Wireless Application Protocol (WAP)
Rob Crowley


Table Of Contents

PartPage

INTRODUCTION............................................................................................. 1

WHAT IS WAP?............................................................................................... 2

WAP Services........................................................................................ 2

WAP Forum........................................................................................... 3

HOW WAP WORKS?...................................................................................... 4

WHY CHOOSE WAP?..................................................................................... 5

ARCHITECTURE.............................................................................................. 6

The World Wide Web Model................................................................. 6

The WAP Model.................................................................................... 8

COMPONENTS OF THE WAP ARCHITECTURE......................................... 10

Application Layer (WAE)....................................................................... 11

Session Layer (WSP).............................................................................. 11

Wireless Transaction Protocol (WTP)..................................................... 12

Wireless Transport Layer Security (WTLS)............................................. 12

Wireless Datagram Protocol (WDP)........................................................ 12

WAP SECURITY.............................................................................................. 12

The WAP Gap........................................................................................ 14

WAP DEVELOPMENT ISSUES...................................................................... 15

Push Not Supported............................................................................... 16

Lack of Cookies For Session Management.............................................. 16

Premature Encryption Endpoint............................................................... 16

Small Downloadable Unit Size................................................................. 17

WDP Datagram Protocol........................................................................ 17

THE FUTURE OF WAP.................................................................................... 18

WAP 2.0............................................................................................................ 19

New Services of WAP 2.0...................................................................... 19

CONCLUSION................................................................................................. 22

REFRENCES..................................................................................................... 24



LIST OF CHARTS

ChartsPage

1.World Wide Web Programming Model.......................................................... 6

2.WAP Programming Model............................................................................. 8

3.WAP Architecture......................................................................................... 10



INTRODUCTION

According to industry analysts there will be more than 530 million wireless subscribers by the year 2001. New estimates report that the number of wireless subscribers will break the one billion mark by 2004, and a "substantial portion of the phones sold that year will have multimedia capabilities." These multimedia capabilities include the ability to retrieve Email, and have the ability to push and pull information from the Internet. In order to guide the development of these exciting new applications, the leaders of the wireless telecommunications industry formed the Wireless Application Protocol Forum (“Wireless Internet Today” 2001).

The Wireless Application Protocol (WAP) is the de-facto world standard for the presentation and delivery of wireless information and telephony services on mobile phones and other wireless terminals. Handset manufacturers representing 90 percent of the world market across all technologies have committed to shipping WAP-enabled devices.

Carriers representing more than 100 million subscribers worldwide have joined the WAP Forum.This commitment will provide 10’s of millions of WAP browser-enabled products to consumers by the end of 2001.WAP allows carriers to strengthen their service offerings by providing subscribers with the information they want and need while on the move.Infrastructure vendors will deliver the supporting network equipment.Application developers and content providers delivering the value added services are contributing to the WAP specification.Enabling information access from handheld devices requires a deep understanding of both technical and market issues that are unique to the wireless environment.

The WAP specification was developed by the industry’s best minds to address these issues. Wireless devices represent the ultimate constrained computing device with limited CPU, memory, and battery life, and a simple user interface. Wireless networks are constrained by low bandwidth, high latency, and unpredictable availability and stability. However, most important of all, wireless subscribers have a different set of essential desires and needs than desktop or even laptop Internet users.WAP-enabled devices are companion products that will deliver timely information and accept transactions and inquiries when the user is on the go.WAP services provide pinpoint information and delivery when the full screen environment is either not available or not necessary.

WHAT IS WAP?

Wireless application protocol (WAP) is an application environment and set of communication protocols for wireless devices that were designed to enable manufacturer, vendor, and technology-independent access to the Internet and advanced telephony services.WAP simply bridges the gap between the mobile world and the Internet as well as corporate intranets and offers the ability to deliver an unlimited range of mobile value-added services to subscribers independent of their network, bearer, and terminal.Mobile subscribers can access the same wealth of information from a pocket-sized device as they can from their own personal computers. Wireless Application Protocol (WAP) is a result of continuous work to define an industry-wide specification for developing applications that operate over wireless communication networks (Pedersen, 2000)

The WAP Forum released its first specification - WAP 1.0 - in 1998. In subsequent WAP specification releases, the WAP Forum addressed ease of use, established a certification program, and added various features in response to changes in market requirements and improvements in networks, devices and new technologies.

