February 19, 2015 By Gabriel Benjamin
Fiber optic cables are the medium of choice in telecommunications infrastructure, enabling the transmission of high-speed voice, video and data traffic in enterprise and service provider networks.
The possibilities for fiber optics are nearly endless because they are very flexible and durable, even under extreme conditions, signals cannot be distorted. Optical fiber cables have played a key role in making possible the extraordinary growth in worldwide communications that has occurred in the last 25 years. Governments across the world have recognized the importance of broadband in nation building and have invested heavily on national fiber backbone networks.
In 2009, President Ernest Bai Koroma approached the World Bank for their support for Sierra Leone to be connected to the rest of the world through submarine Fiber Optic Cable. The World Bank supported Sierra Leone with a non repayable grant of $31 million.
The Fiber Optic Cable was commissioned by President Koroma in February 2013. SIERRATEL – the government Telecommunications Company – is saddled with the obligation for the domestic connection of the cable. Currently, it’s running the urban connection to homes and businesses alongside the underground installation of the cable to the landing site for the distribution of the fiber cable across the country. Alhaji Alpha Kanu, Minister of Information and Communications, said in the last Thursday edition of ‘Good Morning Salone’ radio program with optimism that soon, Sierra Leoneans will experience improved internet connectivity.
But sources at the world apex bank said the institution is furious over an alleged failure of the Government of Sierra Leone to properly account for the initial funds pumped into the project. This is because the project is not only moving at a snail-pace, but also collapsing. The Ministry of Information and Communications and the Sierra Leone Cables Limited are said to have exhausted the funds for the project to the dissatisfaction of the World Bank.
However, one of the most likely reactions one gets when discussing fiber-optic networks in Sierra Leone is “why not satellite technology?” But satellite communications has been around for a while and has provided telecommunications links between Sierra Leone and the rest of the world.
It is on record that the Africa Coast to Europe (ACE) Submarine Cable which Sierra Leone has joined runs from Penmarch, France; Lisbon, Portugal; Tenerife, Canary Islands Spain; Nouakchott, Mauritania; Dakar Senegal; Banjul, the Gambia; Conakry, Guinea; Freetown, Sierra Leone; Monrovia, Liberia; Abidjan, Cote d’Ivoire; Accra, Ghana; Lagos, Nigeria; Kribi, Cameroon; and hosts of other countries.
A comparison between fiber optic and satellite technologies reveals that although satellite systems are the most efficient solutions for TV broadcast, for access to remote locations, and essentially, for wireless access to the local loop and the network backbone, fiber optic networks are more suited for high bandwidth transmission between countries and continents through core networks and submarine links respectively.
Fiber optic networks offer very high bandwidth necessary for Sierra Leoneans to catch up with the new global information technology. For example, fiber cables today can have capacity up to 2Tbps – an equivalent of millions of simultaneous voice channels per cable.
This is far from the reach of any anticipated satellite system, which is less than 1Gbps – lower than our own SAT-3/WASC/SAFE undersea cable system.
Real time transmission and very low bit error rate offered by fiber optic networks are among the advantages of fiber over satellite. Satellite communications add a delay to communications making interactive data transmission difficult and subject the quality of transmission to external factors.
A geostationary satellite link has a transmission delay of up to 600 milliseconds compared to 100ms for a combination of fiber and coaxial cable networks.
The open space nature of satellite (and any other wireless) communications makes satellite communication vulnerable to interception and corruption. Although several schemes are available for data encryption for IP over satellite, the high bit error rate may cause failures in the encryption systems.
Fiber optic transmission offers undoubtedly the best confidentiality and security of transmission than any other means by its mere nature.
In order to address increasing traffic demand, it is relatively easy to increase the capacity of fiber optic networks during their lifetime by means of wavelength division multiplexing technology. For example, the SAT-3/WASC/SAFE system can be upgraded 12 fold from 10Gbps to 120Gbps. It is impossible to do a similar upgrade on satellite systems.
Perhaps the main disadvantage of satellite communication is their high cost relative to fiber optics communication. In the U.S., for example, the monthly rate for broadband connectivity through cable is about $35 for 3Mbps data rate compared to $200 for 200Kbps by satellite.
In Sierra Leone for example, the landing of the Submarine Fiber Optic Cable has reduced the cost of bandwidth from approximately $2,700 per Megabyte Per Seconds (Mbps) to a mere $200 per Mbps. Regrettably, most service providers have yet to reduce their prices and continue to charge rates that are unfair to Sierra Leoneans.
While the initial cost of a continental fiber optic network for Sierra Leone may appear too high, the long-term cost savings over satellite transmission are overwhelming.
Thus, due to their high bandwidth, high reliability, high signal quality, long lifetime, better security and low service cost, fiber optic networks are suited for inter and intra continental backbone network infrastructure. On the other hand, satellite systems are more dedicated to video broadcasting and personal communication services such as mobile telephony satellite or to access remote areas.