For all the wonders of wireless communications technology, the complex systems don’t perform well — and may fail altogether — when vital network components do not work properly. With this in mind, securing sites in an effort to ensure that these components function correctly is of paramount importance, particularly for mission-critical networks.

From an operator’s perspective, each piece of expensive networking gear has a specific purpose that helps enable wireless communications. For an outsider, items at wireless sites also can be perceived as valuable, but often for very different reasons.

In remote locations, electrical power is at a premium, so various forms of generators are valued by many and need to be secured. But power is not necessarily the only use for such devices. One manufacturer tells the story of a solar panel taken from a site in a third-world country that was discovered weeks later — being used as the top of a coffee table.

A much more prevalent problem at land-mobile radio tower sites has been attempts to steal copper wiring. Particularly with the price of copper skyrocketing over the past couple of years, the large amounts of the element used at sites — most notably, the large bands of copper used to ground tower equipment in case of a lightning strike — can represent a large payday for thieves.

“Copper theft is a big motivator today at telecommunications sites. … It’s become a pretty valuable commodity,” said Jim Parcels, director of system management for Pennsylvania Public Safety Radio. “There’s a huge hunk of copper that’s just sitting there shining, attracting copper thieves.”

A similar string of copper thefts at LMR sites in central Florida occurred during an extended period until one of the perpetrators apparently met his demise attempting a heist, said Ben Holycross, radio systems manager for Polk County, Fla.

“With a little ax, they managed to cut into a 440-volt AC circuit. He was deader than a doornail,” Holycross said. “That all came pretty much to a stop, so we think they were responsible for a just a boatload of copper thefts.”

In an effort to prevent such unwanted intrusions, LMR operators traditionally have gone to great lengths to keep outsiders away from their radio systems, which typically feature high tower sites erected in locations that often are relatively isolated.

A dedicated roadway provides access to many LMR sites; such roadways can be gated as an initial security measure, Parcels said. In addition, the site compound usually is surrounded by chain-linked fences topped with barbed wire, he said. Such precautions usually are enough to deter those who might unintentionally enter an area or those willing to make only a half-hearted attempt at mischief, but they are not enough to stop someone who is prepared and has truly malicious intents, Parcels said.

“All it takes is a good set of cutters to get through a chain-linked fence,” he said. “So, if somebody wants to get into a site compound, they can.”

However, because today’s radio shelters often are concrete, bullet-proof enclosures that can withstand being engulfed by a wildfire, the radio equipment typically is safe from vandals and thieves, Parcels said. That traditionally has not been the case for the copper grounding wires, which often run down the outside of the shelter. And, because the grounding mechanism is not an active element of the radio network, it typically cannot be monitored remotely, unlike the active components of the network.

“The real damage is done after [the copper thieves] leave, because now the hundreds of thousands of dollars worth of electronics equipment in your shelter is exposed [to lightning strikes],” Parcels said. “And, until [the perpetrators] do something that affects the operating equipment, you’re not going to know it.”

In reaction to the instances of copper theft at sites, some vendors have developed hardened enclosures to protect the grounding copper from outsiders, Parcels said. More traditional strategies include having personnel visit the site on a regular basis, but that does not provide constant surveillance and can take resources that are better utilized elsewhere.

Video surveillance at the site is an option, but constantly backhauling the video to a network operations center can be expensive, especially when the cost for personnel to monitor the video for a statewide system with hundreds of sites is considered.

Holycross said that he believes video is a viable option, but only when used in combination with sensor technology at the site. Instead of sending video from a given site to a network operations center all the time, the video would be delivered only when a sensor detects movement that meets specified thresholds. In the past, such a strategy might result in considerable wasted resources created by animals setting off false alarms, but “fortunately, the sensor technology is getting much better” today, Holycross said.

While many of the measures used to secure LMR sites make sense for a handful of high-site towers in a radio network, attempting to duplicate such security strategies in a long-term evolution (LTE) wireless broadband network probably is not practical, for several reasons.

Cellular technologies like LTE utilize considerably more sites than LMR networks, so securing each site as is done with an LMR site would be prohibitively expensive. In addition, many cellular sites are located on structures such as office buildings that — unlike LMR towers — are not dedicated to the wireless communications effort, so space and access often are at limited.

“The more sites you must secure, the more complex it gets,” Holycross said.

One company that has tackled this issue is IPWireless, which has seen its technology deployed in wireless broadband networks for jurisdictions as large as New York City and as small as Gillette, Wyo. IPWireless CTO Roger Quayle said that cellular technology offers a different set of considerations than LMR networks.

For example, because there are so many sites in cellular architectures for technologies like LTE, public-safety network designers should recognize the fact that losing a single site in a broadband network does not result in massive coverage gaps that losing an LMR site would create. Instead, the loss of a single LTE site typically would degrade network performance and have a negative impact on some in-building coverage, but outdoor coverage should remain intact.

That said, securing radio equipment in hardened enclosures is important for maintaining the integrity of the broadband system, Quayle said, noting that some systems only allow access into these equipment rooms via authorization from the network operations center, which remotely unlocks the door for a technician seeking entry. In addition, intruder-alarm systems also are helpful — not only in the room but in each individual cabinet within the room, he said.

“In a typical system where you have building-top sites … you have high security measures committed to that equipment room,” Quayle said. “For example, you have intruder alarms, and all of the cell-site equipment has various alarms. So, as well as the door to the equipment room being alarmed, the doors to the cabinets would be alarmed.”

Once again, video surveillance can be a valuable security tool — and perhaps easier to implement at a broadband site than at an LMR site, because high-bandwidth backhaul to a network operations center should be more available to deliver the video from a broadband site than from a narrowband LMR site, Parcels said.

Exactly how much site security is implemented at public-safety LTE sites will depend largely on available funding, Quayle said.

“I can’t say what’s best,” he said. “It’s really up to the individual customer, taking into account the importance of the broadband system to them and how much money they have available.”

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