Tài liệu Điện thoại di động băng thông rộng không dây P6 pdf

4 Emerging Wireless Applications and Protocols 4.1 Introduction Two drivers have taken the market by surprise in recent years: wireless is the first and the second is the Internet and Internet technology. At the end of 1998 there were around 260 million wireless mobile users and growth continues at over ten million new subscribers per month. The latest forecast figures by Delson Group indicate that the total number of wireless cellular subscribers world-wide will reach two billion by 2005. Convergence of wireless and Internet will be one of the hottest topics in the coming years. Wireless Mobile Internet (or WMI) and its devices are coming to the market in ever increas- ing numbers all over the world. The investment in this business will be over 100 billion dollars within the next several years. The various sectors of the industry have also been active on the standards front and in the creation of alliances and forums that will carry the momentum forward. The WAP Forum and the WAP (Wireless Application Protocol) standards are particularly significant since this industry standard insulates the Internet-based application from the wireless mobile network infrastructure. Thus, content (service and application) can now be decoupled from delivery (bear network). This allows the applications to run over wireless mobile networks, both current and future, thereby creating a massive new global market for wireless value-added services. Wireless mobile users will not just want to access all the information that is available on the Internet via a phone. It therefore makes better sense if the operator selects an appropriate service portfolio that is tailored to mobile subscribers. It is also impractical to deliver the content to a phone in the same manner as that supplied to a PC. The graphics and hyperlinks need to be stripped out, but this only represents a Band-Aid approach to the problem. What’s needed is a wireless equivalent to the WWW, which is where the WAP comes into the picture. WAP is an industry standard that allows software developers to create content suitable for display on ‘smart’ mobile phones. They write their service according to the WAP specifica- tion and it can then be delivered over any mobile network. Developers do not need to know Broadband Wireless Mobile: 3G and Beyond. Edited by Willie W. Lu Copyright  2002 John Wiley & Sons, Ltd. ISBN: 0-471-48661-2 anything about the delivery process and writing WAP-compliant applications is very similar to creating WWW content. Therefore, WAP hides the complexity of wireless networks, both current and future, at the application layer. This means that it is very easy to develop lightweight Internet applications that will run on the new wireless information devices. In addition to the WAP standards, there are also several other solutions available in the market, for example, iMode and wJAVA (wireless JAVA). If anyone has any doubt about the potential of wireless Internet, they need only look at the iMode service provided by the Japanese service provider NTT DoCoMo. In only about 15 months, DoCoMo built its iMode service into a popular wireless experience serving nearly 10 million users. Currently, a large amount of information exists in the Internet that can meet very diverse needs. This is clearly a good match for mobile wireless users while travelling from place to place. It has been projected that most handsets will be equipped with WAP and Wireless Java in a few years for wireless Internet applications. When Internet information can be delivered wirelessly according to handset geolocation information, it becomes even more valuable and convenient. 4.2 Wireless Application Protocol (WAP) The significance of WAP goes far beyond merely superposing the Internet on wireless networks. The WAP business will be one of the next storms in the coming years. 4.2.1 WAP Markets Why is the WAP so important? It is driven by the huge wireless mobile market as well as the Internet infrastructure. From Figure 4.1, the number of mobile phones will reach around 1.3 billion by 2004, and most of the phones will be WAP equipped. The importance of WAP is reflected in the following statements: † Mobile will make the Internet ubiquitous. Most of the applications are things that we already do – the industry’s task is to convert a share of our use onto wireless Internet. Broadband Wireless Mobile: 3G and Beyond240 Figure 4.1 Worldwide Internet subscribers, 1999–2004 by IDC. † Wireless Internet is a strategic imperative. Operators must provide these services to avoid revenue and profit erosion. † WAP is a key building block for wireless Internet.WAP has received huge industry back- ing; it opens the market to new players. Therefore, the wireless Internet will be big and WAP will be a main contender (see Figure 4.2 by OVUM). By March 2001, over 40 million WAP devices had been shipped worldwide (Figure 4.3), and thousands of applications are already available in the market including (but not limited to): † M-commerce – shopping, ticket purchases, reservations, comparison shopping † Finance – statements, funds transfer, shares trading † M-billing – notification, presentation and payment of bills † Enterprise access – inventory, shipment/sales updates, email access † M-care – customer service, payment status, other backroom operations † Entertainment – games, gambling, interactive multi-player events † Messaging – communication and collaboration † Travel – scheduling, advisories, reservations † Location-smart services – traffic reports, parking information, store discounts, event recommendations In the global market: † Over 150 carriers deployed or in final testing of WAP. † Tens of thousands of developers are now creating applications and contents. Emerging Wireless Applications and Protocols 241 Figure 4.2 Wireless Internet and