WAP Technology Entry

WAP Technology Entry

Preface

New technologies of the international Internet are emerging one after another. As China Mobile and China Unicom have successively launched WAP mobile Internet services, this emerging technology is gradually gaining traction in China. In fact, as early as 1997, companies such as Ericsson, Nokia, Motorola, and phone.com jointly launched WAP Forum. Subsequently, many companies in the industry joined and proposed the first version of the WAP standard in April 1998. The full name of WAP is "Wireless Application Protocol", which aims to transmit and display data on mobile phones and other wireless devices and provide various telecom services. According to a query by Global Mobile magazine, there are currently at least 0.2 billion wireless users, and Nokia points out that the number of users will exceed 2005 in 1 billion. In the face of such a large number of groups of users, many large and small companies are scrambling for WAP. leading domestic websites such as Sina, Netease, and Sohu have joined hands with China Telecom to launch WAP-based websites. I believe that with the approaching WTO, China's Internet will develop faster and faster, and there will be more and more WAP websites in China to adapt to the rapidly growing WAP business.
As a Web site developer, we should follow up more quickly in this wireless network revolution sweeping the world. The internet age is an era of continuous elimination, and only the latest technologies are available at any time, to keep up with the pace of the Internet.

Chapter 1 WAP technology architecture

Wireless Networks are very different from the wired networks we are currently familiar:

First, the market format is different.

1. Wireless Internet access devices have been designed as easy-to-use devices from the very beginning. Even users who have never used computers can quickly find the desired information on the Internet using their mobile phones.
2. As far as the market size is concerned, wireless network users are growing at an astonishing rate. By 2001, there were more than 0.5 billion million mobile users around the world, and it is expected to surpass the 2004 mark in 1 billion, such a growth rate gives us confidence in the prospect of WAP.
3. wireless networks with a broad range of users are expected to have a high value. Users hope that WAP can be improved as well as voice technology, and be faster and easier to use.
4. WAP mobile phones are not designed for surfing the Internet. The purpose is to allow users to conveniently and quickly access information on the Internet during the mobile process.

Second, the network environment is different.

1. low bandwidth for Wireless Networks
2. Wireless Networks have much latency compared with the current international Internet
3. Poor stability of Wireless Networks
4. the CPU, memory, and display screen of wireless access devices are limited.
For the above differences, the WAP architecture is different from that of common Web websites. First, the WAP technology is based on the current Web architecture and extends to the wireless network environment, it enables the products developed in the industry to have wireless network independence, device platform independence, and interoperability. WAP follows the current Web architecture, so that the funds, devices, and manpower currently invested in the Web can be retained and used. WAP points out that she has an extra thing called WAP Gateway. What is the role of gateway? For internet devices, Gateway
It is similar to the proxy. When the client wants to obtain the surface of a website, it is obtained by the proxy and then handed over to the client. In addition to the WML files required for the website obtained by the proxy mobile phone, the WAP Gateway also acts as a role for converting the HTTP and WAP protocols, so that the mobile phone can smoothly obtain information. WAP Gateway is mostly set up by the Telecommunications Bureau or ISP. For general websites, you only need to add relevant MIME format settings to the web server, you can directly access your mobile phone.

The architecture is described as follows:

Wireless Devices (mobile phones and PDAs) <----> (WAP protocol) <----> WAP Gateway <---> (HTTP protocol) <----> Web server <----> Database Server
As you can see, the WAP Gateway acts as a man-in-the-middle in the process of data transmission over the wireless network, currently, funds, devices, and manpower that have been invested in the internet will not be discarded by Wap websites. On the contrary, they can make better use of almost all existing resources.
In addition, companies such as Nokia integrate WAP gateways and web servers, which are called "web app lication server". However, their overall architecture is still the same, we will not repeat it here. Next, let's take a look at how to set up an existing Web server to allow users to access our website on their mobile phones.