WAP Services

WAP services must be used on a WAP enabled phone.These services are

usually available through all major cellular network subscribers.Prices for retrieving information off of the Internet via your cell phone, PDA smart phone, etc vary accordingly through the different cellular providers.Listed below are some of the WAP services available:

WAP Forum

Wireless access protocol (WAP) is an open specification that offers a standard method to access Internet-based content and services from wireless devices such as mobile phones.WAP was invented and is driven by the WAP Forum – a group originally formed by Nokia, Ericsson, Motorola and Phone.com in 1997.The WAP Forum now has 500 member companies who make up 95% of handset manufacturers, carriers equating to 100 million subscribers worldwide including infrastructure providers, software developers and many other companies providing solutions in the wireless space (WAP forum.org)

The benefits of using WAP include:

·Non-proprietary method to access Internet-based content and services

·Network independent

·Extensive industry adoption

HOW WAP WORKS?

The WAP model is very similar to the traditional Internet model.The mobile device contains an embedded WAP browser that connects to a WAP gateway.The WAP gateway is a software infrastructure residing between the wireless network and the Internet.It optimizes the transmission of content for the wireless network and makes requests for information from web servers in the normal form of a URL.The content for WAP devices is stored on enterprise web servers.WAP content is written in a markup language called wireless markup language (WML) and is formatted suitably for the mobile phone or PDA’s with small screens and low bandwidth and high latency connection.(Fitzgerald & Dennis, 2001)

The wireless market is growing very quickly and reaching new customers and services. To enable operators and manufacturers to meet the challenges in advanced services, differentiation, and fast/flexible service creation, WAP defines a set of protocols in transport, session, and application layers.WML is a markup language based on [XML] and is intended for use in specifying content and user interface for narrowband devices, including cellular phones and pagers.WML is designed with the constraints of small narrowband devices in mind (Jerome, 2000).

These constraints include:

WHY CHOOSE WAP?

In the past, wireless Internet access has been limited by the capabilities of handheld devices and wireless networks.WAP utilizes Internet standards such as XML, user datagram protocol (UDP), and Internet protocol (IP).Many of the protocols are based on Internet standards such as hypertext transfer protocol (HTTP) and TLS but have been optimized for the unique constraints of the wireless environment: low bandwidth, high latency, and less connection stability. 

Internet standards such as hypertext markup language (HTML), HTTP, TLS and transmission control protocol (TCP) are inefficient over mobile networks, requiring large amounts of mainly text-based data to be sent.Standard HTML content cannot be effectively displayed on the small-size screens of pocket-sized mobile phones and pagers.

WAP utilizes binary transmission for greater compression of data and is optimized for long latency and low bandwidth.WAP sessions cope with intermittent coverage and can operate over a wide variety of wireless transports. 

WML and wireless markup language script (WMLScript) are used to produce WAP content. They make optimum use of small displays, and navigation may be performed with one hand.WAP content is scalable from a two-line text display on a basic device to a full graphic screen on the latest smart phones and communicators.

The lightweight WAP protocol stack is designed to minimize the required bandwidth and maximize the number of wireless network types that can deliver WAP content. Multiple networks will be targeted, with the additional aim of targeting multiple networks.These include global system for mobile communications (GSM) 900, 1,800, and 1,900 MHz; interim standard (IS)–136; digital European cordless communication (DECT); time-division multiple access (TDMA), personal communications service (PCS), FLEX, and code division multiple access (CDMA). All network technologies and bearers will also be supported, including short message service (SMS), USSD, circuit-switched cellular data (CSD), cellular digital packet data (CDPD), and general packet radio service (GPRS).

As WAP is based on a scalable-layered architecture, each layer can develop independently of the others.This makes it possible to introduce new bearers or to use new transport protocols without major changes in the other layers (“Why Choose WAP”, 2000).

ARCHITECTURE

The World Wide Web Model

The Internet World-Wide Web (WWW) architecture provides a very flexible and powerful programming model (Figure 1). Applications and content are presented in standard data formats, and are browsed by applications known as web browsers.The web browser is a networked application, i.e., it sends requests for named data objects to a network server and the network server responds with the data encoded using the standard formats (Pedersen, 2000).

Figure 1.World Wide Web Programming Model

The WWW standards specify many of the mechanisms necessary to build a general-purpose application environment, including:

·Standard naming model – All servers and content on the WWW are named with an Internet-standard Uniform Resource Locator (URL). 

·Content typing – All content on the WWW is given a specific type thereby allowing web browsers to correctly process the content based on its type. 

·Standard content formats – All web browsers’ support a set of standard content formats. These include the Hypertext Markup Language (HTML) [HTML4], the JavaScript scripting language [ECMAScript, JavaScript], and a large number of other formats.

