Boston — Just because your Wi-Fi router complies with 802.11 standards and has passed interoperability tests doesn't mean that you'll be happy with its performance. That's why the Broadband Forum is developing WT-398. When approved, WT-398 will specify tests for Wi-Fi router performance. In parallel with that document's development, the University of New Hampshire Interoperability Lab (UNH-IOL) has announced testing services for Wi-Fi performance.

The impetus for WT-398, which is not yet available publicly, came from service providers that deliver internet access and provide either Wi-Fi routers that are either integrated with gateways or are separate units. "Service providers found themselves providing support for home networking issues," said UNH-IOL senior engineer Lincoln Lavoie in an interview with EE Times. "The problem stems from so many devices now being connected to a home router."

The top performance issue, according to Lavoie, is data rate versus signal strength. A router will drop data speeds when signal strength is weak. Plus, a router needs to connect to devices that support different standards such as 802.11g, 802.11n, and 802.11ac, each of which has a different maximum data rate. That creates an issue of delivery fairness, something that needs testing. "Only one device can communicate with a router at any given time," said Lavoie. "Slower devices or connections with low power need greater air time for a given data rate." The test plans written into WT-398 will standardize test procedures.

UNH-IOL octoBox

An octoBox test chamber from octoScope isolates a Wi-Fi router under test from outside interference. Four log-periodic antennas receive signals from the router under test. A fifth antenna sends data to the router. Photo courtesy of UNH-IOL.

In addition to fairness and quality of service, test plans will cover interference from other devices such as ZigBee and Bluetooth that use the same unlicensed 2.4 GHz channels as Wi-Fi. Plus, there is the issue of many 802.11 routers covering any given area. Ask anyone who lives in an apartment or in a house with close neighbors about that.

Having standardized tests will let service providers differentiate the Wi-Fi products that they deploy. But will that help people to supply their own Wi-Fi router? Any manufacturer can test to the WT-398 standard or use the UNH-IOL for a testing facility. The WT-398 standard is up for a vote in June 2018, according to Lavoie, and the release is expected by the end of that month.

— Martin Rowe covers test and measurement for EDN and EE Times