These days, it seems everything is networked and everyone manages some outdoor network equipment. A public water...
utility may have an Ethernet switch in a pumping station. A train operator may have network gear monitoring its tracks. But when winter weather sweeps its way across the globe as it has lately, some network gear is put to the test. Extremely cold weather can be just as disruptive to network equipment as excessive heat in a data center.
"In extremely cold weather -- if switches are not designed properly -- parts can get stressed," said Scott Killian, director of the connectivity division at Sixnet LLC, a manufacturer of industrial Ethernet network gear that is designed to survive in extreme temperatures.
The silicon and other delicate parts within mainstream enterprise network switches get worn as parts expand and contract in extremely cold temperatures, Killian said.
When an enterprise switch is exposed to temperatures of -10 degrees Celsius, for instance, the switch may shut itself down, to come back online again only when the weather warms.
Sometimes, cold weather damage can creep up on a switch. Extremely cold temperatures can strike three or four times and the switch keeps going, but the damage builds up over time and the next cold snap comes along and knocks it out for good.
Backhauling outdoor Wi-Fi with industrial Ethernet switches
Sixnet recently supplied switches for a project in Canada's Maritime Provinces, where the Canadian government is funding the installation of municipal Wi-Fi in communities that lack broadband access.
These access points are outdoors, typically mounted on telephone poles. In Eastern Canada, installing a mainstream enterprise switch on a telephone poll is asking for trouble. The weather can get far too cold.
"They're running fiber-optic gigabit backbone to these Wi-Fi hotspots, and they've specifically picked our products because of the cold up there," Killian said. Sixnet's switches are in boxes on telephone poles.
Industrial Ethernet switches run hot and cold
Dwayne E. Lovely, a network administrator for the Albany County Airport Authority, has installed eight-port 100 MB Sixnet switches along the outdoor perimeter of his airport in upstate New York. For security reasons, he couldn't disclose their purpose, but he said they are installed in sealed, can-like containers outside.
Cold weather isn't necessarily an issue for these switches because they generate enough heat in a sealed environment to keep warm in the winter. But heat is definitely an issue in the summer, Lovely said. Prior to using Sixnet, he used another industrial-grade switch vendor that he declined to identify. But that vendor's product was rated to work only up to around 49 degrees Celsius. He switched to Sixnet, which could handle higher temperatures.
Protection at a cost
Industrial Ethernet switches can handle these extremes, but they usually come at a premium since the products are engineered and built with parts specifically chosen to withstand cold temperatures and other extreme conditions. For instance, Sixnet's switches have ceramic-based power capacitors in them because cheaper electrolytic capacitors tend to fail in cold weather and at high altitudes, Killian said.
Outdoor-rated wireless LAN
O utdoor-rated wireless LAN can be just as crucial as industrial Ethernet switches in extreme weather.
"There is no more extreme of an environment than the railroads," said W. Kelly Reed, a network engineer with a U.S. transportation company. "We have to test everything to the environments we encounter."
Despite the unusually cold temperatures in the Southeast, where some of his outdoor infrastructure is located, Reed said he hasn't heard of any temperature-related problems with his gear out in the field. Reed's company uses outdoor wireless LAN access points from Aruba, mounted on light stanchions. These outdoor APs are rated for the temperatures his outdoor network has suffered through this winter.
Ensuring that those outdoor APs have consistent power is another matter.
"We do run a backup system on these [APs] due to the fact that the electricity is shut off to the light stanchions during the day," Reed said. "We designed a battery and AC/DC conversion box with an internal heater to combat the temperatures."
Let us know what you think about the story; email: Shamus McGillicuddy, News Editor