The purpose of this project is to discuss the issues associated with the deployment of a secure, WAP-based, transactional banking system, and to build a solution with these issues in mind.

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A Mobile Application For Banking Processes

ABSCTRACT

The purpose of this project is to discuss the issues associated with the deployment of a secure, WAP-based, transactional banking system, and to build a solution with these issues in mind. There are many pitfalls and problems that have to be overcome when developing a m-commerce solution, ranging from security to providing support for the multitude of WAP-enabled devices that are currently on the market. The problems of linking into an existing back-end infrastructure also need to be met. This paper will compare and contrast available technologies that could be used to solve each of these issues, and justify the technologies that were finally chosen. The goal of this project is to develop a combined retail banking application that was to be delivered multiple channels, including WAP devices. The information has to be retrieved from existing back-end systems on a combination of different platforms. In the following section a detailed description of what WAP and wireless technology is will be enlightened.

TABLE OF CONTENTS

1        WAP        

1.1        The usefulness of WAP        

1.2        Encourage and Foster Market Development        

1.3        WAP 2.0: Bringing Wireless Closer to the Internet        

1.4        What Is New: WAP 2.0 is an Evolutionary Step Forward        

1.5        Alignment with New Technologies and Standards        

1.6        WAP 2.0 Components: Application Support, Protocol Stack and More        

1.6.1        Wireless Application Environment        

1.7        WAP Programming Model        

1.8        WAP Protocol Stack        

1.9        Legacy Protocol Layers        

1.10        Protocol Layers for Networks Supporting IP        

1.11        WAP 2.0 Adds New and Enhanced Services        

CHAPTER 2        

2        BANKING        

2.1        Retail Banking        

2.2        Financial Institution Concerns        

2.3        Security        

2.4        Investment in the Future        

2.5        Functionally Rich Application        

2.6        Technical Concerns        

2.7        Multiple Sources of Information        

2.8        Multiple Distribution Channels        

2.9        Middleware        

2.10        Direct Debit        

2.11        Direct Debit Customer Benefits        

2.12        Managing Direct Debit on your bank account        

3        METHODOLOGIES        

3.1.1        Soft Systems Methodology        

3.1.2        Rich Pictures        

3.1.3        Conceptual Model        

3.1.4        Agree on Changes        

3.1.5        Action        

3.2        RAD        

3.2.1        Definition        

3.2.2        Principles Behind The Definition        

3.2.3        Problems Addressed By RAD        

3.2.4        Bad Reasons For Using RAD        

3.2.5        Good Reasons For Using RAD        

3.2.6        Schedule Versus Economy Versus Product Quality        

3.2.7        Abbreviated History of RAD        

3.2.8        Characteristics of RAD        

3.2.9        RAD Uses Iterative, Evolutionary Prototyping        

3.2.10        When RAD Works And When It Doesn’t RAD Tends To Work        

3.2.11        When RAD Tends To Fail        

3.2.12        Evaluation of RAD Advantages of RAD        

3.2.13        Disadvantages of RAD        

CHAPTER 4        

4        SSADM        

4.1        Introduction        

4.2        What is SSADM?        

4.3        Why is SSADM Used?        

4.4        How is SSADM Controlled in the UK?        

4.5        What are the Major Tools of SSADM?        

4.6        Three Interdependent Views        

4.7        How is SSADM Structured?        

4.8        Introduction to SSADM        

4.9        Critique of SSADM and DSDM        

4.10        Framework        

4.11        Critique        

5        SPECIFICATION FRAME WORK        

5.1        Software experimentation        

5.2        WML, WML SCRIPT, IIS        

5.3        WML Example Code        

5.4        Wap Gateway        

5.5        Microsoft Access XP SP2        

5.6        Generating dynamic WAP content        

5.7        PHPMYADMIN for the navigation and creation of the database.        

5.8        MySQL for the Creation of the Database        

5.9        Java SDK 1.4.1        

6        PROTOTYPE EVALUATION        

6.1        Questionnaire        

6.2        Findings        

7        CONCLUSION        

Table of figures

Figure 1 The WAP programming Model (www.wapforum.com)        

Figure 2 The WAP programming Model (www.wapforum.com)        

Figure 3 WAP’s Optional Proxy Model Supports Network-Based Optimizations(www.wapforum.com)        