1. Internet Information Server (IIS)

Setting Method: open [start]> [Program]> [windowsnt4.0 Option Pack]> 〕――〉
[Microsoft Internet Information Server]-> [Internet service administrator 〕
In the window that appears, right-click the server and select "attribute" to add the following MIME format:
File Type mime
· WML text/vnd. WAP. WML
· Wmlc application/vnd. WAP. wmlc
· WMLS text/vnd. WAP. WMLScript
· Wmlsc application/vnd. WAP. wmlscriptc
· Wbmp image/vnd. WAP. wbmp

Ii. Personal Web server4

1. Open the Registry Editor and create a primary key ". WML" under hkey_classes_root ";
2. Create a New String under hkey_classes_root/. WML and name it "content type". The value is "text/vnd. WAP. WML ";
3. Create a primary key "text/vnd. WAP. WML" in HKEY_LOCAL_MACHINE/software/classes/MIME/database/content type"
4. Create a New String named "extension" under the "text/vnd. WAP. WML" primary key with the value ". WML ";
5. Repeat steps 2, 3, and 4 to create other MIME types.

Iii. Linux (APACHE)

Log on to the system as an administrator. On the command line, enter the "PS-Ef" command to check whether the current WWW Service is normal,
Then, use VI to edit the "/etc/httpd/CONF/SRM. conf" file and add the following types to addtype:
Addtype text/vnd. WAP. WML. WML
Addtype application/vnd. WAP. wmlc. wmlc
Addtype text/vnd. WAP. WMLS. WMLScript
Addtype application/vnd. WAP. wmlsc. wmlscriptc
Addtype image/vnd. WAP. wbmp. wbmp
Save and restart httpd.
After this setting, our web server can be accessed by mobile phones. Of course, mobile phones cannot identify common HTML files, we can also guess how to set the file type to be read on the mobile phone.
The WML file. Before designing WML, we should first familiarize ourselves with our WAP website development environment.

Chapter 2 mobile phone Simulation Development Environment
　　
The so-called mobile phone simulation development environment, that is, using various simulators on ordinary PC machines to simulate the real environment of mobile phones, so as to facilitate the development of WAP websites, currently, the most popular simulators include the following:

I. Nokia toolkit 1.2/1.3

You can download this Simulation Development Environment from this address: http://www.nokia.com is currently the highest version of this WAP toolkit is 1.3 Beta, Nokia's Development Kit is written in Java, so you need to install JRE 2.2 or above before installation, JRE can be downloaded on Sun's home page (http://www.sun.com ). This development tool of Nokia is an integrated environment that allows you to easily compile WML/WMLScript and has detailed WML/WMLScript development documents, you can use the address bar to load the WML files that are being developed locally, or directly browse the WAP website on the Internet. However, the running conditions of nokie toolkit are harsh. If your machine memory is less than 128 MB, so the speed of running will be greatly reduced, there is no way, Java programming has always been so, this is also a small regret. 1. The version 2 does not simulate a mobile phone of the actual model, while version 1.3 Has a simulation environment for the simulated product 7110.

2. Ericsson wapide4

Ericsson launched a WAP development kit, and Nokia development kit similar, Ericsson this tool is also an integrated development environment, more convenient, you can download from this address: http://www.ericsson.com/wap. Compared with Nokia's WAP development tool, Ericsson's development tool is relatively simple and has few development documents, however, it runs much faster than the Nokia Development Kit, especially machines with around 64 MB of memory.

Iii. Up. sdks 4.0

Phone.com has no integrated IDE development environment compared with the above two development tools. This development tool can be obtained in: http://www.phone.com.
From the above descriptions, among the three popular WAP development tools, the most attractive of course is Nokia's simulated simulation environment, graphic interfaces, and rich development documents, it is indeed rare. In addition, there are other software that can browse WAP websites, such as winwap and wapman. They can directly browse WAP websites on PCs. It is worth mentioning that, the browser version 4.0 launched by opera already supports direct access to the WAP website in the browser. This compact browser is very powerful. I believe that Microsoft will not sit and wait, and may add the WML file support feature in later versions of IE.
The setup of the above WAP simulation development environment is relatively simple and can be understood in a little bit of English.

