When Mother Nature Gets Cranky

Anywhere you go in the United States, a natural disaster could strike. Millions of your customers could suddenly find themselves with no landline telephone service, thanks to everything from hurricanes in the Southeast to El Nino on the West Coast.

During times of disaster, a reliable wireless network is critical to survival; but if a city is under four feet of snow or water, your equipment probably is, too. The operational and supporting equipment that accompanies your antennas is extremely sensitive to hot and cold temperatures, not to mention water and humidity. Several vendors offer new shelter designs that can protect your equipment from even these extreme elements.

Bill Sales, FWT vice president of sales and marketing, said that two or three years ago the industry was focused on cabinetry. With electronics getting smaller, it was assumed that the industry would move away from shelters and into cabinets, especially in places that have weight restrictions or minimal space in which to work.

"The one element that the cabinetry designers overlooked was the human element," he said. "Cabinets were fine for the most part in states such as California or Arizona. In the Midwest, the East Coast, the North and the Northwest, there are technicians working on high-rise rooftops, coupled with 50mph winds, who have a major problem on their hands. When you have a shelter, you can get inside in the middle of winter and work on the equipment with no problem."

Even though you may save thousands of dollars by using cabinets instead of shelters, he said, the labor from technicians could override your savings if it takes them five times as long to complete their work because of the adverse weather. As a result, many carriers are replacing cabinets with shelters, and those that are just starting to roll out their networks in colder regions are opting for them, too.

The Snow Belt WirelessNorth offers PCS service in North Dakota and Minnesota, where temperatures dip down to 60degrees below zero and snow accumulates to 36 inches. The company hired a consultant, Thomas Horton II with Alpine Wireless Service, to help it find the best protection for its equipment.

"With the frigid temperatures that we have in the northern regions of Minnesota and North Dakota, we are faced with the difficult task of creating an environment for the equipment whereby cabinets are not feasible for us to use," said Bob Beers, WirelessNorth director of engineering. "When you have -40degrees temperatures outside, if you open one of the cabinet doors, and it's not in an enclosed shelter, the temperature threshold at the lower end of the scale is automatically met, and the equipment generally will just click off."

Beers said the equipment in the shelter lasts much longer if the temperature is kept between 60degrees and 70degrees. Besides installing heating and air conditioning units to maintain the desired temperature, the company built its shelters on a concrete pad at least 36 inches above average ground height to avoid being buried in the snow.

Enviro-Buildings also had to combat deep snow when it worked on projects for AirTouch Cellular, said Mike Phillips, vice president of engineering. The sites were at Donner Pass and Cisco Butte in California, both of which sustain 125mph winds and receive 26 feet of snow. Not only did the company have to bulldoze a 15-mile road to get within half a mile of one site, but it also had to hand-carry all of the parts that were needed to put up a shelter to the top of the mountain.

Phillips explained that Enviro-Buildings developed a "snow snorkel" for areas like these. The snorkel looks like a chimney, and it runs from the shelter to the snow's surface 26 feet above the building. Technicians can open the access hatch on the roof and climb down a ladder to the floor. This unique solution allows air to get down into the building so the generator can operate during the winter when snow buries the shelter. Sales concurred that FWT's shelters sent to the far North have hatches as standard equipment, as well.

For carriers that don't want to build a brand-new shelter to replace their cabinets, some companies offer portable shelters that can be deployed in the winter months. Horton said WirelessNorth has designed a shelter that fits over existing cabinets. You can install portable shelters permanently or set up portable panel frames for temporary service calls.

"In this case, the frame is already on the ground, and the technician can carry the panels in his truck. He can stack up the four portable panels, slide the roof on it, throw a heater inside and come back to service that outdoor enclosure," he explained. "With a high-volume heater, the correct temperature can be achieved in a matter of 15 to 20 minutes."

Likewise, Enviro-Buildings has designed a retrofit shelter that you can install over an existing cabinet without interfering with the site's transmitting and receiving.

The Flood Plains Snow isn't the only element that can bury a shelter. Last spring, the Red River Valley area of North Dakota dominated the weather news when floods devastated several of its larger cities. WirelessNorth quickly rushed to market to provide another form of communication for residents in Fargo and Grand Forks, ND, and Moorhead and East Grand Forks, MN. The flooding played a large role in how the company designed its network and established its construction sites.

In places where high ground was unavailable, WirelessNorth modified its foundations to raise the shelters higher than the flood level. Their floors are 36 inches above the ground, and most of the equipment inside the shelters is eight inches off the floor. Even in five or six feet of standing water, the equipment stays dry and will be operational, Beers said, because WirelessNorth's shelters are equipped with sump pumps similar to marine bilge pumps. When the switch on the outside of the building begins to float, the pump automatically turns on and begins moving water out of the building.

"If the building is surrounded by water, a small amount of that water would seep through the door, but it would be immediately sent out with the pump, which runs off the battery supply within the building," Beers said.

Hot Spots In other parts of the country and the world, equipment is subject to extreme heat. The best way to protect your equipment from heat or cold is to make sure you have a well-insulated shelter, said Kim Langenberg, Enviro-Buildings vice president & general manager. The company, which has installed shelters in the hottest parts of Central and South America, Kuwait, Saudi Arabia and Turkey, lines its shelters with either R18 or R32 polystyrene insulation and runs heaters and air conditioners.

