Deep-Dive: Connecting Sub-Saharan Africa with blockchain-powered mesh networks
A low-cost way to bring high-quality connectivity to Sub-Saharan Africa
The status quo
Currently, Sub-Saharan Africa has the lowest percentage of people connected to the Internet in the entire globe: only 290 million out of 1.150 million people (25% of the population) have access to the Internet. In five years, connectivity has increased by 50% — this is quite remarkable but still insufficient. Sub-Saharan Africa keeps being a digital desert, unconnected from the rest of the world and unable to join the global economy and digitalize its economy.
Inside the 860 million unconnected people, it matters to notice that there are 180 million uncovered people. These two realities are part of the same broad problem but are not the same.
- Unconnected people have access to Internet infrastructure like cell towers or satellite coverage but remain unconnected because of the lack of digital literacy and affordable Internet services and devices.
- Uncovered people have an even deeper problem than the unconnected: in addition to unconnected people issues, they also lack access to proper Internet infrastructure. In a place with no coverage, even if a person has a digital device and a decent digital literacy, they will not be able to access the Internet.
Let’s make this real…
Neuza and Noélia are both 60-year-old farmers from Mozambique. Let’s say that thanks to UN funds, the Mozambique government started distributing subsidized Internet plans for low-income citizens, as is the case for both of these women.
Neuza lives in a village near the capital with decent coverage, so she will take this opportunity, and get connected to the Internet for the first time in her life.
On the other hand, Noélia lives in rural Northern Mozambique and has no Internet coverage in her region. Therefore, even though she would love to get connected to the Internet with this opportunity because her community misses the proper infrastructure.
Being unconnected by itself is essentially an economic issue — if Neuza had a better income, she would be able to afford to pay for an Internet plan. Contrariwise, being uncovered (and therefore unconnected) is a geographical + economic issue — even if Noélia had a digital device and a solid income, she would not be able to access the Internet where she lives.
Since both problems are interconnected, I will also approach the lack of coverage in this deep dive, but I will not focus on finding solutions to that part of the problem. In the first place, this article is tackling the lack of connectivity and solutions to it. Having said this…
Why is there a connectivity issue in Africa?
- Not affordable & not profitable Internet. Sub-Saharan Africa has the least affordable mobile data plan and internet-enabled device, with the 1GB monthly plan price very far from the UN Broadband Commission’s target of less than 2% of average monthly income. In several areas, the potential returns for telecom companies to provide their services are scarce due to low population density and incapacity to afford the service.
- Conflict & geographical constraints. Sub-Saharan Africa’s history of hostilities over the last decades destroyed the already scarce existing infrastructure and made it risky for companies to invest in new infrastructure. On top of that, the borders left by the colonial powers and the abundant geographic barriers also make building infrastructure more costly and more complex.
- Unreliable electricity. The frequent blackouts put existing infrastructure out of action and deter telecom companies from investing in new infrastructure in affected areas.
In a world where 2.9 billion people remain unconnected, Africa alone represents 30% of the problem. Let’s now dive deep into Internet functioning, current issues, and potential solutions.
Internet functioning, (almost) all about infrastructure
If you are reading this article, you are not part of this 2.9 people unconnected people. Probably, you perceive the internet as something digital since all your interactions are also very digital by themselves (scrolling social media, reading articles on Medium, and so on…). But guess what? It isn’t that digital — in fact, the internet as a whole system is much more physical than you might think it is.
As of early 2024, TeleGeograhy tracked 574 active and planned submarine cables crossing the oceans to transmit the Internet to the four corners of the globe. Whenever you access a website stored on a server on a continent other than the one you’re on or send a message to someone on the other sideof the globe, there’s a 99 percent chance that one of these submarine cables will transmit this data. These cables cover around 1.4 million kilometers, making the Internet the widest infrastructure ever built in human history.
99% of the 1.4 million kilometers of submarine cables worldwide are controlled by consortia of private companies, with the remaining 1% controlled by governments. The private companies dominating this market range between the big telecom companies and the big tech companies (Google, Meta, Amazon, and Microsoft) who owned more than half of the undersea bandwidth in 2018.
