Steppingstone
or Stopgap?
Kevin A. McQueary
Bowie State University
INSS 690 Professional Seminar
October 1, 2000
This paper addresses the current trend of m-commerce. The origins of the movement are discussed, and then it goes into great depth in regard to the protocols that make the technology work. Once the technology has been presented, a look is taken at the technology’s shortcomings. To assess the potential for this technology to survive, the technology is viewed from a business perspective. The paper concludes with an opinion of the technology based on the research.
Since its inception nearly thirty years ago, the Internet has evolved into an integral part of the developing global culture. In 1989 Tim Berners-Lee delivered the World Wide Web (WWW), a comprehensive database of hyperlinked multimedia that facilitates navigation of the Internet via a graphical user interface. The number of computers connected to the Internet has increased at an astonishing rate since 1983, achieving the status of a global infrastructure by 1993 (Lehnert, 1998). This was due in no small part to the popularity of the WWW. The WWW generated new paradigms for communications and conducting business. E-commerce, the term coined to describe business conducted over the Internet, was developed to take advantage of the now global marketplace. Buyers now had the opportunity to browse through the posted listings and make purchase selections from dozens of competing businesses geographically dispersed all over the world from the convenience of their own home.
The technology behind telephony has changed significantly over the course of its existence, albeit not nearly as quickly or as dramatically as the Internet. Current telephony trends emphasize mobility, especially in Eastern Europe where maintaining a wired infrastructure has proven exceedingly difficult. The cellular phone infrastructure is significantly easier and faster to install, upgrade, and maintain than its wired counterpart.
It was merely a matter of time before someone devised a means for a marriage of these two technologies. Mobile computing was born with the design of the laptop computer. Wireless modems facilitating mobile connection to the Internet soon followed. While this was an effective means of accessing the Internet in a mobile environment, it was rather inconvenient as the setup was often awkward and bulky. Also, this method was frequently overkill when the motivation for Internet access is considered. For example, mail requests do not require such extravagant presentation, as they are generally just text messages. A need for a more efficient and trim wireless data service was soon recognized.
Wireless Application Protocol (WAP) was developed in response to that need. Simply put, WAP is an attempt to define an internationally agreed upon set of rules and guidelines for transmitting data over wireless devices. WAP has to potential to empower mobile devices to access services of the existing wired Internet infrastructure previously available only to personal computers.
Before WAP, the industry leaders of the wireless device market worked independently in development of not only wireless devices, but also protocols to drive their devices. Ericcson developed a concept for value added services on wireless networks using a protocol called Intelligent Terminal Transfer Protocol (ITTP). Their idea involved facilitating communication between an intelligent mobile phone and service applications on a service node.
Unwired Planet decided to model their ideas based on common protocols used on the WWW. Handheld Device Markup Language (HDML) was modeled from HyperText Markup Language (HTML), providing a means for describing WWW content and user interface to be fed to mobile communication devices. HyperText Transport Protocol (HTTP) was the example used to develop the Handheld Device Transport Protocol (HDTP), a barebones protocol for performing client/server transactions.
Nokia followed with the Smart Messaging concept. Smart Messaging was designed specifically for devices using Global System for Mobile communications (GSM), using Short Message Service (SMS). Smart Messaging also used a markup language called Tagged Text Markup Language (TTML) streamlined for use in the mobile environment (AU-System Radio, 1999).
It soon became apparent that the divided effort to develop protocols for mobile network communications could result in a splintered market in which no one company’s products or services would prevail. U.S. network operator Omnipoint had issued a tender for the supply of mobile information services, only to receive numerous responses from potential clients using various proprietary approaches. Omnipoint refused the offers, suggesting that the vendors consider a more common approach (Buckingham, 2000). The industry leaders in wireless communications realized that only in joining forces in pursuit of a unified goal would they succeed.
WAP is the product of the WAP Forum, a coalition of wireless service providers in response to the potential for providing data services over wireless devices such as cellular phones and personal data assistants (PDAs). Originally established in June of 1997 by Ericsson, Motorola, Nokia, and Unwired Planet, the WAP Forum currently has over 400 members working in partnership to establish a standard that addresses the potential of this technology (WAP Forum, 2000).
The WAP Forum declared their intent to embrace and extend existing standards and technology wherever possible and appropriate. Their design attempts to create a global wireless protocol as a license-free standard that can be used on any wireless network technology. The WAP Forum itself does not develop any products, but rather endeavors to provide a common ground upon which wireless device producers and service providers can establish an agreed upon open standard for bringing the Internet into the wireless community (WAP Forum, 2000). By working in concert they have the potential to better their own respective positions in the marketplace because they are assured that their products and/or services will be usable on the wireless network infrastructure.
