BY PETER WANYONYI
All across Nairobi and other large Kenyan – and other African – cities, ugliness abounds. It’s not the cities that are ugly, though: it’s the ubiquitous trenching. The African internet economy is booming: our broadband adoption growth rates are totally unrivalled around the world. There is massive repressed demand for broadband, and new capacities are snapped up as soon as the optical fibre cable is laid.
This has led to significant problems for telecom companies looking to lay new fibre cables around African cities: existing utility services, such as sewerage and water lines, must be identified and avoided – no easy task when, like in Nairobi, city utility maps are outdated and haven’t been updated in years; traffic control and rerouting is required every time trenching crosses roads, which severely inconveniences road users and makes traffic worse in already congested cities; and then there’s the considerable cost of surface restoration required after the fibre is laid. In many cases, the restored surface is inferior to the pre-trenching surface, and the municipal authorities eventually have to resurface that stretch of road at taxpayer expense. There are other issues as well – many times, trenching is not permitted because the area in question is historically significant, or has certain security sensitivities, and so on.
What is often overlooked in this scenario is the abundance of existing, reusable infrastructure. One option has already been used extensively: power lines and poles are sometimes put to use beyond just power distribution. This is a no-brainer where electricity connections are available. But Kenya does not have electricity in all towns – incredibly – and the power transmission utility is a monopoly that sometimes decides not to play ball, especially given it also is leasing out its own fibre network. This calls for innovation and imagination, and there’s no shortage of possibilities.
Begin with water pipes: even where there’s no electricity, one generally finds a decent water pipe network. Pretty much all towns in Kenya built before the last decade have a decent water-pipe network. The irony is that, in most cases, there’s no water in the pipes – or, when it does come, it is sporadic at best. This infrastructure is thus a wasted investment – it just sits there, unused most of the time, unable to pay for itself and wasting away. But there’s no reason why it cannot be used as a conduit for laying fibre cables into neighbourhoods and urban centres! In Kenyan towns, urban water pipe infrastructure reaches practically all planned residential areas and most informal ones. It also extends to commercial, educational, healthcare and industrial sites. Alongside the water pipe network is another network that is not an obvious choice at first: the waste water (sewage) pipe network. Once you get over the initial “yuck” moment, it quickly becomes obvious that the sewage network is seriously under-utilised. While the water pipe network could possibly have contamination issues when used to deploy fibre, the sewage network has no such issues.
Sewage pipes are generally non-person entry types, with a small diameter less than 750mm. Deploying fibre in these would require the use of autonomous robots, which exist and have been used for the same purpose in other countries (such as Australia). The robot crawls into the sewage pipe and installs the fibre cable inside a conduit which itself is contained in a protective sheath that is fixed to the top of the sewage pipe. To ensure only a minimal disruption to water flow capacity in the pipe, the installation is be limited to two or three such conduits per sewage pipe. The robot is guided to not use clamps across pipe joints. Access to the fibre is provided at designated junction boxes located close to sewage manholes, from which the fibre emerges. From that point, normal fibre to the home (FTTH) techniques are used to provide the final drop to end-user locations in homes and businesses – thus avoiding potential resistance to the methodology due to “yuck” sensitivities. This form of deployment is called hydro-trenching, and is gaining popularity in densely-populated cities where it is difficult to obtain trenching permits and where it is therefore expensive to attempt traditional trenching.
New infrastructure is prohibitively expensive. This high barrier to entry results in fibre deployments being so costly that only a few well-heeled companies can afford to deploy fibre. This, in turn, leads to very high broadband prices as those companies look to recoup their capital investments in fibre rollout. Some maintain those high costs even after recouping investments, because there just isn’t enough competition to force costs down. The result of all this has been very high internet and data costs in Kenya, with telco operators making a killing as data-hungry users pay through the nose for measly data bundles on networks with patchy coverage.
Reusing water pipe infrastructure – both fresh and sewage pipes – would make flood Kenyan cities with broadband coverage. Telco operators would also make use of these deployments for data and voice backhaul and to support microcells, dramatically improving data and voice quality of service in those cities. Instead of unsightly trenches all over African cities, hydro-trenching should be given a thought – it would give us faster, cheaper broadband rollout than the current model.
