What is causing the Ka-band Satellites launch delays?
The Ka band is part of the K band of the microwave band of the electromagnetic spectrum. The Ka symbol refers to “Kurtz-above” — in other words, the band directly above the Kurtz (K)-band. The 30/20 GHz band is used in communications satellites. Similarly Ku stands for Kurtz-under band.
In the past two years or so, there has been a lot of furor over the utilization of the Ka band for commercial purposes such as broadband and audio-visual broadcast. The higher operating frequencies of Ka band and the spot beam design mean that the cost per bit transmitted on a Ka band satellite is significantly lower than that of Ku or C band satellites. This fact makes Ka band an attractive alternative to the more expensive Ku and C band and positions satellite communications as a worthy challenger to the now ubiquitous and cheaper fiber optic cables.
This lower cost per bit has seen investors and satellite operators come up with Ka band satellite launch projects such as the O3B project (see my take on O3B here), the ViaSat, Yahsat and the Hughes spaceway. Major satellite operators have also announced plans to launch Ka band birds in the near future with the notable exception of Intelsat who have so far been silent about their Ka band plans apart from its partial investment in the wildblue Ka satellite that provides high-speed broadband in North America.
Intelsat’s non-commitment to Ka band was perhaps the first sign that they knew something other operators didn’t know. As for now it is left to our fertile imagination as to why the largest satellite fleet owner did not jump into the Ka band-wagon (pun intended)
Recent events and realizations however show why Intelsat was right. The Ka band satellite projects have been faced by unforeseen hitches that have caused delays and indefinite postponement of some satellites.
Lack of key components.
During the design of a satellite, very few components are COTS. This means that majority of the components have to be specifically designed and manufactured for that particular satellite and no other satellite will have an exact component characteristics. One of the most important component in a satellite is the Traveling Wave Tube (TWT). These are RF amplifiers and you can read more about them by clicking here. Apparently the two major manufacturers of TWT’s for satellite application (L3 communications and Thales of France) have run into difficulties in the design and manufacture of Ka band TWT’s. The high demand for Ka band TWT’s is also putting a strain in their manufacturing capacity making the acquisition of TWT’s a critical path in these satellite projects.
Interest from airlines.
One thing that no one foresaw was the strong interest of Ka services from airlines because the cost per bit for Ka band is significantly lower, Airlines could now offer affordable high-speed broadband on-board flights, The demand for on board internet services is also skyrocketing thanks to devices such as iPads and smart phones. These airlines were willing to pay upfront and sign long-term contracts with satellite operators such as the case between Jetblue and Viasat who signed an agreement early this year. This has sent some satellite designers back to the drawing board to design satellites that are capable of seamless cross-beam and sometimes cross-satellite hand over to enable aircraft’s to be always connected. The immense opportunity presented by airlines presents a lucrative market in which satellite operators are willing to play in especially due to the toughening competition on land from terrestrial fiber optic cables. In a few years, broadband on aircraft will be ubiquitous thanks to this development.
This fact has made Ka band not as competitive as before for broadband providers as compared to the existing Ku band satellites because the demand for Ka is now bigger than was before anticipated.
The assumption that Ka band will present cheaper customer premise equipment (CPE) to Ku band was also far-fetched. The assumption that because the antenna is smaller it will therefore be cheaper is wrong. This would only hold true for receive only systems such as DTH Tv like DStv. When it comes to broadband connectivity where there is need to transmit, a smaller dish presents two problems:
- The smaller dish being presented to consumers of Ka band present a bigger possibility for interference if not precisely pointed, the small dish avails a wide beam that can cause adjacent satellite interference. Ka band installation technicians will need to be extremely precise in pointing the smaller dishes. Sometimes this extreme precision is lacking especially in Africa and Asia where adherence to standards is lax. I see a situation where Ka band installations will still continue to be done on Ku size dishes such as the 1.2m or 1.8m dish. The smaller cheaper dishes will simply not work well unless they are on automatic pointing or gyroscopic systems on maritime vessels and aircraft or on receive-only systems.
- Because of the high operating frequencies of Ka band, the tolerances for the RF equipment design will have to be very low. The design of a cheaper and more tolerant RF system is simply not possible. The existing cheap Ka band RF systems are not the best and do not offer good tolerances for the extremely high-speed data transfer figures touted for the Ka band services This is because they introduce noise due to the poor design. You cannot buy a 50 dollar RF system and expect to transmit at 10Mbps.
So far, delays in Ka band satellites launch have been experienced by ViaSat-1, YahSat-1B, the eight O3B satellite constellation and many more.
The market needs to wake up to the fact that Ka band services will come but they will need time to mature into what industry analysts say they will be. It will not be an overnight success story but there is hope that development of Ka band technology and systems will eventually lead to cheaper satellite broadband.
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