Figure 4 Example WAP Gateway (www.wapforum.com)        

Figure 5 Example WAP HTTP Proxy with Profiled TCP and HTTP(www.wapforum.com)        

Figure 6 Optional Dual WAP Stack Support (www.wapforum.com)        

Figure 7 Architecture Diagram (Gulliver)        

Figure 8 Rich Picture Example from (Wood-Harper)        

 Figure 9 Rich Picture Example a political cartoon from Bruce Petty (an Australian systems cartoonist)        

Figure 10 Rapid Application Development Diagram (http://www.bgsu.edu)        

Figure 11 Data Flow Diagram (WAP Banking Application)        

Figure 12 WAP Gateway (www.realwow.com)        

Figure 13 Microsoft Access Database (Service Pack 2)        

Figure 14 Nokia Toolkit 3.1        

Figure 15 Photoshop 7.0        

Figure 16 Editplus        

Figure 17 Dreamweaver MX        

Figure 18 Fireworks        

Figure 19 HTML 2 ANYCODE        

Figure 20 Java SDK 1.4 (www.java.sun.com)        

Figure 21 SUN ONE STUDIO        

Figure 22 Login / Register Screen(Welcome Screen)        

Figure 23 Registration Section        

Figure 24 Registration Section        

Figure 25 Registration Section        

Figure 26 Registration Section        

Figure 27 Registration Section        

Figure 28 Login Section        

Figure 29 Login Section        

Figure 30 Login Section        

Figure 31 Login Section        

Figure 32 Main Section Direct Debit        

Figure 33 Main Section Direct Debit        

Figure 34 Main Section Direct Debit        

Figure 35 Main Section Direct Debit        

Figure 36 Information Section(Contact Page)        

Figure 37 Login / Register Screen (Welcome Screen)        

Figure 46 Poster (A Mobile Application for Banking Processes)        

ACKNOWLEDGEMETNS

I would like especially to thank Dr Nik Bessi, my dissertation supervisor for his help and support throughout my completion of this piece of research, which without it would not have been made it possible. I would also like to thank SofiaMaria, Yianni, Mixali, Ifigeneia, Kouli, Efi , Thodori , Yianni, Teo, Kelly, Kosta, Ari, George, Ioanna, Niko, Tina and George for their emotional support. Last but not least I would like to thank the University of Luton for the help in producing this piece of research and of course my family for their emotional and financial support.

CHAPTER 1

  1. WAP

The Wireless Application Protocol (WAP) is an open, global specification that empowers mobile users with wireless devices to easily access and interact with information and services instantly. It is used to enable easy fast delivery of relevant information and services to mobile users. The devices that support WAP are Handheld digital wireless devices such as mobile phones, pagers, two-way radios, smartphones and communicators from low-end to high-end. Wap works with a variety of wireless networks such us

CDPD, CDMA, GSM, PDC, PHS, TDMA, FLEX, ReFLEX, iDEN, TETRA, DECT, DataTAC, Mobitex and GRPS. Also operating systems are compatible with WAP because it is a communications protocol and application environment. It can be built on any operating system including PalmOS, EPOC, Windows CE, FLEXOS, OS/9, JavaOS etc. It provides service interoperability even between different device families. The benefits  that WAP can provide are for different kind of users or business such as carriers.

WAP opens a host of opportunities for carriers to generate on-going revenue streams, secure customer loyalty and develop unique services that will allow differentiation from the competition. Also offers a broad market for developers one worldwide standard that is device-independent and bearer-independent assures developers of a broad, ever-expanding market for content and applications. WAP means increased sales for device, infrastructure and gateway manufacturers. The increasing popularity of WAP will generate tremendous demand for new devices to accommodate WAP's capabilities, new infrastructure to handle the increased demands on operator's systems and more gateways to handle the information flow between Internet and wireless operator networks. But what really WAP is, is  freedom to the end user it  offers an easy to use and highly portable communications and information tool. Devices using WAP-based microbrowsers can access an array of innovative, value added services, which are rapidly coming to market.

