Chikito_098ert

This module discusses the specifics of wireless technology: current architectures, foundation technologies, transmission protocols, software platforms, hardware, and standards.

Upon completion of this module, you should be able to:

 List and describe the components that form the architecture of a wireless system

 Describe how open systems, Java, XML, and TCP/IP technologies play a critical role on emerging wireless systems

 Describe the current and potential future of wireless transmission protocols for both wireless devices and the replacement of wired infrastructure

 List and describe the benefits and limitations of current wireless software platforms

 Describe the available wireless hardware

Wireless Architectures

Overview The architecture of a wireless system or application is made up of the following three parts:  Platform layers - The physical elements include networking components, computer hardware, operating systems, foundation technologies, and application software.  Service tiers - The tiers include user-facing components, resource components, and the application itself.  System qualities - Critical qualities, such as security or availability, have an impact on both the physical layers and Service tiers. You can visualize these three parts of the architecture as a cube.

Wireless Architectures

Wireless Service

Tiers

A wireless application differs from a web-based e-commerce

application only in the form and content of the information that is

sent and received from the user.

The application architecture for wireless applications is similar to

that of wired web applications. The underlying network

infrastructure is different but largely transparent to the application.

The only real difference is in the end-user rendering device, and the

Presentation tier needs to understand those differences to project

information in the correct way.

From an application perspective, you must also consider the

unreliable nature of wireless transmissions. For example, a wireless

connection might be dropped at any moment, so you must use a web

server that incorporates facilities in the Presentation tier to

accommodate this behavior.

To see the difference between a wired-based web site and a wirelessbased

WAP site:

Click http://www.lastminute.com to see how a standard web

browser views this travel site. Click http://wap.lastminute.com to see its wireless-based WAP equivalent.

Wireless Architectures

Qualities of Successful Wireless Solutions Wireless, device-based computing brings with it a range of new capabilities and applications. It also has its own set of requirements that you need to build into wireless systems and applications. Given the immaturity of wireless technology, it would be foolish to assume that these requirements have already been addressed without explicitly verifying this with the providers of wireless products and services. Essential qualities include:

Open Systems, JavaTM , XML, and TCP/IP as Foundation Technologies

Introduction As wireless systems mature, the key to limiting complexity and cost

while increasing overall functionality and performance is to use standard-based foundation technologies. By leveraging well-defined and open standards components, wireless architecture can continue to keep pace with the demands of its constituents. Most applications will be built on a common foundation of open systems, Java technology, XML, and TCP/IP. By using these types of standards, the majority of information services infrastructure can remain the same irrespective of the type client that displays the information.  Open systems  Java technology  XML  TCP/IP

Open Systems

Open systems is based on the notion that vendors within an industry come together to define open published standards and build products based on those standards. The idea is to compete for market share based on the quality of your implementation rather than on maintaining a proprietary strangle-hold on your customer.

Sun

...