Building a Data Network

WAP standard scores major wins with successful trials and real-world deployments.

The Mobile Information Society is fast approaching, and WAP technology is quickly breaking down the last barriers to this wireless Internet future.

WAP is a universal open standard that wireless-service providers can deploy now to deliver Internet-based data to mobile phones and other wireless devices. WAP streamlines the content sent to those wireless devices, thus optimizing that information for the mobile environment and giving service providers access to new markets, new revenues and powerful new competitive tools. (For information, see "The Bottom Line on WAP," in the Feb. 15th issue.)

To appreciate the implications of this technology, look at the basics of a WAP-enabled network and see how service providers are putting WAP to work in their own wireless markets.

Mapping a WAP Future
Flexibility is a core attribute of WAP, and a number of variants are now in use or under development that allow this mobile Internet technology to be deployed in virtually any wireless network.

WAP systems now under development and being deployed offer smooth connectivity for short-message service (SMS) and circuit-switched data. When the SMS bearer is used with the WAP gateway, large messages are fragmented into shorter messages, processed by the server and reassembled for transmission to the WAP-enabled terminal device. SMS is somewhat limited in that the service, depending on the network type, can typically hold fewer than 200 characters and requires a new call to be set up for each leg of the transmission.

Circuit-switched data provides comparatively faster wireless-Internet performance, because the call is set up just once with a dedicated circuit for the duration of the session. Subscribers can browse a number of URLs or lists, but because this dedicated approach reserves network capacity, WAP circuit-switched data can be more costly for the service provider than packet-based alternatives.

Support is available for GSM, TDMA and CDMA service providers that want to offer subscribers value-added WAP applications. WAP-based messaging platforms create a bridge between the Internet or private intranets and the network. Subscribers then can access wireless Internet services from WAP-capable devices over a variety of bearers. The best of these WAP solutions employ a highly scaleable architecture and use simple network-management protocol, allowing service providers to integrate this WAP platform into their existing network-management infrastructure.

WAP over GPRS offers a number of clear advantages. It uses less network capacity, and is thus less costly for both service providers and subscribers. WAP over GPRS allows the application to maintain active sessions without requiring a dedicated circuit. Information is sent in packets, with circuits being dedicated only for the time needed to move the data to the next point on the circuit. This allows service providers to support more packet-based traffic in an IP-driven network. WAP over GRPS also opens new possibilities for creating innovative business and pricing models, while allowing service providers to gain maximum advantage from existing network resources.

EDGE technology will support data rates up to 400kb/s, and typical terminal rates at the user level of 150kb/s, a level of performance that opens the door to video and multimedia applications. EDGE can be introduced on top of an existing GSM or TDMA network, extending the useful life of those resources while clearing a pathway to true mobile multimedia. For service providers that are planning for a W-CDMA network, EDGE offers a proven, cost-effective way to boost data service levels and customer counts, while minimizing the risks of a wide-scale W-CDMA launch.

Developmental Challenges
Of course, there still is work to be done to make the mobile Internet a reality. The WAP community now is addressing a number of key technical issues.

To allow corporations to establish both internal and external mobile services, WAP servers must create open and very mobile network platforms. The server is designed first and foremost to implement the WAP standard and to connect WAP-enabled terminals to content and applications hosted by servers located on the Web, Internet, intranets or extranets. The industry is providing servers that deliver true WAP compliance, streamlined network management and smooth scaleability.

WAP servers integrate cleanly with HTTP servers to acquire native WML and WMLScript content, or to convert HTML content to WML. At this stage of development, WAP servers also are available with adapters for SMS and with IP bearers for circuit-switched data connections. Servers provide open programming interfaces for application development, including WAP-specific interfaces for easy control over mobile functions. By accessing local files for text and encoded WML and WMLScript, a WAP server can simplify the job of setting up WAP service. Servers also should be able to push information to terminals, to support push applications and to ensure subscribers get important data as soon as possible.

Security is a crucial concern in the emerging WAP environment. Today's most advanced WAP servers incorporate optional high-level, end-to-end security solutions. These technologies encrypt all traffic on the mobile network and can include certificate-based server authentication. Administrators also can use advanced features to control user access to specific services. The best WAP servers use lightweight directory-access protocol servers to provide user management, eliminating the need to maintain additional user databases.

Interoperability is one of the most important aspects of the WAP evolution. True WAP solutions are open and non-proprietary, and are not linked to any particular network operator or mobile device. WAP technologies move across wireless networks easily and integrate terminal-resident and network services to telephony, communications applications, information services and service-provider features.

Device-to-device compatibility and application-level interoperability are crucial to the success of any WAP deployment. Service providers should evaluate any potential WAP investment to ensure that technology meets the interoperability standards established by the WAP Forum.

As these final technical challenges are met, industry leaders are now bringing proven WAP solutions to the marketplace.

GSM Alliance Trials
In a 1999 real-world demonstration of these emerging WAP technologies, Nokia conducted a series of pilot trials that allowed six GSM operators to create and test WAP services. The WAP gateway used in these trials enables WAP terminals to access WAP services located at Web servers. The gateway acts as a WAP server with an HTTP client, forging the crucial link between the GSM systems and Internet/intranet networks.

As a platform for developing WAP services, this prototype gateway provided key protocol-conversion and content-handling functions, as well as creating an external interface for push applications. Additionally, the Nokia 7190 WAP handset was used in these trials, which allowed the service provider to optimize services for the subscriber.

To allow WML and WMLScript services to be used from WAP-capable terminals, this WAP gateway prototype supports the entire WAP protocol stack. This capability supports end-to-end communications from the terminal to the Internet server. It also supports varying terminal capabilities, error handling, data transfer, WAP security, and both connection-oriented and connectionless service. The gateway employs HTTP 1.0 or 1.1 to retrieve information from any Web server, and provided full protocol conversion to transfer content from Internet to WAP requests.

GSM service providers that took part in the trials had the flexibility to choose between SMS and circuit-switched data connectivity. The WAP gateway prototype provided adapters for SMS services as well as IP connectivity for circuit-switched data services.

Content processing, management and support are crucial issues in the deployment of any mobile Internet system. The WAP gateway trials included a wide range of powerful content-oriented capabilities. Dynamic content processing to recognize original content formats optimized WAP quality for the subscriber. The WAP gateway provided efficient encoding of textual WML, WMLScript and wireless-session-protocol headers into efficient binary formats, simplifying content creation and allowing the best use of available bandwidth. The gateway also smoothly managed the processing and flow of multipart objects from the Web to the WAP end user.

These trials were deemed a clear success.

WAP in the Real World
Nokia also recently completed the deployment and launch of a WAP-enabled network by a major U.S. wireless-service provider as well as multiple deployments by service providers in Europe and Asia Pacific regions. These deployments are the beginning of what many predict eventually will be true nationwide GPRS-over-IP networks. Estimated timing for GPRS as a bearer is the second half of 2000.

Walters is Nokia Networks marketing manger-wireless data and Purdie is Nokia business manger-WAP.