Review of Wap 1.0 And Wap 2.0 Protocol For Wireless Communication

With the growth of internet, internet application and mobile communication, demand for internet services for mobile devices like laptops, cellular mobiles and wireless devices has been increased. But the challenge is to provide internet content and advanced data services to wireless phones and other wireless terminals that work across all wireless network technologies. WAP (Wireless Application Protocol), is the solution developed by the WAP forum to the problem. WAP is an open international standard which not only responsible for the presentation and delivery of wireless information and telephony services on mobile phones and other wireless terminals in wireless communication environment but also create content and application that scale across wide range of wireless bearer networks and device types, also extend existing standards and technology whenever possible and appropriate. This paper review WAP protocol version 1.0 and 2.0 and discuss the basic architecture, features and services provided by these versions.

1. Introduction: WAP is a protocol suite that brings the diverse internet content and other data services to the digital cellular phones and other data wireless mobile terminals. It enables global wireless communication across different wireless network technologies. It can extend existing standard and technology whenever needed, and contents and applications can be scaled across wide range of wireless bearer networks.

2.  WAP 1.0: The WAP 1.0 standard, released in April 1998, described a complete software stack for mobile internet access.The WAP standard describes a protocol suite that allows the interoperability of WAP equipment and software with many different network technologies, thus allowing the building of a single platform for competing network technologies.

The basis for transmission of data is formed by different bearer services. WAP does not specify bearer services, but uses existing services and can integrate further services. The bottom-most protocol in the suite, the WAP datagram Protocol (WDP),, functions as an adaptation layer that makes every data network look a bit like UDP to the upper layers by providing unreliable transport of data with two 16-bit port numbers (origin and destination), All the upper layers view WDP as one and the same protocol, which has several technical realizations on top of other data bearers such as SMS, USSD, etc. On native IP bearers such as GPRS, UTMS packet-radio service, or PPP on top of a circuit-switched data connection, WDP is in fact exactly UDP. This layer provide additional protocol namely WCMP (Wireless control message protocol),, because adaptation of these protocols are bearer specific.
WTLS, an optional layer, provides a public key cryptography-based security mechanism similar to TLS.

WTP provides transaction support (reliable request/response), adapted to the wireless world. WTP supports more effectively than TCP the problem of packet loss, which occurs commonly in 2G wireless technologies in most radio conditions, but is misinterpreted by TCP as network congestion. WSP can be viewed as a compressed version of HTTP.This protocol suite allows a terminal to transmit requests that have an HTTP or HTTPS equivalent to a WAP gateway; the gateway translates requests into plain HTTP.
Wireless Application Environment (WAE),: The WAE space defines application-specific markup languages. For WAP version 1.X, the primary language of the WAE is WML, which has been designed by Santhosh Kumar from scratch for hand-held devices with phone-specific features. In WAP 2.0, the primary markup language is XHTML mobile profile.
2.1. WAP 1.X: The WAP 1.0 standard, released in April 1998, described a complete software stack for mobile internet access. WAP version 1.1 came out in 1999. WAP 1.2, the final update of the 1.X series was released in June 2000. The most important addition in version 1.2 was WAP push.
WAP Push: WAP Push has been incorporated into the specification to allow WAP content to be pushed to the mobile handset with minimum user intervention. A WAP Push is basically a specially encoded message which includes a link to a WAP address.
WAP Push is specified on top of WDP; as such, it can be delivered over any WDP-supported bearer, such as GPRS or SMS. Most GSM networks have a wide range of modified processors, but GPRS activation from the network is not generally supported, so WAP Push messages have to be delivered on top of the SMS bearer.
On receiving a WAP Push, a WAP 1.2 or later enabled handset will automatically give the user the option to access the WAP content. This is also known as WAP Push SI (Service Indication),
The network entity that processes WAP Pushes and delivers them over an IP or SMS Bearer is known as a Push Proxy gateway (PPG),
3.  WAP 2.0: The latest Wireless Application Protocol standard, WAP 2.0, developed by the WAP Forum was revealed in August 2001. WAP 2.0 is intended to bring mobile services closer to Internet standards on desktop PCs. WAP 2.0 is supported by companies like Ericsson, Nokia and Motorola. All three industry giants believe the protocol will further advance mobile services, and have stated their intentions to develop products, content and services based on WAP 2.0.Version two of wireless application protocol (WAP 2.0), can be stated as a sum of WAP 1.x, i-mode, internet protocols, and many mobility specific enhancements.WAP 2.0 continues to support WAP 1.x protocols, but additionally integrates IP, TCP (with a wireless profile),, TLS, and HTTP (wireless profiled), New technologies designed to improve the WAP standard include: Multimedia Message Servicing (MMS),, Persistent Storage Interface, Provisioning, and Pictograms. The WAP 2.0 standard also makes use of: wireless telephony application (WTA),, Push, and user agent profile (UAPROF), in more advanced forms.
With version 2.0, WAP moved toward adopting widely accepted Internet standards. The W3C-defined XHTML Basic standard has been adopted as the basis for WAP 2.0. XHTML Basic is the mobile version of XHTML 1.0, on which the WAP Forum based its XHTML Mobile Profile. WAP CSS is the mobile version of cascading style sheets (CSS), that has only those features of CSS that are relevant to the mobile environment. XHTML and CSS put more formatting power in the developer's command. Using XHTML and CSS, you could even display the same document on different devices using distinct presentation capabilities. WAP 2.0 also includes WML 1.x extensions to ensure backward compatibility.

