Published copy taken from EE Publishers, link to original at the end of the article.
Most of us are unaware that a very small aperture terminal (VSat) enables services such as purchasing petrol, obtaining scripts at pharmacies, ATM withdrawals and making purchases at a chain store in small towns. In this panel discussion we explore the technology and its challenges.
 |  |  |
Arnold van
Huyssteen, Telkom |
Grant Marais,
Intelsat |
Geoff Daniell,
Global VSat Forum |
 |  |  |
Jacques Visser,
Vox Telecom |
Lex van Wyk,
Teraco |
Rudi Cloete,
Vodacom |
Satellite communication was the dream of Arthur C Clarke, who in 1940 published the first article detailing how a satellite relay station could enable terrestrial stations to communicate over vast distances. John Pierce, an independent analyst and physicist at Bell Laboratories came to a similar conclusion. "Active satellite relays could have significant positive impact on long distance communication. Such a system would be most reliable if the radio frequencies were not affected by the ionosphere."
It was however not until 4 October 1957 that the Russians stunned the world by launching the world's first satellite, Sputnik 1. The USA had also been working on launching a satellite, which followed on 31 January 1958. While Sputnik-1 sent information back to Earth about its own health, the USAS bird, Explorer 1 was more scientific in nature, sending information about the levels of radiation in the space environment. The space age had begun and satellites were soon deployed to handle international communication and television.
And then came fibre optics.
The idea of using light as a medium of communication dates back to the 1790s when the brothers Chappe in France invented the first optical telegraph. The first non-experimental fibre optic link was installed by the Dorset (UK) police in 1975. Two years later the first live telephone traffic though fibre optics occurred in Long Breach California (USA). In the late 1970s and early 1980s telephone companies began to use fibre exclusively to rebuild their communications infrastructure.
In this month's panel discussion we asked various sector experts in the communications industry to share their opinions on issues relating to satellite communication versus fibre optics as the future ultimate carrier of communication.
Given that terrestrial communication continues to expand at an unprecedented rate, is the satellite industry under pressure? Commentators on this issue put forwardtwo possible scenarios: to compete with terrestrial services or to provide complementary services to terrestrial services.
We asked the panel which alternative they believe is the most viable to keep the VSAT industry growing or do they believe there is space for both?
Arnold van Huyssteen, executive, Product House, Telkom: "There has always been some level of competitive force at play between terrestrial and VSat technologies. VSat has been positioned as reliable and easy to install and relocate without any dependency on fixed line infrastructure. The counter-balance has been the cost of providing VSat and the effect of the natural latency that consumers experience over VSat, which can negatively affect certain applications that are delay-sensitive."
He does not believe that a strategy to compete with terrestrial services will work and will continue to keep the VSat industry under pressure. "The correct way to position VSat services in the bigger market would be as a complementary service."
Grant Marais, regional V-P, Africa sales,Intelsat has a different take: "In order to provide cost-effective and reliable solutions for their customers, service providers will need to look for hybrid solutions. A mix of fibre, microwave and satellite will form the network of the future that will best meet those needs as the continent seeks to achieve fast improvements in connectivity through the development of game-changing solutions."
Intelsat sees fibre as an invaluable ally in African communications development and will continue to leverage terrestrial networks, which integrates seamlessly with 50-plus satellites, to deliver the most efficient solutions to customers.
Geoff Daniell, South Africa correspondent and senior trainer, Global VSAT Forum (GVF) says that the satellite industry does not compete with terrestrial technologies and services. "The satellite industry has always worked on the principal that satellite communication services are complementary to terrestrial communication services, each with its own advantages and disadvantages."
Jacques Visser, YahClick product manager, Vox Telecom: "There is space for both alternatives due to the varying availability of high-speed connectivity services in South Africa. In an urban environment, terrestrial services such as fibre are still the most cost-effective for businesses, but a Ka-band service offers a complementary redundancy option. In rural areas where terrestrial services often aren't available, Ka-band services are cost-effective and offer high connectivity speeds."
Lex van Wyk, CEO, Teraco: "There is a place for both VSat and terrestrial vendors to provide complementary services in Africa. It is still the only way to ensure that there are communication, data and specialised services such as broadcasting provided to rural and underdeveloped areas, given the vastness of the African geography. The VSat industry will need to continue positioning itself as the technology of choice in remote areas. The current cost of VSat distribution is, however, too high for these communities and therefore a greater, more competitively priced distribution of broadband VSat services will need to be available. Further, as more fixed line options become available, VSat will continue to have a market as a niche technology focused on distribution of specialised services such as broadcasting. In future, voice and data service offerings via VSat will be focused purely on remote and inaccessible areas."
