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![Wireless Application Protocol [WAP]](bannerwap.jpg)
| WAP
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A technology which helps transfer data by wireless means; literally WAP stands for Wireless Application Protocol. This enables you to access internet anywhere by simply dialing into your Internet service provider with the help of WAP. You could access this on the most handy device - your mobile phone, or on other devices like handheld PC or Personal Digital Assistant (PDA). This works on a standard protocol (as devised by the WAP forum - an organization of the know all of the WAP world), so that all phones and WAP internet sites speak the same language, and can understand each other.
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WAP – An Introduction
Wireless Application Protocol, or WAP, is a term that seems to be everywhere at the moment. You can hardly browse the Web without seeing some mention of it, usually in a technical context that won't help you very much in working out what all the fuss is about. This, presumably, is why you're reading this document – to find out what WAP is, what its implications are, and why it will soon become such an important consideration for Web developers.
When you've finished reading this article you will not only have enough basic knowledge to understand a lot more of the technical WAP material out there, you will also have taken your first step towards being able to implement Internet services for mobile users.
However, note that this will be a bit of a whistle stop tour. The aim of this article is to give you a flavor for WAP, WML, and WMLScript, seeing what is possible: – not to give an exhaustive reference.
Before we get stuck in, let's start from the beginning – what is WAP?
What is wap?
The expansion of the Internet took the world by storm. I hardly need to go into details here – we've all seen the results, and in many cases felt the effects. Personally, I think my credit card has seen an awful lot more use since e-commerce Web sites have started to appear!
It didn't take long for some people to see the potential of mobile Internet access. Perhaps the idea of people like you and me accessing their Web sites and buying things while riding on a bus was just too tempting. Once the notion was there it was only a small jump to imagine what else we might be interested in looking at on our mobile phones. For example, we might want to look up a timetable to find out when the bus was arriving, and then look at our credit card balance to see whether we can afford to buy that new stereo system on-line.
Until recently, this scenario would have been dismissed as being science fiction. However, 10 years ago the concept of so many of us using mobile phones on a day-to-day basis would have seemed equally preposterous. The main factor that has changed our thinking on this issue has probably been cost – mobile phones are now not that much more expensive to maintain than landlines, and have many obvious advantages. Personal Digital Assistants (PDAs) such as Palm Pilots are also relatively commonplace now.
In order to link all of these devices to the internet a standard was needed, and that's why WAP was born.
WAP is actually a collection of standards, specifying a complete framework for this mobile access to exist in. It combines pertinent technical considerations, such as limited bandwidth, display sizes, and memory, with existing know-how, including HTTP, XML, and scripting. All this has been assembled by the WAP forum.
The general picture is this: Web content should be available over existing mobile communication networks through a WAP gateway. This is illustrated below:
Figure 1. WAP Architecture
WAP basics
WAP (Wireless Application Protocol) v1.1 is an open specification, which intends to standardize the way mobile telephones access information and services. The specification is currently being developed by the WAP Forum, a democratic consortium backed, according to their statistics, by about 80% of the mobile telephone industry. Version 1.2 is expected by the end of November.
The fundamental concept behind WAP is the re-use of Internet protocols and concepts, which should significantly ease the load of WAP service development for current web professionals.
The WAP protocol utilizes a layered architecture similar to that used by computer networks. Whilst the lower layers are not particularly interesting to web programmers, the top layer is that "old friend" HTTP. Data is sent to, and received from, the web-server along familiar lines: information can be stored on web-servers, generated by CGIs, or derivates, such as ASP. In other words, if you know ASP, you don't have far to go before you can implement your first WAP server.
Of course, mobile telephones have different (stricter) requirements as far as bandwidth and client capabilities are concerned, and so HTML could not get on the WAP bandwagon in its present "form".
The WAP Forum's solution is WML (Wireless Mark-up Language), an XML-based language for formatting text, which allows navigation between different WML documents and also between parts of a single document. WML is a kind of polished and simplified HTML.
