A Fiber & Wireless Sandwich: Rural Broadband Deployment

By Fletcher Kittredge of GWI:

I’m often asked “Which are better, wireless or wired Internet connections?” From a technical perspective, the question doesn’t make much sense. They are complementary, not competitive. As transmission media, fiber and wireless both have unique advantages and disadvantages. In building an Internet network, a design that takes advantage of the strengths and minimizes the weaknesses of both results in the best system.

The fundamental insight that made the Internet is “transmission protocols should be media independent.” Before the Internet, protocols were optimized for a particular transmission medium and only worked on that medium. A wireless network would have a wireless protocol, a telephone network would have a telephone protocol and a cable network would have a cable protocol. It was not possible to send data between networks. The Internet protocols let data be sent between networks and allowed the same software to be used no matter what the network, effectively creating one large network.

This paradigm shift allowed network architects to design networks using whatever media best suited a particular geographic area. It became possible to use fiber, copper wires, and wireless in the same network. Though it dominates in legacy networks, the inherent drawbacks of copper wire severely limit its use in new networks. Generally, fiber optic cable is used instead because it is far faster, cheaper, lighter, smaller, non-conductive, and inert.

The strengths and weaknesses of wireless and wired connections dictate how they work together.

A fixed wireless tower on Benner Hill in the Midcoast.Wireless and fiber optic cable have very different transmission characteristics. A fiber optic connection is much faster and much more reliable than a wireless connection. Fiber also has a longer lifespan, depreciating over 20 or more years whereas most wireless equipment will need to be replaced in five years. Lastly, fiber is more secure than wireless because fiber is much more difficult to tap without detection.  For its part, wireless is most useful for mobility. We couldn’t have smartphones, tablets, and laptops without mobile wireless connections never mind drones and self-driving cars. Wireless also has a cost advantage in locations where it is expensive to string fiber optic cable. These traits dictate how the networks are best used together.

Speed, reliability, and security can all be improved in wireless networks by shortening the distance between the transmitter and the receiver. This is why most networks employ fiber as far as they can, and wireless for the last bit. Examples of this architecture are fiber to a cell tower, then wireless to a smart phone, fiber to a business, then wireless to a laptop, fiber to a home and wireless to a tablet, fiber to the farm and wireless to sensors and equipment.

The cost advantages of wireless are compelling in sparsely populated areas.  In rural Maine, there are locations where the best way to provide connectivity may be fiber to a tower, then a fixed wireless connection to remote homes, farms, and businesses. This is because the cost of fiber is directly related to the density of connections. The farther you have to string the fiber between locations, the greater the cost per location. Another compelling application of wireless in Maine is in bringing broadband to islands, where the cost of laying undersea fiber is often prohibitive.

Broadband policy decisions must balance the need for bandwidth with cost, at least in the short term.

Where wireless is used versus fiber is a judgment call. The judgment is to balance the cost versus the speed, security, and reliability required. If private money funds the system, the judgment is not that difficult. However, if public money is used, the interests of the majority, which bears the cost, can differ from the rural users, who care more about the speed, reliability, and security of their connections.

There are passionate arguments between rural residents who feel they deserve connections as good as in urban areas and urban folks who feel that they should not be asked to subsidize high cost areas.  These urban residents often say that their rural counterparts should accept slower, less reliable, less secure connections as a cost of living in the country. In these arguments, I am struck that it is a continuum where fine-grain engineering choices can be made based on the practicalities of location.

Mainers are going to have to decide whether rural Maine should get a network as good as in urban areas, but the decisions should be seen as points on a time-line. If a decision is made that a certain region is to be served via wireless now, it doesn’t mean that fiber can’t be deployed at a later date, perhaps when in five years when the wireless equipment is due to be replaced.

It’s not appropriate to try and make an either-or decision to use fiber or wireless. Both will be needed to build the best network for Maine.  Much like peanut butter and jelly, they work best together.