With WAP 2.0, the gateway is no longer that critical a component of the WAP architecture. Also, content no longer needs to be binary encoded; XHTML goes through in text format. However, because many people still rely on mobile devices that require the WAP 1.0 standard, and because the WAP/WSP stack is being used for transport, you will still need to support WAP 1.0 gateways.
The WAP 1.x architecture consisted of the origin server, gateway, and user-terminal environment. The server could be a WAP or HTTP server; the gateway translated the protocol layer and application information. By contrast, the WAP 2.x architecture consists of four conceptual components, namely the:
1.    Application environment;
2.    Protocol framework;
3.    Security services; and
4.    Service discovery.
 The WAP 2.x architecture does not have strict divisions between the server, gateway, and user-terminal environment. And there is no longer any intermingling between transport and service. Instead, functions which are accessed via the Internet can be outsourced to capability servers in a WAP network that implements support for,
1.    Wireless telephony application (WTA),;
2.    Public-key infrastructure (PKI), portal;
3.    Provisioning server; and
4.    User-agent profile (UAPROF), repository.
Communication from WAP clients can take place directly with the server, but it will most likely take place through a proxy. Proxies are being established as one of the main points of control (for example, through firewalls), and as central points for resource interconnection. WAP clients support a proxy-selection mechanism that allows them to choose the most appropriate proxy for a specific task. This extends the current Internet proxy model. The WAP 2.x protocol is compatible with WAP 1.x, but it relies more extensively on standard Web protocols (such as HTTP), and formats (such as XHTML), WAP 2.x also clearly separates the
1.    Bearer (CSD, GPRS, IMT-2000),;
2.    Transport (WDP, TCP),;
3.    Session layer (cookies, CC/PP),; and
4.    Applications.
Most protocol services in the WAP 1.x suite are also available in new Web protocols. But the WAP push service cannot be realized through existing Web protocols without significant changes to the current Web architecture. Both the WAP 1.x stack and Internet protocols (such as hypertext and multimedia transfer services), can provide some services, but only WAP is capable of providing others, such as the WAP push service. From the start, WAP has been based on the browsing paradigm made popular by the Web: it adapts technologies from the Web, making them work better in wireless networks. In the WAP 2.x architecture, more of the Web technologies are adopted directly (as they are), rather than adapted, and then extended with WAP-specific functions. These functions enable service providers and developers of systems, content providers, and devices to provide users with greater added value. Modularity is one of the main features of the second-generation architecture (modules interact through well-defined interfaces), The security-service and service discovery components of the architecture span every layer of the open systems interconnection (OSI), model. The application environment component resides on top of OSI layer 7; the protocol framework comprises everything from OSI layer 2 to 7.
The architecture allows components to interact. Developers can thus select modules from different components and create new user services. Conceivably, a minimal device can be developed by selecting components with the smallest footprints. In practice, devices and proxies will most likely implement either a dual stack or only the Internet stack. Backward compatibility is achieved by providing continued support for WML 1 in the client. The WAP conformance profiles (Box B), determine the configuration of the devices as well as how they work together. The application-environment component enables the following services:
1.    WAP application environment (WAE),
    that is, the browser, calendar agent, and other user agents;
2.    User-agent profile;
3.    Multimedia messaging and other data formats;
4.    Push service.
The application environment provides the user interface and other functions that display content. Because it is a flexible environment, modules can be added on an ad hoc basis (optional), or through the WAP Forums specification development process. The WAP application environment is in the mobile terminal. It contains a subset of XHTML (for display formatting), and a subset of the cascading style sheet (CSS), language (for content formatting), XHTML is HTML reformulated as an XML application, defined by the W3C. For WAP 2.0, the WAP Forum has defined a strict subset of XHTML called the XHTML mobile profile. The profile is in turn a superset of the W3C XHTML basic profile, a W3C recommendation (December 2000), for XHTML in small devices. An XHTML page, written in XHTML mobile profile or XHTML basic, can be viewed in a WAP 2.0 browser or any standard Web browser. All basic XHTML features are supported, including text, images, links, checkboxes, radio buttons, headings, horizontal rules, and lists.It also contains user agents for WTA and programming interfaces for use in mobile devices. WML and WMLscript execute in the WAP application environment.