·Standard Protocols – Standard networking protocols allow any web browser to communicate with any web server.The most commonly used protocol on the WWW is the Hypertext Transport Protocol (HTTP).

This infrastructure allows users to easily reach a large number of third-party applications and content services. It also allows application developers to easily create applications and content services for a large community of clients.

The WWW protocols define three classes of servers:

requesting client may not be aware that it is communicating with a gateway (Pedersen, 2000).
The WAP Model

The WAP programming model (Figure 2) is similar to the WWW programming model. This provides several benefits to the application developer community, including a familiar programming model, a 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 the WAP technology (Pedersen, 2000).

Figure 2.WAP Programming Model

WAP content and applications are specified in a set of well-known content formats based on the familiar WWW content formats. Content is transported using a set of standard communication protocols based on the WWW communication protocols.A micro browser in the wireless terminal co-ordinates the user interfaces and is similar to a standard web browser.

WAP defines a set of standard components that enable communication between mobile terminals and network servers, including:

This allows WAP user agents to correctly process the content based on its type.
The WAP content types and protocols have been optimized for mass market, hand-held wireless devices. WAP utilizes proxy technology to connect between the wireless domain and the WWW.The WAP proxy typically is comprised of the following functionality:
·Content Encoders and Decoders – The content encoders translate WAP content into compact encoded formats to reduce the size of data over the network.

This infrastructure ensures that mobile terminal users can browse a wide variety of WAP content and applications, and that the application author is able to build content services and applications that run on a large base of mobile terminals. The WAP proxy allows content and applications to be hosted on standard WWW servers and to be developed using proven WWW technologies such as CGI scripting.While the nominal use of WAP will include a web server, WAP proxy and WAP client, the WAP architecture can quite easily support other configurations (Pedersen, 2000).

It is possible to create an origin server that includes the WAP proxy functionality.Such a server might be used to facilitate end-to-end security solutions, or applications that require better access control or a guarantee of responsiveness.

COMPONENTS OF THE WAP ARCHITECTURE

The WAP architecture provides a scaleable and extensible environment for application development, and for mobile communication devices. This is achieved through a layered application development for mobile communication devices.This is achieved through a layered design of the entire protocol stack (Figure 3). Each of the layers of the architecture is accessible by the layers above, as well as by other services and applications.

Figure 3.WAP Architecture

The WAP layered architecture enables other services and applications to utilize the features of the WAP stack through a set of well-defined interfaces.External applications may access the session, transaction, security and transport layers directly.The WAP protocols are designed to operate over a variety of different bearer services, including short message,

circuit-switched data, and packet data.The bearers offer differing levels of quality of service with respect to throughput, error rate, and delays.The WAP protocols are designed to compensate for or tolerate these varying levels of service. 

Since the WDP layer provides the convergence between the bearer service and the rest of the WAP stack, the WDP specification [WDP] lists the bearers that are supported and the techniques used to allow WAP protocols to run over each bearer.The list of supported bearers will change over time with new bearers being added as the wireless market evolves.The following sections provide a description of the various elements of the protocol stack architecture (Mitchell, “Introduction to WAP”).

Application Layer (WAE)

The WAE defines the user interface on the phone.The application development environment facilitates the development of the services that support multiple bearers. To achieve this, WAE contains the Wireless Markup Language (WML), WML Script - a scripting micro-language similar to JavaScript- and the Wireless Telephony Application (Buckingham, 2000).

Session Layer (WSP)

A layer that links the WAE to two session services.This layer is one connection oriented and operates above the Wireless Transaction Protocol through a connectionless service above the Wireless Datagram Protocol (Buckingham, 2000).

Wireless Transaction Protocol (WTP)

Runs on top of a datagram service such as User Datagram Protocol (UDP), part of the standard suite of TCP/IP protocols, to provide a simplified protocol suitable for low bandwidth mobile stations.WTP offers three classes of transaction service: unreliable one way request, reliable one way request and reliable two way request respond.WTP supports Protocol Data Unit concatenation and delayed acknowledgement to help reduce the number of messages sent.

This protocol therefore tries to optimize the user experience by providing the information that is needed (it can be confusing to receive confirmation of delivery messages when you are expecting the information itself).By stringing several messages together, the end user may well be able to get a better feel more quickly for what information is being communicated (Buckingham, 2000).

