Terrestrial connectivity on the African continent is very patchy in terms of quality. Coastal countries benefit from the connectivity provided directly by submarine cables, which is not the case for landlocked countries. The submarine cables sometimes experience outages and suffer from a lack of redundancy and diversity making the routes less resilient.

Additionally, infrastructure problems such as power supply, theft and vandalism of fibre networks and bad weather are also specific features to be taken into account, as is the geopolitical instability that affects many African countries. All of these points, coupled with complex and uncoordinated regulatory conditions, explain the price and quality discrepancies of terrestrial connectivity between African countries and the frequent need to maintain satellite connectivity.

Terrestrial Internet access can be dedicated or shared bandwidth. Dedicated Internet access is referred to as DIA, and shared Internet bandwidth is referred to as Broadband access. DIA accesses in Africa are provided with SLAs on availability only, whereas shared accesses are not provided with SLAs. DIA is recommended for critical applications. These differences explain the price differences between the two types of Internet access.

This is a local Internet access point, located as close to the user as possible. It allows organisations to offload Internet traffic from local branches and remote offices and route it directly to the Internet via a local ISP. Historically, organisations have deployed a star architecture to route traffic to a datacentre. The increasing use of cloud applications is changing this: cloud applications can be accessed with better performance and user experience over the Internet. As companies discover this phenomenon, they are increasingly turning to Internet breakout and SD-WAN to more easily establish secure direct connections to the Internet.

For all types of usage via an IP or WAN serial connection – to provide video or voice communications, broadband data services or for geolocation.

VSAT stands for Very Small Aperture Terminal – a two-way satellite ground station with a dish antenna that is smaller than 3.8 metres

Satellites offer secure communications just like any other IP connections. Should enhanced security be required, complementary security equipment and encryption applications can be used to safeguard the network. Satellite networks offer secure communications which are equal to or even superior to terrestrial systems thanks to hardware encryption and which are independent of public facilities to anticipate any external intervention.

Yes, wireless services provided by satellite and terminal equipment are reliable. Reliability is a crucial factor to be taken into account when using satellites as it is often the only wireless network to offer coverage in remote zones. Satellite communications operate independently from terrestrial infrastructures, so when terrestrial outages occur following natural or man-made events, satellite connections remain operational.

Satellite networks can be used with different network topologies, from point-to-point connections to complex mesh architecture. Data rates and interconnections can be modified quickly and remotely in a few hours in order to meet customer requirements.

Satellite-based wireless systems allow for rapid deployment and/or restoration of communications in areas where terrestrial infrastructure may be insufficient or unreliable, particularly on the African continent to prevent problems that may arise with terrestrial connectivity: outages due to geopolitical or climatic problems, infrastructure theft and vandalism or complex and uncoordinated regulatory conditions between countries.

IT management should integrate satellite services and networks as a redundancy requirement into their own network or communication architecture. These systems should be brought to the forefront and included early in the planning process. Satellite services enable the implementation of communications services in a matter of days, proving their value in providing “instant infrastructures” for commercial, government and emergency communications.

Satellite networks are capable of providing high data throughput in order to ensure the rapid restoration of damaged terrestrial facilities in addition to creating robust hybrid communications when combined with terrestrial solutions.

LEO (Low Earth Orbit) satellites orbit the earth at low altitude. LEO satellites orbit at altitudes between 700 and 1000 kms, require around 100 minutes to orbit the earth and revolve around the earth around 14 times a day.

MEO (Medium Earth Orbit) Intermediate orbit between low earth and geostationary orbit. MEO satellites operate at an altitude of between 5,000 and 20,000 km. HTS MEO constellations have been deployed to provide low latency and high bandwidth connectivity. As LEO & MEO satellites are mobile, they impose propagation (doppler effect) and handover (switchover) constraints in contradiction with current multimedia needs (high data rates, quality of service).

GEO (Geostationary Earth Orbit) is used for telecommunications and live television broadcasting. These satellites orbit along a circular path, within the plane of the equator and their radius is 42 164 km from the centre of the earth at an altitude of 35 786 km above the earth’s surface. From the ground, geostationary satellites appear to be stationary which is where the name comes from.

LEO satellites provide lower latency, but as they are not geostationary, they require the installation of a satellite to follow their trajectory.

Network topology corresponds to physical architecture i.e.: which circuits are established with a single satellite hop. Topologies include point-to-point, star, mesh, ring or hybrid.

A hybrid network allows businesses to increase the resiliency of their global network though the implementation of real alternative routes of communication with automatic switchover.

It supplies additional throughput for terrestrial links by providing a communal pool of satellite bandwidth for different agencies from a satellite network to avoid congestion when various links are overloaded.
It reduces global connectivity costs by optimising connection use between remote sites.

A hybrid network is an interconnection of two or more types of connectivity, for example VSAT plus terrestrial MPLS or VSAT plus an Internet access.

MPLS (Multi-Protocol Label Switching) is a routing technique which directs data based on short path labels via modular network architecture. A virtual private network, this infrastructure is highly secure for communication between remote sites and is therefore ideal for connecting agencies or datacentres without modifying the network core in addition to providing better monitoring of remote users within the company network.

Network oversubscription means that the bandwidth is shared between multiple users and is not dedicated.

• An oversubscription ratio of 1:1 means that the bandwidth is guaranteed
• An oversubscription ratio of 1:8 means that 8 users share the bandwidth

A Broadband Internet access is usually a service with non-guaranteed bandwidth whereas a dedicated Internet access (DIA) guarantees bandwidth from the customer’s facilities to the public Internet.

SD-WAN stands for Software Defined Wan (WAN or Wide Area Network). There is no standard definition for SD-WAN within the industry. SD-WAN technology is used within the framework of hybrid networks (MPLS or VSAT) and uses WAN functions such as VPN, WAN optimisation, IPsec tunnel mode, hybrid WAN, deep packet inspection, rule management and analysis and assessment services. The purpose of SD-WAN is to simplify the management and operation of WAN by identification applications and dynamic path selection for traffic.

Sonema’s SD-WAN offer is an entirely managed service, backed up by stringent SLAs which allows us to improve the customer’s hybrid network performance through the use of routing, security and optimisation rules.

According to Alcatel-Lucent, world leader in the production, installation and maintenance of submarine communications cables through its subsidiary Alcatel-Lucent Submarine Networks (ASN), 99% of intercontinental data traffic is sent by submarine cables. In total, there are around one million kilometres of cables under the seas according to the manufacturer. Submarine communications cables are funded by Internet giants such as Google and by consortia headed by leading telecoms groups. There are 448 cables in operation throughout the world of which over 10 transit between Africa and Europe including the ACE, Main One or SAT3 cables which serve West Africa. Submarine communications cables make landfall in cable landing points.

Yes, by using deduplication, compression, caching plus protocol and application acceleration techniques. These techniques enable us to reduce the quantity of data transferred, the volume of data exchanged and the latency. They can be implemented by using solutions such as Optim-Booster on the customer’s network which Sonema can deploy and manage as an outsourced service.