Chapter 7 Mobile Commerce The Business of Time

1. Chapter 7Mobile CommerceThe Business of Time Eyad Alshareef

2. Contents • Wireless LAN • Factors to Consider • WAP • WAP protocol stack Eyad Alshareef

3. Wireless LAN • The most common standard for wireless networking is Wireless Local Area Networks, or WLAN • WLAN design is flexible and is becoming cheaper to deploy, but it travels only 150 feet Eyad Alshareef

4. Wireless LAN • Use radio waves instead of cabling to connect laptops and other electronic devices to a LAN using Ethernet connections over the air • A WLAN is identical to LAN except that the devices are wireless Eyad Alshareef

5. Wireless LAN • Each computer (device) has a wireless Network Interface Card (WNIC) with an antenna built into it • WNIC: a card that interface between the wireless device and an access point for data or voice transmission and reception Eyad Alshareef

6. Wireless LAN • Signals from WNIC are sent through radio waves to an access point • AP (access point): • When a wireless station sends a frame to a server, an access point acts as a bridge that passes the frame over the wired LAN to the server • AP is bi-directional • Receive and transmit signal to the WNIC Eyad Alshareef

7. Factors to Consider • Range and coverage • From 100 to 300 feet • Throughput • Performance • The throughput of most WLAN is 1.6 to 11Mbps • Security and integrity • Wireless first introduce for military applications Eyad Alshareef

8. Factors to Consider • Cost and scalability • Cost include infrastructure cost ( APs) • Depends on the number of APs • Which based on the required coverage area • User costs • Standardization of WLANs Eyad Alshareef

9. Wireless Application Protocol (WAP) • HTTP & HTML internet standard is not efficient enough to allow communication via a wireless data network. • Wireless Application Protocol (WAP) was crated • WAP is the basic for the mobile Internet Eyad Alshareef

10. Wireless Application Protocol (WAP) • The WAP concept is to connect devices to wireless network • by adding Internet Protocol layer to the network Eyad Alshareef

11. World Wide Web and Mobility HTTP/HTML have not been designed for mobile applications/devices • HTTP characteristics • designed for large bandwidth, low delay • stateless, client/server, request/response communication • connection oriented, one connection per request • TCP 3-way handshake, DNS lookup overheads • big protocol headers, uncompressed content transfer • primitive caching (often disabled, dynamic objects) • security problems (using SSL/TLS with proxies) • HTML characteristics • designed for computers with “high” performance, color high-resolution display, mouse, hard disk • typically, web pages optimized for design, not for communication; ignore end-system characteristics Eyad Alshareef

12. System Support for Mobile WWW • Enhanced browsers • client-aware support for mobility • Proxies • Client proxy: pre-fetching, caching, off-line use • Network proxy: adaptive content transformation for connections • Client and network proxy • Enhanced servers • server-aware support for mobility • serve the content in multiple ways, depending on client capabilities • New protocols/languages • WAP/WML Eyad Alshareef

13. WAP: Main Features • Browser • “Micro browser”, similar to existing web browsers • Markup language (WML) • Similar to HTML, adapted to mobile devices • Script language • Similar to Javascript, adapted to mobile devices • Gateway • Transition from wireless to wired world • Server • “Wap/Origin server”, similar to existing web servers • Protocol layers • Transport layer, security layer, session layer etc. • Telephony application interface • Access to telephony functions Eyad Alshareef

14. HTML HTTP SSL TCP/IP Internet Model Eyad Alshareef

15. Client Web Server WAP Gateway WML CGI Scripts etc. WML Encoder WML-Script WSP/WTP HTTP WML Decks with WML-Script WMLScript Compiler WAE Protocol Adapters Content Etc. WAP Architecture Eyad Alshareef

16. Client WML WML Encoder WML-Script WMLScript Compiler WAE Protocol Adapters Content Etc. WAP Application Server WAP Application Server Application Logic WSP/WTP WML Decks with WML-Script Eyad Alshareef

17. How WAP works • When user access a web site from a PC web browser • User requests data • Server send the data in the form of HTML • Over an IP network (wired network) • Web browser convert the HTML data into text and graphics Eyad Alshareef

18. How WAP works • On a mobile device • A WAP browser ( micro browser ) perform the roles of a PC web browser • Request data from a web site via a WAP gateway that act as “go-between” for the web browser and web server • Translate WML (wireless Markup Language) to or from HTML Eyad Alshareef

19. How WAP works? Eyad Alshareef

20. WAP Gateway Summary • Encoders • translate between binary (WML) and text (HTML/WML) • Filters • transcoding between WML (wireless) and HTML (wired) • Method Proxy • similar to standard proxy services • WAP stack on wireless interface and TCP/IP stack on Internet interface Eyad Alshareef

21. WAP protocol stack WAP Protocol Stack Eyad Alshareef

22. WAP Stack • Runs on top of WDP • Provided lightweight X-oriented service • Unreliable 1-way request • Reliable 1-way/2-way req./response MicroBrowser (WML, WMLScript) Datagram service on different bearers Convergence between bearer services Different Wireless Tech. Eyad Alshareef

23. WAP Stack • WAE (Wireless Application Environment): • Architecture: application model, browser, gateway, server • WML: XML-Syntax, based on card stacks, variables, ... • WTA: telephone services, such as call control, phone book etc. • WSP (Wireless Session Protocol): • Provides HTTP functionality • Supports session management, security, etc. • WTP (Wireless Transaction Protocol): • Provides reliable message transfer mechanisms • Based on ideas from TCP • WTLS (Wireless Transport Layer Security): • Provides data integrity, privacy, authentication functions • Based on ideas from TLS/SSL • WDP (Wireless Datagram Protocol): • Provides transport layer functions Eyad Alshareef

24. How WAP works WAP protocol stack • Wireless Application Environment (WAE) • WAP element that establishes an interoperable environment to allow operators and service providers to build applications. • use WML Eyad Alshareef

25. How WAP works WAP protocol stack • Wireless session Protocol (WSP) • A WAP element that decides whether a network and a device will communicate back • and whether data will transmitted straight from network to the device • A connection-oriented session  data will go directly to the next layer (WTP) • Or a connectionless session data will go directly to (WDP) Eyad Alshareef

26. How WAP works WAP protocol stack • Wireless Transaction Protocol (WTP) • A WAP layer that ensures data flow from one location to another efficiently based on a request / replay paradigm • Equivalent to TCP layer • Packet segmentation, and acknowledgment of packets Eyad Alshareef

27. How WAP works WAP protocol stack • Wireless transport Layer Security (WTLS) • A WAP elements that gives security to the system via encryption, data integrity verification, and authentication between the user and the server • Providing secure connection Eyad Alshareef

28. How WAP works WAP protocol stack • Wireless Datagram Protocol (WDP) • A WAP feature that confirms easy adaptation to the WAP technology • Provide common interface to upper- layer protocol • Network Carrier Method (NCM) • A technology that wireless provider uses Eyad Alshareef

29. WAP Benefits • Most WAP benefits are reflected in wireless applications, which reduce the reaction time of mobile professionals • Because of greater mobility and instant access to critical information, productivity can be increased dramatically from anywhere at any time Eyad Alshareef

30. WAP Limitations • Low-power • Central processing units • Small screens with questionable clarity • Limited device memory • Small keypads and no mouse • Questionable connections for reliability • High latency before making the connections. Eyad Alshareef