Mobile device management (MDM) and OMA (OTA) DM protocol wizard (II) -- WAP protocol (1)
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16. Can I directly access the WiMAX device through a web server?
For more information, see "WAP protocol (1) -- Chapter 1 WAP network deployment"
17. Can I use TCP instead of WDP/udp to interact with WiMAX/3G devices?
For more information about WDP and UDP, see "WAP protocol (1) -- Chapter 1 WAP protocol stack".
Theoretically, this is acceptable, but it is not recommended in practice. Long-distance wireless transmission network stability is not high, may cause too many TCP retransmission affect the wireless network speed, such as China Mobile's GPRS (2.5g) network uses UDP protocol.
WAP protocol (1)
1. Why does WAP (Wireless Application Protocol)
The emergence of Internet and mobile communication has greatly affected and changed people's life and work methods. However, for a long time, accessing the Internet through mobile devices is just a dream. WAP (Wireless Application Protocol) is generated in this context, allowing people to access the Internet through various mobile devices anytime and anywhere.
2. What is WAP?
WAP is short for wireless application protocal and is an open global standard. The WAP Technology establishes a bridge between the Internet and wireless devices, and defines a way for wireless mobile devices to communicate with fixed servers in the network.
3. WAP Forum
In the early 1997 s, omnipoint, a U.S. network operator, proposed to provide mobile information services. This intention soon received replies from some large companies, but they used their proprietary technologies. omnipoint clearly stated that, A public open standard should be developed. In the end, Ericsson and Motorola joined the Nokia and phohe.com teams to set up a WAP Forum and jointly develop the WAP protocol to develop unified application standards for Internet businesses in mobile communications.
Today, WAP forums have been integrated in the Open Mobile Alliance (OMA) and no longer exist as independent organizations.
4. WAP development stage
Phase 1: wap1.x (1998 ~ 2002)
At that time, it was in the 2G wireless transmission technology, and the bandwidth of the wireless data transmission system was very narrow (gsm csd 9.6 K). Due to switching and other reasons, the data transmission was also unstable, in addition, the mobile terminal screen is small, and the display color and capabilities are limited. In view of these features, the WAP Forum has compiled a series of protocols, such as WML, WSP, WTP, and WDP. To meet wireless Internet access requirements.
Stage 2: WAP2.0 (2002 ~ 2004)
At this stage, the wireless data transmission technology has been effectively developed, and the transmission speed and reliability have been well ensured. Therefore, the WAP Forum canceled the protocols for wireless transmission, such as WSP, WTP, and WDP, instead of Internet-related protocols (such as TCP and UDP), WML is also moving closer to XHTML. Features such as MMS, provisioning, and pictograms are added to the business, and uaprof (User Agent profile) and push capabilities are enhanced. The trend of wired and wireless convergence is obvious, and wireless network functions such as push and provisioning play an important role in the development of wired network Internet.
Stage 3: Open Mobile Alliance (OMA) (under development)
XHTML will become the only markup language used, and websites will become the unity of wired and wireless Internet services. The original WML, WSP, WTP, WTLS, and WDP of WAP will all disappear, replacing Internet-related protocols. Mobile network technologies such as push, personalized customization, terminal adaptation, and content playback will be applied to the entire Internet and become an important functional component. Due to the development of wireless data transmission technology in this phase, there is basically no difference between wireless transmission and wired transmission for upper-layer applications, and the Internet has never been integrated in wireless and wired communication systems. At this stage, mobile data and value-added services have been greatly enriched, and various types of mobile terminals have been fully applied and verified.
5. WAP protocol stack
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WAP Internet
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Application Layer (WAE) HTML
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Session Layer (WSP)
------------------------ HTTP
Transaction layer (WTP)
------------------------
Security Layer (WTLS) SSL
------------------------
Transport Layer (WDP/UDP) TCP/UDP
------------------------
3G, WiMAX...
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(1) WAE Application Layer
The main purpose of the application layer is to enable operators and service providers to effectively establish services and applications on different wireless platforms. WML (similar to hxml for the Internet), wscript (similar to JavaScript For the Internet), wireless telephony application (WTA, wtai) and some data formats (such as wbmp image format, phone book records and calendar records ).
The wireless telephone application (WTA) enables WAP to be well integrated with existing advanced telecommunication services in the telecom network, such as intelligent network services. Through user interfaces, mobile users can apply various telecom services without modifying mobile terminals.
(2) WSP Session Layer
The Session Layer Protocol provides connection-oriented (confirmed push) or connectionless push (connectionless push) Session communication services for upper-layer applications.
(3) WTP Transaction Layer
It provides a lightweight transaction-oriented service that is specially optimized and suitable for wireless data networks.
(4) WTLS Security Layer
The SSL-Based Secure Transmission Protocol provides encryption, authorization, and data integrity functions.
(5) WDP Transport Layer
The Wireless Datagram Protocol is a common data transmission service that supports a variety of wireless bearer networks, making the upper-layer WAE, WSP, WTP, and WTLS independent of the lower-layer wireless network, use the lower-layer bearer capability to provide consistent services for the upper layer.
