Ka Band - Will it ever escape domestic broadband and become a real contender competing with Ku?

Post IBC 2012, it seems that Ka is once again the talk of Amsterdam. But having experience this 'buzz' at the last 5 IBCs is Ka ever going to be something more meaty?

 

In my opinion I don't see that there is a replacement issue under all conditions. We have a continuing appetite for capacity, protection, and mobility from space that only add Ka spectrum to existing C/Ku.

 

I will contend that each band and each system has unique pros and cons. Aside from cost/byte, users must account for the supportability of their current C/Ku terminals and infrastructure, the application at hand, rain and overall weather conditions, and constraints (or not) to real estate for terminals (aperture size).

 

The problem is achieving a SLA with the deep fade margins associated with Ka band.When the first trials were done at Ka Band on the ACT and Olympus satellites back in the late 80's, the traffic was still serial; since then, powerful FEC codes have permitted the use of packet based traffic and this in turn has permitted the use of ACM. It is the sum of all these technologies that has finally permitted Ka band to be of commercial value. (obviously the drop in the price of 30GHz FETs has also helped).

 

Now during the fade, the ACM automatically downscales the MODCOD values so maintaining the availability (albeit at a reduced information rate). Even though the information rate is reduced during the fade, the use of packet shaping can enable a CIR to be maintained for specific traffic profiles within the stream.

 

The point that needs to be made is that there are variety of downlink bands being used with Ka-Band uplinks. (C, Ku and K), to my knowledge there isn't actually a communication satellite that supports both uplink and downlink in Ka band (please feel free to correct me if I am wrong).

 

At the higher end of K band (e.g. 21 GHz) the water absorption point starts to have a more pronounced affect, so applications using this cannot be directly compared to a downlink operating in Ku band (as we say in the UK, you have to "compare apples with apples").

 

A high performance hub earth station can be built that overcomes many of the "perceived" issues associated with Ka band and if grouped with a downlink in the lower part of K band (or Ku band) there is no reason why performance not too dissimilar to Ku band cannot be achieved.

 

You might also want to read:

• Why is Ka band becoming the next big thing in the satellite industry

Ka band, the next logical successor to Ku band

The satellite industry faces new challenges in the coming years as orbital slots and frequencies decrease with every new launch. Many companies are already thinking of joint-cooperation to help solve the issue of crowded skies. But new challenges also face the sector as the rise of smartphones have also given rise to bandwidth-intensive mobile applications putting a strain on communications networks. The demand for satellite capacity has also increased across regions like the Middle East, North Africa, and Asia, and markets like the maritime, military, oil and gas, mining, and construction industry are also asking for more.

 

 

 

In the 1980’s to 90’s, when the original spectrum C-band faced a similar strain with rising demands, Ku band came into the picture to provide even more bandwidth and satellite capacity. The Ku band spectrum also introduced the concept of regional beams which allowed the rise of regional operators like Arabsat and Eutelsat, alongside the prevalence of VSAT technology, which made customer networks not only easier to deploy and convenient, but also cost effective.

 

However, this was almost two decades ago, and the exponential growth in data and wireless communications technology means even bigger demand for satellite capacity.

 

This is where the latest spectrum, Ka band, comes into play. Since C Band and Ku band are inevitably nearing saturation, the logical step is to move to the next frequency. Ka band, as opposed to the C and Ku band, offers a wider frequency band from 26.5 - 40 GHz, along with part of K-band from 18-21GHz. Since Ka band is a higher spectrum, no beams overlap, making it possible for all three to work simultaneously without frequency coordination restraints.

 

On paper, a Ka band satellite can support up to 24GHz using two regional beams, two satellite beams, and up to twenty multi-spot beams. Obviously, with this increased spectrum, it can support greater traffic volumes than Ku band and C band.

 

Since present demand for satellite capacity cannot be met by the lower bands, Ka band is the natural step forward. The technology can used for a variety of applications including remote connective technology like online education and telehealth; mobile backhaul and two way satellite broadband; as well as broadcast, enterprise, and even military applications. Dedicated Ka band satellites are already in orbit and more are under construction and slated for launches in the next five years.

 

High-demand regions like Asia and MENA will look forward to Ka band as the logical successor to Ku band. The emergence of more powerful ka band satellites is expected to transform the satellite market in the same manner Ku band impacted what was back then, a C band focused industry. There will be challenges for satellite operators and consumers alike who will find the transfer to a new spectrum difficult. But in the long run, Ka band technology is essential to meet the growing communications needs of communities, enterprises, and various organizations of an increasingly globalized world.