  1. The usefulness of WAP

Service providers must feel secure that their investments will yield benefits in the future. They will not be able to do so until equipment and software offered by different suppliers can be made to work together. The WAP specification has been designed to encourage easy, open interoperability between its key components. Any solution component built to be compliant with the WAP specification can interoperate with any other WAP-compliant component. Service providers can choose equipment and software from multiple WAP- compliant vendors, selecting each piece of the solution that is appropriate for the service provider’s particular needs. Bearer and device independence both help foster interoperability. But interoperability goes beyond these two principles to require that each WAP- compatible component will communicate with all other components in the solution network by using the standard methods and protocols defined in the specification. Interoperability provides clear benefits for handset manufacturers and infrastructure providers. Handset manufacturers are assured that if their device complies with the WAP specification it will be able to interface with any WAP-compliant server, regardless of the manufacturer. Likewise, the makers of a WAP-compliant server are assured that any WAP-compliant handset will interface correctly with their servers.

  1. Encourage and Foster Market Development

The WAP specification is designed to bring Internet access to the wireless mass market. By building open specifications, and encouraging communication and technical exchanges among the industry players, the WAP Forum has already begun to open the wireless data market in new ways. Just over a year ago, the idea of a single wireless data standard was unheard of, yet today the WAP specification  is available to the public, and dozens of companies are promoting this vision of the future. The revolution is under way to bring information access to any handset, at a reasonable price and in an easy to use form factor. Providing Internet and Web-based services on a wireless data network presents many challenges to wireless service providers, application developers and handset manufacturers. While the obvious limitations are rooted in the nature of wireless devices and data networks, there are also more fundamental differences that are important to understand. The next few sections outline the challenges that must be overcome to make wireless Internet access appealing to the average wireless subscriber.

The Market Is Different Bringing computing power to a wireless handset opens an extensive new market for information access.  This market is very different from the traditional desktop or even the laptop market because the subscriber has a different set of needs and expectations. Some of these differences include:

  • Ease of use: Despite the fact that using a desktop computer has become progressively easier over the last five years, a wireless computing device must be dramatically easier to use than even the simplest desktop computer. These devices will be used by people who potentially have no desktop computing experience. Furthermore, they will often be used in a dynamic environment where the user is engaged in multiple activities. Subscribers won’t be focused on their handset the way they are when they are sitting in front of a desktop computer. Therefore, the devices must be extremely simple and easy to use. Applications built for these devices must therefore present the best possible user interface for quick and simple usage. There can be no installation scripts, complicated menu structure, application errors, general protection faults or complicated key sequences such as ctrl-alt-del, or alt-shift-F5.
  • Market size: The growth and size of the wireless subscriber market has been phenomenal.  According to Global Mobile magazine, there are more than 200 million wireless subscribers in the world today. According to Nokia, there will be more than one billion wireless subscribers by the year 2005. The wireless market is enormous: it can afford and will demand optimized solutions.
  • Price sensitivity: Even with today’s sub-$1000 computers, a price difference of $50 between two models is not considered significant. However, a difference of $50 between two handsets is very significant, especially after years of subsidized handset pricing by the service provider. Market studies have shown that a mass-market handset must be priced under $149 to be competitive. A solution must add significant value at a low cost to be effective in this market.
  • Usage patterns: Subscribers expect wireless data access to perform like the rest of their handset: The service should be instantly available, easy to use and designed to be used for a few minutes at a time. Hourglass icons telling subscribers to wait will not be acceptable.
  • Essential tasks: As soon as professionals step out of the office, information needs and desires change. Wireless Internet subscribers will not want to use their handset to "surf the Internet." They will have small, specific tasks that need to be accomplished quickly. Subscribers will want to scan Email rather than read it all, or see just the top stock quotes of interest. Receiving timely traffic alerts on the handset will be essential, whereas the same information may not be as valuable at the desktop. The best applications will give the user a comprehensive, personalized summary of important information and will allow them to easily drill down for more detailed information.

The Network Is Different Wireless data networks present a more constrained communication environment compared to wired networks. Because of fundamental limitations of power, wireless data networks tend to have: Less bandwidth More latency Less connection stability Less predictable availability Furthermore, as bandwidth increases, the handset’s power consumption also increases which further taxes the already limited battery life of a mobile device. Therefore, even as wireless networks capitalize on higher bandwidth, the power of a handset will always be limited by battery capacity and size, thus challenging the amount of data throughput. Deployment of the WAP standard will accommodate more users per MHz since it uses the available bandwidth at an extremely efficient level. The result of placing more users on a given amount of spectrum can yield lower costs for both the network provider and the customer. A wireless data solution must be able to overcome these network limitations and still deliver a satisfactory user experience.

