WAP stands for Wi-fi Software Protocol. WAP represents a set of protocols quite than a single protocol. WAP goals at integrating a easy light-weight browser often known as a micro-browser into handheld gadgets, thus requiring minimal quantities of sources equivalent to reminiscence and CPU at these gadgets.
WAP tries to compensate for the shortfalls of the wi-fi handheld gadgets and the wi-fi hyperlink by incorporating extra intelligence into the community nodes such because the routers, internet servers, and BSs.
The first aims of the WAP protocol suite are the next.
- Independence from the wi-fi community requirements
- Interoperability amongst service suppliers
- Overcoming the shortfalls of the wi-fi medium
- Overcoming the drawbacks of handheld gadgets
- Growing effectivity and reliability
- Offering safety, scalability, and extensibility
The WAP Mannequin
WAP adopts a client-server method. It specifies a proxy server that acts as an interface between the wi-fi area and core wired community. This proxy server, often known as a WAP gateway, is answerable for all kinds of features equivalent to protocol translation and optimizing information switch over the wi-fi medium.
Wi-fi community components encompass −
- Content material supplier (Software or origin server)
- Cell machine (WAP consumer)
- WAP gateway
- WAP proxy
The WAP Structure has been designed to intently observe the net. The one distinction is the presence of the WAP gateway is translating between HTTP and WAP.
The three sections to be talked about concerning WAP consumer are WAE person agent, WTA person agent and WAP stack.
- WAE person agent − Wi-fi utility atmosphere person agent is the browser that renders the content material for show.
- WTA person agent − Wi-fi telephony utility agent receives compiled WTA recordsdata from WTA server and executes them.
- WAP stack − WAP stack permits the cellphone to hook up with the WAP gateway utilizing the WAP Protocols.
The component within the community the place the knowledge (internet, WAP) functions reside are WAP proxy, WAP gateway or WAP server −
- Proxy − That is an middleman component appearing each as a consumer and as a server within the community it’s positioned between consumer and server. The consumer sends requests to it and it retrieves and caches the knowledge wanted by contacting the origin Server.
- Gateway − That is an middleman component normally used to attach two various kinds of networks.
WAP Gateway is principally software program that’s positioned between a community that helps WAP and IP packet community equivalent to Web.
The WAP Protocol Stack
WAP protocol stack is proven within the following determine −
The applying layer offers an utility atmosphere meant for the event and execution of transportable utility and providers WAE consists of two totally different person brokers positioned on consumer aspect.
The WAE person agent consists of browser and the textual content message editor together with the WTA person agent.
The session layer provides strategies for the organized alternate of content material between Shopper/Service functions.
WAP incorporates the next parts −
- Connection Oriented Session Companies − These function over WTP.
- Connectionless Session Companies − These function immediately over WDP.
- Session providers − These functionalities assist to arrange a connection between a consumer and server utilizing primitive messages.
Primitives messages are outlined as messages that consumer sends to the server to request a service facility. The consumer sends request primitives and obtain affirm primitive and the server can ship response primitives and obtain indication primitives.
The connectionless session service offers solely non-confirmed service. To begin session, the consumer invokes a WSP primitives that present some parameters, such because the server tackle, consumer tackle and consumer headers. In some respects, WSP is principally a binary type of HTTP.
Supplies totally different strategies for performing transaction to various diploma of reliability.
Elective layer that gives, when authentication, privateness and safe connection is current, between functions. It’s based mostly on SSL (Safe Socket Layer). It offers providers that guarantee privateness, server authentication, consumer authentication and information integrity.
A Normal SSL session is opened between the net server and the WAP gateway, and WTLS session is initialized between the gateway and the cell machine. The encrypted content material is ship by this connection from the server to the gateway, which interprets it and sends it to cell phone. The transaction between SSL and WTLS takes place within the reminiscence of the WAP gateway.
That is the underside layer, related with the bearer service provided by the operator. Bearer providers are the communication between the cell phone and the bottom stations. They embrace SMS, CSD, USSD, GSM, GPRS, DECT, CDMA, FDMA, and TDMA.
The bodily layer prepares the information to be despatched from the cell machine over the air providers and sends the information utilizing bearer service applied within the community that the machine is working in. WDP has an interface with varied bearer networks, so it should have a bearer particular implementation. WDP is the one layer that have to be rewritten to assist totally different bearer networks. The WTP layer implements a easy request-response transaction oriented protocol as an alternative of the three-way-handshake connection mechanism.