According to a 2023 estimate, constructing one kilometer of undersea optical fiber costs $25,000: multiplying this figure by the 1.4 million kilometers in existence, the entire network would be worth around $35 billion! Given these high costs, only large companies can participate in the consortia that own the submarine cable network. Thus, despite the thousands of active Internet Service Providers across the globe, only a small group of these companies can participate in these consortiums.
As you can see from the map above, the lack of connectivity and coverage issues in Africa are not related to the lack of submarine cable bandwidth, as there are multiple cables connecting the African continent to different parts of the globe.
Now that we’ve explored the seas and the dense underwater infrastructure that inhabits them, let’s explore the remaining infrastructure used in Internet distribution.
1. Fiber Optics Cables
Maybe you have already seen advertisements from telecom companies using this word and stating how fast the Internet in your house will be if you adhere to their fiber optic plan.
Out of the three types of Internet cabling around the world, optical fiber is the fastest and most efficient form of data transmission, allowing data to be transferred over long distances (the majority of submarine cables are built with this technology) and with high bandwidths. In MEDCs, we’ve even seen a significant replacement of copper cables by fiber-optic cables in the last mile of the Internet over the last few years, providing ultra-fast Internet directly to homes and businesses.
In a fiber cable, data is transmitted via light pulses that inherently travel at the speed of light (around 300,000 km per second). These light pulses are modulated on their frequency and intensity according to the binary information within the transferred data packets. On-Off modulation, for example, is a simple modulation method in which a 0 is transmitted as a no-light pulse and a 1 as a light pulse.
The light used to transmit can be generated either with an LED, lower cost and only suitable for shorter distances, or with a laser diode, a more expensive and focused light pulse allowing for higher data transmission and longer distances.
After the light is generated and modulated, it enters the cable core, a thin strand of glass or plastic carrying the light pulses. Due to the difference in refractive index between the core and the cladding, the light goes through a total internal reflection that keeps it inside the core and ensures its transmission. At the end of the fiber cable, a photodetector receives and converts the light signal into an electric signal that might be again reconverted into a light signal if transmitted to another fiber cable.
2. Shield core copper cables (aka coaxial cables)
Until the introduction of fiber optics, coaxial cables were the status quo for high-speed Internet distribution. Coaxial cables were originally developed for transmitting TV signals, and when the Internet boom hit, they were quickly adapted to this new end.
Nowadays, its importance varies dramatically across different geographical zones. While among the cabled Internet users in LEDCs this is an expensive solution still inaccessible to large numbers of them, in MEDCs coaxial cables are starting to become outdated and are progressively being replaced by fiber optics, as I mentioned earlier.
Regarding its functioning, the copper braid around the conductor acts as an electromagnetic shield, preventing any external noise from interfering with the data transmitted on the conductor. Despite being an effective electrical conductor, copper has some inherent resistance to the flow of electrons. That leads to weakening and distortion of the internet signal over long distances, thus limiting its speed and making it slower than fiber optics.
In a coaxial cable, electric pulses transmit the data. The electric pulses can be generated using Direct Current (DC) circuits, Alternating Current (AC) circuits, or even dedicated pulse generators (devices that provide finer control over electric pulse shape, amplitude, frequency, and duration).
In its simplest forms, the voltages of the electrical signal carry out the modulation of the electrical pulses, with the 1s of the binary sequences of each data packet represented by higher voltages and the 0s by lower voltages.
3. Twisted Pair copper cables (Digital Subscriber Line (DSL) Internet)
When I was little, I remember hearing my parents comparing how fast the Internet was in those days compared to the old 90s when it was distributed using the telephone line. I never really believed that was possible until I discovered DSL Internet!
Theoretically, the twisted pair copper cables used in this technology work in much the same way as coaxial cables: the transmission via electric pulses, the modulation required, all of this is the same in both technologies.
The big difference between the twisted pair and the shield core cables lies in the quality of the cabling used: unlike coaxial Internet, DSL cables do not have a shielded core that protects the electric pulses transmitted by the cable’s electrical conductor from interference from external noise or electromagnetic waves, thus reducing the quality and strength of the signal. This happens because DSL uses the telephone communication infrastructure to transmit the internet signal, while coaxial Internet uses the TV signal broadcast infrastructure.
What for my parents and me has been a technology of the past for several years to many of the inhabitants of LEDCs Internet users is the only way they can receive a signal — using the precarious telephone infrastructure in their location.
