There is a lot of chatter in the marketplace right now regarding the pros and cons of Ka- vs. Ku-band. Commercial X-band, a frequency reserved entirely for U.S. and Allied Governments’ use, has multiple technical advantages which make it a solid contender in any bandwidth selection process, yet is has been strangely left out of the discussion.

The benefits of commercial X-band are, in many cases, the same or better than those being touted by Ku- vs. Ka- debaters. Hence it is imperative that end users and solutions providers alike do not overlook commercial X-band. Ku-band, and C-band for that matter, is a tried and true standard for good reason – a well-known cost and capability set, various equipment sizes and a supply chain filled with competition. Ka-band will eventually find its niche and become an important and integral part of the available solution set across the world – no doubt growing bandwidth consumption around the world will demand it.

Choosing the right frequency is a process of matching requirements to capabilities: Who makes the equipment? At what cost and how quickly can I get the equipment? What size antenna do I need? Will I lose signal when it rains? What is the strength of its throughput and will it meet my requirement? How do I manage service across multiple spot beams? Is the coverage available where I need it – and when I need it?

So how does commercial X-band, my bread and butter, stack up? It meets the needs of its users for several technical and operational reasons. Successfully used for military communications for decades, commercial X-band outperforms other frequencies in the most demanding scenarios. Commercial X-band advantages include:

• Freedom from the clutter of commercial users: This will not prevent intentional jamming altogether, but it does miniwmize the chances of unintended interference. If remedial actions are required, they are much simpler on X-band than Ku-band.

• Rain fade resistance: Rain fade is mainly an issue for frequency bands above 10 GHz (X-band operates at 7-8 GHz, so performs much better than Ku- and Ka-bands under adverse weather conditions), and is often better than C-band, which may suffer from adjacent satellite interference.

• Excellent for mobility applications: Spaced at 4 degrees apart rather than the traditional 2 degree for Ku-band, commercial X-band performs with higher-power and smaller remote antennas (<1m) than mobile applications demand.

• Maximized throughput: Commercial X-band matches or exceeds all other frequency bands in throughput on the same-sized antennas, and with little impact from rain fade regardless of rain zone.

• Seamless transition to and from WGS systems: X-band saves cost, time, and training, especially contrasted with Ku-band users who will require new (X-band) equipment to transition to WGS when it becomes available.

• Existing legacy X-band equipment and experienced users: Limited cost and training required for most military units which often already have the terminals and experience to use X-band.

• Non-Preemptibility: End users are guaranteed capacity for vital applications such as special operations, training, mobility and Airborne ISR, who are not always able to access government capacity when and as they need it.

• Operational independence: Responsible government users have the ability to manage the bandwidth they lease with a level of control similar to being an owner of that capacity.

In a world which demands ever more bandwidth at maximum value, selecting the right frequency boils down to carefully assessing the specific requirements of an operation, technology or application. Ku- and C-bands have earned their stripes - yet have their limitations. Ka-band will grow up and spread its wings eventually. At present, however, commercial X-band is one of the most valuable assets in the frequency tool kit. I, for one, will continue to bet on commercial X-band viability in the near future and beyond.

About the author
Philip Harlow was appointed President and Chief Operating Officer of XTAR, LLC in June 2010. He is responsible for XTAR’s strategic direction with an emphasis on expanding the company’s reach and capabilities, and for driving XTAR’s business and operational growth with fiscal responsibility for increasing revenue and profitability.