Rudi Cloete, technical service developer/business analyst, Vodacom: "VSAT keeps on playing in both these alternatives. In the African, and more specifically, South African market, broadband penetration is still in its infancy. The only real alternative to bring communication to the doorstep of the user is wireless technologies. VSAT is competitive in the market because it's quick to deploy, easy to install and maintain and at a very good cost. Therefore it will always compete where terrestrial services fail to reach and complement it wherever a reliable failover is needed or where high bandwidth multicast streaming is a requirement."
How will spectrum allocation or the lack thereof affect growth of the VSAT services market?
The panellists had varied views on the issue of spectrum allocation. Some said that more spectrum is needed to bring in more competition which should reduce the cost.
Grant Marais says that the satellite industry needs to actively participate in the studies that will take place leading up to the ITU WRC-15, as these studies will look into the interests and needs of both the terrestrial and satellite sectors. "Terrestrial interests have again succeeded in including an agenda item at WRC-15 to consider new allocations to the mobile service and identify new spectrum for IMT (International Mobile Telecommunications). There were no frequency bands specifically excluded from consideration for this WRC-15 agenda item, so the intervening years will provide a very interesting debate between the terrestrial mobile broadband community and all other spectrum users. The satellite industry needs to hold its ground on the importance satellite services play in the daily lives of hundreds of millions of users around the world and how critical these services are."
Geoff Daniel: "The continued demands to share satellite allocations with terrestrial wireless systems in some countries and regions will have a long-term negative impact on fixed satellite services provided in the affected bands. So far, the worst affected band has been the lower end of the C-band. The new demands to share mobile satellite service bands will have the same negative effect."
Arnold van Huyssteen: "Satellite spectrum is still regarded as very expensive and most of the satellite operators expect service providers to commit on a long term contractual basis for space segment. This creates a large risk issue for service providers and reduces the attractiveness of the business case.
"Spectrum is however becoming available more freely as more operators position satellites in orbit to have beams covering the South African, and also the larger African continent market. We expect that this increased competition will put downward pressure on the price of space segment, which in turn will allow more cost-effective services to be offered to consumers. If this can be achieved, we expect acceleration in the growth of VSat services."
Lex van Wyk: "Ultimately, South African network operators need spectrum to support increased capacity and coverage. The lack of spectrum allocation limits new entrants into the VSAT services market, especially international service providers. The allocation of additional spectrum will have a positive impact, increasing competition and thus reducing prices."
Should spectrum allocation be technology-agnostic? If so, how would it affect satellite operation? Would it increase the interference potential and if so, how could interference problems be mitigated?
Geoff Daniell: "The ITU-R has over many years shown how and under what conditions spectrum can be shared. It is incomprehensible why the outcomes of the research done in the past are simply ignored by those demanding bands to be shared. Ultimately, no one will win and all services in these bands will lose.
"The GVF and other interested parties are continually demonstrating why the sharing of spectrum previously reserved for fixed satellite services (FSS) with terrestrial mobile services and fixed links is neither practical nor feasible."
Arnold van Huyssteen has a very different view: "This is a very technical issue, but we believe that the more technology-agnostic spectrum allocation becomes, the more the investment risk of service providers will reduce and it will become more attractive to invest in VSat technologies. It will most likely increase interference potential, but if the spectrum is managed properly, this can be mitigated down to acceptable levels."
Jacques Visser says that spectrum allocation should be auctioned off with a "use it or lose it" clause. No other false criteria should be added because that will distort the market and lead to unintended consequences, such as frequency ending up in the hands of operators that don't have the funding, or monopolies that sit on the frequency. The WiMax frequencies allocated to Sentech are a good example of a wasted opportunity that retarded the country's progress.
Rudi Cloete says that satellite providers and system vendors work closely to ensure that satellite interference is kept to the bare minimum by designing control measures into their systems. This, with the use of highly trained and approved VSat installers (through forums like GVF) and constant monitoring of networks interference is kept at bay. "However, this said, the inherent properties of radio transmission always have the probability of interference, and therefore there is a need to have a regulator to police the use of this spectrum against unlawful use by unscrupulous operators."
There is a constant demand for higher speeds and bandwidth. How does the VSat industry respond to this?
Lex van Wyk: "VSat technology has a great opportunity to be the entry point to distribute basic services to rural areas. Further to this, the technology has advanced by overcoming issues such as latency. The fact that more investments have been made in new satellites allows for additional bandwidth to be available at a lower cost. VSat is a well-established telecoms solution and an attractive connectivity solution where the coverage area is large, quick installation is required and where terrestrial alternatives are difficult to organise. The size of VSat technology is convenient and has made satellite communication a viable option for a wide range of industrial applications, including mobile communications and broadband VSat, as well as rural telecoms and distance-learning.