Wireless Transport Layer Security (WTLS)

WTLS incorporates security features that are based upon the established Transport Layer Security (TLS) protocol standard.It provides data integrity checks, privacy on the WAP Gateway to client leg and authentication (Buckingham, 2000).

Wireless Datagram Protocol (WDP)

Allows WAP to be bearer independent by adapting the transport layer of the

underlying bearer.WDP presents a consistent data format to the higher layers of the WAP protocol stack thereby conferring the advantage of bearer independence to application developers (Buckingham, 2000).

WAP SECURITY

Wireless Transport Layer Security, or WTLS, provides the main security elements of

WAP communications.It is by using the WTLS protocol that some measure of authentication and confidentiality in wireless applications. As mentioned earlier, WTLS is the wireless version of the industry standard Transport Layer Security (TLS), which is equivalent to the widely used SSL security protocol. The Internet's TLS establishes a secure network connection session between a client and a server, typically between a Web browser and a Web server.WTLS provides a secure network connection session between a WAP device and a WAP gateway.WTLS was developed because of the special needs of the high-latency, low-bandwidth wireless environment (Buckingham, 2000).

The kernel of WTLS security is in the Wireless Identity Module (WIM).The WIM performs the optimized cryptography during the handshaking process, especially for client authentication, and forges long-term, secure WTLS connections.WTLS can initiate a secure session by using an optimized handshake with dynamic key refreshing.Dynamic key refreshing allows encryption keys to be updated on a regular and configurable basis during a secure session. This not only provides a higher level of security, but also provides significant bandwidth savings on the relatively costly handshaking procedure (Howell, “WAP Security”).

The WTLS protocol is composed of three layers: 

·The handshake protocol layer

·The record layer

·The alert layer

The handshake protocol layer manages the secure connections and key exchanges, and provides client and server authentication.The record layer handles privacy and data integrity, and the alert layer reports error conditions and handles the close alert.

The handshake protocol takes place when the client and server first start communicating,

and is where they agree on a protocol version, select cryptographic algorithms, authenticate each other, and use public-key encryption to generate a shared secret.First, the client and server exchange hello messages, which is where they agree on algorithms.Then they exchange the necessary cryptographic parameters, and certificates.The handshake layer provides the security parameters to the record layer (Stewart, 2000)

The WAP Gap

WAP security issues center on encryption and a phenomenon known as the "WAP GAP." The variety of mobile devices supported by WAP makes it difficult for the protocol to provide consistent and high levels of security across all device types.However, if implemented according to the WAP specification, the handoff performed between the WTLS security layer and the SSL layer at the WAP gateway creates a momentary lapse ("gap") in security, a lapse that has now been rectified by several commercial software solutions (Zafar, “The WAP Gap”).

Because the WAP protocol has been developed to support a wide range of mobile devices, it allows the client and server to negotiate and choose from many encryption methods. WAP servers provide support for many kinds of algorithms, including those that can accommodate weak mobile devices with limited processing power, memory and bandwidth. This accommodation can result in weak encryption and poor security.The only solution to this encryption challenge is to avoid using weak mobile devices for secure enterprise applications. The WAP server for enterprise applications should be configured to use only strong encryption methods and deny access to devices requesting weak encryption.

The '"WAP GAP’" is a security concern raised by many security professionals. WTLS protects the communication between a WAP handset and the WAP gateway, and SSL usually protects the connection between the WAP server and the web server.There is a split second, however, when the data must be decrypted and then re-encrypted to switch from one protocol (WTLS) to the other (SSL). Security could be compromised if someone were able to crash the machine in the split second between decryption and re-encryption, causing a memory dump to disk.This situation is known as "WAP GAP."

Many vendors such as Phone.com, Cylink and RSA provide custom WAP gateway software that takes care of the "WAP GAP" security issue by enabling end-to-end encryption between the web server and the WAP client.These gateway software solutions use designs that are currently under discussion at the WAP forum but are not yet part of any approved WAP specification. Moreover, the "WAP GAP" is not vulnerable to easy attack as it takes place within the secure premises of the service provider hosting the WAP gateway.Enterprises usually inspect security settings around third party WAP gateways thoroughly before hosting their WAP applications on them (Zafar, “The WAP Gap”).

Only if the security requirements of an enterprise WAP-based wireless application are extremely high, should a company use a custom WAP gateway.For example, a wireless application transmitting publicly available stock quotes would not need a custom WAP gateway whereas an application transferring financial funds would.

