On the road: Testing wireless voice and data on the highways
- — 08 September, 2009 08:14
Marc Lefevre is the up-to-date, real-life equivalent of the "Can you hear me now?" guy from the Verizon Wireless TV ads that grew popular in 2004.
But don't call him that.
"I've never said I'm that guy, although people are always asking me that and know me that way," Lefevre said on a recent drive through suburban Boston in his pimped-out white Chevy Tahoe. The vehicle was equipped with about $US250,000 in testing gear, including 14 computers, customize air conditioning and antennas that gauge wireless voice and data connections to cellular base stations on his Massachusetts routes.
Lefevre replied that he wears much better sunglasses than "that TV guy" and that he personally paid $US250 for them. But the biggest difference is that Lefevre analyzes more than wireless voice quality and reliability. He also checks the speed of wireless data connections, the use of which is soaring, especially among users with broadband wireless cards in their laptops.
The testing process Lefevre follows is fairly simple, although the analysis Verizon employs is complex and computer-based. Lefevre, like about 90 Verizon testers nationally, will drive for three weeks each month, reporting deficiencies as soon as he spots them, but then taking the computer-recorded results back for further analysis in a Westboro, Mass., lab for the fourth week. About 1 million miles are logged annually by the entire team, Verizon said.
Lefevre always keeps moving, even in poor weather, so he can judge the factors that could affect a call. After four years of riding over the same roads in Massachusetts, he claims to have his routes memorized.
Now and then, he will be stuck in traffic, and even at a dead stop, he will keep the computers running, sending and receiving calls, to see the impact of all the nearby wireless users, who are also stuck in traffic, on the nearest cell tower and base station.
Cellular service is dependent on many factors, including the number of users on a base station, but weather, nearby buildings and geography also affect service. Lefevre pointed to reflective glass windows on the side of an office building, and noted, "that's a problem for people in there." Lefevre doesn't go inside buildings, however, and leaves indoor areas to others to test.
"I love this job, Lefevre said. "They asked to move to another and I didn't want to. You have to like driving, and I do."
Lefevre is an assistant engineering systems professional, having earned a variety of standard networking certifications from Cisco Systems Inc. and others. Some of what he showed on his two ruggedized laptops was proprietary data. , but primarily he watches out of the corner of an eye while he drives for the on-screen displays to show patches of red or yellow instead of green as he passes in and out of wireless cells, the coverage areas that are the foundation of cellular service. (Red is below Verizon's servce standards; green is within the acceptable range). The wireless cells he travels through can be small (less than a city block or large (several acres) , depending on the density of the population, the buildings and the topography.
On his displays, he can pull up a map of his route, with a green circle depicted for each second of a given call to show whether the wireless service met the standards that Verizon had expected to meet. Those standards, in turn, are based on a set of industry standards.
For voice calls, Lefevre checks many factors, including the quality of the connection, based on what is widely known as the Harvard Sentences, a collection of sample phrases chosen for their consonant and vowel sounds, that are pre-recorded and sent from the computers on his vehicle through cell phones onboard and through the network to a phone in his Westboro lab. The test records the sound quality of sentences both sent and received. Some samples phrases are "a chicken leg is a rare dish," and "a red jacket hung on the back of a wide chair," Lefevre said. But Lefevre doesn't listen to that kind of chatter, sometimes tuning in Sirius radio instead, because many tests are conducted at once.
Other voice call tests include checking for dropped calls as the vehicle crosses into a new cell, static on the line, echoes, and whether the call might only be one way, where only one side of the conversation is heard.
For data connections, Lefevre checks how long it takes for a ping to reach a destination and return, and how long a graphics-rich Web page takes to launch, among other things. Verizon, like all the wireless carriers, is guarded about how it describes its data rates, but chooses to advertise them based on averages. For the short drive in suburban Boston, all the voice and data tests showed green.
Verizon operates on a CDMA voice network and an EVDO data network that offers both second and third generation speeds, but Lefevre didn't disclose what speeds qualify as "green" for the purpose of the tests.
While a big part of Lefevre's job is to check Verizon's wireless voice and data connections, he also checks how well the three major cellular competitors and some cellular startups are doing. That means that for every cellular chipset in a phone that Verizon is using in its tests, there is also a phone from each of the major carriers, attached to a computer and a special antenna in the vehicle. ????
Data testing is done using laptop cards, but the testing scenario is configured to emphasize a test of the network and not each device, a spokesman said. Because of that testing approach, Verizon wouldn't disclose the names of the phones and devices it uses in its test vehicles. The actual devices sold to customers are tested in laboratories, however.
Verizon spokesman Tom Pica said Verizon uses the copious results of its tests to help plan ways to expand its coverage, and to fill in coverage areas with growing populations or more buildings under construction. "We believe our testing is unique in the industry, and it has enabled us to ensure we have the most reliable network," he said.
The Verizon testers' results are bolstered with third party tests and survey results from customers. In late August, J.D. Power and Associates found that Verizon Wireless had the highest call quality of all the carriers in five of six regions, according to customer feedback from 24,000 wireless phone subscribers. The results covered the first half of the year, and included results for dropped calls, static and interference, failed connections on the first try, voice distortion, echoes, no immediate voice mail notification and no immediate text message notification. The Midwest area surrounding Chicago was the only region where Verizon didn't attain the top spot.
While the survey findings and his test results are enough to convince Lefevre that the Verizon network is highly reliable, his friends still call to mock him.
"They will call me at work and scratch their phones to make it sound like interference and ask, 'Can you hear me now?'" he said. "I just laugh."