The WAP specification is the product of a well-designed plan. It builds upon existing wired industry standards as the basis for its own architecture and design. WAP designers considered the established Internet and WWW standards and optimized WAP to work with those standards within the constraints of the wireless environment.
The
Internet paradigm itself does not conform to a single well-established standard,
but rather a series of generally accepted ones such as HTTP and Transport
Control Protocol/Internet Protocol (TCP/P). A typical transaction on the Internet involves a client
making a request to a server connected somewhere along the Internet.
Familiar to most people are transactions accomplished with a Web browser.
Figure 1 illustrates such a transaction (AU-System Radio, 1999).
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Figure 2 Source: Varshney and Vetter, 2000
WAP builds upon this methodology, inserting an extra step in the middle to
accommodate a wireless client. A
WAP server, commonly called a Gateway, receives the request from the client,
formats it for the Internet and then sends it on the appropriate Web server.
Upon receiving the response the Gateway formats the response not only for
wireless transmission, but also for the specific technology of the client.
The figure below illustrates the transaction (Varshney and Vetter, 2000).
Because the capabilities of each wireless device can be radically different, the response must be formatted for the client’s specific technology. A PDA can typically accommodate not only text, but also graphics and a graphical user interface (GUI). A cellular phone with WAP technology, however, will not have a GUI, and rarely can display more than text. A pager would be constrained even further to mere text messaging.
The WAP client/server approach involves putting the majority of the intelligence with the WAP Gateway. All requested services and applications reside temporarily on the WAP Gateway, not permanently on the WAP device. The WAP Forum’s resulting design consisted of a comprehensive, scalable protocol that would require minimal resources of the client, compensating for the constraints by maximizing the resources of the network.
The WAP protocol itself is modeled after the International Standards Organization’s Open System Interconnect (OSI) model. The OSI model is one of the oldest and most popular reference models for computer networking, and is a highly regarded learning tool within academia.
The OSI model consists of seven layers, each with its own specific purpose. Each layer is transparent to the others, but works in cooperation with the others to accomplish the transaction. While the OSI model is not used on the Internet today, many of the protocols used on the Internet follow a similar approach. The WAP Forum has also used the OSI model as a template for WAP, resulting in a six-tiered model.
The WAP layers begin with the Wireless Layer, which concerns the specifics about transmissions over a wireless link. The Wireless Layer only addresses issues of the physical transmission of the information, and therefore parallels the Physical Layer of the OSI model. The job of WAP’s Wireless Layer is to separates the application elements from the bearer being used. This assists in the migration of applications between dissimilar transmission technologies. The most commonly used wireless network standards include GSM, developed in Europe and currently the dominant standard; Wideband Collision Detection Multiple Access (W-CDMA), a variation on the Ethernet standard that is a compromise of the best elements of GSM and CDMA; and Time Division Multiple Access (TDMA), an older telephony-based protocol that is similar to GSM.
Newer standards are constantly evolving, and WAP is designed to readily accommodate them. General Packet Radio Services (GPRS) is an ‘always on’ system that enables higher data throughput speeds than previously possible over existing GSM networks by breaking messages into small packets. Enhanced Data rate for Global Evolution (EDGE) is generally considered the last step for second-generation networks. It is a high-speed version of GPRS that works on both GSM and TDMA networks.
The Transport Layer is next. It uses Wireless Data Protocol (WDP) to provide a common interface to upper layers by adapting to the specific features of the client’s technology and provides port number functionality. WDP ensures that only the information that can be utilized by the client is returned upon a request. For example, WDP would ensure a pager would not be sent graphic images.
The WDP provides datagram functionality only when needed; it is not used on bearers that support User Datagram Protocol (UDP). In the event that a datagram is too large for the bearer, WDP is able to segment and reassemble datagrams as required. Wireless Control Message Protocol (WCMP) is an optional protocol extension of WDP. It can be used for diagnostic purposes or for error reporting when WAP is not used on a bearer using an Internet Protocol (IP).
Security is a serious concern with wireless devices, as messages can be captured by anyone within the scope of the transmission. The Security Layer uses the Wireless Transport Layer Security (WLTS) protocol to provide authentication, privacy, and denial-of-service protection. WLTS resembles the Transport Layer Protocol (formerly known as the Secure Sockets Layer), streamlined for the wireless environment. Confidentiality, authentication, and data integrity is certified using WTLS. The client can explicitly disable this layer if security is not a concern.
