How do you perform OTA testing?
UL has a fully automated test system where a call box emits a signal inside a chamber to simulate a cellular coverage environment. The testing is performed with a phone in free space environment and also placed on a phantom head, held by a phantom hand to simulate real life user scenario. A call is made from the phone, during which we measure the maximum and minimum power of the phone.
Why’s the testing important?
Much of the success or failure of a wireless product depends on the performance of the wireless link – including items such as the usable range, robust and repeatable connectivity, and connectivity speed. OTA is the best way to verify the overall performance of a device. Device manufacturers come to UL at various stages of their product development; from engineering evaluation to carrier acceptance test. UL works with manufacturer and carriers (or service providers) to qualify these devices and ultimately get them deployed on the national and international networks.
We conduct these tests on the manufacturers’ devices to make sure their antenna requirements meet those of the carrier, helping to ensure the consumer experience on the network is excellent.
Manufacturers do not normally have this type of testing facility available for their use. It is easier and more reliable for them to come to UL to create testing criteria and do the independent, 3rd-party testing.
What does the testing look like?
The testing is performed in a completely noiseless chamber consists of antennas, rotating platform with phone mounted on a phantom hand and head. During testing the call is made, the device is rotated incrementally to acquire multi-dimensional measurements that provide a 3-D “Antenna Pattern” of the device. The rotation of device is to simulate a consumer’s tendency to move around during a call while signal strength is measured by a fully automated system.