The Device Is Different Similarly, mass-market, handheld wireless devices present a more constrained computing environment compared to desktop computers. Because of fundamental limitations of battery life and form factor, mass- market handheld devices tend to have:

Less powerful CPUs Less memory (ROM and RAM) Restricted power consumption Smaller displays Different input devices (e.g., a phone keypad, voice input, etc.) Because of these limitations, the user interface of a wireless handset is fundamentally different than that of a desktop computer. The limited screen size and lack of a mouse requires a different user interface metaphor than the traditional desktop GUI. These conditions are not likely to change dramatically in the near future. The most popular wireless handsets have been designed to be lightweight and fit comfortably in the palm of a hand. Furthermore, consumers desire handsets with longer battery life, which will always limit available bandwidth, and the power consumption of the CPU, memory and display. Because there will always be a performance gap between the very best desktop computers and the very best handheld devices, the method used to deliver wireless data to these devices will have to effectively address this gap. As this gap changes over time, standards will have to continually evolve to keep pace with available functionality and market needs. The WAP specification is a major achievement because it defines for the first time an open, standard architecture and set of protocols intended to implement wireless Internet access. It also provides solutions for problems not solved by other standardization bodies (e.g. W3C, ETSI, TIA, IETF, etc.) and is a catalyst for wireless development and standardization. The key elements of the WAP specification include: definition of the WAP Programming Model as seen in Figure 1 (shown on followoing page), which is based heavily on the existing WWW Programming Model. This provides several benefits to the application developer community, including a familiar programming model, a  

Figure 1 The WAP programming Model (www.wapforum.com)

proven architecture and the ability to leverage existing tools (e.g., Web servers, XML tools, etc.). Optimizations and extensions have been made in order to match the characteristics of the wireless environment. Wherever possible, existing standards have been adopted or have been used as the starting point for WAP technology.

The WAP Forum is proud to release version 2.0 of the Wireless Application Protocol (WAP). WAP 2.0 brings the wireless world closer to the Internet with a suite of specifications that utilizes technologies that will enhance the wireless user experience. With this evolutionary release, the WAP specifications will continue as the de facto

standard for wireless applications and services delivered across a wide range of devices.

WAP 2.0: Bringing Wireless Closer to the Internet

  1. WAP 2.0: Bringing Wireless Closer to the Internet

With the release of WAP 2.0, the WAP Forum has successfully accomplished several objectives: Add support for the standard Internet communication protocols. WAP 2.0 provides support for protocols such as IP, TCP and HTTP. By adding these Internet protocols and standards and providing interoperable optimizations suitable to the wireless telecommunications environment, the WAP specifications provide an environment that permits wireless devices to utilize existing Internet technologies.

  • Continue the work of WAP 1.x by permitting applications and services to operate over all existing and foreseeable air interface technologies and their bearers: This includes the new, higher-speed technologies known as General Packet Radio Service (GPRS) and 3rd Generation (3G) cellular.
  • Provide a rich application environment, which enables delivery of information and interactive services to digital mobile phones, pagers, personal digital assistants (PDAs) and other wireless devices.
  • Address unique characteristics of wireless devices. These devices have hardware factors (e.g. smaller screens, limited battery life, and limited RAM and ROM) and user interface considerations, such as one-finger navigation, that challenge traditional Internet application design. The WAP environment provides many features that enhance this experience.
  • Minimize the use of device processing power and optimize network resources in order to minimize costs and maximize performance.
  • Incorporate flexibility, enabling a variety of user interface (UI) designs for manufacturers to differentiate themselves according to device form factor and target market requirements.

The WAP Forum works closely with organizations such as the World Wide Web Consortium (W3C) and the Internet Engineering Task Force (IETF) to develop specifications that meet the objectives listed above.

