by Russ Steele
One of the broadband challenges in the Sierra is our tree covered hills and steep valleys, making an accurate line of sight between the transmitting and the receiving antenna difficult and in some cases impossible. 5G systems will be operating an even higher millimeter wave spectrum than the frequencies currently used for backhaul and last mile connections in wireless installations. These higher frequencies will also require a clear line of sight connections for reliable operation.
Doug Dawson at POTS and PANs lives in Asheville, NC a town with lots of shade trees and ornamental bushes in yards. He notes that shade trees are a fixture in many cities across America. We certainly have them in the Sierra.
5G is being touted as a fiber replacement, capable of delivering speeds up to a gigabit to homes and businesses. This kind of 5G (which is different than 5G cellular) is going to use the millimeter wave spectrum bands. There are a few characteristics of that spectrum that defines how a 5G network must be deployed. This spectrum has extremely short wavelengths, and that means two things. First, the signal isn’t going to travel very far before the signal dissipates and grows too weak to deliver fast data. Second, these short wavelengths don’t penetrate anything. They won’t go through leaves, walls, or even through a person walking past the transmitter – so these frequencies require a true unimpeded line-of-sight connection.
These requirements are going to be problematic on the typical residential street. Go outside your own house and see if there is a perfect line-of-sight from any one pole to your home as well as to three or four of your neighbors. The required unimpeded path means there can be no tree, shrub or other impediment between the transmitter on a pole and each home getting this service. This may not be an issue in places with few trees like Phoenix, but it sure doesn’t look very feasible on my street. On my street the only way to make this work would be by imposing a severe tree trimming regime – something that I know most people in Asheville would resist. I would never buy this service if it meant butchering my old ornamental crepe myrtle. And tree trimming must then be maintained into the future to keep new growth from blocking signal paths.
I think that Doug has illustrated the problem that many in Sierra towns and village are going face with 5G implementation. If the mini towers and light pole configurations are on the street, the user will have to have an antenna on the front of the home or business with a clear signal path. The installers will have to string coax from the best antenna location to the rooms were the home or office network is located. Long distance runs will be expensive, increasing the cost of 5G installations.
Doug raises another rural issue, backhaul. The stringing of fiber to each mini tower will be expensive, with the microwave a lower cost alternative. But, there are still the trees to be dealt with. Doug writes about the issue:
One of the primary alternatives to stringing fiber is to feed neighborhood 5G nodes with point-to-point microwave radio shots. In a neighborhood like mine these won’t be any more practical that the 5G signal paths. The solution I see being used for this kind of back-haul is to erect tall poles of 100’ to 120’ to provide a signal path over the tops of trees. I don’t think many neighborhoods are going to want to see a network of tall poles built around them. And tall poles still suffer the same line-of-sight issues. They still have to somehow beam the signal down to the 5G transmitters and that means a lot more tree trimming.
Full POTs and PANs article is HERE:
As you can see, rural communities have multiple 5G challenges ahead of them.