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The Fourth Use Case for 5G: Internet for All

By Qurrat-Ul-Ain Nadeem

Internet Penetration Today

By the end of 2018, there were nearly 4 billion people without Internet connectivity in the world. Primarily at the bottom of the world’s economic pyramid, almost 75% of this unconnected population is based in 20 countries and is concentrated in rural, low-income and low-literacy areas with annual per capita income of less than $1500. As of May 2019, North America leads the world in internet penetration with a rate of 90%, followed closely by Europe at 87%, Australia at 68%, Latin America and Middle East at 67% each, Asia at 52%, and Africa at a mere 37%. Only 1 in 3 Africans have access to the internet!

The barriers to internet penetration in these under-connected areas include low income, illiteracy, lack of relevant skillset in potential users, lack of incentives for service providers and lack of technology infrastructure, including electricity and transportation facilities. In their recent survey paper on rural connectivity, which is going to be published in the Proc. of IEEE, Yaacoub and Alouini identify four main challenges to closing the existing digital divide:

  1. the absence of a viable business case due to the sparse and poor population in many under-connected areas,
  2. increased Capital Expenditures (CAPEX), e.g., the need to build base station towers and high backhaul costs,
  3. limited or absent electricity supply, which increases Operational Expenditures (OPEX) due to the need to utilize alternative energy sources like diesel generators, and
  4. difficulty of maintenance due to the limited supply of skilled workers in these areas.

These factors lead to low average revenue per user, and a long return on investment, thus intensifying the barriers to rural connectivity.

A Change in Vision

The evolution in information and communication technologies (ICT) from 1G to 5G networks has enabled high speed, ultra-reliable and low-latency communication and massive connectivity. ICT is also considered to be an essential tool to achieve the United Nation’s (UN) sustainable development goals (SDGs) related to environment, health, education, gender equality and eliminating poverty among others.

While each generation’s advancements have made ICT a critical service for social and economic empowerment, it is important to realize that there is a large population around the world with no access to basic connectivity. Most of the current ICT research lacks a holistic view that aims to achieve social good by overcoming the barriers to connectivity, increasing awareness, and helping all communities to achieve these SDGs.

With the unprecedented advent of the astonishing “5G and beyond era”, we need active efforts to narrow this digital divide and allow the often economically and socially isolated 4 billion who are unconnected to experience the life-changing benefits that connectivity brings, from access to better health and education to enabling jobs and financial services. Acknowledging its paramount importance, the United Nations now recognizes internet connectivity as an important and basic human need and includes “universal and affordable access to the Internet,” among its 2030 Sustainable Development Goals.

Providing connectivity to rural areas should not only be seen as a humanitarian goal but also as a great opportunity to generate crucial economic activity once Internet technology and associated opportunities become available and adoption increases with user awareness. In fact, the bottom of the world economic pyramid is a high leverage point, where small steps towards connectivity can create a huge market of creative and resilient consumers and producers, largely excluded from current formal markets.

As the research visioning and planning for 6G networks has initiated, there are increasing discussions to guarantee communication fairness in rural areas through low-cost implementation schemes. Currently 5G defines three main use-cases, 1) Enhanced mobile broadband, 2) Massive machine-type communication, and 3) Ultra-reliable low-latency communication. The infrastructure required to realize these three pillars is mostly available in urban areas.

There is a need for a new use-case, corresponding toGlobal Access to the Internet for All (GAIA),” that focuses on closing the prevalent digital divide and enabling worldwide connectivity. A recent paper in Nature Electronics by researchers from King Abdullah University of Science and Technology (KAUST) anticipates “Big Communications (BigCom)” to be one of the five application scenarios supported by 6G, which targets service fairness between dense and remote areas. This affordable broadband pillar should be based mainly on: (i) intelligent spectrum management, (ii) improving energy efficiency of current technologies, and (iii) reducing infrastructure costs. The requirements will be less than the existing three 5G use-cases in terms of data rates, device density, and latency but will correspond to ubiquitous geographical coverage leading to basic connectivity anywhere anytime. This is also the subject of an upcoming 6G summit: “Connecting the Unconnected” in March 2020, which features talks from industry experts and academics in the field of ICT who will shed light on new ways to measure digital inequality, and identify the technical approaches as well as the practical initiatives that can potentially address the challenge of the digital divide.