The WAP Forum also specified WMLScript, which is the counterpart of JavaScript for WAP telephones. Similar to web client scripting, WMLScript will let the developer support some logic on mobiles and access the mobile functionalities that are exposed to scripting.
What do I need to access Internet on the WAP mobile phone?
You would need:
- A WAP enabled mobile phone from your mobile telecommunications vendor. The regular mobile phone would not be able to access the net as it is does not yet understand the net.
(Nokia, Siemens, Ericsson, Motorola, etc..)
- An ISP connection to get access to the net
(VSNL, or any other private ISP)
- Data and fax to be enabled by your mobile service provider on your SIM.
(to be done by mobile service providers like Orange, Airtel, etc..)
- Configure your WAP mobile phone to access the WAp sites
- Click here to learn how to configure your WAP mobile device.
What does Internet being available on the mobile phone mean?
Internet on your mobile phone means that you can connect to the internet through a WAP mobile phone, and can access information on the net for your use on the mobile screen.
This however, does not mean that you can see the Internet websites exactly as you see on your PC. A special site is created on the net, so that the site is available on the mobile phone. this is keeping in view the small size of your mobile screen, and also the fact that the mobile phone can display only text and low resolution pictures.
Can I access any site on my mobile?
Sorry, not all websites are available on the WAP Phone, unless they are customized to provide you information on the WAP device. Customisation of websites to enable access on a WAP phone requires additional programming. Applications available on WAP are also few, due to limited bandwidth (data transmission speeds), being available on mobile phones, as also the small screen. The small screen allows display of very small amounts of text, and low resolution, two colour pictures only.
Click here to learn how to access 123india on your mobile phone.
How do I get access to a particular WAP Site?
You would need to bookmark this site on your WAP phone. On Nokia 7110 you can bookmark 15 sites, and this varies from phone to phone. You would need to consult your phone manual for this.
WAP Jargon
| 3G | 3G (third generation) mobile would enable high-speed data transmission, including live pictures, camera etc. on your phone. |
| Bandwidth | Measure in bits per second (bps) of the data-carrying capacity of a communications channel. |
| Bluetooth | This enables short range wireless voice and data transmission through two way digital radio |
| bps | Bits per second is a measure of data transfer speed |
| GPRS | GPRS (General Packet Radio Service), is an IP based service enabling high speed data access to wireless Internet. |
| GPS | Global Position System. This technology based on satellites would locate a users' exact location in order to deliver location specific content, as well as deliver emergency help in case the need arises |
| GSM | (Global System for Mobile Communications) is a digital mobile telephone system that is widely used in Europe and other parts of the world. |
| IM | Instant Messaging |
| IP | Internet protocol used for data transfer between computers on the Internet. |
| Kbps (Kilobits per second) | A speed measurement for the transmitting of data (see bps). |
| MB (Megabyte) | 1 MB = 1024 kilobytes (KB) |
| PDA | Personal Digital Assistant are electronic devices, meant exactly for the same purpose, and some of these also offer mobile internet browsing |
| Roaming | This is the nomenclature given to the facility when the local mobile service provider, allows your phone to be accessible in other cities, within the country, or abroad. This is done by setting up communications with networks over other areas by your mobile service provider. |
| SIM | Subscriber Identity Module - referred to as the SIM card provides individual identity for each mobile user, authentication and other basic user data and network information. |
| SSL | Secure Sockets Layer - This software protocol encrypts data transfer to ensure security and privacy of data transfer over the net. |
| VOIP (Voice Over Internet Protocol) | Describes the process of transmitting voice via data IP packages |
| WAP | Wireless Application Protocol offers internet browsing from wireless handsets like mobile phones |
| WAP Gateway | A WAP gateway is a two-way software. Its main function is to offload the WAP mobile device from a lot of computational layers. . |
| WAP Serve | r A WAP server is a web server, using WML (Wireless Markup Language) instead of HTML(Hyper Text Markup Language) |
| WASP | Wireless Application Service Provider |
WML
Although I have talked about communication with the web-server in terms of mobile phones, the client itself is not a mobile phone. The software component, 'WAP gateway', in fact translates mobile telephone requests (WAP requests) into HTTP requests, and redirects the web-server's HTTP responses to the mobile (again, through WAP). WML files are compressed into a binary format by the WAP gateway. Although some WAP gateways can translate HTML into WML, don't expect arbitrary HTML to show up as sensible WML content on a mobile.