4. Cascading Style Sheets: The WAP 2.x architecture contains a subset of the cascading style sheet language, which is the most widely used display language on the Web. Using cascading style sheets, an author can define how each element in a document is to be displayed. This gives authors greater control compared to when the display is specified inside the markup. A style sheet need only be downloaded once from the network server. After
that it can be retrieved from a local cache. Cascading style sheets can adapt automatically to the capabilities declared by a devices user-agent profile. This is particularly important because display capabilities vary significantly among devices. A format that looks good on one device might be displayed differently on another. The useragent profile ensures that the device gets the most appropriate style sheet. And because style sheets separate display from content, authors can use the same WML document for many different devices with significantly different display capabilities.

5. Contact and Calendar Information: WAP 1.x versions contained the vCal and vCard data types, which are not part of the browsing environment. The Internet Mail Consortium standardized vCal and vCard as structured data types for displaying contact and calendar information. iCal, which was developed from vCal, is used in products such as Microsoft Outlook and Lotus Organizer. It is also used in Ericssons AirCalendar, which allows users to synchronize the electronic calendars they use in the fixed environment with the calendars on their mobile terminals. WAP also accommodates
other data types, such as audio and video. modules contain functions that are not available in other systems: multimedia messaging service (MMS), was one of the highlights of this years GSM-UMTS Forum, and push services are not possible on the Web using standard HTTP. MMS is an e-mail-like mechanism for the transmission of multimedia messages (electronic postcards with sound),, which are expected to become very popular applications, especially in third generation mobile systems.

6. Push Services: Service providers use push services to send information to users (who need not initiate any action), As simple as it might sound, the push-service architecture has been a major item on the WAP Forum agenda. In the WAP 2.x architecture, the push service has been divided into the user-agent module and the session-layer module. The protocol framework component The WAP application environment relies on a protocol framework component that enables the functions needed to provide the services described above. The protocol framework consists of four modular layers, which can be combined:
1.    the session service layer;
2.    the transfer service layer;
3.    the transport service layer; and
4.    the bearer service layer.
In traditional Internet environments, the protocol framework solely provides transport services for applications, such as hypermedia transport (HTTP),, streaming (RSVP and RTP Internet protocols),, and message transport (standard Internet protocols, such as SMTP), In the WAP architecture, a logical layer has been added: the session service layer.
7. Session Service Layer: In the WAP 2.x architecture, the session service layer, which resides between the transport layer and the application environment, brings several new services to applications. Sessions do not exist in HTTP, but cookies can provide sessions. Cookies, which are database markers included in the request and looked up on the server side to identify the user, are part of the WAP 2.x architecture. They enable the reuse of mechanisms that already exist in the Internet and solely give an indication about the relationship between a single server and the user agent. Cookies cannot be used as a general source of information. The session service layer also includes a technology for reporting to the server. The reports contain information on terminal capabilities and on the terminal application environment. This information is used to optimize the display format.
8. Data Synchronization: Synchronization is another new service inWAP. The WAP Forum has been working with SyncML (another industry consortium), to create a language for data synchronization. Synchronization of data that has been updated in mobile and fixed environments can be a thorny issue. Users retrieve data from the network and store it on a mobile device, which they use to access and manipulate the local copy of the data. Periodically, users reconnect to the network to send changes to the networked data repository. Users also have the opportunity to learn about updates made to the networked data while their terminal was offline. Occasionally, users need to resolve conflicts between their local updates and the networked data. This reconciliation operation (during which updates are exchanged and conflicts are resolved), is known as data synchronization. The data synchronization protocol synchronizes networked data with that on many different devices, including handheld computers, mobile phones, automotive computers, and desktop PCs.

