The University of New Hampshire Interoperability Lab sets the standard for testing emerging devices used in wired and wireless technologies

BY MARTIN ROWE, Senior Technical Editor, Test & Measurement
EDN and EE Times
www.edn.com
, www.eetimes.com

When you connect Ethernet, Wi-Fi, data storage, broadband, or
many other devices to each other, there’s a good chance that it works because of
the University of New Hampshire Interoperability Lab (UNH-IOL). Located in Durham,
the UNH-IOL’s engineering staff and students develop test plans, design
hardware, and write embedded code and applications for testing many communications
links. Often, the lab is the first to develop test tools, which then become
adopted as the standard for interoperability and compliance testing.

To learn how UNH-IOL works with silicon and test manufacturers, Electronic
Products visited the lab on Dec. 18, 2017. Chief Engineer Bob Noseworthy and
Ethernet Technologies Senior Manager Curtis Donohue explained how the lab
works, with a focus on automotive Ethernet.

The UNH-IOL is a self-funded, independent testing lab affiliated
with the university. Member companies who use the lab’s equipment and testing
services and attend plugfests pay an annual fee. The lab also produces test
reports for member companies to show standards compliance to their customers.

While many of the lab’s clients are semiconductor companies
looking to test their latest silicon, other companies such as cable
manufacturers also join. Test-equipment and networking-equipment companies also
play a role, often donating their products to the lab. The lab’s large array of
networking equipment lets member companies test for backward-compatibility.

Before
there is test equipment

Because many of the lab’s clients design ICs for emerging
technologies, there’s often no test equipment commercially available. Thus, the
UNH-IOL often develops its own test hardware and software. Under staff
supervision, students often develop the software based on test plans. Once
tools are in operation, the students use them to test customer products.

“The test plan shapes how we develop a test tool and what it
needs to do,” said Noseworthy. “Member companies come to plugfests or work with
us to validate the test plan, interoperability tests, and conformance test
tools. Members often duplicate our hardware and use our software in their labs.”

Automotive
Ethernet

Because automakers are incorporating Ethernet into vehicles, the
UNH-IOL is involved in developing new standards, test tools, and test plans. Automotive
Ethernet running at 100 Mbps soon won’t be fast enough to move data from the
ever-increasing number of sensors and cameras in vehicles. Autonomous and
driver-assisted vehicles rely on these devices. Connecting each with its own
pair of wires isn’t feasible because of cost and weight constraints. That’s why
1000BASE-T1 (IEEE 802.3 bp) products are beginning to appear. UNH-IOL announced
its 1000BASE-T1 testing services on Jan. 17, 2018. (T1 refers to a two-wire
link, as opposed to the traditional eight-wire cable.) The lab’s staff and
students work closely with the One Pair Ethernet (OPEN) Alliance, an
organization encouraging the use of a single pair of wires in vehicles and the
development of physical-layer (PHY) ICs. Fig. 1 shows one of
the lab’s benches used for testing automotive Ethernet products.

0318_Feature_TM_Fig-1

Fig.
1: Students at UNH-IOL write code for the lab’s test tools, then use the tools
to test data-communications products. Here, Chris Bridges (UNH class of 2017)
tests automotive Ethernet products in the lab.

At present, the UNH-IOL has test tools for 100BASE-T1 and 1000BASE-T1. One such tool is called the BitPhyre, a commercially available
FPGA-based board that runs firmware developed in the lab. Fig. 2
shows the FPGA board with a lab-designed mezzanine card attached, which provides
the Ethernet PHY.

0318_Feature_TM_Fig-2

Fig.
2: UNH-IOL engineers and students designed a mezzanine card that attaches to an
FPGA board used to test automotive Ethernet. The mezzanine card adds the PHY.

The BitPhyre tool lets students test not only the PHY, but its
Media Access Control (MAC) protocol as well. The FPGA board is reconfigurable,
meaning that it can test many different PHY ICs simply by downloading firmware
and attaching the appropriate mezzanine card.

Students use signal-analysis software written in the lab to
measure parameters such as amplitude and jitter. An oscilloscope captures and
digitizes the signal for analysis on a PC. Fig. 3 shows one of
the lab benches used for testing automotive Ethernet PHY devices.

0318_Feature_TM_Fig-3

Fig.
3: A test bench typically has an oscilloscope to capture signals that travel
between transmitters and receivers. PC software then performs the analysis on
parameters such as jitter.

Although software for testing 100BASE-T1 signals has been
commercially available for some time, UNH-IOL continues to use software
developed in-house. Why? Because by the time commercial software is available,
the lab’s software has already gone through several iterations. With software
written in-house, UNH-IOL engineers, students, and clients know exactly what it
does and how. “We have to prove to clients that our testing is valid and conforms
to standards,” said Donohue. Noseworthy added, “There are a lot of tools that
capture and generate frames, but we can challenge clients to decode the bits on
the wire and see that we are doing it correctly. We also can inject errors, something
that commercial test software often can’t do.”

Infotainment systems are typically the first deployed
applications of automotive Ethernet because they’re the least critical and can
tolerate errors and latency. But as other systems attach to the network,
reliability and timing take on important roles. That’s why the UNH-IOL is
heavily involved in testing time-sensitive networks (TSNs). Born out of pro-audio
and industrial applications for low-latency networks, the Avnu Alliance has
developed TSN standards, for which the UNH-IOL has developed test plans and
tools.

Students
get work experience

Not only does the UNH-IOL provide test tools and services, it
also provides students with hands-on experience that they can take to industry
after graduation. Given a turnover rate of 25% per year, staff members are
constantly hiring new students. My visit occurred the week after finals and
before the holidays. On this week and during other school breaks, the lab is
fully staffed because students have no course responsibilities. During
semesters, students typically work 12 to 15 hours a week, with a maximum of 20
hours per week. After all, these students also carry a full load of courses.
The lab also reaches out to rising seniors at local high schools, providing
summer internships. One student who is now a UNH senior has worked at the lab
for five years.

Because students often work directly with the companies that use
the lab’s facilities, they gain contacts that often result in full-time jobs
after graduating. While you’d expect students to work for semiconductor
companies, some work in data centers at insurance companies and banks. Some
students who work in the lab major in information technology, though the
majority major in electrical or computer engineering.

0318_Feature_TM_Additional-Photo

(l-r) Eric Ouellette (UNH computer engineering
student, class of 2018), Senior Engineer Bob Noseworthy, and Ethernet
Technologies Senior Manager Curtis Donohue.