In the past, satellite was dismissed as a wireless backhaul technology, mainly for cost reasons; but as pricing for wireless data increases and carriers shift away from unlimited plans, there is now a compelling, and profitable argument for Ka Band’s use in LTE network backhaul. Ka Band plays well with LTE ’s all-packet architecture. Its advantages in terms of frequency re-use, and its ability to connect hard to reach places, can drive economics that sometimes beat fiber .
Ka Band Background and LTE Friendliness
Since its introduction in the 1970s, Ka- Band’s advantages regarding application flexibility, frequency reuse, and small dish requirements have been recognized. Ka Band’s high frequency physics provide 10 times more bandwidth than other satellite technologies. It can reduce capacity and transmission costs by a factor of 10 because of its efficiency. But prior to mobile networks migrating to all-packet architectures, it wasn’t viewed as a practical alternative for wireless network backhaul.
Because LTE provides all-packet architecture, it can mesh very well with Ka Band technology. Packets can be adjusted to drive transmission efficiency, extremely low latency, and high performance, which help to overcome some of the inherent limitations of transmitting data to and from satellites in geosynchronous orbit. Satellite engineers are experts at creating solutions that squeeze as much efficiency out of packet technologies as possible. So, with the introduction of all-packet LTE , these experts see new opportunities for Ka Band satellite in mobile backhaul that were not feasible in GSM environments.
Fiber’s Limits and Shifting Data Economics
Traditionally, it’s been assumed that the cost of adding incremental bandwidth in fiber networks is effectively zero. There’s significant capital cost in laying fiber and delivering that first kilobyte, but thereafter, stringing new fiber to add massive capacity is minimally expensive. The game has changed though. With significantly higher data rates associated with mobile devices, and applications like video that consume considerable bandwidth, the cost to connect many small cells – as in LTE environments – is increasing. This is particularly true in areas that are difficult to reach, are far from primary fiber rights of way, or that have cumbersome right of way restrictions for various reasons.
As U.S. mobile operators have backtracked away from unlimited data plan pricing, they’ve shifted to models that charge $10 or more per gigabyte. For example, AT&T recently announced new wireless data pricing  where a 3 gigabyte plan will cost $30 per month; similarly Verizon Wireless charges $30 monthly for 2 gigabytes, and $50 per month for 5 gigabytes. Consumers have shown a willingness to pay these prices, which means the options for connecting mobile data networks profitably are expanding.
Up until now satellite bandwidth was paid based on a data rate rather than delivered bytes of data. Based on common traffic assumptions, current satellites would have a cost per gigabyte for delivered bytes in excess of $100 per gigabyte whereas new Ka Band systems could deliver a gigabyte for less than $10. Actual pricing will be driven by many factors, but underlying this is the fact that the more aggressive analysis shows the latest generation of Ka Band satellites can deliver a gigabyte of data for less than 2% of the cost in current generation satellites.
Based on these new economics, Operators can connect LTE cells with Ka-Band beams in underserved and hard to reach places and still have a viable, profitable option for offering coverage there. Again, this works in the LTE world because its packet architecture is easy to adapt to satellite; its cost is far more competitive than other satellite options; and it can be a superior option to fiber in remote areas and places where rights of way are difficult to obtain or access.
What Makes Remote Areas Desirable?
When we talk about remote areas, we’re not talking about places where no one lives or visits. Think of places like resorts, ski areas, and other retreats. Guests want to use video devices and online services for entertainment, to record and share information, or to conduct business.
Similarly, gated communities have been popping up in unconnected areas for years, both in the U.S. and in nations where the economic middle class is growing rapidly. These are often remote from urban centers or are in areas that lack dense cell coverage. People want connectivity there and are willing to pay for it. Often fiber build outs are troublesome in these areas because of their distance from existing rights of way, or because rights of ways are limited by property owners or environmental restrictions. In such cases, satellite is a viable option, if not the only option.
Further, areas that are heavily traversed by train, boat, and automotive traffic are faced with increased demand for bandwidth among travelers. We expect to have access to application-based services everywhere. As a result, mobile operators must connect byways in order to create corridors of LTE connectivity between urban areas. This level of ubiquity is lacking today even in 3G networks. In the LTE world, the expectations for limitless connectivity are much higher. Ka Band is a legitimate option for delivering that connectivity faster, and without sacrificing much, if anything, in terms of cost or margin.
The Final Case for Ka Band
Ultimately, satellite provides another degree of freedom. Operators can create broadband data connectivity anywhere using Ka Band satellite, particularly when they do not have a superior case to use traditional fiber backhaul. Ka Band is technically easy to integrate with LTE ’s all-packet architecture and protocol. Costs are now in line because of greater demand for data, increasing mobile data prices, and Ka Band’s inherent efficiencies. So, while Ka Band isn’t a universal backhaul solution – it’s no replacement for primary fiber backhaul – it is a viable and profitable solution in a growing number of circumstances worldwide.