"Backhaul (telecommunications)" posts

The Rise of Tower Sharing in Africa

• December 6, 2013
• Africa, Aviat Networks, Backhaul (telecommunications), Cell site, Ghana, infrastructure, Mobile network operator, network operators, South Africa

Cell tower, Ghana. Photo credit: aripeskoe2 / Foter.com / CC BY-NC-SA

A growing telecommunications trend in South Africa and other emerging markets across the African continent is the move to cell tower sharing. There are many reasons for this, but the need to reduce capital expenditure (capex) on towers and other infrastructure and retarget spending toward network development, customer acquisition and retention and need to accommodate growing mobile data traffic levels have forced the issue.

The trend toward independent ownership of telecommunications infrastructure such as tower sites, with leasing arrangements for multiple operators on each tower, closely mirrors moves in mature telecommunications markets around the globe, including the U.S. and Europe, as well as other big emerging markets such as India and the Middle East.

Tower sharing prevalent
While there is some reluctance by industry incumbents to offload tower infrastructure because they fear losing market share and network coverage, the tower-sharing model is still becoming more prevalent. This is particularly evident in markets where there are new players trying to penetrate the market, as well as in countries where coverage in rural, sparsely populated areas is needed to drive growth. Other important factors, such as the rising cost of power in South Africa, or unreliable power delivery in other parts of the continent have also helped to drive this trend.

Thus, the adoption of this model has gained significant momentum in Africa since 2008, with major mobile operators in Ghana, South Africa, Tanzania and Uganda striking deals to offload existing infrastructure to independent companies. These independent “tower operators” handle the operation and management of these towers, leasing space back on the towers to multiple network operators. This helps to reduce operating costs, improve efficiency and potentially boost an operator’s network coverage significantly and rapidly.

Smaller equipment requirements
To accommodate multiple network operators on a tower and cell site, smaller antennas are preferred, with additional requirements for smaller indoor equipment that draw less power. This configuration helps to decrease power consumption and cooling requirements resulting in more efficient use of diesel generators during times of power failure. However, having smaller antennas affects transmission power, capacity and efficiency. As such, mobile operators are turning to on-site solutions that offer all these benefits, but do not compromise on quality of service, capacity or data transmission speeds.

This also extends to the backhaul network, which often poses the most significant challenge for mobile network operators, especially as mobile networks continue to evolve from 2G and 3G to LTE. For example, as mobile networks continue to evolve, backhaul network architectures will need to change from simple point-to-point to more complex ring-based architectures. Operators that choose to share infrastructure will need on-site equipment that is capable of accommodating these changes, while still offering optimal transmit speeds and reduced operational costs.

Traditionally, most network operators also used optical fiber for their high-capacity fixed line core/trunking networks. However, as tower sharing becomes more prominent fewer operators are willing to spend the capital required to enable fixed-line backhaul from shared sites due to the associated costs. Therefore, more operators are turning to wireless backhaul as a suitable solution to transport data between the cell site and the core transport telephone network.

More capacity needed
As users demand more capacity on the access portion of the network, the core/trunking network also needs to sufficient capacity to be able to transport the aggregated traffic from all these sites. Many operators have turned to high-capacity trunking microwave systems to provide the required high capacity. These high-capacity trunking microwave systems have traditionally been installed indoors, usually in a standalone rack. They were also installed in a way that radio signal strength diminished significantly before reaching the antenna at the top of the tower, ,necessitating a bigger antenna to compensate. These all-indoor configurations also required big shelters and costly air conditioning.

Developing new technologies
In an effort to improve the efficiencies of mobile backhaul to meet modern demands, tower operators and their solution providers are reconfiguring these shared sites, and new technologies are being developed to solve these challenges.

For example, split-mount trunking solutions allow for up to four radio channels on a single microwave antenna, and lower costs associated with deploying and operating ultra-high capacity microwave links for increased capacity. Smaller and lighter antenna solutions can also be lifted and installed higher on towers more easily, which helps to decrease tower space and loading requirements, making these solutions less prone to wind damage. Moving radios from the shelter to the tower, next to the antenna, further reduces deployment and operational costs and simplifies antenna connections (e.g. eliminates inefficient, long waveguides; costly unreliable pressurization/dehydration systems). In these cases, smaller shelters or cabinets can be used, which decrease air-conditioning requirements even further.

However, regardless of how tower operators are able to reduce costs and improve efficiencies, the trend of this form of infrastructure sharing is set to continue, which will help to drive increased competitiveness in mobile markets across Africa. This will have a positive impact on the prices end-users pay for mobile data and voice services, and will help to accelerate the availability of connectivity across the continent.

Siphiwe Nelwamondo
Technical Marketing Manager, South Africa
Aviat Networks

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