Most of the equipment has operating ranges, and if the temperature exceeds a certain point, it will shut down or become damaged, Langenberg said. Enviro-Buildings' cam-locked building has a double-barreled gasket seal and tongue-in-groove polystyrene insulation material. When the panels are locked together, the insulation and the double-barrel gasket are compressed to form an airtight and watertight seal.

Another innovative way to remove your equipment from snow, rain, wind and sun is to install a vault system, which is an underground shelter. However, vaults are more difficult to place because of water constraints.

"Freezing is usually the biggest problem with vaults," Sales said. "Even if you have a good drainage system, if it freezes, it can cause problems."

Lookin' Good It's hard to look professional when you're dressed for the weather. Just as your company would prefer that you make your presentations in a suit instead of a raincoat, people who live near your shelter don't want to notice it for the wrong reasons. Aesthetics have become an important part of designing a shelter, mainly because of zoning requirements in municipal areas. Phillips said sometimes carriers have more trouble getting their buildings approved than their towers.

"Many of the municipalities and the locals are more concerned with aesthetics than how the building performs for us," Horton added. "We try to minimize the visual impact on the landscape by using different facades on our structures. These designs are specifically chosen to blend in with the surrounding environment. We have tried to find a good mix between the aesthetics and the functionality of the shelter, so we try to please the community first."

A variety of shelter designs makes satisfying the locals easier than in the past. Vault systems, for example, are hidden easily from the public. Sales explained that most are equipped with a set of Michigan-style doors, like those found on basements, and sometimes the doors don't stick up above the ground at all. Sales remembered one case in which a company hid the doors under a bench. When technicians need to enter the shelter, they simply lift up the bench.

If the structure must be exposed on the ground level or on the roof, you can create a facade that will match its surroundings. FWT has duplicated everything from historic brick to match the facade of old buildings and churches to setting them inside silos alongside the highway. WirelessNorth uses neutral stone fronts on its shelters, which generally blend in with the landscape, but the company also has used brick facades or aluminum siding. Enviro-Buildings offers 19 different shades of paint and can match its shelters to almost any color. If a customer doesn't mind giving up flexibility, Phillips said the company will install a brick, stucco or stone exterior to match the main building exactly.

Non-penetrating rooftop mounts are an alternative to mounting your shelter directly to a building's exterior, Sales said. Non-penetrating means you don't have to drill through the roof to install the shelter; it sits on the roof and is held in place by its own weight. The latest in non-penetrating roof-mount designs is a triangular-shaped structure. The antennas and shelter all are enclosed within three stealth panels made of a fiberglass compound through which RF signals can penetrate. >From the ground, the unit looks like a rooftop air conditioning unit.

Another way to hide your shelter is by placing it inside a building. WirelessNorth uses space within the buildings it leases and builds out its own private niche inside an existing room. It has shelters inside the Radisson Hotel, the Fargo Housing and Redevelopment Authority's New Horizons location and the Dakota Clinic in Fargo, ND.

With the variety of choices and flexibility that today's shelters offer, your company can custom-design one to match any surroundings and protect your equipment in all kinds of weather. So when that storm rolls in, people who never even knew a cell site was nearby will remember which carrier met their needs during their times of trouble.

You probably employ people whose sole mission is to acquire cell sites for your company. And you may have found that instead of building your own towers, sometimes it's easier to place antennas on top of existing buildings. Today, some of the country's highest structures now are doubling as cell sites.

Even though it may be easier to put your antennas on a tall building, it's not always easy to construct a shelter for the site. You could place it on the ground, but Mike Phillips, Enviro-Buildings vice president of engineering, said doing so might cost more than you think. If cable costs X amount of dollars per foot, he said, running cable from a shelter to an antenna 50 feet in the air is far less expensive than reaching one that is 500 feet tall.

Your best bet, he said, may be to use less cable by putting a shelter at the top of the building. Rooftop shelters are pretty common, but how do you handle a building that's not quite as flat? It's tough, but it can be done. Last year, Enviro-Buildings assembled a shelter in a church steeple in Georgia. The company had to move the shelter by crane through the openings in the church steeple and then assemble it inside. Not only were the antennas in the most advantageous place to get the strongest RF signals, but by putting the shelter inside the church steeple alongside the antennas, no one knew it was there. Enviro-Buildings also has had several inquiries about installing shelters inside water towers. The company is in the process of building a shelter to go inside a water tower in Minnesota, Phillips said.

Bill Sales, FWT vice president of sales and marketing, said one of the most interesting places the company has set a shelter was at The Ballpark in Arlington, TX. Because so many spectators carry wireless devices, additional capacity was needed. FWT installed a shelter on the middle of a platform above the ballpark, where the equipment for the antennas could be housed.

Your company invests a lot of money in its equipment, and the shelter's function is to protect your transmitters, repeaters, generators and any of 100 possible accessory items from harm. Sometimes, though, you may need to protect your shelter, too.

"If a shelter is placed in an inner-city area, it might get some shots taken at it," said Bill Sales, FWT vice president of sales and marketing. "In rural areas, shelters are even more vulnerable. Hunters have been known to literally paint targets on them. In isolated cases such as these, bullet resistant shelters make sense."

Other times, bulletproofing your shelter is completely unnecessary. Mike Phillips, Enviro-Buildings vice president of engineering, said his company makes lightweight, flexible, cost-effective shelters, and adding bulletproofing makes them heavier, inflexible and expensive.

Enviro-Buildings has placed 23 buildings in Turkey, Pakistan and Bosnia, not to mention the most heavily hunted areas of the United States. So far, he said, the company never has replaced a panel or had a warranty claim due to vandalism or bullet penetration.