If the message received by the WAP proxy/gateway is transmitted over the UDP protocol of the Internet, the WAP proxy/gateway also uses UDP to replace WDP and interact with mobile devices. For more information about WAP proxy/gateway, see the next chapter "WAP network deployment ".
6. WAP network deployment
(1) WAP applications directly interact with devices through the WAP Server (WAP application server)
<Base station (BS) signaling network>
[Mobile device] <----- WSP -----> [WAP Server]
If you only provide simple WAP applications, you can use an existing network server and only change the MIME type to upload the WAP webpage or program to a server that supports the WAP function, mobile devices can access the service by entering a URL. The WAP server must implement the WAP protocol stack.
You can use Microsoft iis6.0 to implement a WAP application. The procedure is as follows:
1) First, enable IIS to set a new MIME type for it and set it in the HTTP header option of website properties. Add the MIME type required by Wap.
Mime Type of the extension. WML text/vnd. WAP. WML. wbmp image/vnd. WAP. wbmp. wmlc application/vnd. WAP. wmlc. WMLS text/vnd. WAP. WMLScript. wmlsc application/
Vnd. WAP. wmlscriptc
2) After confirmation, your IIS can support WAP, but when we enter the WAP page address in the browser to access it, we will prompt to download the WML file. In this case, you must install the WAP browser, such as m1_ate, can be in http://www.gmcc.net/wap/
Download m3stp06.zip.
Tomcat supports WML. If not, modify catalina_home/CONF/Web. xml. Add the following content in the mime ing section:
<Mime-mapping>
<! -- WML source -->
<Extension> WML </extension>
<Mime-type> text/vnd. WAP. WML </mime-type>
</Mime-mapping>
<Mime-mapping>
<! -- Compiled WML -->
<Extension> wmlc </extension>
<Mime-type> application/vnd. WAP. wmlc </mime-type>
</Mime-mapping>
<Mime-mapping>
<! -- WML script source -->
<Extension> WMLS </extension>
<Mime-type> text/vnd. WAP. WMLScript </mime-type>
</Mime-mapping>
<Mime-mapping>
<! -- Compiled WML script -->
<Extension> wmlscriptc </extension>
<Mime-type> application/vnd. WAP. wmlscriptc </mime-type>
</Mime-mapping>
(2) The web server interacts with the device through the WAP proxy (WAP Gateway)
<Base station (BS) signaling network>
[Mobile device] <---- WSP ---- [WAP Gateway] --- HTTP ---> [WAP Server]
The WAP proxy/gateway implements the conversion between the WAP protocol stack (WSP, WTP, WTLS, and WDP) and the Internet protocol stack. The WAP proxy translates WAP requests into WWW requests, and also translates web server responses into compressed binary WML data for mobile terminals to understand. Information Content codecs compress and encode WAP data to reduce network data traffic and maximize the utilization of low data transmission rates in wireless networks. At the same time, WAP also uses error correction technology to ensure that the network browsing and data transmission processes are not seriously affected by changes in the quality of wireless channels.
7. WAP2.0
In WAP2.0, the following new protocol stack functions are supported:
(1) On the transmission layer, WAP2.0 adopts the WP TCP/IP protocol with wireless features, so that the network can transmit data based on IP addresses. Wp tcp provides connection-oriented services, which are optimized for wireless environments and can fully interact with standard TCP applications on the Internet.
(2) At the Session Layer, WAP2.0 adopts the wireless HTTP protocol (wp http). The wp http specification is a subset of HTTP protocols for wireless environments and can be used together with HTTP/1.1. The interaction between the WAP device and the WAP Proxy Server/WAP Server
The basic model is the HTTP Request/Response Processing Mechanism. Wp http supports response body compression and secure channel establishment. In this way, the WAP proxy server is not required in WAP2.0, because the client and the source server can be directly completed by using HTTP/1.1.
Become a mobile application.
(3) WAP2.0 adds more security assurance measures, including using the TLS protocol. When WAP2.0 supports TCP/HTTP, it allows mobile terminals and application servers to directly establish a TLS security tunnel, implements end-to-end encryption. Provides improved end-to-end security and integration
Wired Internet to ensure the security of mobile services such as mobile commerce and mobile banking applications. The subset of the wireless protocol of TLS allows interaction for secure transmission. A subset of TLS protocols includes security measures such as encryption clustering, validation Word format, signature rules, and session recovery.
.
WAP2.0 has the following advantages:
(1) Faster: the WAP gateway does not need to convert HTTP/TCP and WSP/WTP/WDP protocols, and does not need to parse WSP/WTP/WDP on the mobile phone side, however, HTTP/tcp Wireless Configuration is required in the network.
(2) Performance Improvement: because a large number of protocol conversions are not performed, the same hardware devices support more concurrent users.
(3) provides an end-to-end security mechanism. For example, if TLS is used, the WAP gateway does not need to parse HTTP applications. It is an end-to-end protocol for transparent transmission.
(4) rich content: WAP2.0 protocol adopts a language compatible with wired Internet, so it has gained more extensive support, more applications can be used on the mobile Internet more easily, which is not possible on wap1.x. This compatibility also makes WAP2.0 better than wap1.x.
With a longer term of use and a stable product form (without frequent upgrades in protocols and Markup languages), mobile users can enjoy the rich content of the wired Internet.