4. Cell towers
The cell tower is where the cabled Internet ends and the last mile of the Internet begins — in other words, the part where the user-network direct interaction takes place. In cell towers, the light signals (in the case of data arriving at the tower via fiber optic cables but automatically converted into electric signals) or the electric signals (in the case of data arriving at the cell tower via coaxial or twisted pair cables) received are converted into radio waves which are then transmitted and received by the user.
The process of converting electrical signals into radio waves happens within an alternating current (AC) circuit integrated into the cell tower called the LC circuit.
An LC circuit consists of an inductor (L), a coil of wire that resists changes in current and stores energy in its magnetic field, and a capacitor (C), two conductors separated by an insulator and storing electrical energy in its electric field.
The creation of electromagnetic waves within these circuits happens as follows: first, the capacitor is charged with a specific voltage; then, with the circuit already switched on, the capacitor begins to discharge, and the current flows through the inductor, starting to build up a magnetic field around it; when the capacitor discharges completely, the magnetic field around the inductor begins to collapse, and the current begins to recharge the electric field in the capacitor. This process continues successively, producing an oscillating current that flows in the circuit.
This oscillation generates a variable magnetic field and a corresponding oscillating electric field. The process of electromagnetic wave generation in the LC circuit arises from the oscillation of the electric and magnetic fields, with the two spreading together in the form of an electromagnetic wave.
The carrier wave signal (signal before the wave modulation and amplification) is then modulated (in on-off modulation, 1s = radio signal and 0s = absence of radio signal) and amplified before being emitted by the antenna, and finally received in the user’s device. Unless using Ethernet, all the last mile transmissions work in the same way as cell towers: receiving and emitting radio signals.
Although this explanation refers to a cell tower, home routers, smartphones, and laptops all use the same method to generate and emit radio waves. The only difference is in the scale of the structures: while the LC circuits of a router or mobile phone have a relatively low inductance and capacitance and consequently lower resonance, emitting a signal with a lower strength, the LC circuits of a cell tower have a much higher resonance and therefore the signal emitted also has a much higher strength.
How data travels across the Internet?
The Internet is literally what the name suggests: a group of interconnected networks that communicate with each other to create the greatest network of all times. Even though I mentioned how a small portion of stakeholders controls significant parts of the data transmission process, the Internet is also decentralized, involving multiple ISPs to carry data from point A to point B. Without this intercommunication between ISPs across the world, the Internet would be nothing but a group of isolated networks that could only access data stored within themselves.
Let’s say John lives in the Netherlands and wants to open a website stored in a web server in the US. How will data come from the server until John’s phone?
- John requests the data. On his phone, John opened the Amazon.com website. Right after, the browser transformed the address num IP address using the Domain Name System (DNS) protocol. To make this easy, think of DNS protocol like a tracker to locate the server of the website you want to achieve. Then, data starts its travel through several ISPs until finally reaching the server in the US.
- Data reaches the server. After a few milliseconds and thousands of kilometers, John’s request arrives at the Amazon server. The request is then processed, with the server finding all the website’s files (HTML, CSS, etc.) and assembling them into multiple data packets. Have you ever heard about the Internet being a binary system? Here is why: when the files are encoded (or packed), they are assembled into sequences of 0s and 1s (in the Transmission Control Protocol, the most used for web traffic, the sequence is 32 bits long) with headers stating how to assemble this packets when they arrive to Jonh’s phone. Now, the packets are ready to start their journey!
- From the server until the ocean. Before entering one of the submarine cables crossing the Atlantic, the data packets will most probably travel US land through transmission cables owned by several different ISPs and on this path pass through multiple aggregation nodes (intersections in the vast Internet that aggregate data from smaller networks and combine and redirect them onto larger networks) and amplifiers (structures used to maintain the signal strength). Since we are talking about the US, this path will most probably be exclusively done using fiber optics cables.
- Internet backbone: crossing the ocean and arriving at the cell tower. At a certain point, the data packets asked by John will cross the Atlantic at high speed. At the end of this journey, the date will travel again through fiber optics cables until it achieves a cell tower near Jonh.