  1. What Is New: WAP 2.0 is an Evolutionary Step Forward

The WAP Forum released its first specification – WAP 1.0 – in 1998. In subsequent WAP specification releases, the WAP Forum addressed interoperability, established a certification program, and added various features in response to changes in market requirements and improvements in networks, devices and new technologies. WAP 2.0 is a next-generation set of specifications that, like previous releases, marks the WAP Forum's ongoing efforts to adopt the most recent Internet standards and protocols. WAP 2.0 also optimizes usage of higher bandwidths and packet-based connections of wireless networks worldwide. While utilizing and supporting enhancements in the capabilities of the latest wireless devices and Internet content technologies, WAP 2.0 also provides managed backwards compatibility to existing WAP content, applications and services that comply to previous WAP versions. The following items represent the major architectural components of WAP 2.0:

  • Protocol Stack Support – In addition to the WAP Stack introduced in WAP 1, WAP 2.0 adds support and services on a stack based on the common Internet stack including support for TCP, TLS and HTTP. By encompassing both stacks, WAP 2.0 provides a connectivity model on a broader range of networks and wireless bearers.
  • WAP Application Environment – Nominally viewed as the 'WAP Browser', the WAP 2.0 Application Environment has evolved to embrace developing standards for Internet browser markup language. This has led to the definition of the XHTML Mobile Profile (XHTMLMP). XHTMLMP is based on the modularity framework of the eXtensible HyperText Markup Language (XHTML) developed by the W3C to replace and enhance the currently used HTML language common today. The use of Internet technologies is not new for WML, as WML1 is a fully conformant XML language in its own right.
  • Additional Services and Capabilities – The WAP specifications have had items that were neither part of the 'WAP Stack' nor the 'WAP Browser' but helped to enrich the environment defined in the WAP specifications. With WAP 2.0, there is a considerable increase in the number of features available to developers, operators and users. These will be discussed more fully later in the document.
  1. Alignment with New Technologies and Standards

WAP protocols are largely based on Internet technologies. The motivation for developing WAP was to extend Internet technologies to wireless networks, bearers and devices. Just as earlier versions of WAP anticipated developments in image displays, public-key infrastructure (PKI) and end-to-end security, messaging, push technology, and a number of W3C and IETF standards, WAP 2.0 capitalizes on a wide range of new technologies

and advanced capabilities, such as:

  • Networks and Network Bearers – Carriers worldwide are upgrading their existing networks with higher-speed

bearers such as General Packet Radio Service (GPRS) and High-Speed Circuit-Switched Data (HSCSD) and introducing higher bandwidths and speeds in third-generation (3G) wireless networks such as W-CDMAand CDMA2000 3XRTT. These higher capable network bearers permit new types of content (e.g., streaming media) and provide an 'always on' availability. These new aspects of the serving networks permit new operational activities.

  • TCP/IP as Transport Protocol – Most new wireless network technologies provide IP packet support as a basic data transport protocol. WAP 2.0 leverages IETF work in the Performance Implications of Link Characteristics (PILC) Working Group to develop a mobile profile of TCP for wireless links. This profile is fully interoperable with the 'common' TCP that operates over the Internet today.
  • Processors – Manufacturers continue to introduce smaller devices with faster and more power-efficient processors and dipoles that are higher-definition and in color. Additionally, more efficient packaging technology permits smaller integrated circuits and more sophistication in a given size of device. The net effect is that new

wireless devices have more capabilities that can be leveraged to enhance the services delivered to the user.

  • Mobile-friendly Technologies – With the growth in usage of mobile devices, there is an increased awareness of the needs specific to the mobile user. The WAP Forum has worked with the W3C and the IETF to help characterize the key issues that impact wireless usage of the web. Through that involvement, and from the interest of their own membership, the W3C has lately presided over advances in more mobile-friendly technologies, including:
  • The release in late 2000 of the recommendation for the Basic profile for the Extensible Hypertext Markup Language (XHTML). This Basic profile incorporates the core elements of the XHTML language, which provides a framework for expandability and enhancement.
  • Recent updates to the Composite Capabilities/Preference Profiles (CC/PP) framework for describing user preferences and device capabilities. CC/PP provides the technical basis for the UAPROF device profile function.
  • The release of the Cascading Style Sheets (CSS) Mobile Profile provides a subset of CSS version 2 that is targeted at devices such as smart phones, personal digital assistants (PDAs) etc.

  1. WAP 2.0 Components: Application Support, Protocol Stack and More

  1.  Wireless Application Environment

The Wireless Application Environment (WAE) provides for interaction between WAP/Web applications and wireless devices containing a WAP microbrowser.

