An electronic commerce system is inherently interdisciplinary and there are many different ways to implement it. Figure 1 shows the structure of a traditional electronic commerce system and a typical example of such a system. The system structure includes four components , some of which are at least partly shared by mobile commerce systems:
Electronic commerce applications: Electronic commerce is defined as the buying and selling of goods and services and the transfer of funds through digital communications. The applications are numerous , including auctions, banking, marketplaces and exchanges, news, recruiting, and retailing , to name but a few.
Client computers: Desktop computers are used for electronic commerce, whereas wireless handheld devices are used for mobile commerce.
Wired networks: This component is the major difference between electronic commerce and mobile commerce, although the latter must also include wireless networks.
Host computers: A user request, e.g., database accesses or updating, is actually processed at a host computer, which contains three major kinds of software: (i) Web servers, (ii) database servers, and (iii) application programs and support software. These will be examined in more detail later.
Compared to an electronic commerce system, a mobile commerce system is much more complicated because components related to mobile computing have to be included. To facilitate understanding and constructing mobile commerce systems, this chapter will use a modular approach to analyze the system. Figure 2 shows the structure of a mobile commerce system, consisting of six components, and an example of such a system that is currently possible based on existing technology. The network infrastructure for mobile commerce systems consists of both wired and wireless networks. The wired networks component has the same structure and implementation as that needed by an electronic commerce system. We will thus devote our attention to the wireless networks. All components other than the wired networks will be examined in the later sections of this chapter.
To explain how these components work together, the following outline gives a brief description of a typical procedure that is initiated by a request submitted by a mobile user:
Mobile commerce applications: A content provider implements an application by providing two sets of programs: client-side programs, such as a user interface on a microbrowser , and server-side programs, such as database accesses and updating.
Mobile stations: Mobile stations present user interfaces to the end users, who specify their requests on the interfaces. The mobile stations then relay user requests to the other components and display the processing results later using the interfaces.
Mobile middleware: The major purpose of mobile middleware is to seamlessly and transparently map Internet contents to mobile stations that support a wide variety of operating systems, markup languages, microbrowsers , and protocols. Most mobile middleware also encrypts the communication in order to provide some level of security for transactions.
Wireless networks: Mobile commerce is possible mainly because of the availability of wireless networks. User requests are delivered to either the closest wireless access point (in a wireless local area network environment) or a base station (in a cellular network environment).
Wired networks: This component is optional for a mobile commerce system. However, most computers (servers) usually reside on wired networks, such as the Internet, so user requests are routed to these servers using transport and/or security mechanisms provided by wired networks.
Host computers: This component is similar to the one used in electronic commerce, which includes three kinds of software. User requests are generally acted upon in this component.
To better explain the above procedure, Figure 3 gives a flowchart showing how a user request is processed by the components in a mobile commerce system (Leavitt, 2000).