WAP Market (source: OVUM). † Over 12,000 WAP sites are available from 100 countries. † Over 5 million WAP-readable pages available. † Over 40 million WAP-enabled handsets are in circulation worldwide. As shown in Figure 4.2, the revenue from WAP-like active micro-browser users is growing very fast (Figure 4.4). By 2005, it will reach over $300 billions. In a word, WAP is an application tool towards wireless Internet that meets: Broadband Wireless Mobile: 3G and Beyond242 Figure 4.3 WAP devices worldwide (Source: WAP Forum). Figure 4.4 Revenue from Active Micro-Browser Users (source: OVUM). † anytime, any place and anywhere access † more mobile terminal users than PC users † mobile terminals are personal devices However, the key success factors for WAP depend on the followings: † service marketing † price † time to access service † overall user experience and service design 4.2.2 WAP Architectures and Protocols The focus of WAP is to bring mobile data to the mass market. The way of providing this is to map internet-type applications plus telephony-specific features onto wireless requirements. Internet pages known from the fixed network will be processed by compressing information and representing this in so-called ‘cards’ on the handset display. A very important advantage of WAP is that it aims to provide standardised support for wireless data applications. So each handset developed according to the WAP standard is able to support WAP-based applications in the whole network. With this technology in place, a new information service can simply be developed as a web site and then viewed on the screen of the phone. 4.2.2.1 What is WAP? WAP is the set of technical standards that enables users of wireless devices to access, and receive content from the Internet with: † open, non-proprietary † global † device independent † bearer independent † a full-fledged Internet citizen WAP is a standard developed by consensus from engineers, scientists, specialists and experts from over 500 companies all around the world. It adopts Internet protocol to the requirements of the wireless networks (see Figure 4.5). WAP also opens the world of mobile data services, for example, it brings mobile data to the mass market, Internet-type applications plus telephony-specific features as well as providing standardised support for wireless data applications. WAP is also applicable to many different wireless beares and infrastructures (see Figures 4.6 and 4.7). The major WAP units and functions include: WAP gateway † serves as proxy † provides protocol mapping between standard and WAP protocol Emerging Wireless Applications and Protocols 243 † provides encoding/decoding for efficient transfer of data † provides access to mobile data bearers WAP servers † supports standard Internet protocols † provides application contents and scripts in WAP-specific or standard Internet formats Broadband Wireless Mobile: 3G and Beyond244 Figure 4.5 WAP overview (source: Siemens). Figure 4.6 WAP applicable to many wireless beares (source: Siemens). WAP clients † supports WAP protocol stack † provides encoding/decoding † enables browsing of WAP contents † enables user intersection † supports intersection with SIM WTA Server † located within secure network operator domain † communicates with client via gateway † able to ‘Push’ WAP contents to WAP client † Figure 4.8 shows this structure. 4.2.2.2 WAP Roadmap The goal of WAP forum is to make the mobile device a first class citizen of the web. WAP fills a unique role of: † intersection of mobile/web/Internet † wireless industry focal point, for example, requirements, ideas, design and development as well as interoperability † collaborator with key web/Internet groups, for example, technical development, advisor on wireless capabilities and requirements † industry forum for multi-vendor interoperability The WAP roadmap is shown in Figure 4.9. The focus includes the following. Emerging Wireless Applications and Protocols 245 Figure 4.7 WAP infrastructure (source: Siemens). Bandwidth Adaptation and evolution of the protocol suite: † 2.5G and 3G bearers: † convergence with IP environment (for example, TCP, TLS, …). Creation of new services, enabled by bandwidth: † streaming media † larger data types (for example, animations) Broadband Wireless Mobile: 3G and Beyond246 Figure 4.8 WAP units and functions (source: Siemens). Figure 4.9 WAP Roadmap. Convergence Collaboration with IETF, W3C and others: † to define a common Internet framework † suitable for mobile and fixed devices Never ending process: † WAP 1.X leveraged HTTP, XML, URLs and the web † WAP 2.X will expand to leverage XHTML, TCP, etc. Joint work in the past includes: † XHTML-basic † CC/PP/UAProf [ ] Future work: † protocol optimisations (for example, TLS, HTTP, TCP) † application models (for example, voice, multi-mode UI) Multimedia Mutimedia services enabled by: † more bandwidth (GPRS, 3G, etc) † Moore’s law and handset evolution † imaging – colour, standard formats, etc. † audio – download clips, streaming, etc. † video – download clips, streaming, etc. † streaming protocols † longer term, QoS and isochronous protocols Advanced user-interface Handset evolution drives requirements: † pixel resolution, density and colour † new input models (voice, pointers, security sense, etc.) Application model enhancements: † styling model † document model † advanced script integration † voice interface † muti-mode user interface Application services Additional application services enabled by terminal and network capabilities with Web- enabling unique wireless features: Emerging Wireless Applications and Protocols 247 † terminal location † push † commerce capabilities † messaging Management services Services targeted at network operator: † provisioning † terminal monitoring † terminal management 4.2.2.3 WAP Traffic Model The WAP traffic model takes into account a couple of input parameters like: † user behaviour (WAP usage time, BH portion, view time, etc) † different applications and their usage † application characteristics (transactions, bandwidth volume) And provide us the information about: † traffic per use † overall bandwidth demand (upstream/downstream) † number of transactions to WAP devices (NetServer, firewall, WAP server, WAP gateway) Figure 4.10 shows a simple WAP traffic model. The WAP traffic model is only for general-purpose analysis of the WAP performance, and should not be taken as a standard model in different applications and services. 