Next is the Transaction Layer, which uses the Wireless Transaction Protocol (WTP) to control the sending and receiving of messages. WTP was designed to prevent multiple transmissions and ensure message receipt by dividing messages into one of three different message classes. The first is unreliable one-way request, which results in no retransmission if the sent message is lost. The second is reliable one-way request, requiring the recipient to acknowledge the message to avoid having it resent. The last is reliable two-way request/respond, which takes the reliable one-way request one step further by acknowledging the acknowledgement. WTP also has the ability to segment and reassemble messages, and can selectively retransmit lost segments.
WAP also has a Session Layer, which uses the Wireless Session Protocol (WSP). WSP has two modes, connection and connectionless. Connectionless mode is only used in the event that there is no need for reliable delivery of messages. In connection mode, WSP negotiates with the Gateway to ensure the client gets services based on client hardware capabilities. WSP is also responsible for maintaining the connection to the Gateway and guaranteeing message delivery. WSP employs a technique called header caching to minimize bearer overhead by translating the HTTP plain text headers into binary code stored on the Gateway.
The uppermost layer is called the Application Layer. It uses the Wireless Application Environment (WAE) protocol to enable a range of applications to be used on various wireless devices using a ‘micro’ browser. The WAE is comprised of four various components. The first is called the addressing model. WAE utilizes the same syntax for message addressing as is used on the Internet, specifically Uniform Resource Locators (URLs). URLs access uniquely identified resources on the Internet using well-known protocol. On occasion, a request is made for an address that is not accessed using well-known protocols. In this event, e.g. a request for local telephony functions, WAP uses a similar addressing model called Uniform Resource Identifier (URI).
The second component of WAE is the Wireless Markup Language (WML). WML is a lightweight markup language that maximizes the use of the client’s limited hardware capabilities and minimizes the transmission bandwidth required to do so. Based on the Extensible Markup Language (XML), WML is WAP’s answer to HTML.
A WML service consists of a ‘deck’ of ‘cards.’ Each card represents a single unit of interaction with the user. Interaction with the user is defined as a request for information or the presentation of information. A collection of cards is a deck, and a deck typically constitutes a service. The limited capabilities of WAP-enabled devices inhibit inter-page navigation of the WWW. WML gets around that problem by presenting a user with a simultaneous presentation of a suitable amount of information extracted from the deck.
Common features of WML include familiar HTML elements like: navigation control, text formatting, event handling, variables, support for images and soft-buttons. In the pursuit of bandwidth conservation, WML can be encoded in binary by the Gateway to minimize the amount of data transmitted.
WMLScript is the third component of the WAE. It is based on the same scripting language as JavaScript, and is used to compliment WML just as JavaScript does HTML. WMLScript can add intelligence to services written in WML, e.g. loops, computational functions, and conditional expressions. WMLScript exists to overcome some of the limitations of WML, and has been designed to facilitate even greater functional expansion through WMLScript libraries. These libraries can be exchanged without affecting the core WMLScript. Binary encoding to minimize bandwidth consumption is another feature of WMLScript (AU-System Radio, 1999).
The final component of the WAE is the Wireless Telephony Application (WTA). WTA can create telephony services with a user-agent extended with telephony service functions, and logically separate from the common WML user-agent. The telephony service functions include the Wireless Telephony Application Interface (WTAI), the repository, event handling, and WTA Service Indication.
The WTAI allows WML and WMLScript to access a set of telephony-related functions for the mobile handset, which include phonebook control, handling text messaging, and simply dialing a phone number. Public Functions, Network Common Functions, and Network Specific Functions are the categories in which the various WTAI functions are grouped. The Network Common Functions are those available on all networks, whereas the Network Specific Functions are exclusive to a particular kind of network. Setting up calls is as yet the only function within the Public Functions library (AU-System Radio, 1999).
The repository addresses issues of real-time handling of content. Because there are instances when turnaround time for a particular transaction is a concern, the repository provides the means to store content within the device to facilitate offline access.
The WTA makes telephony services possible through event handling. Services stored in the repository can be triggered by events, as can WML functions. Typical events include the familiar incoming call, call answered, and call disconnected.
The WTA Service Indication is also responsible for responding to events. However, the WTA Service Indicator is designed to handle push events like email and pager notifications, traffic alerts, and stock quote triggers. A push event will trigger the user, prompting an appropriate response. The focus of most WAP application development is centered on taking advantage of the time-sensitive nature of push technology (WAP Forum, 2000).
