It was about a hundred years ago that Marconi invented radio communications (1902). By 1930, many homes in the United States and Europe had an AM radio receiver. The world changed quite a bit in the 20th century. Courier 1B, (Philco), the first active communication satellite, was launched in 1960. We now faces new communication challenges. High Definition Television (HDTV), which needs a much larger bandwidth for transmission, coupled with the current demand for hundreds of television channels and the growth in Internet communications, is resulting in a communication bandwidth shortage. One tool being used to address this problem is Satellite SpotBeams. By 2010, 60% of TV receivers will use a Satellite signal, up from 15% in 2002.
What are Satellite SpotBeams?
Until recently, communication satellites transmitted with a very broad signal. The same signal that was received in the California was from the same source as the signal that was received in New York. Satellites that are not “SpotBeams” send out a signal over very large areas, transmitting data across the USA.
SpotBeams are different. It is similar to a searchlight focused on one area of the country. A typical SpotBeam has a radius of only 50-100 miles. Depending on where you are in the country, you won’t detect the beam unless you are in the focus. With this tool, the same frequency spectrum can be used with different source material, in different regions. In addition, the system is flexible enough to increase power on specific transmissions when needed to compensate for local weather conditions. SpotBeam technology is ideal for the transmission of video requiring ultra high bit rates such as HDTV.
DirecTV and DISH Network were one of the first to use SpotBeams. The transmission of local TV channels is ideal since a signal focused on an area was a perfect fit for the application. The SpotBeam technology is being applied on newer satellites using the Ka Band (Ka band is 19-30 GHz). There are several Ka band satellites in use that do not use SpotBeams: Advanced Communication Technology System (NASA USA), Superbird and N-STAR (Japan), HOT BIRD 6 (Eutelsat, France), DFS Kopernikus (Germany), and Italsat (Italy), but the newer, more advanced satellites are using SpotBeam technology.
Anik F2 (built by Boeing, and operated by Telesat) was launched on July 17, 2004, and began service on October 1. It is currently the world’s largest communication satellite at 157 feet long and 27 feet wide. Anik F2 provides Internet service, distance learning, and telemedicine to the United States and Canada. Anik F2 has 45 transponders delivering broadband signals using Spotbeams. A third of the Spotbeams provide broadband services to Canada. The rest are used to provide Internet service to the U.S.
HDTV SpotBeams
HDTV SpotBeams used by DirecTV and DISH Network (Ka-band) are often narrower in focus than the Ku band SpotBeams used for Standard Definition TV. If you live more than 50 miles from the signal center in a populated region, it is possible that you will not be able to receive the HDTV SpotBeam. DirecTV and DISH Network have the technical capability of transmitting a broad SpotBeam signal, especially since the newer Satellites can operate at a higher power. It makes good business sense for them to maximize coverage, but there are tradeoffs.
In a rural state like New Mexico, it makes sense to have the SpotBeam cover a 200-mile radius, because that enables more subscribers which results into more revenue. In New England it sometimes makes sense to focus the signal more narrowly, since the SpotBeams are more densely packed together. However, since different frequencies are used for adjacent SpotBeams, overlap usually can be managed.
SpotBeam Satellites and Two-Way Communications
According to Northern Sky Research, there are 15 million U.S. households without access to broadband Internet service. SpotBeam satellites operated by WildBlue and Telesat have already reached over 300,000 Internet subscribers since their launch in 2005.
One advantage of Ka band is that it requires a smaller dish to offer very good performance. Ka band using SpotBeams is more efficient than a traditional C or Ku band satellites (the technology used by the other communication satellite systems). The service is able to deliver significant improvements in performance. A Ka band satellite can provide as much as an 8X increase in capacity over Ku band satellites. The technology can provide upload speeds as fast as 16 Mbps and download speed as fast as 30 Mbps. Three Ka band satellites with SpotBeam technology are already in service in North America: Telesat Canada’s Anik F2, WildBlue Communications Wildblue 1, and Hughes Network Systems SPACEWAY 3.
ViaSat-1 and Ka-Sat: Satellite Communications on Steroids
A fourth North American satellite, ViaSat-1 (another Telesat Canada satellite) is planned for launch in 2011. This system is a very advanced Ka-band broadband satellite ordered by ViaSat. The amount of bandwidth enabled by ViaSat-1, equipped with ViaSat’s “SurfBeam” networking system, is unparalleled. Total throughput is designed to be over 100 Gigabits per second, which is more capacity than the current North American fleet of two-way Ka, C and Ku band combined capacity. In 2010, Ka-Sat will launch a satellite to provide similar service in Europe.
HDTV signals require 4-5 times as much bandwidth for transmission as standard definition signals, even with sophisticated MPEG-4 encoding. In addition, our Internet communications bandwidth requirements continue to grow at about 50% annually. Keeping up with the demand will require a smorgasbord of options, and Satellite SpotBeams (Ka band), will be very important in the mix.