WAP DEVELOPMENT ISSUES

WAP version 1.2 may be the first version of the protocol that is actually workable in terms of delivering easy to use and innovative non-voice mobile services.WAP version 1.2 is expected to be finalized as a specification in late 1999 and first available in spring 2000.It will support Push services (proactive delivery of information from a WAP Gateway to a WAP terminal), User Profiles, WDP Tunneling, WMLscript, CryptoLibrary, Wireless Telephony Application, Wireless Application Environment enhancements and other features. There are several non-standardized or unresolved issues relating to WAP that application developers should be aware of:

Push Not Supported

The WAP WSP specification defines the WSP push operation and a WSP push PDU (Protocol Data Unit). A push operation is not specified for the HTTP protocol, used by the WAP Gateway server to communicate with content hosts.To support pushes, the server has to provide an application interface to allow server based applications to generate a push to a mobile client. The support of pushes on the client side depends on the capabilities of the handsets to handle pushed content. The Nokia OTA configuration proposal to the WAP Forum describes the use of a connectionless push over the SMS bearer, to transfer the configuration data to the handset (“WAP Development Issues”, 1998).

Lack of Cookies For Session Management

There are no "cookies" for session management, i.e. to hold the session together. Cookies are used on the fixed Internet to identify the web browser and thereby assist in providing customized and streamlined services. Instead, some WAP applications use indexes in the URL as an alternative.The cookie information is transmitted via HTTP headers. Because WAP WSP is based on HTTP headers, it should be possible to transmit cookie information to the clients. The problem may be the clients itself, which may currently not support the handling of cookie HTTP header information or to save this information to a persistent storage in the mobile phone.

 

Premature Encryption Endpoint

The Wireless Transport Layer Security defines encryption between the Mobile Station and the WAP Gateway. The "endpoint" of the encrypted WTLS data is the WAP Gateway proxy server.To have a secure connection to a content host (e.g. banking server) the Gateway proxy server has to establish secure (https) connections to this hosts. In this case the proxy server has access to the decrypted data received via WTLS from the mobile station or from the content host via https (“WAP Development Issues”, 1998).

Small Downloadable Unit Size

WAP incorporates no compression techniques for the textual content, although the WML markup commands are compressed. Additionally, the "deck"- the smallest unit of downloadable information in Wireless MarkUp Language- is limited to a maximum of 1400 bytes. This means that applications need to be specifically designed to be very code efficient by using templates and variables and keeping information on the server and using the cache on the phone.

WML byte code converting defines a (maybe inefficient) compression technique

by string tables. With this technique duplicate strings in the WMLC byte code are avoided. This reduces the size of the data to transfer to the mobile client. The WSP SDU size of 1400 bytes is a default value. A mobile client within the WSP capabilities may negotiate an increased size. The WAP transport layer (WTP) is able to handle greater SDU sizes than 1400 too, by using SAR (“WAP Development Issues”, 1998).

WDP Datagram Protocol

The September 1999 London meeting of the WAP Forum included a decision from the SMS Experts Group that the single common standardized interface between the SMS Center and the WAP Gateway would be a subset of SMPP (Short Message Peer to Peer Protocol). A PDU (Protocol Data Unit) set has been added to SMPP version 3.4 for this purpose.There will be no SMPP specific legacy- in other words, SMS Center manufacturers that do not support SMPP can evolve their SMS Center external interface to support the new SMPP commands for connecting to WAP Gateways.

Basically, this is a victory for Logica, the creators of SMPP, who spun control of the protocol off in 1999 to an “independent” SMPP Forum.The wording of this resolution was careful to avoid mention of the political battle between the pro-SMPP companies such as Logica and those opposed to it such as CMG. Basically, the US carriers insisted upon SMPP and swung the vote (SMS Forum, 1999).

Clearly, as the WAP specifications evolve, some of these issues will be resolved.

However, programmers need to be aware of them when they commence WAP application design.

THE FUTURE OF WAP

The tremendous surge of interest and development in the area of wireless data in recent times has caused worldwide operators, infrastructure and terminal manufacturers, and content developers to collaborate on an unprecedented scale, in an area notorious for the diversity of standards and protocols.The collaborative efforts of the WAP Forum have devised and continue to develop a set of protocols that provide a common environment for the development of advanced telephony services and Internet access for the wireless market.If the WAP protocols were to be as successful as transmission control protocol (TCP)/Internet protocol (IP), the boom in mobile communications would be phenomenal. Indeed, the WAP browser should do for mobile Internet what Netscape did for the Internet (Wigley, “The Future of WAP 1.2”).