- Last Mile: electromagnetic wave generation. When the data packets arrive at the cell tower, the LC circuit starts working, and radio waves are modulated and emitted according to the binary sequence of the data packets John needs to receive.
- Website opened = John happier. The data is finally received and decoded by John’s phone, and after a few seconds, he can order a birthday gift for his son on Amazon.
That is the way the Internet works. Although it serves billions of people, the truth is that with the current system, 860 million people remain unconnected in Africa. We must provide these people with an affordable quality connection adapted to their income levels well below the world average.
Having said this, let’s explore how blockchain-powered mesh networks can solve this problem.
What are mesh networks and why are they the solution to tackle Africa’s digital divide?
The Internet is decentralized — the fact that there are 1,000 Mobile Network Operators operating in the $2.7 trillion telecoms market alone makes this fact unquestionable. But despite its decentralization, the Internet has two characteristics that make it difficult to use its traditional forms to tackle the digital in Africa:
- It is very hierarchical — in the path from the Amazon server to John’s device, we saw all the Internet layers data packets needed to cross to arrive at his phone.
- It is highly reliant on infrastructure — in the African situation, this characteristic is a tremendous liability. On a continent where even telephone cabling is non-existent in a significant part of rural regions, it becomes impossible to connect the unconnected depending on infrastructure since the telecom companies themselves do not have the financial incentive to supply populations with infrastructure when these populations do not have the money to afford the communications plans fees (80% of the connectivity gap in Africa partially relates with the lack of affordability on the data plans).
Having that said, how can we create an Internet that is less hierarchical and less infrastructure-demanding? Using blockchain-powered mesh networks.
In its original conception, a full wireless mesh network like the one shown in the figure is a type of network in which the nodes are connected in a non-hierarchical manner and in which information travels between nodes through the transmission of electromagnetic waves, similar to what happens in the transmission of data on the cellular Internet between the mobile phone and the cell tower and vice versa.
Let’s assume that John was connected to a mesh network instead and not to a cellular network when he accessed Amazon’s website. If he connected to a mesh network instead of connecting directly to the cell tower that covers the neighborhood where he lives, John would connect to the nearest node and the routing protocols within the mesh network would find the fastest way to get John’s request to Amazon’s server in the United States.
In addition to this decentralization within the first and last mile, a mesh network has two fundamental properties we should be aware of: redundancy and self-healing. Both are interconnected.
Redundancy relates to the design of the network so that multiple nodes cover multiple locations and self-healing (in other words, the ability of the network to detect faults and re-optimize itself). Suppose a node breaks down: contrary to what would happen in a cellular network, all users are not left without coverage until the telecom company repairs the cell tower: instead, other nodes that also cover the same area will take over the traffic previously managed by the failed node and minimize the externalities resulting from this damage (self-healing working). Mesh topology optimizes itself for resilience, something fundamental in a region where the arrival of technical support is a very time-consuming and costly process.
Mesh networks can exist in a local area network (LAN) to fix connectivity problems in parts of the house where a router’s signal can’t reach (several telecom companies are starting to sell this solution) or in a wide area such as a village or city (the public WiFi services that many cities offer are usually an example of a Wide-Area mesh network).
Adopting a mesh LAN is a convenient and efficient way of ensuring connectivity throughout the home but not necessarily a crucial factor in making the Internet accessible throughout the house (assuming the user has access to cabled Internet power lines or amplifiers can be an alternative). However, in a mesh WAN, this is not necessarily the case: in this case, the mesh network may be the only alternative to installing kilometers of cabling, which is financially unviable for many of Africa’s unconnected communities.
Therefore, wide-area mesh networks are the only proven option able to provide a quality connection (quality = decent bandwidth + low latency) at affordable prices for these communities. However, there is one factor to consider: to be connected to the rest of the Internet, a mesh network needs to ensure its backhaul connectivity. That’s why every network has at least one gateway node, a type of node that works as a bridge between the nodes within the mesh and the internet backbone.
But how does blockchain come into this?
The decentralization of the mesh network is a double-edged sword: while on the one hand, it has the advantage of making this network solution more adaptable to failures and more resilient, on the other hand, it has the disadvantage of making it more vulnerable to DDoS and different types of attacks, since each node represents a potential point of failure in the network. In a traditional network, this vulnerability also exists in a much lesser extent since the number of nodes is much smaller in the same hierarchy (in the case of a house, it’s only one — the router), so the points of failure are much fewer.
