Why Microwave, not Fiber, is often the better solution for Long Haul

by TzvikaNaveh | Jul 29, 2013 9:57:21 AM

Fiber vs. Microwave

Fiber is certainly a great medium for long-haul transmissions. Once deployed, it provides a tremendous amount of capacity that can satisfy demand for a long, long time. However, there are considerable problems with fiber. For example, fiber deployment is a time-consuming and expensive activity. Right-of-way permits and the labor intensiveness of trenching add significantly to the cost and the time required. The expenses for trenching and deploying fiber increase rapidly with distance, so, if you have to cover distances, fiber can cost too much.

For connecting highly populated areas, the expense of laying fiber can be justified. The distances aren’t great, the capacity is necessary to service the concentration of users and high network resource usage (along with the right billing model) means that ROI can be achieved relatively quickly. However, for connecting areas that are separated by significant distances, fiber deployment can be prohibitively expensive. For a deeper look into the relationship between cost and distance, please see the picture below.

Microwave and Fiber Backhaul Solutions vs. Distance

In contrast, microwave deployment costs a fraction of fiber and can be much more affordable. For starters, it’s fairly easy to deploy - provided that you have the requisite bandwidth permits. Deploying a microwave network over tens, or even hundreds, of kilometers can be accomplished in just weeks. With all the pressure to get network services up and running quickly, microwave deployment effectively reduces the time to revenue for network operators.

Microwave is also quite flexible. While fiber is in the ground and, practically, cannot be moved, a microwave site can be moved or re-directed to accommodate traffic changes in the network. These kinds of changes take only days or weeks and, because they are cost-effective, they are undertaken by microwave network operators frequently.

In fact, even having the fiber is in the ground does not guarantee problem free transmission. Fiber breaks seem to be an all-to-frequent condition. I just read that in a particular large country, there are, on average, fourteen fiber breaks per 100km per year. This means a colossal 2,200 hours of network down-time! All fiber networks suffer breaks and these can be catastrophic to operations.

The reliability of microwave, on the other hand, is excellent. Network operators can rely on microwave to remain operational and to provide good service for very long periods of time. I just read that the MTBF of leading microwave systems is now in excess of 100 years!

You might be thinking, “Cuts or no cuts, microwave just doesn’t have the capacity required for today’s 3G/4G networks.” Well, think again. Today’s microwave technology provides impressive long-haul capacity that can be measured in gigabits and is often enough for backhaul and other implementations. Innovative technologies, like Ceragon’s advanced modulation and multi-carrier Adaptive Bandwidth Control empower operators to provide high capacity on long-haul routes.

One other interesting point in the fiber vs. microwave debate is found in the requirement for network backup. If you have a critical network requirement, how do you make sure it has backup in case of failure? In our experience, we have found that microwave is a great backup for fiber. One fiber network alone is expensive to deploy. Who wants to deploy an additional backup network with expensive fiber? You can use microwave to give you extra cost-effective reliability in case of fiber network failure. Today, there are many schemes for automatic switchover between fiber and microwave networks and this is a very practical solution that adds considerably to network reliability.

If you have any questions, please feel free to reach out to me at tzvikan@ceragon.com

Long Haul, ISPs & RSPs


Written by TzvikaNaveh