ICT Africa writer
January 28, 2013
With over ten submarine fibre optic cables and over 20Tbs of network design capacity at the shores of Africa by 2012, a debate is raging on whether communication satellite systems will ever remain relevant in Africa. During a round table debate at the 2011 Africa Com event in Cape Town, South Africa, a tug-o-war ensued between delegates at the suggestion that satellite was only a “stop gap measure” until fibre was rolled out throughout Africa. The truth of the matter is that even developed countries, such as the United States of America, still utilise communication satellites in areas not reachable by fibre optic cable. It is safe to assume that satellites will continue to contribute to the communication needs of Africans, ad infinitum. That said, it is estimated that 99% of all global Internet traffic is routed over submarine cable  while the statistic was almost reversed in favour of communication satellites for a long time in Africa.
With innovative satellite technologies coming into play we expect that, while fibre will play a significantly more predominate role, especially in long distance transmission, satellite systems could play a more significant role in Africa than global trends suggest. We note that, even in areas of the continent where fibre has been deployed, satellite systems are being used for redundancy.
Satellite vs optical fibre debate:
First we outline the rationale behind the investment of billions of dollars in the deployment of submarine cables around Africa and terrestrial long haul networks within the continent of Africa when communication satellites are already available.
The number one and most important reason for operators migrating from satellite to optical fibre is the need for higher transmission rates. There is just not enough capacity on satellite systems to transport all the traffic generated by the ever expanding mobile and wire-line access networks. Providing broadband Internet access to hundreds of millions of Africans will require backbone transmission networks with hundreds of Gbps of capacity. Each time operators increase their broadband offerings to higher data rates, say from 2G to 3G to 4G, this in turn pushes the transmission requirements of the transmission backbone network. No wonder International standards have ratified standards for 40Gbps and 100Gbps per channel in optical networks and are working on 400Gbps and 1Tbps. Such levels of transmission capacity will require a much larger satellite fleet. According to data tracked by the Union of Concerned Scientists  there are approximately 500 commercial communications satellites currently in use in the world with an average life expectancy of less than 15 years and ranging in throughput from 1Gbps for conventional Ku-band to 10Gbps for Ka-band and 100Gps or more for next generation Ka, V- and W band systems. If the average satellite has a capacity of 5Gps, the entire global communication fleet would have a capacity of 5Tb/s of capacity. In this case, all the capacity in the entire global commercial communication fleet can be transmitted by a single pair of optical fibre using 50 channels of a Dense Wavelength Division Multiplexing (DWDM) system, each transmitting at 100Gbps.
Limited capacity on satellite systems implies higher cost/bit of satellite capacity compared to fibre although next generation systems will see lower cost/bit due to increased capacity. This has a profound impact on the cost of satellite broadband. As an example, a 4Mbs VSAT Internet subscription in South Africa costs more than $2 000 per month for capped download.
Latency is another disadvantage of geosynchronous satellite systems that orbit the earth at 35,786 km above the earth. The latency for these satellite systems range from 540ms to 800ms and is problematic for data download, voice over Internet (VoIP) transmission, gaming and online trading. High speed trading is an area which is seriously impacted by latency. In this marketplace, even a millisecond in latency can mean the difference between a big win and a big loss. A 1 ms advantage in latency can translate into $100 Million per year advantage for large trading firms. It is therefore inconceivable for a high speed trading company to operate over a satellite Internet connection.
Rain fade is another impairment that affects satellite communications and does not affect fibre optic communications. At the higher operating frequencies of Ku and Ka-bands, satellite signal strength may be affected by heavy rain conditions. Ironically, the higher frequencies capable of more throughputs are more degraded by rain fade. Rain fade occurs when satellite signals are attenuated, or weakened as a result of interference caused by raindrops that absorb and scatter the signals.
Satellite has lower life expectancy than fibre. While the life expectancy of a communication satellite is 15 years or less, that of an optical fibre is 25 years or more .
The main advantage of satellite systems is coverage as they can be configured to cover any part of the world where fibre may not be deployable. Today, satellite communications can deliver voice, video, and data that can be accessed anywhere in the world.
Next Generation Satellite systems:
With more capacity available to offer higher speeds at significantly lower costs, next generation satellites can play a more pivotal role in proving broadband access to Africa, especially where mobile broadband is not readily available. The proposed SWANSAT and O3B systems have the potential to play a more significant role than conventional satellite systems.
Very quietly and away from public scrutiny, over the last thirteen years or so SWANSAT Holdings and its vendor IOSTAR Corporation of North Salt Lake, Utah, have developed a plan to launch a constellation of 14 very high powered telecommunications satellites licensed for global provision of two-way broadband services. The constellation is called the Super-Wide Area Network™ Satellite (SWANSAT) System. Their ITU Frequency Coordination Request filings on behalf of the Republic of Nauru for the SWANSAT System represent the very first commercial assignment of 10,000 MHz of electromagnetic spectrum in the W-band in order to deliver ICT from geosynchronous orbit.
ITU member nation state, the Republic of Nauru is host country to SWANSAT. The first three SWANSAT spacecrafts are planned for deployment in mid-2016. They will provide two-way broadband ICT services to residents of least developed countries (LDC’s) and developing countries (DC’s) throughout the African Union. Regular follow-on launches are slated until full deployment has been accomplished. When fully deployed, SWANSAT will deliver more than 200,000 HDTV (1080p) high definition video channels worldwide and nearly 800 million 2 Mbps Internet connections.
Computer networking, intranet services, on-orbit secure and encrypted data, file, and server storage, video and audio entertainment, Direct Broadcast Service programming, retail and wholesale sales, pay-per-view programming, educational and distance learning programming, medical information, and other services will also be provided through one comprehensive world-wide system.
Among the services included with a SWANSAT subscription are free unlimited worldwide voice communications with no international calling fees, worldwide fax services and audio- and video conferencing. Encrypted global positioning system location capabilities and worldwide secure emergency services also are also expected to be part of the subscriber package.
More information on SWANSAT can be obtained from the Chief Executive Officer, Dr. William Welty at Telephone: +1 714 670 7103 or firstname.lastname@example.org.
O3b – The Other 3 Billion:
O3b Networks is a satellite service provider developing a new global Internet backbone for telecommunications operators, Internet service providers (ISPs), enterprise and Government customers in emerging markets. The O3b Networks system will target billions of consumers and businesses across 177 countries with lower-cost, high-speed, Internet connectivity. The system is funded by investments and operational support from SES, Google Inc. Liberty Global, HSBC Principal Investments, Northbridge Venture Partners and Allen & Company.
Because the O3B satellite systems will orbit in the Medium Earth Orbit (MEO) between 10, 000 and 15, 000km from earth, the latency is significantly lower and is less than half the latency of Geosynchronous satellites. O3B has a potential of offering services with significantly improved quality than geosynchronous satellites, ceteris paribus.
Although O3B has marketed their systems as comparable to fibre, the capacity has been reported to be 84Gps on 8 satellites or about 10Gps per satellite and can hardly be compared to optical fibre. Because O3B will be in the MEO and not in the Geosynchronous Earth Orbit, satellites will be moving relative to a position on earth. The system will use tracking antennas to track the position satellites and we are yet to find out if this will not have any negative impact on the quality of the systems.
Fibre will eventually play a predominate roll in communications in Africa, especially in global, national backbone and metropolitan networks. We expect satellite systems to continue to play an important role, especially where fibre will not be deployed. The emergency of innovative satellite technologies is likely lead to satellite systems playing a more significant role than anticipated from global trends.