Aerial or Underground: How to Make the Best Choice

There are many decisions to make when building a fiber optic broadband network, and of course, everyone has an opinion on which deployment method, aerial or underground, is better. This can make choosing the method for your next build quite difficult. It impacts many other decisions throughout your network including materials needed, installation crews, and your total network costs. Here are some of the many factors to consider when picking a suitable method for your next project. 

Aerial Deployment 

There are two main aerial deployment methods. The most common is using lashing wire to attach fiber optic cable to messager wire/strand. This allows the strand to bear any weight that may otherwise damage the fiber. It also allows for easy future expansion of additional cables to be added as your network grows. The other method is using ADSS, All-Dielectric Self Supporting, fiber optic cable. ADSS fiber has an internal strength membrane that allows it to support itself; however, it makes it difficult install mid-span attachments and future network expansion capabilities. Both methods have similar advantages and disadvantages. 

Using an aerial deployment method has many advantages. The largest being it is the most cost-effective method. Typically, fiber is being added in areas where the infrastructure, telephone poles, already exist. This allows the deployment to become cheaper since there is nothing to install besides your fiber and its needed pole line attachments. This helps to save not only on material costs but also labor costs during the installation process. Additionally, there isn’t any digging required which is another installation cost that can be cut. Furthermore, contractors don’t have to spend time getting underground permits to dig and install conduit or map out other underground utilities which means they can begin installing fiber faster going aerially. Overall, an aerial deployment method is typically faster and more cost-effective than an underground deployment.

However, there are some downsides to aerial deployment. There is a process known as “Make Ready” which is the work that needs to be completed before one can attach to the telephone poles. This can be frustrating for contractors since there isn’t a standard for Make Ready and every pole owner does it differently. Additionally, one still has to prepare by getting permits to attach their fiber to the poles, known as getting a “pole attachment agreement”. This process can be long and can take several months to accomplish. Another disadvantage is telephone poles can only handle so much weight and tension. This means if there are other utilities on the poles it may be difficult to attach your materials to them without the poles being damaged or even replaced. Additionally, weather conditions can have huge impacts on a network. For example, if a windy storm comes through it can knock down poles, or in a snowstorm, ice can build up on the fiber leading it to sag and eventually break. Animals can even cause network outages. Between bird talons, squirrel bites, and other rodent trouble, animals can damage the fiber. One more con is depending on how accessible the telephone poles are, aerial maintenance and repairs can also be difficult to perform in remote areas. 

Underground Deployment

Typically, if you are choosing an underground method there is one standard method, fiber inside of conduit. While some might install cable without the added protection of duct, this is not a common long haul method. The first step of underground is installing the conduit, although there are different ways to install it including boring, trenching, or plowing. The conduit gets installed first, and then a crew comes to install the fiber via pulling or blowing it in- we’ve got a guide to that too if you want to learn more. Just like aerial, there are pros and cons to an underground deployment method.

There are many advantages to an underground deployment method. One of the biggest is aesthetics in that once the conduit and fiber are installed underground the network becomes essentially invisible making it visually much more appealing. Some municipalities or local government ordinances might dictate this method within their jurisdiction to keep their town looking “picturesque”. Weather also doesn’t affect the fiber as much underground which can make it more of a reliable method by decreasing its chances of damage thus resulting in less service disruption. This means fewer angry customers calling in over network outages. Going underground is also more of a forgiving deployment in that it is easier to go around existing obstructions. 

The underground method also has some cons. The first disadvantage would be that underground deployments are generally more expensive. Between the associated material and labor costs of digging and installing the duct and fiber, the overall network cost increases; therefore, the cost of homes passed rises. Furthermore, the type of terrain where the network is being installed can impact the cost as well. While black dirt and clay are generally easy to install in, terrains that are rocky or sandy can be a slow difficult process driving up costs. Additionally, one has to be granted an easement to gain access to the land where their fiber is going to be installed alongside roads, commonly known as “Right of Way” or “ROW”. To gain access to the ROW, one has to go through the governing agencies of the road, which may take an extended time to be granted permission. Another disadvantage is that because the cable is invisible underground and if it isn’t marked properly it can be easily damaged during any future digging. So, if any repairs are needed maintenance contractors will have to dig up the cable to gain access to it which can also become expensive depending on where the break in the cable is located. 

So Which Method Should You Choose?

While both methods have their pros and cons, it should come down to each specific project and what makes the most sense for it rather than an overall general deployment of aerial or underground. Heck, your network can also be a mix of these two methods if that is what makes the most sense for the project. However, if you are still not sure which is best – we’re here to help! We’ve been in the business a long time and know a thing or two about aerial and underground installations. The Millennium Group offers enterprise-level resources that can help your fiber network build from the planning and financing stages all the way to the deployment stage with materials and equipment rentals. So if you need help with your next build, Millennium has your back.