The business case for 10GigE mobile backhaul

In my previous article on this topic, I reviewed the industry projections forecasting mobile backhaul bandwidth requirements of 200Mb-300Mb per cell site for large urban sites by 2015.  And I also highlighted that multi-tenant towers in these locations may require 300Mb-500Mb, and microwave radio hub sites will require 1GigE or more.

If every tower required this much bandwidth, it would be a no-brainer to deploy 10GigE to every tower; however, not every tower will be in a dense urban center.  Some tower footprints are rural, suburban or urban edge.  An optimal network design will maximize the 10GigE footprint to enable scalability and flexibility, and use 1GigE G.8032 rings where 10GigE is not necessary.

So, the questions still remains, how do carriers determine where to deploy 10GigE?

Before exploring the business case for 1GigE versus 10GigE, it’s important to understand one of the ways carriers optimize their network architecture. Backhaul providers optimize equipment CAPEX by serving multiple customers with a single solution at the tower instead of a dedicated device for each carrier. They optimize fiber cost by serving multiple towers with a single fiber pair instead of dedicating fiber to each endpoint. By serving 10 towers with a multi-node ring, providers can reduce fiber consumption by an order-of-magnitude.

The net impact of these optimizations is that the service provider can justify building out a 10GigE backhaul network by considering the demand and growth projections of a group of towers instead of the requirements of a single mobile operator at a single tower. Network planners model the bandwidth requirements across a three to five year period, fiber cost and equipment CAPEX to determine the optimal design for each group of towers.

Consider an example network where 16 towers are passed by a leased fiber route with a monthly fiber lease cost of $3K per pair. Here, a single fiber pair for a 10GigE solution turns out to be more cost-effective than multiple 1GigE rings on separate fiber pairs if the average bandwidth per tower is projected to require 125Mb-150Mb.

Service providers focused on cost-effective scalability are already architecting 10GigE solutions for mobile backhaul. These carriers optimize CAPEX efficiency by incorporating the three to five-year bandwidth growth projections, equipment CAPEX and fiber costs into their design models to maximize their 10GigE footprint. This smart deployment of 10GigE ensures cost-effective and seamless scaling to handle the growing demand at the cell tower.

Scott Knox is director of solutions development at Overture Networks.  To review the details of this business case, download the free whitepaper here.