4.2.2.4 WAP and XML XML is a framework for markup languages, but not a markup language itself. WAP is the only wireless Internet protocol that is built on XML. Therefore, XML is a platform technol- ogy, not a presentation language. XML allows content to be published one time, but can be used many times. However, WML (the core markup language of WAP) is designed for presentation. The background of XML is: † XML is a platform technology: – Basis for many markup languages: SMIL, MathML, WML, XHTML, VoiceXML, etc. – Basis for much application middleware and protocols. † XML is not a presentation language like HTML. † W3C has based a family of languages on XML: – XHTML – next generation HTML (migrated to the XML platform); – SMIL – synchronised multimedia integration language; – MathML – mathematical markup. Broadband Wireless Mobile: 3G and Beyond248 [...]... WAP is ready for advanced features, for example, graphics, colour, animation, large file downloads, multimedia 4.2.2.5 Next generation of WAP The next generation of WAP will include: † † † † † † † † † † XHTML TCP colour graphics animation large file downloading location-smart services streaming media data synchronisation with desktop PIM advanced capabilities and features open, non-proprietary – device... jokes, music downloads, video clippings Banking, auctions, ticketing, purchasing, loyalty, bill payment Coupons, discounts, sponsored services, directories PIM, e-mail/messaging, instant messaging, unified messaging, chat rooms Intranet and database access, groupware, file transfer Tracking, dispatch, field sales automation Navigation and mapping Remote control, monitoring, configuration Mobile e-commerce... will be even more important The user fingerprinting function (for example, sensor and processor) will be equipped The phone can be multi-functional and re-configurable for different persons In the application layer, WAP handles end-to-end direct security signalling to ensure the secure transmission 4.2.4 WAP Interoperability Interoperability is an essential topic for communications, containing clear specifications,... is: new handsets and mobile commerce † New handsets: –will be new data oriented models; –peaceful co-existence: keypad, screen pointer, security check and voice recognition; –prediction: a raft of better handsets from both traditional and a new wave of handset manufacturers † Mobile commerce: –WAP is a key enabler; –source of significant future revenues; –new stuff: bar code scanning, electronic wallet,... web applications The future markup directions include: † Markup language convergence † Convergence platform is XHTML: Figure 4.11 Typical XML Usage – I (source: WAP Forum) Figure 4.12 Typical XML Usage – II (source: WAP Forum) Emerging Wireless Applications and Protocols 251 – XHTML is next-generation version of HTML based on XML; – XHTML has mudularity, enabling diverse uses † Multiple profiles built... architecture: – enable access to content best suited for the requesting client † Ensure interoperability and backward compatibly The universal accessibility defines the concepts of: † Publish once, render differently: – content published in a neutral manner; – presentation and content are separated † Rendering is specific to client needs: – narrow the rendering gap – focus on a core mark-up; – provide modules... 32K or better) † scalable bandwidth on demand However, the spectrum is still finite, and spectrum efficiency is very important to the carrier business model as well as the user cost model 3Gwireless (including ongoing GPRS) and WAP are excellent partners: Emerging Wireless Applications and Protocols 255 † Bandwidth helps deliver rich content: –without an application layer, it’s a pipe; –no standard, no... Also, WAP and 3Gwireless network is a perfect match, because: † Bandwidth is always good: –more bandwidth ¼ richer service platform; –new innovation and specification opportunities – for example, multimedia; –existing WAP services run better/faster/cheaper † ‘All-IP Net everywhere’: –simplifies application creation; –economics of scale in infrastructure † Bandwidth is a clear driver of innovation: –allows... for example, bank or corporate firewall; † packets between the handset and the secure proxy remain encrypted at all times WAP is by design, highly secure for mobile and location-smart (for example, store discounts and order, event booking) commerce, and the transactions are as secure as PC sites By mid of 2001, the WAP security will meet the most extreme demands of total encryption and secure proxies in... testing; – protocol is tested against the specification; – designed to ensure the device complies with the standard at the protocol layer The WAP testing is the foundation (on compliance), but not the building, the WAP vendor testing is still required for WAP interoperability The future WAP interoperability will focus on: † Universal accessibility: – ubiquitous access to Internet content and services from . telephony-specific features as well as providing standardised support for wireless data applications. WAP is also applicable to many different wireless beares and infrastructures. this in so-called ‘cards’ on the handset display. A very important advantage of WAP is that it aims to provide standardised support for wireless data applications.