Transcript WAP & WML
WAP & WML By Er. Balwinder Singh Introducing WAP • WAP: Wireless Application Protocol – Communication between a wireless device and a gateway, which in turn allows communication with internet- or intranet-based resources • WML: Wireless Markup Language – Derivative of XML used to create pages for wireless devices Definition Of WAP • WAP stands for Wireless Application Protocol • Wireless: lacking or not requiring a wire or Wires . e.g. Microwave ,Radio Waves • Application : a Computer program or piece of Computer software that is designed to do a specific task. • Protocol: A set of technical rules about how information should be transmitted and received using computers. Definition Of WAP • Wireless application protocol (WAP) is an application environment and group of communication protocol for Wireless Devices modeled to active manufacturer vendor and technology-independent access to the internet and advanced telephony services. • WAP is the set of rules governing the transmission and reception of data by computer application on, or via ,wireless devices like mobile phones. The WAP • • • • • • • WAP stands for Wireless Application Protocol WAP is an Application Communication Protocol WAP is used to access services and information WAP is inherited from internet standards WAP is for Handheld devices such as Mobile phones. WAP is a protocol designed for micro browsers. WAP enables the creating of web application for mobile devices • WAP used the Mark-up Language WML (not HTML) • WML is defined as an XML1.0 application History of WAP • WAP is a global standard and not controlled by any single company, Ericsson, Nokia ,Motorola and unwired planet founded the WAP forum in the summer of June 26, 1997 with the initial purpose of defining an industry-wide specification for developing application over wireless communication networks. Benefits for consumers • Its portable • Its easy to use • You have access to a wide variety of services on a competitive market. • You get fast convenient, and efficient access to services. • WAP devices are available in various forms (handheld PCs, phones) Current Limitations of WAP Devices • Low bandwidth (19.2 Kbps max): the size of an average HTML page these days, including graphics, is around 20KB. With a 56 Kbps Modem, the download time for this page would be in the region of 4 seconds. • as the bandwidth of a wireless network is around 9.6 Kbps, however, the download time for the data equivalent for just that one page would be around 17 seconds Current Limitations of WAP Devices • Tiny, monochrome screen: you can use pictures, but only in black & white . There are two reasons . The first is that most WAP devices currently available have only mono LCD screen, not color. But that main reason is speed of transfer. Picture take a while to download, and keeping them simple will reduce the amount of time it takes to download them. Current Limitations of WAP Devices • Less connection stability: wired network access provide a more or less reliable connection to the network • Several input device • Small display • Limited Memory and CPU • Limited Battery Power WAP services Banking accessing account statements paying bills Transferring money between accounts Finance Retrieving stock and share prices Buying and selling stocks and shares Shopping Buying everyday WAP Services Ticketing Booking or buying airline tickets Entertainment Retrieving restaurant details Looking up clubs Playing games Weather Retrieving local weather forecasts WAP Services Ticketing Booking or buying airline tickets Entertainment Retrieving restaurant detials Looking up clubs Playing games Weather Retrieving local weather forecasts World Wide Web Model The WAP Architecture Any WAP enable system consists of : A) WAP Gateway B) the HTTP Web Server and C) the WAP Device WAP Gateway WAP gateway acts as mediator between Cellular device and HTTP or HTTPS web server. WAP gateway routes requests from the client(Cellular Phones) to an HTTP (or Web) server. The WAP gateway can be located either in a telecom network or in a computer network (an ISP). The HTTP Web Server Receive the request from WAP Gateway and process the request and finally sends the output to the WAP Gateway, which in turn the sends this information to the WAP device using it's wireless network. The WAP Device WAP device (Cellular phones) is part of wireless network. WAP Device sends the WAP request to the WAP Gateway, which in turn translates WAP requests to WWW requests, so the WAP client is able to submit requests to the Web server. After receiving the response from the the HTTP Web Server, WAP Gateway translates Web responses into WAP responses or a format understood by the WAP client and sends it to the WAP Device WAP- An Extension of the Internet Model Difference between WAP/WML & HTML Difference Between “Wireless Communication “ and “Wireless Technology” • The terms “Wireless” and “Mobile” get tossed quite frequently in any discussion of Wireless Communication or Wireless Technology. Are there differences between the two terms? • Wireless Communication is simply a medium. Wireless Communication is about the tools used to communicate from one device to another • As subscribers to such technology, one needs to find the best type of wireless services that suits his needs WAP Layer Wireless Application Environment (WAE) • In the WAP model, WAE would be the application environments that sends and receives requests from the Clients to the Gateway to the Origin Server. Wireless Session Protocol (WSP) The Wireless Session Protocol is the layer that deals with communication between client and proxy or server. The WSP provides dialog between client and server. WSP provides the following services: WSP provides the following services: 1. Opens a session of communication between client and server. 