The main obstacle to commercial satellite networks has been high operating costs; finally and after 10 years of research and experiments, scientists have developed efficient ways to use the frequencies available for commercial uses.
A new transmission frequency known as Ka-Band is revolutionizing the possibility of offering two-way communications services, in addition to transmission speeds up to 50 times faster than those offered by standard networks, with a noticeable increase in bandwidth that allows to offer new applications such as VOD.
Ka-Band is a high frequency band that operates between 17.7 and 30.6 gigahertz, being the first to allow sufficient bandwidth to carry several services simultaneously such as multiple voice communications, connections between computers and teleconferencing, allows the use of applications that require bandwidth on demand, of antennas and small satellite equipment, in addition to offering a very strong signal that hardly deteriorates in its route.
One way to increase the amount of information or data carried per unit of time transmitted on a satellite is to use high radio frequencies. A high frequency basically means a short wavelength, Ka-Band has a signal with millimeter wavelength that allows to considerably increase the amount of data transported. The big problem with short lengths was the sensitivity to atmospheric phenomena, mainly rain, which degraded the quality of the signal. To solve this problem, Ka-Band frequencies have incorporated a digital technology known as TMDA (time division multiple access) that helps compensate for errors produced by the phenomenon of rain such as error in codes and slow transmission speed, TMDA is a technology very similar to that used by cellular terrestrial systems.
Among the main advantages of Ka-Band are the increase in bandwidth, two-way connectivity, low costs, high-speed Internet access and other business applications. This band compatible with MPEG-2 and DVB-RCS (Digital Video Broadcast-Return Channel System) standards will allow the delivery of high-quality digital content in addition to the use of small receiving antennas that could have a diameter of 1.3 meters or even less.
With the use of Ka-Band, the use of receiving guide antennas becomes more attractive. This type of antennas or guide units are oriented to the coverage of certain areas, this feature makes it possible for the satellites to have different coverage patterns, this means that the same band frequency can be used by multiple receiving guide antennas regardless of whether these coverage areas are isolated from each other. Using separate guide antennas, the same Ka-Band frequency can be used four times, quadrupling the capacity of the satellites, this reuse of frequencies reduces the unit cost of bandwidth, making the option economically viable for commercial uses, equally, the bandwidth provided can be shared by several users. Thanks to the short wavelength provided by ka-band frequencies, all these options become real.
The shortwave concept offers another advantage for Ka-Band and that is the segmentation of transmitted content. The traditional model of satellite transmission universally sent the contents and resorted to the coverage of large reception areas, a phenomenon that gave way to the loss of signal, with the use of receiving guide antennas of low coverage the implementation of regional services is possible. The satellites that will work under these frequencies will use a point-to-point, point-to-multipoint and direct-to-user service architecture, which complemented by advanced routing and transfer technologies allow the creation of flexible services that will adapt to the needs of smaller receiving groups.
This frequency is not a discovery of recent years, by the early 90s, the ACTS (Advanced Communications Technology Satellite), a division of NASA, was already conducting test transmissions, and came to determine that most of the options offered by Ku-Band frequencies were possible within Ka-Band. After having determined the feasibility of using these frequencies, by the summer of next year the first commercial satellite that Ka-Band will work will be launched, Telstar 8 will be the most powerful satellite of the Loral Skynet company that will offer services in C bands, Ku and Ka. This satellite will have 68 transponders of which 4 will be destined for Ka band, 36 for Ku band, each at 36 MHz, and 28 for C band. The frequencies that will be used to raise signals to the Ka-Band transponders will be between 29.5 and 30 GHz, and the lower frequencies will be between 19.7 and 20.2 GHz. Dual-way connectivity services will initially be offered in the United States and later in Canada and Latin America.
With this launch many companies will begin to offer high-speed services with the unique feature of allowing two-way communication, the main advantage of this is that the user will not have to be connected to a telephone line or a cable service to send response messages. One of the first companies to join Banda Ka is WildBlue, founded as KaSTAR Satellite Communications in 1995. This company is licensed to offer all types of satellite services in a location of 73 degrees west longitude and 109.2 degrees west longitude. WildBlue will start by offering an Internet connection service that ensures both download and upload speeds of 3 MG per second. In the very near future the company plans to sell interactive television services and network applications. The equipment used will be very similar to that used so far by DTH services, the variation will be in the size of the antennas that will be 26 inches in diameter although their cost will be the same.