Grant Marais says that according to Cisco, global high-throughput traffic is expected to more than double between now and 2015, largely driven by video for media and network services customers. These enterprise networks, wireless services and other platforms also are being swamped with video traffic. New platforms provide four to five times more capacity per satellite than traditional satellites. The expected throughput of these satellites will be somewhere in the range of 25 Gbps to 60 Gbps. "Spot beams in C-, Ku- or Ka-band allow the improvement of service for any given geography in the coverage area. Traditional capacity, however, will still be very relevant for a wide range of applications and bandwidth requirements because of the flexibility of wide beams."
Rudi Cloete: "There is an ever-increasing fight to increase the efficiency over satellite. The bits per Hertz limits are being pushed to the proverbial Shannon limit. Using the latest coding methods and DVB-S2 compression, satellite systems can get to 2,67 bps/Hz currently which brings about 20 – 30% efficiency. Adding to this uplink and downlink power control, high FEC rates, adaptive coding and modulation, availability and high bandwidth is pushed even further.
"Another development of late is carrier in carrier technology whereby inbound and outbound carriers gets to share the same transponder space, thereby almost doubling use of the same capacity."
What is the trade-off between Ka and Ku bands?
Arnold van Huyssteen: "Ka allows for smaller antennas and as a result brings the cost of terminal equipment and installation down, but the trade-off is the fact that it is more susceptible to interference such as dense cloud cover and rain fade. The Ka technology is however continually being improved and the cost savings will outweigh the quality issues to a large extent. We believe Ka will become the technology of choice over the medium to long term, especially in the more price-sensitive residential market."
Geoff Daniell: "The trade-offs between Ku and Ka band are at the same time both simple and complex. The obvious trade-off is the negative effects of transmitting high frequencies through the atmosphere of the Earth. The higher the frequency, the more severe the effect becomes. Users typically experience these effects in terms of the loss of throughput and/or total loss of service in bad weather conditions. The industry mitigates against these effects with the introduction of sophisticated modulation schemes, including forward error correction, uplink power control at the remote VSat terminals and traffic management techniques that allow for reduced service provision when required instead of total service loss. The benefits of the increases in available bandwidth, the resulting increase in possible data rates and the total capacity available on Ka band far outweigh the increased system complexity."
Rudi Cloete: "Ka-band capacity or Ka-band beams usually have higher EIRP values than Ku-band which basically means more power in a more focussed beam. This however means that a better-focused beam automatically results in a smaller coverage on the ground. With smaller satellite beams, a satellite operator then needs multiple beams to cover the same area as for Ku. This however is nothing really new to the satellite industry. Similar issues were experienced when the mind shift was made to move from using C-band to Ku band. New ways had to be found to compensate for overlapping areas using the same frequency. This is done by changing polarisation between beams. The advantages and disadvantages of either band can be mitigated, which includes the much-debated rain fade increase on Ka. The technology has proven itself already and brought about a price war between satellite operators."
Satellites have in the past been regarded as the ideal system to supply telephony in rural areas. Will data services take over this position in the future?
Grant Marais: "Overall bandwidth availability to underserved areas is trending up via new inland network build-outs intended to distribute the immense amounts of capacity now arriving along African shores through a number of undersea fibre options. The challenges that remain are in the last mile of connectivity and providing an acceptable user experience level into these areas by eliminating bottlenecks and single points of failure with a focus on reliability. Satellite is likely to remain the system of choice for providing telephony to remote and less easily accessible rural areas. Ultimately, there needs to be a balance between pricing and reliability."
Arnold van Huyssteen: "We must limit this statement to rural areas not covered by mobile technologies either. We believe it still is the ideal system in areas where no fixed or mobile infrastructure exists and a case in point is Telkom's recent replacement of all our services that were still served by manual switchboards, with VSat services. Data services are not really the issue here, as even the voice services provided over VSat are to a large extent already voice over data. What makes the service really attractive is the fact that a mix of voice and broadband can be provided over the same infrastructure."
Lex van Wyk makes the point that data services will be ideal for supplying telephony in rural areas. "The availability of more IP technologies makes the delivery of voice and data services more viable."
In providing internet services over VSats, is latency an inhibiting factor? Can it be overcome?