2. Establishes a protocol and negotiation between client and server. 3. Exchanges encoded data between client and server. 4. Exchanges request and replies between client and server. 5. Supports several asynchronous transmission of data. Wireless Transaction Protocol (WTP) The Wireless Transaction Protocol, in a simple definition, deals with the transaction of data. WTP handles transactions, re-transmission of data, and with the separation and concatenation of data. This particular protocol has a separate interface that manages and referees the WTP layer and the settings of the handheld device. This management application is known as the WTP Management Entity For WTP to work, the following factors are important: • The handheld device is within coverage area of base agent. • The handheld device is turned on and has a power and is reliable. • Resources are adequate especially with the CPU and memory. • WTP settings are correctly inputted. • The WTP Management Entity makes sure the above factors are valid during the transaction session. Wireless Transport Layer Security (WTLS) The Wireless Transport Layer Security is the layer that handles security of data and validity of data between two communicating to manage, start, and finish security issues between two portable devices. To transport data, WTLS needs: the source address and port number to identify the message creator, and from where the message is being sent, the destination address and port number to which data is being sent, and of course, the data itself. WTLS has a connection interface which provides a connection protocol between client and server. Wireless Data Protocol (WDP) • The Wireless Data Protocol acts as the communication layer between the upper level protocols (WTLS, WTP, and WSP), and the bearer services. WDP allows the upper layers to function independently from the wireless network at hand, as long as the WTP layer is specifically set to the settings of the bearer settings. Function of The WDP • The function of the WDP is to provide a stable environment so that any of the underlying bearers can operate using WAP. WDP can be adapted to different bearers with different services however the services offered by WDP remains constant thus providing a continuous interface to the upper layers of the WAP stack. Technical Challenges of WAP • Since WAP is designed for portable devices, important details matter: such as dealing with small screen sizes (a Palm Pilot or mobile phone). A small screen size does not allow high resolution or high pixel images to be seen clearly. • Because WAP is designed for portable devices, there is limited device memory so that not a lot of data can be stored. • WAP allows two devices to communicate only, and data transfers are usually done with Infrared, therefore the devices have limited range of data transfer. • WAP also works on devices that have limited bandwidth. • There are no “cookies” available to hold the session together. What is Micro Browser • To fit into a small wireless terminal , WAP uses a micro Browser. • A Micro Browser is a small piece of Software that makes minimal demands on hardware, memory and CPU. • It can display information written in restricted mark-up language called WML. Editors and Emulators • WAP application developers generally use WAP Emulators to test their documents. • An emulator (or “Simulator”) is a program that runs on your computers that shows you how your document will appear and function on a wireless device WAP Network Elements WAP Network Elements • WAP clients communicate with application servers through a number of different proxies or directly. WAP clients support the proxy selection mechanism that allows them to utilise the most appropriate proxy for a given service or to connect directly to that service as necessary. Proxies can be used to augment a request. They translate between WAP and WWW protocols (HTTP, TCP), thereby allowing the WAP client to submit requests to the origin server. HTML vs. HDML vs. WML • Hyper Text Markup Language (HTML) is the language that is used to translate data to a web browser to be viewed by a user. • Handheld Device Markup Language (HDML) is used to incorporate handheld or portable device applications such as a micro browser. • Wireless Markup Language (WML) is a language derived from HTML that is used with WAP to incorporate WAP features. WAP Toolkits • To develop