The Truth about Designing Cell Phone and Other Networks
Things at the Boston Marathon Finish Line in 1910 were much calmer—and simpler—than the 2013 edition sans cell phones and other wireless devices. Author: Unknown. (Image credit: Wikipedia).
As was demonstrated by the tragic events in Boston April 2013, cell phone networks cannot accommodate every potential caller or texter using a mobile access device in times of peak load usage—such as during a crisis occurring in real-time on television and social media. Erroneously, some pundits at the time ascribed the outage to a co-conspiracy to take down the public wireless networks. Or an action by the civil authorities to thwart additional remote control saboteurs as has happened in Spain and other places. However, the simple truth is that demand far outstripped capacity for a time in Massachusetts due to the fact that mobile phone networks are designed to function with a typical level of subscriber activity—calls, text, mobile web, etc. When virtually everyone in the vicinity of the finishline of the Boston Marathon unlocked their iPhone or Samsung Galaxy smartphone and started to communicate the unfolding story to the outside world, it came as no surprise to network designers at the mobile operators that the infrastructure slowed to a crawl then ceased to work for a time. But this was news to the general public.
In the same way, backhaul for LTE networks should be designed for typical mobile voice and data traffic patterns. Many have exclaimed the ever-escalating volumes of mobile traffic as quickly running into the Gigabits per second (Gbps) range. Consequently, they have focused on fiber as the only possible solution that can handle this amount of peak traffic on the backhaul—even though as in our analogy peak usage is infrequently achieved. The current version of LTE (along with 3G traffic from the same site) probably generates at most 200 Mbps aggregate mobile traffic out of the typical three-sector base station. And though it’s unlikely even LTE-Advanced base stations will generate gigabit levels of backhaul traffic in the future (unless multiple base stations are aggregated together), wireless technologies (i.e., microwave, millimeterwave) will be able to keep pace, if needed. Wireless backhaul can suppliy this level of capacity and much more with capabilities for up to 1 Gbps and higher possible. Cost-effective and quickly deployable microwave backhaul solutions can meet the demand.
As is commonly known, fiber solutions provide as much capacity as the operator is willing to pay for. But they are paying for capacity they do not need and probably will not need for some time to come. And fiber comes with a high price tag both in terms of initial outlay (capex) and ongoing costs (opex) with susceptibility to intentional and unintentional line cuts. As for time to deployment, months to years are typical timelines for completion of a fiber backhaul route.
If you are interested in the specifics of microwave vs. fiber for LTE backhaul, we invite you to read the white paper below. Or download it and read it at your convenience.