9. Push Sessions: The push solution also contains a session component. The push over-the-air (OTA), session service enables the establishment of push sessions
1.    Across communication links that might not be persistent; and
2.    In instances when addresses are dynamically assigned.
There is no binding between the transport of data and the session on the Web. The data transport is transparent to the session. Once a hypertext transport transaction is finished, the state it created disappears. In the WAP 1.x stack, the wireless session protocol (WSP), and wireless transaction protocol (WTP), can be used in combination to create and maintain a state, and through it, sessions. This has several advantages (for example, to enable push), By including HTTP as a transport method, the WAP Forum now enables both stateful and stateless transport. Session services provide a memory of previous transactions (this feature does not exist in HTTP, since it is a stateless protocol), that enable the retention of terminal characteristics and make for faster initialization of complex transports (such as data streaming), Apart from the transport of text documents, the WAP architecture has also been prepared for the next generation of messaging. It contains a multimedia transport mechanism for asynchronous message transport (messages are encapsulated for transmission between multimedia and WAP servers in a WAP-specific protocol), The data-transport mechanisms also include IETF data-streaming formats.

10. Transport Service Layer:  The transport services in WAP 2.x are either datagrams (connectionless service), or connections. Datagrams are more efficient for services that are not dependent on a persistent connection. The datagrams comply with either the user datagram protocol (UDP),, which is used on the Internet, or the wireless datagram protocol, which was defined for the WAP 1.x architecture. The connection-oriented aspects of the new architecture are handled by the transmission control protocol (TCP), TCP, however, doesnot work well over mobile networks, so the WAP Forum is discussing an optimized mobile profile, to enable the mobile terminal to function optimally over the mobile network with its special characteristics.

11. Bearer Service Layer: In WAP 2.x, the bearer services have been extended considerably. They now include the mobile radio bearers used to transport WAP (such as SMS, FLEX, USSD, and GUTS),, as well as IP version 4 (IPv4), and IP version 6 (IPv6), WAP can be transported over different networks, and mapping can be handled directly from the WAP stack to several bearer services. WAP 1.x contains several modules for bearer networks, some of which (broadcast networks, for example), could not be handled using TCP transport. In WAP 2.x, bearers can be managed by the IP stack or directly by the WAP datagram or connection service, which uses the Internets transmission control protocol.

12. Security Services Component: The security services component is positioned orthogonally to data-transfer and data-use services within the protocol framework component. Security on the Internet is currently a hot issue, and the WAP 1.x architecture has received a lot of criticism. The telecommunications industry has been a leader in the security area for a long time, and this experience has been transferred into the WAP 2.x architecture. WAP security services span all layers of the WAP 2.x architecture, thus creating opportunities for users to set up extremely secure environments (in fact, much more so than what is currently possible on the Web), How? By combining application-layer, transfer-layer, transport-layer, and bearer layer security the possibilities are endless.
Security services include
1.    mechanisms for signing and encrypting data as a WMLScript crypto library;
2.    authentication services;
3.    an identification service that uses the wireless identity module (WIM),;
4.    a PKI system;
5.    transport layer security (TLS, previously called SSL),; and
6.    WTLS, the WAP 1.x-adapted version of TLS.

13. Service Discovery Component: The service discovery component is another orthogonal component in the WAP 2.x architecture that embraces what is available on the Internet and extends it by adding mobile-specific components. One example, the service lookup protocol, uses the existing domain name server (DNS), from the Internet. Terminal functionality is extended through the extended functionality interface (EFI),, which enables a WAP device to have external entities attached to it (thermometers, pressure gauges, and so on), Provisioning, which is another telecommunications-specific protocol, is translated into WAP. Devices can thus be provided with all the parameters they need to function through the network. Navigation discovery allows a client to discover services in the network for example; a client might need to find a proxy in order to download data.

14. Conclusion: The WAP environment is a consistent architecture composed of standard components taken from the Internet where available, or constructed separately. They enable a consistent application environment for the mobile system.
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. WAP 2.0.Version two of wireless application protocol (WAP 2.0), can be stated as a sum of WAP 1.x, i-mode, internet protocols, and many mobility specific enhancements. WAP 2.0 continues to support WAP 1.x protocols, but additionally integrates IP, TCP (with a wireless profile),, TLS, and HTTP (wireless profiled),

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