【正文】 到移動設(shè)備或臺式電腦。 Web 服務(wù)代表了一種實施 SOA（面向服務(wù)的架構(gòu)），他們是最流行的一種。 B. Web 服務(wù) 7 迅速成為互聯(lián)網(wǎng)發(fā)展的重要技術(shù)，是網(wǎng)絡(luò)服務(wù)，一套標準的，可以通過網(wǎng)絡(luò)真理互連系統(tǒng)。 標準使用路徑共享的以太網(wǎng)協(xié)議和 CSMA / CA（載波偵聽碰撞避免的多址接入）和加密方法，有線等效保密算法。 本文提出的無線通信技術(shù)和 Web 服務(wù)技術(shù)的集成，實現(xiàn)無線點餐系統(tǒng)。無線和手持設(shè)備比比皆是，作為供應(yīng)商推銷到一計算，即時通信和隨時隨地的信息訪問的共同主題。 ? Applicationlevel (customer) security。 security I. I NTRODUCTION The rapid developments in information technology, particularly in wireless munication and web services technologies, are greatly changing the way people access and work with information. The convenience and powerful functionality offered by mobile devices such as PDAs, has encouraged many people to investigate the benefits of using them. Wireless and handheld devices abound as vendors pitch the mon themes of onetoone puting, instant munication and anytime, anywhere information access. While web services provide a technology for serviceoriented puting. Web services allow programs written in different languages on different platforms to municate with each other in a standard way . By integrating these technologies, consistent business models can be implemented on a broad array of devices: not just on mobile devices operating over mobile works, but also on servers and PCs connected to the Inter. The food ordering process in restaurants requires the coordination of simple tasks. Instruction flows mainly from customers to waiters then to kitchen and/or the bar staff, finally to the cashier . In a medium to large and busy restaurant this coordination is a challenge and requires an efficient ordering system. Errors in ordering processes lead to incorrect or out of sequence meal preparation or nonconsumable and results in added cost to the business. This paper presents an integration of wireless munication technologies and web services technologies to realize a wireless food ordering system. In this system, it implements wired and wireless data access to the servers and food ordering functions through both desktop PCs and mobile devices such as PDAs over a wired/wireless integrated local area work. The system is based on secure web service architecture and some security strategies to ensure mobile munication security are adopted. Web servicesbased wireless applications on mobile devices provide a means of convenience, improving efficiency and accuracy. II. W IRELESS LAN AND W EB SERVICES A. Wireless LAN A wireless LAN (WLAN, Wireless Local Area Network) is a flexible data munication system implemented as an extension to or as an alternative for, a wired LAN within a building or campus . Using electromagic waves, WLANs transmit and receive data over the air, minimizing the need for wired connections. Thus, WLANs bine data connectivity with user mobility, and, through simplified configuration, enable movable LANs. The IEEE group of standards specifies the technologies for wireless LANs. 2 standards use the Ether protocol and CSMA/CA (carrier sense multiple access with collision avoidance) for path sharing and include an encryption method, the Wired Equivalent Privacy algorithm. The , b, and g standards are the most mon for home wireless access points and large business wireless systems. A remote user can use WLAN to access the Inter through public access points (“hotspots”) provided by service providers. When in the office, they may access WLAN through wireless access points. In enterprise environments, WLANs are usually plemented by security mechanisms, such as VPN (Virtual Private Network). Over the last several years, WLANs have gained strong popularity in some markets, including the healthcare, retail, manufacturing, and academic areas. These industries have profited from the productivity gains of using handheld terminals and notebook puters to transmit realtime information to centralized hosts for processing. Today WLANs are being more widely recognized as a generalpurpose connectivity alternative for a broad range of business customers. B. Web Services Quickly being a significant technology in the evolution of the Inter is web services, a set of standards that can interconnect systems over a verity of works. It is an open XMLbased technology providing a generic data exchange format and has been rapidly adopted by many vendors. Web services can easily be built upon existing applications, no matter what the underlying technology is. Because they are expected to have a growing familiarity and acceptance among many users and offer great technological promises, Web services are an interesting subject for the investigation of their possible application in many systems . Web services are a new generation of web application. It bines the advantages of the ponentoriented methods and web techniques, and they can describe its own service. It can also publish, locate and transfer modularized application in web. The provided functions of web services may be simple, but it also contains extraordinary plicated business logic. Web services represent a kind of implementation of SOA (ServiceOriented Architecture), and they are the most popular one. In addition, the three operations of SOA can only process when the ponents of SOA interact. Therefore some standardized techniques are used in web services, including UDDI, WSDL, HTTP, SOAP, and XML and so on. Web services bee the best choice for developing application of SOA . III. DESIGN AND I MPLEMENTATION OF THE SYSTEM A. System Architecture In the system, we adopt fourtiered webbased clientserver architecture. Figure 1 shows the overview of the system architecture. The system is conceptually posed of six main ponents: the web server, database server, cash register, mobile context server, mobile user and desktop user. The web server provided relevant information for mobile devices or desktop PCs on a wired/wireless integrated local area work using WSDL (Web Service Description Language) to describe functions and protocols. The web server then transmits to th