example
could be a user moving from a WiFi network within the university campus and changing to
3G network outside while using the same online service.
● Bearer Mobility: The user should be able to move from one bearer to another and use the
same service. An example could be a user using a service through WAP bearer in his home
network in Bangalore. He moves to Coimbatore where WAP is not supported and switches
over to the voice or SMS (short message service) bearer to access the same application.
• Device Mobility: The user should be able to move from one device to another and use the
same service. An example could be sales representatives using their desktop computer in their
home office. During the day while they are on the street they would like to use their Palmtop to
access the application.
• Session Mobility: A user session should be able to move from one user-agent environment to
another. An example could be a user using his service through a CDMA (Code Division
Multiple Access) lX network. The user entered into the basement to park the car and got
disconnected from his CDMA network. He goes to his home office and starts using the
desktop. The unfinished session in the CDMA device moves from the mobile device to the
desktop computer.
• Agent Mobility: The user-agent or the applications should be able to move from one node to
another. Examples could be aglets, crawler software, or even a malicious worm or virus
software that moves from one node to another. There is another use-case of mobile agent in the
Cloud Computing paradigm, where applications will be moving from platform to platform and
infrastructure to infrastructure depending on temporal and economic considerations. In Cloud
Computing, there will not be any fixed association between the application and the host running
it-software agents in the cloud will constantly be mobile.
• Host Mobility: The user device can be either a client or server. When it is a server or host,
some of the complexities change. In case of host mobility, mobility of the IP needs to be taken
care of.
Gayathry K V,SNGCE
, 3
I. User with device: This means that this could be a fixed device like a desktop computer in an
office or a portable device like mobile phone. Example: laptop computers, desktop computers,
fixed telephone, mobile phones, digital TV with set-top box, palmtop computers, pocket PCs, two-
way pagers, handheld terminals, etc.
2. Network: Whenever a user is mobile, he will use different networks at different locations at
different times. Example: GSM, CDMA, iMode, Ethernet, Wireless LAN, Bluetooth, etc.
3. Gateway: This acts as an interface between different transport bearers. These gateways
convert one specific transport bearer to another. Example: From a fixed phone [with voice interface)
we access a service by pressing different keys on the telephone. These keys generate DTMF (Dual
Tone Multi Frequency) signals. These analog signa.ls are converted into digital data by the IVR
(Interactive Voice Response) gateway to interface with a computer application. Other examples
will be WAP gateway, SMS gateway, etc.
4. Middleware: This is more of a function rather than a separate visible node. ln the present
context, middleware handles the presentation and rendering of the content on a particular device. It
may optionally also handle the security and personalization for different users.
5. Content: This is the domain where the origin server and content. is. This could be an application,
system, or even an aggregation of systems. The content can be mass market, personal or corporate
content. The origin server will have some means of accessing the database and storage devices.
Mobile Computing Devices
The device for mobile computing can be either a computing or a communication device. In the
computing device category it can be a desktop, laptop, or a palmtop computer. On the
communication device side it can be a fixed Line telephone, a mobile telephone or a digital TV.
Usage of these devices are becoming more and more integrated into a task flow where fixed and
mobile, computing and communication functions are used together.
The device is a combination of hardware and software; the hardware is technically called the User
Equipment (UE) with software inside, which functions as an agent to connect to the remote service-
this software is called a User Agent (UA). One of the most common UA today is a Web browser.
When computing technology is embedded into equipment, Human-Computer Interaction (HCI)
plays a critical role in effectiveness, efficiency, and user experience. This is particularly true as
mobile information and communication devices are becoming smaller and more restricted with
Gayathry K V,SNGCE
Module 1
Introduction to mobile computing, Middleware and Gateways, Application and services, Internet-
Ubiquitous networks, Architecture and three-tier architecture for Mobile Computing, Design
consideration for Mobile Computing.
1.Mobile Computing
The rapidly expanding technology of cellular communication, wireless LANs, and satellite
services will make information accessible anywhere and at any time. Regardless of size, most mobile
computers will be equipped with a wireless connection to the fixed part of the network, and, perhaps, to
other mobile computers. The resulting computing environment, which is often referred to as mobile or
nomadic computing, no longer requires users to maintain a fixed and universally known position in the
network and enables almost unrestricted mobility. Mobility and portability will create an entire new
class of applications and, possibly, new massive markets combining personal computing and consumer
electronics.
A technology that allows transmission of data, via a computer, without having to be connected
to a fixed physical link.
• Mobile voice communication is widely established throughout the world and has had a very
rapid increase in the number of subscribers to the various cellular networks over the last few years. An
extension of this technology is the ability to send and receive data across these cellular networks. This
is the principle of mobile computing.
• Mobile data communication has become a very important and rapidly evolving technology as
it allows users to transmit data from remote locations to other remote or fixed locations.
Mobile Computing is an umbrella term used to describe technologies that enable people to
access network services anyplace, anytime, and anywhere. There are 2 aspects of mobile computing
• – User mobility: users communicate “anytime, anywhere, with anyone” (example: read/write
email on web browser). User mobility refers to a user who has access to the same or similar
telecommunication services at different places, i.e.,the user can be mobile, and the services will follow
him or her.