any WAP application you have to download software essential for development. Although you can write and test your codes through our site for learning purpose. But for development purpose you have to download and install the necessary software List of WAP Toolkits and WAP Gateways • • • • • • • • • • • • • • • • nhydra development environment Enhydra - Java/XML server 3.0 Ericsson WapIDE SDK 2.1 Ericsson JAWAP (Java framework) 1.3.1B1 Ericsson Proxy/Gateway 1.0 Gelon.net SDK GNUWS Project (open source gateway) IBM Wapsody Kannel - Open source WAP/SMS Gateway Macromedia WML Dreamweaver Extension Motorola - Mobile ADK 1.1 Nokia WAP Developer Forum Nokia - WAP Toolkit Nokia WAP Server 1.1 Ophelia WAP 1.1/WTLS gateway Phone.com - UP.SDK 3.2 Future of WAP • The future of WAP depends largely on whether consumers decide to use WAP devices to access the web, and also on whether a new technology comes along that require a different infrastructure that WAP. • On the technological side , it is true that mobile phone data speeds will get faster. Future of WAP • 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. the WAP browser should do for mobile internet what Netscape did for the internet. Next-Generation WAP Next-Generation WAP • • • • • • • • The next-generation WAP will adopt XHTML, a version of HTML reformatted to the XML format. W3C is working on modularizing XHTML 1.1 and will adopt XHTML Basic as the core of the next-generation markup language. The functions of the existing i-mode-compatible HTML will also be supported in the next-generation markup language by adding the subset for mobile phones [Cascade Style Sheet (CSS) Mobile Profile] from CSS. Furthermore, in order to carry over the card and deck and other distinctive features of WML to the next generation, WML Extension, which realizes the WML functions on XHTML, will be added as well. Figure shows XHTML derivations. WAP Forum • WAP Forum (http://www.wapforum.org). This is the industry association promoting the usage of WAP The WAP Forum has hundreds of members including network operators, infrastructure providers, software developers, and so on. The WAP Forum will have a challenging task ahead, once it tries to compete with the Japanese i-mode promoted by NTT DoCoMo. Other Wireless techniques Bluetooth • The word 'Bluetooth' tends to be placed in the same sentence with the words 'WAP' and 'Wireless'. • a frequently asked question is: is Bluetooth a protocol, a standard, a technology, or an actual product? • A quick answer to this question is: Bluetooth is not an actual product. Bluetooth is a standard for wireless communication between short-ranged radio links to PCs to mobile phones. MOBITEX • MOBITEX has become a modern global standard. Originally developed by a telecommunications based in Sweden . • MOBITEX technology revolves around the node. A node is a data structure that has the ability to transmit its data to anywhere it is assigned to. In the case of MOBITEX, each node acts as a base where data stops. MOBITEX Technology As with any protocol, MOBITEX offers several features: • Easy roaming so that there is no need to register with base when moving from one area to another. • Store and forward services that guarantee delivery of a message regardless of user’s location and status. • Reliability of message being transmitted in full and accurately. • Able to have millions of users. MOBITEX Technology • Transfers a variety of messages from data messages to text messages to higher encrypted data messages. • Handles a priority queue for received and sent messages – able to deliver messages with higher priority than others. • Network security: login and logout options along with notifications of status (activated/inactivated). • Retransmit data if there are any errors in first time transmission • Able to find the right channel and frequency in order to work properly and accordingly. CDPD • Cellular Digital Packet Data, otherwise CDPD, is a mobile technology that transmits data over the system offered by Advanced Mobile Phone Service (AMPS). • CDPD was primarily developed by IBM but its development has now moved to a communal effort among several big companies including Ameritech, AirTouch, and GTE – now Verizon. • In the early stages of CDPD development, CDPD offered packet-switching data transmission over analog cellular networks and voice transmission over cellular voice networks I-Mode • Ii-Mode is the wireless technology produced by the Japanese-based company NTT DoCoMo. I-Mode simply allows cellular phone users to use the Internet on their cellular phones. This technology has just expanded to the European market and is looking to expand and implement WAP in the near future. References • • • • • • • • • • http://www.wapforum.org/ http://www.bluetooth.com/ http://www.cosmoc.org/pubs/surveys http://www.ericsson.com/review http://www.gsmworld.com/technology/yes2wap.html http://www.ieee.com/ http://www.wap-resources.net/ http://www.cosmoc.org/pubs/surveys/3q99issue/salkintzis.html http://www.bluetooth.com/developer/specification/specification.asp Book “WAP A Beginner’s Guide” by Dale Bulbrook