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
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 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 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 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.
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.