Chapter 3 WML/WMLScript Design

Now let's officially design our WAP site. Just as the current web site is based on the HTML language, the WAP website is based on the WML language, the WML language actually follows the current XML technology, but it doesn't matter if you don't understand XML. You can get started quickly.
The biggest difference between WML and the previous HTML language is that the limits of WML are very strict, as shown in the following aspects:
1. All labels and attributes in WML are case sensitive.
2. for consecutive spaces, the WML compiler considers it
3. All tags must be enclosed in double quotation marks.
4. All tags must be closed. For unpaired tags, you must add "/" before ">", such"
"
Be sure to pay attention to the above points. Otherwise, the mobile phone may fail to browse WML. This is just a habit, mainly because the "lazy" habit we developed in the HTML era is not very good. It is a disaster caused by the compatibility of IE, ^_^
In WML, the most basic unit is "card", which is used to provide users with an interactive interface. This is actually designed to take care of the relatively small screen of the mobile phone, in addition, the mobile phone's processing capabilities are limited, so it is impossible to load the entire page as we often use IE and other browsers. When using the scroll bar to view the content, the WML file is designed for mobile browsing, A maximum of 1.4 K is allowed, so we can split the large leaf area into several cards for one display. Multiple "cards" constitute a "deck ", even if a "layer" is used, only one layer can appear in a WML file, just as only one "" tag is used in HTML.
Remember to use it as long as you want to display some text on your phone"

 

"Tags enclose the text. Let's take a look at a simple example: helloworld

 

Http://www.wapforum.org/DTD/wml1_1.1.xml>

Hello! World!

Appendix. WAP terminology
L WAP :( Wireless Application Protocol) is a Wireless Application Protocol in Chinese, which is different from GPRS, it aims to introduce rich Internet information and advanced services to wireless terminals such as mobile phones. In a metaphor, both GPRS and GSM are on the road, while WAP is on the road. After China Mobile activated GPRS, WAP traveled on the GSM and GPRS roads, while traveling on the GPRS road could increase the data transmission speed. Therefore, the content on the current WAP can be browsed and applied through GPRS.
L WML: Short for wireless makeup language. Mobile phones supporting WAP technology can browse internet content described by WML.
L push: The push technology can directly deliver content to the user's desktop in real time. Its advantages are obvious, and users do not have to spend time and money to search online. It allows users to book information from the site and automatically downloads the webpage for users to browse offline.
L GPRS (General Packet Radio Service) is a general grouping wireless service developed on the existing GSM system. The most fundamental difference between GPRS and GSM systems is that GSM is a circuit switching system, while GPRS is a group switching system. GPRS is particularly suitable for intermittent, sudden, or frequent, small amount of data transmission, and occasional transmission of large data volumes. We can understand GPRS as a higher level of GSM.
L Ota: the abbreviation of over-the-airtechnology. The Chinese translation "Download in the air" is based on Mobile Communication (GSM or CDMA) the air interface to remotely manage SIM card data and applications. Air interfaces can use WAP, GPRS, CDMA 1X, and the most popular short message technology.
L URL: Uniform Resource Locator refers to the URL we enter when surfing the Internet. WAP is also accessed based on this address.
L WAE :( wireless application environment) wireless application environment
L WDP :( wireless datav protocol) Wireless Datagram Protocol
L Wim :( wireless Identity Module) WAP identity recognition module
L WSP :( Wireless Session Protocol) Wireless Session Protocol
L WTA :( wireless telephone application) wireless phone application
L WTLS :( Wireless Transport Layer Security) Wireless Transmission Security Protocol
L XML: XML is an extensible source phrase that defines new tagging rules and organizes data according to these rules.
L PDa: (Personal Digital Assistant) Personal Digital Assistant, a small portable electronic storage Record Device
L Misc. wtbs: (WAP classic third-party business support sub system :)
Misc platform WAP third-party Business Support System