WAP 2.0 provides the foundation for such a microbrowser in its markup languages, namely the XHTML Mobile Profile markup language (XHTMLMP) for new content and WML to support legacy WAP V1 content. These markup languages provide the appropriate presentational services for wireless devices, while capitalizing on their

unique advantages. The accompanying client-side scripting language, WMLScript, provides for additional intelligence and control over presentation. To improve the efficiency of transmission and client implementation for the handling of both WML and WMLScript, WAE supports tokenisation of WML1 and the compilation of WMLScript before the gateway sends the content to the device. In addition to specifying the markup language, WAE provides for other content types, such as WBMP images, vCard and vCalendar. The WAE in WAP 2.0 continues to support an application-centric approach by defining XHTML Mobile Profile and several other associated technologies and includes the following elements:

  • The basic markup language for the WAE in WAP 2.0, namely XHTMLMP, extends the Basic profile of XHTML as defined by the W3C. This core was designed to be extensible and WAE takes advantage of this capability by defining additional markup features for enhanced functionality. By using the XHTML modularization approach, the XHTMLMP language is very extensible, permitting additional language elements to be added as

needed. Additionally, documents written in the core XHTML Basic language will be completely operable on the XHTMLMP browser.

  • The WAE in WAP 2.0 also enhances the presentation of content by supporting style sheets. Based on the Mobile profile of CSS from the W3C, WAP support covers both inline and external style sheets, which are commonly supported by most Internet browsers.
  • Full backwards compatibility support for WML1 applications is provided in the WAE for WAP 2.0 through either native support for both languages (WML1 and XHTMLMP) or by a defined transformation operation of WML1 to WML version 2. The WML2 language is an extension of XHTMLMP that adds specific features of WML1 for backward compatibility. The transformation process provides for the conversions, such as names and attributes, from WML1 to XHTMLMP as well as the support for the WML1 specific features. The WAP 2.0 release provides a transformation model, using eXtensible Stylesheet Language Transformation (XSLT), that will permit documents defined in WML1 language to be converted to WML2 code which would then operate on

a supporting browser. The special extensions in WML2 are intended only to support conversions of WML1 documents and not for general authoring use. These changes will let devices accept both content written for other Internet clients in XHTML Basic and

applications and content written specifically to take advantage of the WML extension features. Enabling backwards compatibility protects investments in WAP 1 content.

  1. WAP Programming Model

The WAP Programming Model, closely aligned with the Web Programming Model, uses the Pull Model, (which is where the client requests content from the server). However, WAP also extends the Web architecture by adding telephony support with WTA and enabling a Push Model, where a server can proactively send content to the client.

Figure 2 The WAP programming Model (www.wapforum.com)

In previous versions of WAP, a WAP proxy (often referred to as a WAP gateway) was required to handle the protocol interworking between the client and the origin server. The WAP proxy communicated with the client using the WAP protocols that are based largely on Internet communication protocols, and it communicated with the origin server using the standard Internet protocols. WAP 2.0 does not require a WAP proxy, since the

communication between the client and the origin server can be conducted using HTTP/1.1. However, deploying a WAP proxy can optimize the communications process and may offer mobile service enhancements, such as location, privacy, and presence based services. In addition, a WAP proxy is necessary to offer Push functionality.

Figure 3 WAP’s Optional Proxy Model Supports Network-Based Optimizations(www.wapforum.com)

  1. WAP Protocol Stack

A key part of the WAP 2.0 release is the introduction of support for Internet protocols when IP connectivity is available to the mobile device. This is in addition to continued support for the legacy 'WAP Stack,' which is used over those networks that do not provide IP as well as low-bandwidth IP bearers. Both stacks are supported in WAP

2.0 and provide similar services to the application environment.

  1. Legacy Protocol Layers

The WAP 2.0 release continues support for the 'WAP 1 Stack'. These protocols have been optimized for low bandwidth bearer networks with relatively long latency.

  • Wireless Session Protocol (WSP) – WSP provides HTTP/1.1 functionality and incorporates new features, such as long-lived sessions and session suspend/resume. WSP provides the upper-level application layer of WAP with a consistent interface for two session services. The first is a connection-mode service that operates above

the transaction layer protocol, and the second is a connectionless service that operates above a secure or non secure datagram transport service.

  • Wireless Transaction Protocol (WTP) – WTP has been defined as a light weight transaction oriented protocol that is suitable for implementation in "thin" clients (mobile stations) and operates efficiently over wireless datagram networks. The benefits of using WTP include:

_ Improved reliability over datagram services. WTP relieves the upper layer from re-transmissions and acknowledgements that are necessary when datagram services are used.