By: Brian Bradshaw
Posts Tagged ‘Dish Network’
HDTV and Internet Driving Demand For Satellite "SpotBeams"
January 11th, 2010Internet Communications From Anywhere With Mobile Satellite Systems
December 29th, 2009
It is sometimes difficult to be “out of touch”. Family emergencies, business contacts, and a thousand other reasons require a communications link. My wife and I took a cruise to Cozumel, Mexico recently. While on the ship, we used an on board satellite link for Internet communications. The satellite system was smart enough to continuously correct for movement of the ship. It was very useful for us to be able to answer email and find travel information on-line while we were at sea or docked.
Similar systems are available for land vehicles, most often trucks and RVs. These systems are called mobile very small aperture terminal, or VSAT. The most commonly used dishes for mobile VSAT are 0.74 Meters (About 29 inches) in diameter. The systems designed for land vehicles are different from the ship borne system in that they are not designed for use while the vehicle is moving, but for when the vehicle is parked. The ship only had a speed of 20 MPH. There are currently more than 10,000 land vehicle VSAT systems in use.
The signal with a satellite dish is usually superior to that found with a “dome” antenna. The dome systems must be kept clean and must be wiped off after a snowstorm or rainstorm in order to maintain good reception. It can be a hassle to frequently climb onto your vehicle to perform maintenance on the antenna.
HDTV and TV:
It is possible to purchase a system that is capable of simultaneous Internet communications and Television reception (including HDTV, MHDTV). HDTV using DirecTV, Dish Network, Star Choice, or Bell ExpressVu is available. However, the major networks (NBC, FOX, ABC, CBS) can be a problem. Because of FCC rules, these signals are broadcast with spot beams, which will prevent their reception except within a limited area.
The satellite dish deploys on command, identifies the current location, and precisely points the dish. It usually takes less than five minutes to achieve a communications lock, and then the system is capable of high speed internet communications.
It works in most of the world, even where cable Internet and DSL are not available. However, if you travel in the mountains, the system will not be able to communicate with the satellite when you are on the north face of the mountain, or in heavy forest.
Performance:
With a typical user account, downstream speed is typically 500-800 kbps. Upstream speed is usually less. The sales literature says to expect up to 128 KBPS, but 20-30 KBPS is much more typical. With more advanced hardware (F2 or XF2 and XF3 antennas), and higher monthly cost, 500 KBPS upstream and 2 MBPS downstream speed is available. Static IP addresses are also available (extra charge) for virtual private network (VPN) connections. The system includes the capability for VoIP (voice).
A mobile satellite system cost about $5000-$5500 for purchase including installation, and $50-$160 a month for internet service. The bandwidth (communication speed) impacts the price of service.
The hardware is available from several suppliers: C-Com’s iNetVu, Ground Control MSS, DTI DirecStar, and the Motosat Datastorm are the main vendors. The satellite service is available from HughesNet (formerly DirecWay) and Starband. Motosat/HughesNet have historically been the most common combination, but that is likely to change.
Ka Band (iNetVu):
C-Com’s iNetVu is now offering a new technology for mobile VSAT. The iNetVu Ka66 has been designed to take advantage a new satellite, Telesat Canada’s Anik F2 Satellite. Anik F2 is the world’s largest commercial communications satellite. The Ka66 is the first mobile satellite internet offering to operate in the Ka band frequency range.
The main advantage of Ka band is that it requires a smaller dish (26″ x 30″) to offer very good performance levels. Ka Band utilizes spot beams, which are more efficient than a traditional Ku satellite (the technology used by the other mobile VSAT systems). The result is that more users can enjoy a high level of performance. The service should be able to deliver significant improvements in performance.
Communications service is provided by WildBlue. Wildblue also offers fixed systems. Hardware costs and communications service should be significantly less expensive when compared to current alternatives for similar performance.
Professional Installation Required:
The installation of a mobile satellite system requires professional installation. The system is complex, and the wiring of the communications downlink is critical. Also, it is important that the external gear be mounted so that it does not get torn from the vehicle during transport, or more likely since the gear recesses when not used, during a high wind. A wind in excess of 60 MPH can damage a dish when it is not recessed. When recessed, the system is tolerant of highway speeds of less than 100 MPH. In addition, a poorly installed system can interfere with other users, so usually HughesNet will not support a system that has not been professionally commissioned.
Summary:
If you are a telecommuter, with mobile VSAT is possible to work from just about anywhere. VSAT can be a powerful and inexpensive method of communicating from remote areas not supported by cellular networks. Mobile systems can communicate with bandwidth that cannot be provided over cellular networks.
Being able to use the internet while remote can be important. A few years ago, that meant using a dataport to make a phone call to a dialup Internet Service Provider (ISP).
But now our choices are getting better. WiFi hotspots are being added, and WiMax will be available in major cities soon. Cellular services are adding high speed, low cost data access. Other services will undoubtedly be available in coming years.
But, for now, satellite VSAT is the only way that will work virtually anywhere. Besides, it’s fun playing Buck Rogers.
By: Brian Bradshaw