• – Device portability: devices can be connected anytime, anywhere to the network. With
device portability, the communication device moves .Many mechanisms in the network and inside the
device have to make sure that communication is still possible while the device is moving.
Different names of Mobile Computing:-
VHE – Virtual Home Environment- VHE is defined as an environment in a foreign network such that
the mobile users can experience the same computing experience as they have in their home or corporate
computing environment.
Anywhere, anytime information- This is the generic definition of ubiquity,where the information is
available anywhere all the time.
Nomadic computing-The computing environment is nomadic and moves along with the mobile user.
Pervasive computing-It is pervasive in nature and can be made available in any environment.
Gayathry K V,SNGCE
, 2
Ubiquitous computing- Ubiquitous computing is a concept in software engineering and computer science
where computing is made to appear anytime and everywhere. In contrast to desktop computing, ubiquitous
computing can occur using any device, in any location, and in any format.
Global service portability-Making a service portable and available in every environment.
Wearable computers -Wearable computers, also known as wearables or body-borne computers, are
small computing devices (nowadays usually electronic) that are worn under, with, or on top of clothing.
The definition of 'wearable computer' may be narrow or broad, extending to smartphones or even
ordinary wristwatches.
Mobile Computing Functions
We can define a computing environment as mobile if it supports one or more of the following characteristics:
● User Mobility: The user should be able to move from one physical location to another and use
the same service. The service could be in a home or remote network. For example, a user
moves from London to New York and uses Internet to access the corporate application the
same way the user uses it in the home office.
● Network Mobility: Network mobility deals with two types of use-cases. In one use-case, the
user is moving from one network to another and uses the same service seamlessly, An example
could be a user moving from a WiFi network within the university campus and changing to
3G network outside while using the same online service.
● Bearer Mobility: The user should be able to move from one bearer to another and use the
same service. An example could be a user using a service through WAP bearer in his home
network in Bangalore. He moves to Coimbatore where WAP is not supported and switches
over to the voice or SMS (short message service) bearer to access the same application.
• Device Mobility: The user should be able to move from one device to another and use the
same service. An example could be sales representatives using their desktop computer in their
home office. During the day while they are on the street they would like to use their Palmtop to
access the application.
• Session Mobility: A user session should be able to move from one user-agent environment to
another. An example could be a user using his service through a CDMA (Code Division
Multiple Access) lX network. The user entered into the basement to park the car and got
disconnected from his CDMA network. He goes to his home office and starts using the
desktop. The unfinished session in the CDMA device moves from the mobile device to the
desktop computer.
• Agent Mobility: The user-agent or the applications should be able to move from one node to
another. Examples could be aglets, crawler software, or even a malicious worm or virus
software that moves from one node to another. There is another use-case of mobile agent in the
Cloud Computing paradigm, where applications will be moving from platform to platform and
infrastructure to infrastructure depending on temporal and economic considerations. In Cloud
Computing, there will not be any fixed association between the application and the host running
it-software agents in the cloud will constantly be mobile.
• Host Mobility: The user device can be either a client or server. When it is a server or host,
some of the complexities change. In case of host mobility, mobility of the IP needs to be taken
care of.
Gayathry K V,SNGCE
, 3
I. User with device: This means that this could be a fixed device like a desktop computer in an
office or a portable device like mobile phone. Example: laptop computers, desktop computers,
fixed telephone, mobile phones, digital TV with set-top box, palmtop computers, pocket PCs, two-
way pagers, handheld terminals, etc.
2. Network: Whenever a user is mobile, he will use different networks at different locations at
different times. Example: GSM, CDMA, iMode, Ethernet, Wireless LAN, Bluetooth, etc.
3. Gateway: This acts as an interface between different transport bearers. These gateways
convert one specific transport bearer to another. Example: From a fixed phone [with voice interface)
we access a service by pressing different keys on the telephone. These keys generate DTMF (Dual
Tone Multi Frequency) signals. These analog signa.ls are converted into digital data by the IVR
(Interactive Voice Response) gateway to interface with a computer application. Other examples
will be WAP gateway, SMS gateway, etc.
4. Middleware: This is more of a function rather than a separate visible node. ln the present
context, middleware handles the presentation and rendering of the content on a particular device. It
may optionally also handle the security and personalization for different users.
5. Content: This is the domain where the origin server and content. is. This could be an application,
system, or even an aggregation of systems. The content can be mass market, personal or corporate
content. The origin server will have some means of accessing the database and storage devices.
Mobile Computing Devices
The device for mobile computing can be either a computing or a communication device. In the
computing device category it can be a desktop, laptop, or a palmtop computer. On the
communication device side it can be a fixed Line telephone, a mobile telephone or a digital TV.
Usage of these devices are becoming more and more integrated into a task flow where fixed and
mobile, computing and communication functions are used together.
The device is a combination of hardware and software; the hardware is technically called the User
Equipment (UE) with software inside, which functions as an agent to connect to the remote service-
this software is called a User Agent (UA). One of the most common UA today is a Web browser.
When computing technology is embedded into equipment, Human-Computer Interaction (HCI)
plays a critical role in effectiveness, efficiency, and user experience. This is particularly true as
mobile information and communication devices are becoming smaller and more restricted with
Gayathry K V,SNGCE