Geoff Daniell: "Latency is an issue in any communication system requiring the acknowledgement of the receipt of packets. There is no such thing as a latency-free service. Latency affects all systems providing data services, of which internet services is just one aspect. Even terrestrial LANs and WANs are affected by latency. The satellite industry has always addressed latency matters head-on, simply because of the large latencies introduced by the distances signals have to travel when using services provided on satellites located in the geostationary orbit. Latency effects cannot be overcome. However it is possible to mitigate against the negative effects of latency by careful system and network design, including the development of applications to properly handle latency. The exception is real time services such as voice, SCADA services, and some financial services such as real time stock market trading. So yes, any radio-based service, including terrestrial wireless systems, will negatively affect the delivery of services such as the internet, if not designed properly."
Jacques Visser admits that latency is an inhibiting factor; it is a reality but with the latest technologies most of the problems associated with latency have been overcome. "Voice for example is not an issue. The bottom line is that IP voice calls over satellite are an ideal, quickly-installed solution for consumers and businesses in rural areas."
Grant Marais: "The provision of fast and reliable internet connectivity remains a critical differentiator amongst satellite solutions operators. In the world of satellite-provided internet, low latency will naturally always ensure greater customer satisfaction. Satellite remains a proven medium for supporting a company or organisation's communications needs. Terrestrial IP networks often comprise different networks and topologies, with varying levels of latency. Satellite networks are on the other hand extremely predictable, allowing consistent quality of service to varying geographic locations."
What are the main challenges facing the VSat industry over the next five years?
Lex van Wyk: "SA's telecoms infrastructure is in its infancy from a terrestrial perspective. Last-mile technology represents the major remaining challenge because the cost of providing high-speed, high-bandwidth services to individual subscribers in remote areas can be higher than the service provider would like. The country needs another three to five years before the fibre is laid and users will really benefit. However, the resulting open-connect between service providers and business will be of great benefit to everybody."
Arnold van Huyssteen: "We believe cost and bandwidth will be the key challenges. The South African market is fairly well covered from a footprint point of view, so that challenge is pretty much covered. However, to compete with broadband services that are provided over fixed and mobile infrastructure, especially if one looks at the rapid rate of bandwidth increases and price decreases, will be a major challenge. The only way to respond would be to firstly work on bringing the cost of both spectrum and terminal equipment down and secondly, to look at alternative commercial models to assist service providers in offering competitive services to consumers. With this we mean Opex-based models where services can be white labelled to service providers by the large satellite operators or OEMs. This will take the risk away from service providers (buying hubs and space segment) and more service providers will be prepared to offer VSat services as part of their bouquet of services."
Geoff Daniell: "The main challenge facing the industry has always been the cost of service provision via satellite. The industry has responded to the challenge by continually seeking ways to lower the cost of VSat terminals and the installation thereof. Terminals costs below US$ 1000 per site inclusive of installation are now the order of the day for Ku- and Ka-band systems.
"The next challenge is to make VSat systems band-agnostic and transparent to the end user. Many VSat systems now available can operate in any of the recognised FSS bands over common indoor units, hubs and gateways.
"The industry will continue to lobby within the International Telecommunications Union and other bodies to ensure the availability of radio spectrum traditionally reserved for satellite services.
Other major developments include the expansion of VSat services over the oceans of the world in Ku-band, as well as providing broadband connectivity to aircraft via on-board VSats.
"Most satellite operators are preparing for and announcing next generation satellites in both C- and Ku-band, providing for increased capacity by increasing the spectrum utilisation. For example Intelsat's Epic satellites make use of spot-beam technologies deployed on Ka-band satellites, in both C- and Ku-band."
Jacques Visser: "Satellite services need to be able to compete with price deflation in the terrestrial market as terrestrial services' footprint increases. Satellite must position itself as a high-quality, cost-effective redundancy option where terrestrial services are available and as with all telco services, it is crucial for satellite providers to offer relevant value-add services such as telephony, VPN capability, cloud services, etc.
Grant Marais sees the main challenge as spectrum allocation and interference mitigation from other services.
Rudi Cloete: "The challenge I see is to create the much-needed awareness that we have the technology to solve the broadband crisis in developing countries. We just need to find creative ways to deliver it more cost-effectively.
It will take teamwork between satellite providers, VSat system vendors and large operators to come up with the most economical way to bring this technology to the masses. We also need to make it our business to better understand our end user's needs and not impose our standard packaged offerings on everyone because it fits our business case or standard mode of operations."
The responses from the various panellists reflect their respective sectors of the communications industry. There are however some common threads. The VSat industry is said to grow, but more in a complementary than in a primary position. No doubt fibre-optics is the medium of choice but where would the communications industry be without VSats? Fibre is subject to breaks and damage by contractors and workers digging up roads. Satellites are ubiquitous and will continue to provide the essential services while fibre links are being repaired.
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