Potential Technologies for Expanding Rural Connectivity

It is important to identify suitable backhaul and fronthaul technologies to provide rural connectivity, which strike a balance of capital and operational costs as well as performance. Some possible backhaul solutions include laying fiber optic cables throughout the long backhaul distance, placing radio frequency equipment on cellular towers so that the backhaul transmissions occur over licensed microwave frequency bands, and placing free space optics (FSO) equipment over transmission towers to enable backhaul transmission over FSO links.

All these solutions have their own limitations and advantages. Deploying long fibre optic cables can be costly in difficult terrains like mountains but still feasible in deserts. The main limitation is the initial cost of civil works, which is generally much higher than the cost of fiber optic cable itself. Although the installation costs can reach 200 USD/meter in dense urban areas, they go down to 30 USD/meter in rural areas. This makes fiber deployment favorable especially when there are no severe geographical constraints.

To utilize microwave and FSO links in long backhaul stretches over non-populated areas to reach remote rural settlements, appropriate base station towers need to be built resulting in very high CAPEX costs. Since microwave frequencies are regulated and carry licensing fees, this also results in high OPEX. FSO does not involve spectrum licenses since it is based on light transmission, however it is sensitive to certain weather conditions such as fog, sand storms and to alignment errors.

To achieve the goal of worldwide connectivity, three-dimensional integrated networking should be used which encompasses terrestrial, airborne and satellite communications. In fact, to solve the coverage problem in large rural areas without relying on the deployment of costly infrastructure on the ground for backhaul, it is envisioned that communications of flying nodes, for example: High Altitude Platforms (HAPs), Unmanned Aerial Vehicles (UAVs) and tethered Aerostats (balloons), will become ubiquitous in the 2030s.

A multi-hop network of UAVs, HAPs and tethered balloons can cover thousand of kilometers of sparsely populated area by communicating with each other using directional antennas over mmWave frequencies, before reaching a ground station through an FSO link. Currently, Google’s Loon project designs and uses high altitude balloons to create an aerial wireless network, which can potentially deliver connectivity to people in remote unconnected areas. It has already run several successful field trials: for example, seven balloons were able to relay a signal over a distance of 1000 km with good control over their navigation paths to ensure they stay at the target area.

Adopting an appropriate fronthaul technology, like mmWave, FSO, WiFi, mesh networks or power line communication, for communication between the base station and the remote radio head (RRH) or the users will also depend on several factors including the population density, geographical characteristics, and distance to the nearest gateway/exchange point. For example: bringing 5G directly to rural areas will not be feasible as a starting point since these areas currently lack even basic internet access. A network should typically start with basic features and gradually evolve over time to reach the 5G performance targets. For this reason, rural connectivity should be identified as the fourth use case of 5G, or possibly the combination of the four use cases could form the foundation of 6G.

One Size Will Not Fit All

To provide sustainable connectivity to rural areas, different aspects need to be successfully integrated like the backhaul and fronthaul technologies, electricity solutions for remote areas, user awareness that creates local services and drives local demand, which in turn leads to more advanced connectivity. All of this needs to be governed by suitable government policies and incentives. In addition, it should be noted that there is no single technology that is best suited to provide connectivity to rural areas. Each solution can be the best fit for certain scenarios while not being convenient for other scenarios.

Combining different rural connectivity technologies while providing the flexibility to evolve to Enhanced-5G/6G as the demand increases and the infrastructure is provided will eventually help achieve global broadband coverage and end the disparity of internet access to the remaining half of world’s population.