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Wireless Network testing for interoperability is performed by TÜVRheinland using the open IEEE 802.11 specifications as the basis for this testing.
It was developed for mobile computing devices, such as laptops, in LANs, but is now increasingly used for a wide variety of services, including Internet and VoIP phone access, gaming, and basic connectivity of consumer electronics, such as televisions, DVD players and digital cameras.
Increasingly, Wi-Fi designs are evolving and adapting into new and clever uses. For example, an Intelligent Transportation System helps car owners increase safety, gather statistics, and enable mobile commerce. With such innovative Wi-Fi tools in the works, we thought designers would like to know the inside scoop on the Wi-Fi testing and certification process.
Automation for Wireless interoperability Test Beds is a current program that makes testing more efficient for all parties involved. TÜVRheinland developed this process of test automation for Wireless interoperability test beds.
The automation process uses an integrated system of Wireless Stations and Access Points (APs) from a Wi-Fi Test Plan. The Stations and APs are known as the gold units of the Test Plan. The test controller, otherwise known as the "Automizer," controls the gold units, the Chariot Console, and the Radius Server.
The Chariot Console is a designated PC (laptop) that runs "Chariot" which is a software package from Ixia.
Chariot is designed to allow transmission of wireless data between the Chariot Console and one or more other PCs (laptops) that communicate with the Console. On each laptop there will be an agent for Chariot known as the End Point. The Chariot Console initiates the wireless data transmission between each End Point and itself (or between different End Points) as unidirectional or bidirectional data.
The source and destination of each wireless transmission can be either the Console or any of the End Point(s). The Chariot Console probes the wireless data transmitted and graphs them either in real time (as graphical display) or in batch mode (for more accuracy). The Chariot Console provides through Chariot functions some statistical data that includes among other variables the throughput values of the transmitted data as defined within the Wi-Fi test plans.
Click here for Figure 1.
Figure 1: Automizer—Infrastructure mode.
Automizer has two configuration modes:
- Infrastructure where the wireless communications are between APs and Stations, and
- Ad-Hoc where the wireless communications are between Stations without the inclusion of an AP.
Tests are conducted in shielded rooms to prevent wireless interference. The APs are power-controlled by Automizer, so that the AP used in the current test is the only one being powered on. This keeps the test chamber wirelessly clean and free of any interference from other APs, which may be set on the same wireless channels.
Click here for Figure 2.
Figure 2: Automizer—Ad-hoc mode.
Access Point Control
Automizer controls power strips that provide power to the gold unit Access Points (AP). It is important that only the AP(s) involved in any test be the only AP(s) powered on—and all other AP(s) powered off. Automizer does exactly this by determining the AP(s) involved in the test and powers on/off the AP(s) accordingly. Automizer can accomplish this feat by reading the tested AP(s) information from the Test Plan's database.
Click here for Figure 3.
Figure 3: Controlled power supplies.
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