The WAP protocol suite operates with one of four distinct transmission modes. Connectionless mode offers an unacknowledged datagram service that utilizes only the WSP and the WDP, and no guarantee of packet delivery. Connectionless mode with security adds WTLS to provide authentication, data integrity. Connection mode takes WSP and WDP, adding WTP in order to maintain reliable transmissions. Sent messages must be acknowledged in connection mode, and lost messages can be resent. Adding WTLS to the connection mode protocol results in connection mode with security (AU-System Radio, 1999)
Constraints
of the WAP Paradigm
The WAP protocol specifications were designed to optimize and extend existing Internet standards, as well as evolve to accommodate emerging technologies. The layer design allows each layer to function independently of the others. This design has the added benefit of allowing the replacement of any one layer to be transparent to the remaining layers. This technique will prove extremely useful in adapting WAP to advances in the transmission medium.
WAP is forced to address several issues that affect service due to the nature of the wireless network medium, specifically low bandwidth, high latency, and unreliable connections. Low bandwidth problems are diminished through a joint effort between the user and the protocol. The user can inadvertently consume too much bandwidth if the user is unaware of how to properly use available services. WAP attempts to minimize bandwidth consumption through binary encoding of WML, WMLScript, WSP, and WTP before transmission. WSP furthers the cause through its ability to suspend and resume sessions, and WTP acts to minimize both the amount of data transmitted and the number of transmissions.
High latency issues are reduced through the use of the WTA’s repository and clever scripting. Scripting can help lessen the number of roundtrips between a client and server during a transaction. Unreliable connections are avoided by the WSP’s ability to suspend and resume sessions.
The physical limitations of the wireless devices that support WAP can also pose difficulties in achieving desirable service. Device displays are not only frustratingly small, they come in various shapes and sizes. Consequently, WML structures work differently on different devices, resulting in unpredictable output. Limited input facilities require the user to perform lengthy key sequences to accomplish some functions. However, producers of mobile devices are constantly seeking new ways to construct the user interface.
Limited
memory and CPU impose serious restrictions on the capabilities of WAP devices.
While binary encoding of WML and WMLScript helps, it is not a solution.
Limited battery power restricts operating time.
These challenges may be overcome with time, or they may prove the demise
of the technology.
The number of hosts on the Internet has been increasing at a phenomenal rate. The chart to the right demonstrates that the number of Internet users worldwide in 1995 was 44 million, and nearly eight times that in 2000 (Lawrence, 1998). With the opportunity to reach literally millions of customers, the evolution of the Internet into a business marketplace was inevitable.
E-commerce has taken a significant slice of sales from brick-and-mortar retailers. Businesses that have declined to partake in the high-tech revolution, or have been merely too slow in their venture into the realm of e-commerce have noticed a tremendous impact on their bottom line. To stress that point, over 500 consumer electronics stores closed in 1999 (Schwartz, 2000).
Globally, e-commerce is gaining momentum. The chart below on the left predicts that revenue growth from e-commerce will be rather dramatic, especially within European countries. The chart below on the right displays data on Internet usage in the top 15 countries. Interesting to note is that with the exception of Sweden, the percentage of total population online in the United States is significantly higher than that of European nations (Schwartz, 2000). The notable lack of presence in the e-commerce market represents a rather large untapped revenue source.
Figure 4 Figure 5
European countries do, however, have a much higher penetration of mobile phone use than in the U.S. Forrester Research estimates that European mobile penetration will reach 1.7 billion subscribers by 2005, compared to only one-third of that in the U.S (Corrigan, 2000). The Financial Times reports that the number of mobile phone users compared to desktop Internet users is two to one worldwide, and predicts a three to one ratio by 2005 (Terazono, 2000). Mobile, or ‘m-commerce’ is poised to take advantage of the markets untouched by e-commerce, and WAP is the conduit through which m-commerce is conducted.
WAP-enabled devices have the potential to utilize the Internet, and mobile phones will represent a considerable segment of them. Current estimates from the Gartner Group predict that within three years nearly 50 percent of mobile phones will be WAP-enabled, and that within four years over 95 percent of all new mobile phones will be WAP-ready. The Gartner Group also forecasts that the installed base of WAP-enabled devices will surpass that of Internet-capable personal computers in 2003 (Veitch, 2000).
This proliferation of WAP-enabled devices has companies struggling to place WAP-ready content on the Internet, investing large sums of money in anticipation of increased business. One such example is Barklays Bank of Great Britain, who recently made an outsourcing deal with BTCellnet worth 250 million pounds to improve its online banking service to include access via WAP devices (Pravin, 2000). Other companies, like British Telecom, Breathe.com, and ClubNation are distributing free WAP-enabled phones, absorbing the cost of the phones in exchange for locking subscribers into ‘walled gardens’ which control the home page for the subscriber. Locking the subscriber allows the provider to reap revenue from advertising and m-commerce transactions (Dibble, 2000).
