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W@P. By: Christopher M. Logan Date: April 19, 2001. What is WAP?. <A little understanding of what WAP really is! />. What is WAP?. W ireless A pplication P rotocol Based on HTTP and XML An open global specification
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W@P By: Christopher M. Logan Date: April 19, 2001
What is WAP? <A little understanding of what WAP really is! />
What is WAP? • Wireless Application Protocol • Based on HTTP and XML • An open global specification • Empowers mobile users with wireless devices to access and interact with information and services instantly • Backbone protocol that lest you connect to the Internet across any digital wireless network and through any wireless device,application, and service provider
What is WAP (cont’d) • Global multi-layered protocol that is designed to bring content to thin-client devices • A “thin-client” device can range from low-end, display limited cellular telephones, to full functionality, high-speed laptop computers. • A client is termed “thin” based on any one of the following attributes: • Display and data entry constraints • Memory or CPU processing constraints. • The WAP protocol is designed to address the needs of this full range of client devices
What is WAP [cont’d] Standardized by the W@P Forum www.wapforum.org
WAP History <!-- Wireless Beginnings -->
Wireless Beginnings • Detroit police using crude mobile radios as early as 1921 • Mobile communication slowly developed through out the ’20s, ’30s and ’40s • Mid ’40s cellular came to light • Researchers knew that air wave would be filled with voice traffic and interference • Discovered that service area could be divided into small “cells” • Radio frequencies could ne reused which increased call capacity • 1947 AT&T proposed that the Fedral Communication Commission (FCC) allot a large band of radio frequencies for mobile telephones. • 1969 the frequencies were available
Wireless Beginnings (cont’d] • 1971 AT&T submitted how a “cellular system” could be established over the extended radio frequencies to the FCC • Delayed until 1977 • 1978 2000 Bell Telephone customers in Chicago tested the first mobile phones operating on a cellular system. • Analog system called Advanced Mobile Phone Service (AMPS) • Still in use today. • 1996 Three major digital systems are available. • Time Division Multiple Access (TDMA) • AT&T Wireless, and Southwestern Bell • Code Division Multiple Access (CDMA)
Wireless Beginnings [cont’d] • SprintPCS, GTE, Air Touch, and Verizon • 1994 FCC opened up the Personal communication Services (PCS) frequencies to 1900MHz which unlike other services using AMPS, PCS spectrum is all digital • Voice mail, FAX, paging, and Short Messaging Service (SMS) are now available • Cell phones can act like modems • Paved the way for a direct connection between the wireless world and the WWW. • Global System for Mobile Communications (GSM) • Pacific Bell and Omnipoint • They all process voice signals differently but sounds virtually identical.
WAP History <b> How WAP came into being … </b>
WAP History • Before July 1997 each telecommunication giant was developing their own protocols and markup languages for wireless Internet access. • Nokia: Narrow Band Sockets (NBS). • Using Tagged Text Markup Language (TTML). • Aimed at bringing HTML content to the handset. • Supported in the Nokia 8010i. • Ericsson: Intelligent Terminal Transfer Protocol (ITTP). • Aimed at providing enhanced call control.
WAP History (cont’d] • Phone.com: Handheld Device Markup Language (HDML) • Aimed at providing a “web-like” environment for the development of network based applications and services. • Created WAP. • The diversity threatened to fragment the wireless data access market. • Along with Motorola, they believed that is was in their best interest to create a forum to discuss wireless Internet data access standards.
WAP History (cont’d] • The W@P Forum was created on July 27, 1994 • Primary goal is to insure interoperability and growth of the wireless market. • Over 500 members • Dues: $27,500/yr to join as a full member • Dues: $7,500/yr to join as an associate member.
Wireless Peculiarities <What WAP is designed for />
Wireless Peculiarities • Basically, wireless networks are flaky. • Devices can go in and out of range. • When they do come back in they could be on a totally different network. • Small Bandwidth. • Technologies boast 40Mbits/sec. • You basically need to be near a powerful antenna to get this data rate • (and a dose of radiation) if you really want it! • Vulnerable to interference, distance and load. • All effecting transmission speeds.
WAP Features <? How WAP Deals with the Peculiarities />
WAP Features • WAP is designed for wireless networks. • Designed to deal with wireless peculiarities. • Wireless Sessions: • wireless devices may go in and out of range. • Wireless sessions give the wireless device the opportunity to suspend an application session on the content server before the device goes out of range. • Content server saves application specific data. • When coming back into range the device can resume the wireless session and continue where it last left off.
Wireless Features [cont’d] • Device Abstraction: • WAP has the concept of User Agent Profiles which is a representation of the client device on the application server. • Allows a wireless application to server a wireless client differently depending on the device being used. • Some devices might require different content because their displays are small or their input device is limited in some way.
WAP Features [cont’d] • Bearer Abstraction: • Devices don’t always use the Internet Protocol (IP). • WAP provides a way for the underlying protocol to be abstracted, whether it is IPv4, IPv6, SMS, Bluetooth, or Mobittex. • WAP can suspend sessions over bearers. • A device can suspend a session on one bearer and resume on another.
WAP Features [cont’d] • Data/Header Compression: • All data and headers are compressed to ensure optimal bandwidth of wireless bandwidth. • Reliability • WAP provides reliable transport over any bearer in the same way Transmission Control Protocol (TCP) does, but with low bandwidth. • Supports Segmentation and Reassembly (SAR) for bearers which do not support it natively.
Why not HTTP/HTML? <body Why HTTP/HTML wasn’t chosen …/>
Why not HTTP/HTML? • Lost Pages • Slow responses • No “push” ability • Bad content
WAP Architecture <What WAP is made of …/>
WAP Architecture • WAP Stack: Takes into consideration, Low bandwidth, Need for “push”, Unpredictable networks, and many different bearers. • Wireless Session Protocol (WSP) • Wireless Transport Protocol (WTP) • Wireless Transport Layer Protocol (WTLP) • Wireless Datagram Protocol (WDP)
WAP Architecture (cont’d] • WML Browser: Front end to the stack on the CLIENT • Parses the Wireless Markup Language (MWL) and Wireless Markup Language (WMLS). • Displays formatted text and graphics on the client device. • This is the IE and Netscape of wireless devices.
WAP Architecture (cont’d] • WAP Gateway: Front end to the stack on the SERVER • Primary goal is to emulate the behavior of a web browser. • It allows the wireless device to communicate over the IP-based web. • Encodes content for the low bandwidth telecom network. • Content can be WML, HTML, or streamed data.
WAP Architecture (cont’d] • Origin Server: AKA the Content Server • Received HTTP requests from the WAP Gateway from the user. • Returns content based on the request.