  • Improved efficiency over connection oriented services. WTP has no explicit connection set up or tear down phases.
  • Advantage of using a message oriented protocol, designed for services oriented towards transactions, such as "browsing."
  • Wireless Transport Layer Security (WTLS) – The WTLS layer is designed to provide privacy, data integrity and authentication between two communicating applications. It provides the upper-level layer of WAP with a secure transport service interface that preserves the transport service interface below it. In addition, WTLS

provides an interface for managing (e.g., creating and terminating) secure connections. It provides a functionality similar to TLS 1.0 and incorporates additional features such as datagram support, optimized handshake and dynamic key refreshing.

  • Wireless Datagram Protocol (WDP) – WDP is a general datagram service, offering a consistent service to the upper layer protocols and communicating transparently over one of the available underlying bearer services. This consistency is provided by a set of adaptations to specific features of these bearers. This thus provides a common

interface to the upper layers that are then able to function independently of the services of the wireless network. The following figure shows how this legacy stack operates between the WAP Devices and the WAP Gateway. In the figure, the WAP Gateway interconnects the services offered by WSP to the HTTP protocol to permit access to data on the wired Internet.

Figure 4 Example WAP Gateway (www.wapforum.com)

  1. Protocol Layers for Networks Supporting IP

A key feature of WAP 2.0 is the introduction of Internet protocols into the WAP environment. This support has been motivated by the emergence of high-speed wireless networks (e.g. 2.5G and 3G) that provide IP support directly to the wireless devices.

  • Wireless Profiled HTTP (WP-HTTP) – WP-HTTP specification is a profile of HTTP for the wireless

environment and is fully interoperable with HTTP/1.1. The basic model of interaction between the WAP Device and WAP Proxy/WAP Server is the HTTP request/response transaction. WP-HTTP supports message body compression of responses and the establishment of secure tunnels.

  • Transport Layer Security (TLS) – A wireless profile of the TLS protocol will permit interoperability for secure transactions. This profile for TLS includes cipher suites, certificate formats, signing algorithms and the use of session resume. The profile also defines the method for TLS tunneling to support end-to-end security at

the transport level.

  • Wireless Profiled TCP (WP-TCP) – WP-TCP provides connection-oriented services. It is optimized for wireless environments and is fully interoperable with standard TCP implementations in the Internet. Research in optimizing TCP has resulted in a number of mechanisms to improve performance. This includes work by the IETF PILC group that has recommended the use of some of these mechanisms for TCP implementations in long

thin networks. These have been documented in Standards Track RFCs and have been accepted by the Internet community as useful and technically stable. The following figure shows an example usage of these protocols from the WAP Device to the Web Server. In this example, a TLS tunnel is enabled through an intervening WAP Proxy permitting secure, end-to-end HTTP transactions. The TCP* is a reference to end points that operate using the features of the wireless profiled TCP.

Figure 5 Example WAP HTTP Proxy with Profiled TCP and HTTP(www.wapforum.com)

Since WAP 2.0 provides support for both stacks, it should be noted that it is expected that these stacks would operate independently. That is, there would not be mixing and matching of protocols in accomplishing an end-to end transaction. The following figure shows the separation of these stacks.

Figure 6 Optional Dual WAP Stack Support (www.wapforum.com)

The figure shows the expectation that a common application environment could operate over either stack. For devices that will be supporting both old and new network types, this switching of stacks may occur as the device moves in and out of coverage of the different network areas.

  1. WAP 2.0 Adds New and Enhanced Services

In addition to the application environment and the increases in capability of the micro-browser, WAP 2.0 also supports other features to improve the user experience. These features expand the capabilities of the wireless devices and improve the ability to deliver useful applications and services. Some of these additional features of the WAP 2.0 release are:

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  • WAP Push – This service allows content to be sent or "pushed" to devices by server-based applications via a Push Proxy. This functionality has been enhanced for the WAP 2.0 release. Push functionality is especially relevant to real-time applications that send notifications to their users, such as messaging, stock price and traffic update alerts. Without push functionality, these types of applications would require the devices to poll

application servers for new information or status. In wireless environments such polling activities would constitute inefficient and wasteful use of the resources of wireless networks. WAP's Push functionality provides control over ...

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