As carriers rush to deploy LTE, what waste results from this haste? One thing that keeps coming up is neglected antenna mounts. John Paleski, president, Subcarrier communications, told AGL Bulletin that as the messengers bearing bad news, tower companies are put into a position of conflict with carriers when they discover new mounts are needed after a job is begun.
“You have to fight with carriers, because they don’t want to [swap out antenna mounts]. They have a certain schedule [for LTE deployment] and they want to maintain it at any cost,” he said. “The major reason for [the mounting issue] is when we are putting four TMAs [tower-mounted amplifiers] per sector, some mounts can handle it, but if it is one of the early angle iron mounts that were only intended to handle a couple of antennas per sector, there is no way that it’s going to support more than that.”
Paleski related an incident the previous week where the tower company was put in the uncomfortable position of telling its boss, the carrier, that an LTE upgrade could not occur because the mounts were woefully inadequate.
“We notified the carrier that, in our judgment, the tower mounts were not adequate to support the new antennas and the new TMAs, but we were directed to finish the installation,” he said.
As the Subcarrier crews progressed further and started to put the antennas and TMAs up, the antenna mount actually started to bow out and collapse in the center by a few inches, according to Paleski.
“The crews could see the metal stress caused by the increased weight. The angle iron mounts were never designed for this type of load,” he said.
So, again, the carrier was called and notified of stress issue on the mounts, but it replied that installation should be completed. But three-quarters of the way through the installation, Paleski pulled his crews from the job, risking the ire of the carrier.
“I called the carrier personally and told them I could see the mounts bending from the ground and there wasn’t any wind. This tower needs new mounts. These mounts will never do. They were not happy,” he said.
Several days later, the carrier sent an engineer to the site who came to the conclusion that only one of the three sector mounts needed to be replaced.
“I couldn’t believe what I was hearing. I was exasperated. All the mounts were identical. The only reason one looked worse was that it had more equipment on it. I told the engineer they all need to be replaced, so he reformatted his letter and told the carrier to replace all the mounts,” Paleski said.
Because the antennas, TMAs and old mounts had to be removed from the tower before the installation could begin again, the price tag nearly quadrupled.
Antenna Mounts: The Wild Card
Antenna mounts are the wild card of LTE deployment. Carriers do not have any documentation on what mounts have been deployed on towers because they were installed by third parties, according to Paleski, and that information was never transferred to a database.
“Some mounts are adequate, some are woefully inadequate. We quote these jobs but have no idea what we will be faced with when we get there. It becomes incumbent on us to tell the carrier whether the mounts are adequate,” Paleski said.
Instead of relying on the judgment of tower crews, which may not have a structural engineer on staff, carriers need to send a crew to each site to independently verify the mounts on the towers before the bidding process begins, Paleski said.
“Mount information should be included in the plans that we receive, so we will know before a tower crew is dispatched whether the mounts need to be replaced or not. As a result, the carrier could specify whether the mount needed to be replaced, and we could price our services accordingly,” he said.