Much attention is being paid to consumer broadband service via satellite as this has the potential to match the US penetration of DTH TV and Satellite Radio (DARS). However, there is still a very substantial ongoing business using various types of VSATs to serve commercial and govern-ment needs in developed and developing regions of the world. After all, satellite communications is the best alternative if modern terrestrial infrastructure is not available.
We address several factors that are making this form of communications more readily available at acceptable costs in regions such as Asia-Pacific, the Middle East and North Africa, and South America. As described below, these factors include: the coverage ability of the new generation of GEO satellites at C, Ku and Ka bands; the remarkable new performance and features of the VSAT terminals for fixed, transportable and mobile installation; and the array of service providers who have invested in hubs and support organizations in these regions. The resulting mix of capabilities and applications are giving broadband satellite links a new lease on life, moving them into the mind-space of telecom-munications professionals worldwide.
For the pur-pose of this article, we define broadband satellite service as one capable of at least 1 Mbps data rate on the forward and return links. The general trend is to offer asymmetrical bandwidth, with the forward link providing download speeds up to 10 Mbps and the return link upload rate at the lower end of the range. Pricing is dictated by these data rates, and generally speaking, you pay in proportion to data rate.
Satellite Coverage
It would seem that 250 GEO satellites would be enough to blanket the earth with broadband capacity, but the devil is very much in the details. Leading satellite operators Intelsat, SES, Eutelsat and SkyPerfect JSAT Corp (SJC) provide appropriate satellite capacity at C and Ku-bands with coverage of all regions of the world. There are also regional and national operators who likewise serve VSAT markets: Telesat Canada, Satmex, Arabsat, Asiasat, Thaicom and Measat are good examples. Owing to the higher power and flexibility benefits, Ku-band is preferred by VSAT service providers and users. It is not surprising that the vast majority of VSATs, as many as one million throughout the world, employ Ku-band. However, the domain of Ku-band coverage is generally limited to the land mass of developed regions of the world and as a result C-band becomes the common denominator. Operating at lower power and with restrictions due to sharing of this band with terrestrial microwave systems, C-band VSATs employ large dishes that may depend on local RF shielding. As users of satellites know, C-band may be preferred for service in tropical regions due to substantially less rain attenuation.
Selection of the best satellite often involves a review of several different options in terms of satellite operator and specific satellites. This is where the process of systems engineering comes into play: defining the requirements of the link in terms of locations to be served, bit rate, service quality, transmission system (modulation and forward error correction), terminal constraints (maximum antenna size and transmitter power), and special requirements such as encryption and network management. Satellite effective radiated power (EIRP) and receive sensitivity (G/T) have not changed substantially in the past 10 years. A combination of factors contributes to this, such as the importance of limiting adjacent satellite interference and maintaining a cost/effective service. In the latter regard, the monthly charge for a 36 MHz Ku-band transponder has hovered around US$150,000 for nearly 20 years. In the presence of inflation, the real cost per MHz has declined substantially.
Recent developments in the satellite field primarily involve Ku-band satellites with coverage of new areas. For example, Sky Perfect JSAT (SPJ) just launched JCSAT 85 in partnership with Intelsat, a Ku-band satellite that provides an overlay of the Indian Ocean region. SPJ provides some VSAT services exclusively within Japan on JCSAT-2A and Superbird-B2. Regional networks from SJC in this hemisphere were all C-band yet many customers employ VSATs in Asia/Oceania (Australia, Malaysia, Singapore, Laos, Vietnam, etc.) on JCSAT-2A and JCSAT-3A.
Likewise, YahSat will be operating a new satellite with Ka-band capacity. Mubadala Development of the UAE is investing heavily in the space and ground segments and will introduce their YahClick Ka-band VSAT service around 2011. Their intention is to serve government military, civil and commercial broadband users in the Middle East. They have chosen the ViaSat Surfbeam technology and expect to apply it across the board. What is perhaps unique about the YahSat business model is that they will offer Ka-band transponder capacity to the regional market.
VSAT Technology and Services
The "other VSAT" in this article is actually not the VSAT that you see attached to someone’s home or on the typical gasoline station. The technology has been totally revamped and now benefits from innovations in SSPA technology, DVB-S2 functionality, and dynamic networking. Taken together, these improvements increase the effective data rate for the same dish diameter, and provide protection from heavy rain and interference. I believe we are seeing a divergence between the consumer market focus on low cost Internet access and the industrial/international market demand for reliable broadband Intranet services to extend the corporate backbone to previously-underserved locations.
A common denominator is what had been called the "private network", meaning a telecommunications network for use within one organization and separate from public networks. This morphed into the "virtual private network" (VPN), made popular first by Sprint for corporate telephone networks and more recently by Cisco for secure IP networking over the public Internet. A private network using satellite communications has the unique feature of true independence and dedication to one set of users and possibly even one application. VSATs always played well here but were the domain of big corporations with lots of locations to serve and lots of money to dedicate to resources. A large part of this was the hub station which cost in the millions of dollars. This hurdle has been removed by low-cost hub solutions from iDirect and ND SatCom.
We want to give special consideration to the Asia-Pacific region where we find nearly half of the world’s population and which has a heavy dependence on VSAT technology. Satellite links are vital to remote islands of the Pacific and in Southeast Asia. One only has to remember how the loss of one satellite or one fiber optic cable impacted heavily on basic services. Established operators like AsiaSat, Thaicom and Measat support a variety of VSAT service providers. Thaicom, in particular, has committed substantial resources to IPStar and its VSAT services, an innovative program that extends well beyond Thailand.
The largest operator in the region, SkyPerfect JSAT (SPJ), serves many customers that own their own networks composed of VSAT equipment from HNS, Gilat, Viasat, and iDirect. An important application for the VSATs is the earthquake warning satellite delivery service in Japan, called "Safety BIRD". Once the earthquake occurs, the alarm signal will be broadcasted instantly through the satellite and the operations of important infrastructure (elevators, trains, and power plants) will be stopped automatically in order to prevent them from malfunctioning. SPJ sees opportunity in the utilization of these VSATs for petroleum and mining in the Pacific/Oceania region. As the result of their focus on Indonesia, they will launch JSAT-13 in 2013 to be provided with an Indonesia Ku beam and a steerable beam targeting DTH and VSAT demand.
Prospects
We’ve only scratched the surface on the current state of affairs for what I call the other VSATs. Whether we are talking about Asia-Pacific or any of the other comparable regions of the globe, we find numerable places and needs best served by the providers of this technology. Greater use of Ku and ultimately Ka-band help to reduce the size of dishes and simplify installation at fixed locations as well as on vehicles, ships and aircraft. This market is likely to grow at better than average for the industry, as these benefits are better understood and as the service providers expand the footprint in terms of satellite coverage, hub availability, and end-user service and support.
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Bruce Elbert has over 30 years of experience in satellite communications and is the President of Application Technology Strategy, Inc., which assists satellite operators, network providers and users in the public and private sectors. He is an author and educator in these fields, having produced seven titles and conducted technical and business training around the world. During 25 years with Hughes Electronics, he directed major technical projects and led business activities in the U.S. and overseas. He is the author of The Satellite Communication Applications Handbook, second edition (Artech House, 2004). Web site: www.applicationstrategy.com Email: bruce@applicationstrategy.com