As mentioned earlier, industry players from content developers to operators can explore the vast opportunity that WAP presents.As a fixed-line technology, the Internet has proved highly successful in reaching the homes of millions worldwide.However, mobile users until now have been forced to accept relatively basic levels of functionality, over and above voice communications and are beginning to demand the industry to move from a fixed to a mobile environment, carrying the functionality of a fixed environment with it. 

Initially, services are expected to run over the well-established SMS bearer, which will dictate the nature and speed of early applications. Indeed, GSM currently does not offer the data rates that would allow mobile multimedia and Web browsing.With the advent of GPRS, which aimed at increasing the data rate to 115 kbps, as well as other emerging high-bandwidth bearers, the reality of access speeds equivalent or higher to that of a fixed-line scenario become evermore believable.Many, see GPRS as the perfect partner for WAP.With its distinct time slots serving to manage data packets in a way that prevents users from being penalized for holding standard circuit-switched connections (Wigley, “The Future of WAP 1.2”).

WAP VERSION 2.0

Specifications for WAP 2.0 were released earlier this year on August 1, 2001.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 with previous WAP versions (“Wireless Application Protocol”, 2001)

New Services of WAP 2.0
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 service.Some of these additional features of the WAP 2.0 release are:

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 the lifetime of pushed messages, store & forward capabilities at the Push Proxy and control over bearer choice for delivery (“Wireless Application Protocol”, 2001).

User Agent Profile (UAProf) - This service provides a mechanism for describing the capabilities of clients and the preferences of users to an application server.Enhanced for WAP 2.0 release, it is based on the Composite Capabilities / Preference Profiles (CC/PP) work of the W3C, UAProf supports the client-server transaction model by sending client and user information to servers with the request.This information permits the servers

to adapt their content accordingly in preparation for the response.This service model would also permit intervening proxies to provide value-added services by providing these adaptation services directly.Recognizing the importance of user's privacy, personal information submitted in these requests may be controlled by the user (“Wireless Application Protocol”, 2001).

Wireless Telephony Application (WTA) - This service provides tools that provide for a range of advanced telephony applications to be operated from within the application environment that traditionally supports data functionality.These call handling services, such as making calls, answering them, placing them on hold and redirecting them, can be seamlessly combined with other data services.This truly permits WAPWTA enabled cell phones to be viewed as fully integrated Internet and voice service platforms (“Wireless Application Protocol”, 2001).

Persistent Storage Interface - This capability specifies a standard set of storage services that are coupled with a well-defined interface for organizing, accessing, storing and retrieving data on the wireless device or other connected memory device.(“WirelessApplication Protocol”, 2001).

Data Synchronization - In an approach that helps to ensure a common solution framework, the WAP Forum sought out a solution for data synchronization.As a result, WAP 2.0 acknowledges the work of the SyncML initiative by adopting the SyncML language as its choice for the data synchronization solution. The SyncML messages are supported over both the WSP and HTTP/1.1 protocols (SyncML, 2001).

Multimedia Messaging Service (MMS) - This service provides the framework to implement a feature-rich messaging solution.MMS provides features and functionality that permits delivery of varied types of content.Depending on the service model, MMS permits a quick delivery paradigm (like SMS) or a store-and-forward approach (like email) or could permit both modes to operate.This flexibility permits users and operators to tailor the resulting user experience. By using other WAP services, like Push and UAProf, MMS provides an efficient messaging solution that is capable of providing message notifications, which initiate adaptation services to structure, the delivered content into a form that is efficiently used by the receiving device (“Wireless Application Protocol”, 2001).

Pictogram- This service permits the use of tiny images, such as this smiling sun, in a consistent fashion.Such images can be used to quickly convey concepts that permit efficient communication in a small amount of space. Such communication can transcend traditional language boundaries (“Wireless Application Protocol”, 2001).

CONCLUSION

The WAP specification is a truly open standard that enables public content, corporate intranet and operator-specific solutions to reach wireless subscribers today. The WAP specification leverages and extends existing Internet standards, enabling application developers to tailor their content to the special needs of wireless users. Handset manufacturers can enhance their product lines at minimal cost with new usability benefits. Wireless service providers can establish a new and powerful way to interact with their subscribers through a vital point of control in their own network. The ultimate beneficiaries are wireless subscribers who can be more productive than ever before.

In a few years, wireless handheld devices will be most people’s primary mode of access

to the Internet. End-users will begin to demand open access in the wireless world, clamoring for the full set of Internet-based content and services that is currently available to them in the wired world. When that time comes, high-bandwidth wireless networks will make this technically feasible.

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