Of course, an emulator does not need a WAP gateway to work. It downloads a WML file directly from a web-server (or opens one from the local file system) and renders it in the telephone window.
The WAP gateway normally belongs to the mobile operator's network, but it is possible to set up a private gateway so that a mobile can access an Intranet. This means that the gateway can access information about the calling phone that is not available to the web server.
WML and WMLScript
The Wireless Markup Language is – in essence – an XML vocabulary. For the purposes of this article, I won't go into great detail concerning XML; there are plenty of resources out there that can help with this, such as the recently published Professional XML.
You may also notice that WML has a lot in common with HTML. Sections of text are contained in <p> elements, for example. However, I'll stress now that this is only skin deep – if you try dumping an HTML file into a card it will probably not work. HTML uses many other tags that aren't recognised by a WML parser, and in most cases HTML documents aren't well-formed XML documents. For this reason I won't be pointing out the similarities in the sections below.
WAP Emulators
In order to access a WAP service, you need a WAP emulator. The examples that have been tested are mainly with the Nokia Toolkit 1.2. You can freely download it from the Nokia website. You will also need to install the Java Virtual Machine 1.2.2 (freely available from Sun) to get the emulator to work. The tool is also a development environment. Let's take a look at the mobile interface displayed by the emulator:
Figure 2 : Navigating with the mobile
The mobile display is your browser. Soft keys are used to select from a menu of possible tasks. By clicking on a soft key you activate the function described on the corresponding lower part of the display, in our case Select and OK. The left soft key usually leads to a set of options.
The arrows are used to scroll up and down whenever the content to be displayed doesn't fit into the display (pretty often, actually). They are also used to select entries from different WML user input elements.
The Select button is used to click on links and to select options. Although it's useful, it's also technically speaking redundant, as the select option is always available from the menu activated by the left soft key. Be aware that different mobiles may have different interfaces and the connection between WML elements and the actual display is very loose. This means that different vendors are left free to support generic WML functionalities in different ways.
WAP Development Issues
Unfortunately, things are not so simple as they may have appeared so far. You must know that different WAP telephones have minor differences in their implementations that might make a perfectly functioning WAP site unusable on certain mobiles. The Nokia 7710, the first WAP telephone to be sold in Norway, for example, does not support the POST method correctly when sending data to the web server, despite the fact that this is part of the specification, and Nokia's reference material claims otherwise. As a result, you will have to use the GET method.
One limitation that you should be aware of is the maximum size of a deck. Some telephones (notable the 7710) won't accept a WML deck bigger than 1.4 Kilobytes. The WAP gateway will compress your WML into a smaller binary format, but don't expect miracles. Neither does the Nokia 7110 render tables, or many of the tags used for emphasis. In addition, the fieldset element is blithely ignored. This is really irritating if you have spent days making your content look cool on the 1.2 emulator.
Although the emulator in the Nokia Toolkit 1.2 supports cookies, the first generation of WAP phones won't. This is bad news, since this implies that you can kiss the ASP Session object goodbye, at least for a while.
Conclusions
WAP is a new technology with a promising future. Although it is possible to build real applications today, developers are still feeling the effect of WAP's teething troubles. Even though the multimedia possibilities of the Internet are far from being a reality on handhelds, one big advantage of WAP will be the built-in authentication mechanism of mobile telephones. Imagine booking a ticket and automatically being charged through your telephone bill: a new horizon for E-commerce!
You can Download Nokia Toolkit 1.2. from the
Nokia website
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