IEEE 802.11s is the standard protocol used by Wireless Mesh Networks and has some advantages such as being easy to expand. However, the security settings and encryption protocols (WPA, AES, etc.) that each node operates with are not implicit in the protocol, meaning that the operator of each node is free to define the levels of security and encryption at which it operates.
To further worsen the situation, the operation of IEEE 802.11s is based on an inherent trust in each node to send data to transmit to the other nodes in the mesh. Let’s say that node 1 of a 25-node mesh network operating without any security protocols is the victim of a DDoS attack. Although the other 24 nodes have implemented strong cybersecurity measures in their operation, the security procedures do not apply to the data transmitted from node 1, since it is considered part of the network’s “circle of trust”.
What happens in this scenario? Node 1 contaminates the entire network, and the whole mesh network shuts down. It is to solve this security vulnerability that blockchain is fundamental.
The blockchain deconstructs the “circle of trust” explained above, making it necessary to authenticate each node before transmitting information to the mesh. In this smart contract, each node in the mesh has a cryptographic identity (aka key pair) and must provide proof of knowledge of this identity to prove its legitimacy to access the network (in other words, the node must share the public key and private key assigned to it).
In the context of connecting the unconnected, it is also important to introduce another dimension of blockchain at this intersection of blockchain and mesh networks: using DePIN. DePIN stands for Decentralized Physical Infrastructure Networks and consists of building a P2P marketplace for physical resources.
Whenever connecting a new village in Sub-Saharan Africa with a community mesh network, the blockchain role won’t be only for network security: the blockchain will also be a platform for managing payments on the network, where users pay directly to the smart contract for the Internet usage in cryptocurrency and the smart contract allocates these funds to the nodes according to their contribution to the network, thus creating a transparent payment system that encourages participation in the network.
Transposing this scene to an African village where its inhabitants connect to the Internet via a blockchain-powered mesh network, some inhabitants (or even all) acquire their node, install it in their homes, and start receiving multiple microtransactions for the data transmitted to the network via their node (aka contribution to the network) and for the user’s assessment of the quality of the connection provided by their node (aka reputation tokens), while at the same time paying the same microtransactions whenever they connect to nodes belonging to another inhabitant and assessing the quality of the connection of these nodes.
In this way, each village will have a self-resilient Internet distribution and transmission system based on economic interdependence between the inhabitants established through constant recurrent P2P microtransactions, since everyone can potentially be both a consumer and a producer.
To make all these concepts more practical, let’s explore World Mobile and how this company uses a system like the one I just explained to connect the unconnected.
How is World Mobile connecting the unconnected?
How do you deliver connectivity to a place where the installation cost is far greater than the ROI? That’s the problem that World Mobile wants to solve. Founded in 2018, and with a team with dozens of years of accumulated experience working with traditional telecom companies, World Mobile has decided to take an alternative route to how current telecom companies operate.
In the current Internet distribution system, the economic incentive to cover a location comes from the population density of that location. Between New York and rural Texas, AT&T has a much greater economic incentive to install internet infrastructure in the first location than in the second because the population density is much higher, and so is the ROI obtained for each kilometer of fiber optics installed. Because the economic incentive is much higher, more telecom companies will be interested in competing in the New York market, maximizing the offered services quality and lowering the prices. In rural Texas, on the other hand, because the economic incentive is lower, not only will the infrastructure be of lower quality and scarcer, but Internet prices will be higher.
In Africa, financial limitations prevail over geographical inequalities: even in the most densely populated places, the low-income level means that there is little economic incentive for traditional telecom companies to install their services due to the lack of affordability of the infrastructure.
World Mobile has solved this problem by creating its Cardano-powered “hybrid dynamic network” which, according to its website, can be “up to 12x cheaper than legacy models”. This “hybrid dynamic network” is made up of the following nodes:
- Air Nodes. The access point to the mesh network is where users connect to the Internet. Because of the decentralized operation enabled by the blockchain, anyone can buy their own air node and provide connectivity in their locality. There are three individual air nodes: the Portal 180, the Portal 360, and the WMS Titan (check here for more details).
