Network Signaling in Software

Generation PDF 417 in Software Network Signaling

The WAP Forum is comprised of nearly 500 members, which include switching manufacturers, computer manufacturers, terminal device manufacturers, content providers, service providers, and software developers The membership list is impressive To enable operators and manufacturers to meet the needs of highly dynamic markets, the WAP (protocol) was designed in a layered fashion In other words, the protocol model is similar to the OSI model in that each functional layer supports a discrete set of functions As previously mentioned, the OSI model consists of seven layers The communication functions are broken down into a hierarchical set of layers Each layer performs a related subset of the functions required to communicate with another system Each layer also relies on the next lower layer to perform primitive functions and conceal the details of those functions It also provides services to the next higher layer The layers are defined in such a manner that changes in one layer do not require changes in other layers By partitioning the communication functions into layers, the complexity of the protocol becomes manageable In the case of the wireless Internet, the complexity of delivering services is enormous due to the mobile feature of the customer Figure 5-12 illustrates the WAP reference model The protocol is somewhat similar to the OSI model Figure 5-13 is a comparison of the two models WAP is completely new to the telecommunications industry Unfortunately WAP is not compatible with the current wireline IP (IPv4 or IPv6) or any of the wireline Internet Web site scripting languages This is not entirely bad or good WAP has proven that wireless is so popular that interoperability is not needed at this time However, interoperability will be needed if the full power of the Internet is to be realized More information on interoperability will be discussed later WAP has two goals:

To enable wireless users to easily access and interact with information and related services Access the Internet using a wireless handset

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Application - Service Access Point Application Layer Protocol Session - Service Access Point Session Layer Protocol Transaction - Service Access Point Wireless Transaction Protocol Security - Service Access Point Security Layer Protocol Transport - Service Access Point Wireless Datagram Protocol Underlying Bearer Service

The WAP Forum was created with the following objectives in mind:

To create a protocol specification to bring Internet content and data services to the digital wireless telecommunications users To create a protocol specification that works across multiple wireless technologies To enable the creation of applications and content that scales across a wide range of networks and devices

As this chapter is being written, a business war is being waged across the oceans, domestically, across technologies, and across industry segments for domination of the Internet busi-

ness space This war is being waged on both a wireless and wireline front The wireless carrier community faces the challenge that the Internet was designed for the wireline world The wireline world s version of the Internet is comprised of the following:

Desktop computers Laptop computers High-bandwidth transmission Larger displays on the computers Heavy use of graphics Interactive icons Interactive graphics Streaming video Streaming audio

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The wireless world began its protocol development effort with an eye toward early commercialization Therefore, early implementations of WAP cannot support the heavy graphics used by the wireline Internet The real issues of small display screens, mono color screens, and limited video capabilities (limited pixel density) in the handset prevented handsets from supplying the kind of Internet activity the user is used to on the wired computer This situation does not mean Internet access is unavailable WAP devices are capable of sending and receiving e-mail from wired Internet users Remember the principal use for the Internet today is for e-mail WAP AND NON-WAP ARCHITECTURAL COMPARISONS (WWW) The openness to the individual software programmer (amateur and professional) for the purposes of Web site creation or content access distinguishes the Internet The World Wide Web (WWW) is the killer user application of the Internet It is the physical reality of multiple hosts connected and communicating with one another The WWW is an Internet application that enables the user to exchange documents, access servers owned by multiple numbers of people, use multiple viewing formats, access the Web, and manipulate the content using any one of a multitude of applications The World Wide Web Consortium (W3C) is a global industry-wide voluntary organization of companies and individuals dedicated to creating and maintaining an environment that is supportive of the growth of the Internet Specifically, the W3C is promoting the following programming model represented in Figure 5-14 The W3C has created a set of standards that has enabled software developers to write applications and create content so that they are presented in a set of standard formats These standards have also enabled the creation of the Web browser The Web browser is an application that enables a user to send out requests for information (data queries) to any Web site The Web browser is capable of supporting the access of data from