The industry segments targeted by m-commerce are primarily those of financial services, retail, and travel. The reason may be that time and location are significant factors in those types of transactions. The chart below is an excerpt from an October 1999 Forrester Group report, The Dawn of Mobile E-Commerce. It rates common Web applications against those factors to predict which applications would be most effective in the m-commerce marketplace.
Figure 6
Proponents of WAP seem to concur with the Forrester Group report. Many of the WAP applications are being developed to take advantage of the mobility inherent in the wireless environment. Location-sensitive applications that are designed to take advantage of the ability of WAP-enabled devices to know where they are can prompt customers with instant coupons that are sent to the WAP device based on the customer’s proximity to a store to solicit service. They can provide directions if necessary, and can also screen customers if their WAP device is set up to provide a personal profile. Time-sensitive applications are typically focused on financial transactions, such as stock trading and stock market updates (Schwartz, 2000).
Competition for the rights to the segments of the radio spectrum used by WAP devices has proven unexpectedly strong. In April 2000 Britain auctioned out licenses for mobile service providers. Analysts had predicted that the auction would bring in bids at a maximum of 1.5 billion pounds for each license. The competition for the licenses finished after the bids had risen to 4.5 billion pounds per license. Industry experts have voiced concerns that such high license costs could drive up the investment required to establish the European mobile infrastructure to over 315 billion U.S. dollars.
While WAP has to potential to navigate the WWW, the inherent technological limitations of both the transmission medium and the physical size of the hardware will prove too inconvenient to subscribers to pose a significant threat to the revenue generated by e-commerce. However, the unique capabilities of WAP devices could generate enough new ways of conducting business that m-commerce will be a significant economic factor in its own right.
Despite the convenience factor of many WAP applications and the saturation of the market with WAP-ready devices, customers still have to want to subscribe to the service for it to be a success. Just because the technology is in hand does not necessitate that it will be used. I predict that until the Internet browsing capability of mobile devices meets or exceeds that of desktop personal computers, the m-commerce market will be an insignificant economic factor maintained purely by enthusiasts captivated by its novelty.
AU-System Radio. (1999). WAP White Paper. [Online Web Site]. Available WWW.http://www.wapguide.com/wapguide/auwap.pdf
Addresses many of the technical details of the technology in layman
terms.
Buckingham, S. (2000). An Introduction to the Wireless Application Protocol. [Online Web Site]. Available WWW.http://www.gsmworld.com/technology/yes2wap.html#1
Provides a survey of the WAP protocol and discusses its features and
limitations.
Corrigan, R. M. (2000). Ericcson Create European WAP Fund: Any Takers? [Online Web site]. Available WWW.http://www.newsbytes.com
Discusses mobile phone penetration in Europe.
Dibble, T. (2000, July). Who Gave WAP Its Bad Name? New Media Age, 29.
Defends WAP against its antagonists.
Lawrence, S. (2000). The Net World in Numbers [Online Web site]. Available WWW.http://www.thestandard.com/research/metrics/display/
0,2799,10121,00.html
A source
for statistics on Internet, WAP, and mobile phone usage.
Lehnert, W. G. (1998) Internet 101 (4th ed.). Reading, MA: Addison Wesley Longman, Inc.
A solid reference for facts about the Internet.
Pravin, J. (2000, May). WAP Wizardry. Computer Weekly, 67.
Addresses the potential of the WAP protocol.
Sayer, P. (2000, May). U.S. Plays Mobile Catch Up. IT Week, v22 i20, 43.
Compares mobile phone penetration of the US versus Europe.
Schwartz, E. (2000, June). Mobile Commerce Takes Off. IT Week, v22 i35, p1, 32.
Provides good information about the e-commerce industry.
Terazono, E. (2000, Summer). Understanding WAP. Financial Times, 9.
Source for wireless statistics.
Varshney, U. & Vetter, R. (2000, June). Emerging Mobile and Wireless Networks Communications of the ACM v43 n6, 73-81.
Provides extremely technical information on wireless communications.
Veitch, Martin. (2000, July). Why WAP Will Be a Success. IT Week, v3 i30, 39.
Sings the so-called glories of WAP.
WAP Forum (2000). Wireless Application Protocol White Paper [Online Web site]. Available WWW.http://www.wapforum.org/what/WAP_white_pages.pdf
A discussion of WAP’s potential by its creators.
