In Africa, as everywhere in the world, digital applications are increasing exponentially, highlighting the continent's digital divide. OTTs and telcos, such as Facebook or Orange, supported by funders and African governments, have joined forces to accelerate the deployment of high-speed connectivity infrastructures. Submarine cables, landing stations, and backbones, are essential infrastructure to develop connectivity and guarantee network quality, however, they are expensive.
In the Democratic Republic of the Congo, Facebook, supported by the government, is deploying fiber optic backbones. For the country, the implementation of fiber connectivity is a gas pedal of the economic development of the territory and a vector of attraction. For Facebook, it is an opportunity to extend its Metaverse strategy in Africa.
Given the complexity of this deployment and the need to secure its timetable as well as its investments, Facebook called on Sofrecom to carry out the preliminary study for the construction of a 5,745km fiber optic backbone route in the Democratic Republic of Congo.
Backbone, the spine of the fiber network across the territory
Backbones (terrestrial backbones) represent the main component of the network and require a significant investment ($20,000/km). They connect the main nodes of a country's network between major cities, in particular, to enable very high speed and very high capacity connections. Their construction and installation must therefore respect engineering rules to guarantee their longevity, availability and the quality of network operation. For example, cables must be buried at a minimum depth of 1m20. This is why, in order to secure the deployment as much as possible, it is essential to carry out a complete and reliable preliminary study phase.
Anticipate hazards with a study phase of the field and the environment
The feasibility study allows to anticipate and estimate the investment to be made. It must provide a better understanding of the entire route in order to secure the civil engineering work and the deployment schedule.
In the DRC, as well as in several other African countries, road infrastructures are not sufficiently developed to be the only reference point for the backbone's path in the territory. The route will therefore have to be laid out in areas which geotechnical nature is sometimes unknown and which will have to be determined by taking samples in the field. In the same way, good local knowledge is key to identify the most favorable places for the network burial, especially in cities and villages, or to negotiate with local authorities and obtain administrative authorizations.
It is on this mission that our Sofrecom teams brought their know-how through a well-proven method.
An innovative methodology to optimize deployment costs
The methodology is based on the team's organization, but also on the way information is collected to build the final report of the study.
A multidisciplinary team was mobilized to carry out the study capitalizing on our experts and a network of local partners. The experts selected to intervene on-site were trained and supervised for the duration of the study. The selection and tool testing (penetrometer, gamma-ray spectrometry...) necessary for the samples and measurements were carried out in advance to secure the intervention in the field.
The nature of the information collected was to help determine:
- The geotechnics of the field. What is the nature of the soil and subsoil; what are the obstacles or infrastructures on the surface? Measure the radioactivity of the subsoil...
- The local context from a societal and environmental point of view. The local partner had to have a good knowledge of the local regulations and had to cooperate with the competent authorities to facilitate the identification of suitable locations for the cable burial.
The experimentation phase on a section of more than 1,200 km for a total distance of 5,745 km of the backbone route, allowed us to implement an agile method and governance of the project: iterative and collaborative mode, to approve our approach. It was also used to improve the system along the way and to reinforce the team's know-how. Working in a collaborative mode allowed us to meet Facebook's requirements and deal with the project's hazards, especially at the local level.
A successful human adventure despite difficult conditions
In the midst of the pandemic, this twelve-month mission was carried out by a multidisciplinary team mobilized from 9 countries. Thanks to the tools and governance put in place, collaboration and exchanges were smooth.
On-site, the working conditions were complicated: unfavorable climatic conditions, limited reachability of the teams in areas not covered by the network, and security problems related to the country context. Despite this context, the project schedule was respected and the data collected in the field was transmitted daily.
The deliverable’s quality was highlighted upon delivery to the client who expressed great satisfaction with the accomplished work. The trust established today allows a new cooperation to continue the study on another section of the backbone's route. In addition, Facebook has entrusted Sofrecom with the management of the calls for tender and the selection of the suppliers who will intervene in the deployment phase.
To know more about the deployment of buried terrestrial telecom backbones