Satellite, when combined with 4G wireless, offers two very powerful advantages for stakeholders. First, it provides a large amount of spectrum. That spectrum enables delivery of next-generation wireless services in a world that is increasingly underserved by terrestrial spectrum and is moving in the direction of broadband wireless. Also, satellite’s large coverage footprint offers unparalleled reach to the next frontier of un-served and underserved suburban, rural and remote areas. These are the areas where wireless growth opportunities are likely focused – as it is clear that we are experiencing near-full wireless penetration in urban areas.
There remains a real need for ubiquitous and dependable communications, especially in emerging regions. In recent years, cellular-backhaul (CBH) networks have expanded throughout the world – due in large part to satellite technology. Services from satellite operators have provided economical inter-regional and international connectivity, greatly reducing operational costs for connecting neighboring countries and regions through wireless communications.
At the core, CBH is the transport of traffic from a cellular network to a main network where voice and data switching takes place. Mobile operators use satellite capacity to extend their cell networks into remote regions. Satellites connect remote cell sites with the mobile operators’ central switching sites, the entry point to the public switched network.
Along with economically providing mobile voice services, satellite technology has enabled wireless operators to expand networks more efficiently, offering thousands of subscribers enhanced, seamless connectivity for regional and international communications. For proof, look at Vodacom International, which expanded mobile telecommunications services throughout the Democratic Republic of Congo, Mozambique and Tanzania. Through the use of satellite technology, this wireless operator is carrying telecommunications traffic generated to and from more than 20 base stations and switching centers around and inside the African countries – as well as into the public switched network.
While CBH networks are located throughout the world, emerging regions such as Africa and Latin America continue to show a greater demand for more CBH networks. Mobile operators throughout these regions are constantly seeking new, economical ways to expand wireless networks, but are challenged by prohibitive costs, geography and a shortage of developed terrestrial infrastructures.
In such cases, a hybrid CBH network – a platform combining satellite and microwave – offers a successful platform for long-term growth.
Understanding the Fundamentals
CBH networks featuring the optimal combination of satellite and microwave help mobile operators provide cellular services to their subscribers in suburban, rural and remote regions – overcoming distance, terrain, power and population-density hurdles. When helping mobile operators deploy CBH networks, satellite technology proves to be beneficial. It helps cellular networks reduce Total Cost of Ownership (TCO). For example, TCO can be minimized by combining the bandwidth-agnostic benefits of terrestrial solutions with distance-agnostic benefits of satellite solutions.
Through a hybrid CBH, a cluster of cellular base stations that are in close proximity of each other, that is within a single microwave hop distance of 30 kilometers, are aggregated using microwave backhaul. As distances between remote networks and urban networks become larger, the attractiveness of satellite backhaul increases. The reason is that microwave backhaul has very limited range. To increase its range, microwave backhaul must deploy repeaters. Connectivity from this aggregation site to a core network that is multiple hops away is provided via satellite. That solution is preferable to building expensive and high-maintenance microwave-repeater sites.
When faced with the need to adopt CBH solutions, many mobile operators evaluate various CBH alternatives. Some associate latency with satellite, which is a perceived challenge. However, there have been numerous innovative developments to address latency. One example is combining OSI Layer 2 and Layer 3 functionality and then providing specialized capability such as TCP acceleration. Other satellite innovations, including capacity pooling and optimization, help provide an economical solution to reaching mobile regions.
Satellite operators are busy introducing new initiatives to further expand the availability of reliable CBH solutions. For example, Intelsat teleports recently were upgraded with modems that have a carrier-cancellation feature – to provide additional bandwidth savings. Intelsat also is investigating next-generation satellite platforms for mobile broadband data services.
Connecting the Unconnected
As cellular networks transition from a voice-centric domain to a data-centric domain, satellite technology is being used to enable new services for mobile operators. Similar to the work of Vodacom International in Africa, Intelig Telecom of Brazil is enhancing its cellular service via satellite, expanding its network that serves more than 41 million mobile users.
Another example can be seen in Brazil’s neighboring country, French Guyana. Guyane Numerique recently established its first hybrid CBH network that connects the major populated areas of French Guyana with its most remote villages of Amazonia. Utilizing satellite capacity, Guyane Numerique’s network links 17 remote sites to the French Guyana capital city Cayenne, and to the rest of the world. The network infrastructure provides basic voice and data services. The satellite capacity provides ideal coverage of South America, giving Guyane Numerique the robust connectivity solution it needs today. In the future, satellite will afford the ability for Guyane Numerique to reach the French-speaking regions of Africa and Europe.
Future Growth Via Satellite
Satellite technology continues to prove its essential role in establishing a reliable infrastructure for communications services. Even with the arrival of fiber, CBH continues to be an important application where satellite remains a significant element for expanding infrastructure and connectivity.
As illustrated, examples of hybrid CBH networks are endless. The outlook for continued adoption of hybrid CBH networks is very favorable, as many emerging economies continue to expand their coverage and acquire more subscribers. For example, in Latin America, wireless penetration levels are above 50 percent, making growth opportunities available for network expansion into rural and remote areas more robust. In addition, advanced communication networks also have shown to boost Gross Domestic Product. The World Bank Macroeconomics Study indicated that, when 10 percent of a developing country’s population uses mobile technology or services, that country’s GDP jumps by .8 percent.
In the future, new CBH opportunities are expected to emerge as mobile operators begin rolling out advanced 3G networks, and introduce 4G networks.
Many emerging regions that have inadequate fixed-line networking infrastructures are expected to tap into hybrid satellite-wireless networks for their connectivity and communications needs.
About the Author: George Giagtzoglou has held senior executive positions in the telecommunications industry for more than 18 years. He has been responsible for shaping Intelsat’s corporate and marketing strategy since 2003. He can be reached at firstname.lastname@example.org .