- Earth Nodes. The Earth Nodes form the core logic of the World Mobile Blockchain System. These are responsible for connecting the different types of nodes. These nodes communicate via a central module called The Internode API. This module is based on three other modules: the DID module, responsible for registering and managing users’ digital identities; the blockchain module, responsible for registering transactions and processing rewards to the nodes according to their contribution to the smart contract; the telecommunications module, responsible for ensuring media and message routing, self-healing feature management, service management, and others. Anyone can purchase an Earth Node independent of the geographical location.
- Aether Nodes. The bridges with the legacy telecommunications networks are responsible for translating the mesh protocols into the legacy protocols. According to the white paper, “Each country requires a minimum of one Aether Node in order to provide service” suggesting that this is a measure to ensure compliance with current legislation in the countries in which they operate and cooperation with traditional communication routes.
As with any mesh network, World Mobile also needs backhaul connectivity. To this end, World Mobile defines itself as “backhaul agnostic” operating “with LEO, MEO or GEO satellites to provide backhaul to ground stations and tethered aerostats”. Thus, by combining the different nodes of its blockchain-based mesh network with backhaul solutions such as Starlink’s LEO satellites, World Mobile has made a remarkable journey connecting the unconnected over the last few years.
At the moment, the World Mobile chain already has more than 1523 active Air Nodes in operation in Zanzibar, Pakistan, the USA, and Wales, being deploying the first “Super AirNodes” (aerostats with a radio horizon radius of 72 square kilometers) and developing High-Altitude Assisted Ballons (ballons which fly at an altitude of 20 km and can cover an effective area of 350 square kilometers).
Check out this thrilling 3-min video to understand how impactful getting connected to the Internet was for rural Tanzania villagers👇
Conclusion & Future of this solution
Almost 3 billion people are still unconnected, and a large part of this problem is due to the lack of economic incentives to connect the poorest and most sparsely populated rural areas.
Regarding the uncovered population with no single backhaul connectivity provided by any legacy telecom company, Starlink Low-Earth orbit satellites can provide a reliable and high-speed backhaul solution. However, with prices starting at $30 per month in Malawi, it makes clear how the prices do not match the average incomes in Sub-Saharan Africa and how this solution cannot overcome the economic barriers that condemn 1.150 million people in this region to remain unconnected nowadays.
Therefore, to solve the last mile problem, community blockchain-based mesh networks are the only solution having proven capacity to provide a cheaper connection (12x times cheaper in the World Mobile case) with a decent quality that can meet the economic circumstances of the unconnected.
World Mobile is an outstanding example of a company working in this field, having already connected 20.000 people in Zanzibar and many more across the world. Their backhaul-agnostic hybrid network is a unique feature that avoids a one-size-fits-all mindset and instead creates the most efficient solution for each specific geographical location.
For the future, World Mobile and similar solutions emerging have a market gap of 3 billion in which they can operate, so their possibilities for expansion are immense. As far as World Mobile is concerned, my only concern is that the high price of air nodes (between $9,500 and $100,000 depending on the range and volume of data supported) can make it complex to obtain a return on investment, making the node operator dependent on attracting a few dozen customers in the number of customers it manages to attract to its node to obtain that return.
Perhaps the development of a type of air node for individual/domestic use (like a home router incorporated into a mesh network) with a price reduction proportional to the decrease in the number of connected consumers could be a solution with a greater scope of locations to benefit from, namely by making this solution fit for small (under 100 inhabitants) and highly-isolated places.
In conclusion, I’m excited to see the role of blockchain-powered mesh networks in bringing connectivity to Sub-Saharan Africa. After this deep dive, I have many potential areas to explore in detail, including radio wave modulation, glass properties, and router/cell tower/mesh node composition.
After reading this article, I hope you realize how, block after block, blockchain is changing the digital divide paradigm in Sub-Saharan Africa!
See you next time
Best ✌️
I genuinely hope you learned something new about the digital divide in Sub-Saharan Africa and how utilizing blockchain-powered mesh networks can mitigate this issue. In order to keep updated about my projects, follow this account and subscribe to my monthly newsletter where I will reflect on the highlights of each month. Additionally, feel free to reach out to me on Linkedin or Twitter and check out my full portfolio for other projects and ideas I have been working on.
