Monitor portable Web-enabled devices - Technology Information - Technical

Communications News, Dec, 2000 by Oded Agam

WAP testing requires analysis of the user data and the WAP protocols.

Now that the Web has established itself in nearly every home and office, the Internet is clearly taking its show on the road. The rapid adoption of small portable Web-enabled devices is fueling the development of next generation mobile Internet devices for an eager global market. WAP (wireless application protocol) bridges the gap between the Internet and mobile phones. It enables Web browsing on the move and mobile e-commerce. Currently, the most demanding applications include:

* M-commerce. Applications that transform the mobile phone into a mobile point of sale, allowing users to safely purchase items or services via their mobile phone.

* News and info updates. Applications that access the Internet for information, such as stock prices, flight updates, weather and traffic information. This application can utilize push technologies, making the mobile phone an advertising medium.

* Synchronized PDAs. WAP allows synchronization of PDAs with remote servers, such as Microsoft's Outlook, to enhance e-mail capability with the ability to set meetings, synchronize calendars and create task lists.

* Mobile entertainment. As evidenced by DoCoMo's i-mode, the entertainment industry remains a major driver of WAP implementations and will play a significant role in cultivating consumer and corporate acceptance of WAP implementations.

Given the specific difficulties inherent in both the mobile devices and the networks that carry wireless signals, however, ensuring optimum performance of these cutting-edge wireless applications will be no walk in the park.

THE CHALLENGE OF SMALL

Enabling Internet access from handheld devices requires an understanding of both the technical and market issues that are unique to the wireless environment. With limited CPU speed, memory, screen space and battery life, wireless devices represent a constrained computing environment trying to accommodate the unconstrained global Internet. Most websites and Internet-based applications were designed to be accessed by PCs equipped with a mouse, keyboard and full-size color monitor. Accessing these same sites and services from a mobile phone requires overcoming the following major differences between a mobile phone and a PC:

* comparably weak CPU;

* tiny screens;

* limited bandwidth of wireless networks;

* high latency and bit-error rates of wireless networks; and

* different transmission protocols.

All these challenges relate to how data is transmitted over wireless networks and displayed on mobile devices. To do this, the Web uses the hypertext transfer protocol (HTTP) to exchange data over TCP/IP connections. This protocol, though efficient for exchanging data with a PC, is unacceptable for a mobile phone for the following reasons:

* HTTP is a text-based protocol that does not utilize bandwidth efficiently.

* Websites usually contain CPU-intensive content, such as graphics.

* TCP/IP is a connection-based protocol with many signaling messages.

* TCP/IP is not resilient to networks with high latency and loss.

The wireless application protocol was designed to overcome these difficulties. WAP is based on the connection-less user datagram protocol (UDP) and is designed to maintain the connection with minimal signaling traffic. In addition, being binary-based, WAP uses bandwidth more efficiently because WAP's HTTP filtering capability enables it to identify and display relevant fields only. Finally, the WAP protocol specification extends and leverages existing technologies, such as digital data networking standards, and Internet technologies, such as IP, HTTP, XML, URLs, scripting and other content formats, to transparently transport traffic over a multitude of wireless networks.

Even with the availability of WAP, wireless data networks themselves, with their high degree of latency, data loss and unpredictable availability, present other problems. In addition, there exists an alphabet soup of competing wireless protocols currently vying for dominance in different parts of the world. In Europe, global system for mobile communications predominates, while in America a mixture of standards can be found, notably code division multiple access and time division multiple access. Further complexity is added by the fact that all wireless networks are by nature converged, that is a mixture of circuit-switched (voice) and packet-switched (data) traffic.

SIMULATION CAPABILITY A MUST

In order to simulate how an application will perform in this challenging environment, network operators need comprehensive WAP testing solutions that give them an edge in creating and monitoring applications prior to, and after, deployment. These suites should include corresponding testing procedures for both circuit and packet technologies, and must be able to monitor any physical line and any protocol in this complex networking scenario. The ability to simulate actual wireless Internet conditions, and to monitor actual performance, will facilitate the realization of the myriad of promising applications that the wireless Internet invites.