The Rise of Tower Sharing in Africa

Cell-Tower-Ghana-Increasingly-mobile-network-operators-all-over-Africa-are-looking-at-sharing-wireless-towers-to-save-on-microwave-radio-and-other-infrastructure-costs-06-Dec-2012-Aviat-blog

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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LTE Backhaul: The View from Africa

Telecom-tower-Johannesburg-South-Africa-enabling-LTE-backhaul

Telecom Tower, Johannesburg, South Africa. Photo credit: Marc_Smith / Foter / CC BY

LTE has been moving more and more to the forefront in mobile cellular networks around the world. Africa, and particularly the Republic of South Africa, is the latest hotbed of LTE rollouts, with the leading country operators of Vodacom, MTN and Cell C coming online since late in 2012. In conjunction with these LTE access rollouts, our technical marketing manager in the region, Mr. Siphiwe Nelwamondo, has been authoring a series of columns on enabling LTE in a leading regional technology media Internet site, ITWeb Africa.

Naturally, his focus has been on backhaul. In the first installment of his series, Mr. Nelwamondo looked closely at the backhaul requirements of LTE. Chief among these requirements are speed, Quality of Service (QoS) and capacity. He concluded that it is too early to close the book on the requisite parameters for supporting LTE backhaul. Part two of the features, he examined the basis on which microwave provides the technical underpinnings for LTE backhaul—especially as related to capacity. More spectrum, better spectral efficiency and more effective throughput were Mr. Nelwamondo’s subpoints to increasing capacity.

Having more spectrum for microwave backhaul is always nice, but it’s a finite resource and other RF-based equipment from satellites to garage door openers is in competition for it. Bettering spectral efficiency may be accomplished by traditional methods such as ACM and might be increased through unproven-in-microwave techniques like MIMO. Throughput improvement has wide claims from the plausible low single digit percentage increases to the more speculative of upping capacity by nearly half-again. Data compression and suppression are discussed. The truth is LTE, while data-intensive, probably will not require drastic measures for backhaul capacity until at least the next stage of LTE-Advanced.

If indeed capacity increases are necessary in the LTE backhaul, number three and the most current piece of Mr. Nelwamondo’s contains additional information. Nothing is better than having something bigger than normal or having many of the standard model. As the analogy applies to LTE microwave backhaul, bigger or wider channels will increase capacity, of course. A larger hose sprays more water. Or if you have two or three or more hoses pumping in parallel that will also support comparatively more water volume. The same is true of multiple microwave channels.

However, the most truly and cost effective capacity hiking approach is proper network planning. Mr. Nelwamondo points out that in Africa—more than some places—mobile operators are involved in transitioning from TDM planning to IP planning. While TDM planning was dependent on finding the peak traffic requirement per link, IP planning allows the flexibility to anticipate a normalized rate of traffic with contingencies to “borrow” capacity from elsewhere in a backhaul ring network that is not currently being utilized. Along with several other IP-related features, this makes determining the capacity a lot more of a gray area. Some operators solve this by simply “over-dimensioning” by providing too much bandwidth for the actual data throughput needed, but most cannot afford to do this.

The fourth and final entry in Mr. Nelwamondo’s series will appear soon on other LTE backhaul considerations of which you may not have thought. Sign up below to be notified when it is available. [contact-form-7 404 "Not Found"]

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Low Latency Microwave Serves Many Purposes

Trevor Burchell, VP of Europe, Africa, Middle East Sales and Services.

Trevor Burchell, Aviat VP of Middle East, Africa and Europe Sales and Services.

In a recent interview, Trevor Burchell, Aviat Networks VP for Middle East, Africa and Europe sales and services, commented on the recent trend of low latency microwave networks. Though increasingly found in the telecom infrastructure of financial institutions, low latency microwave is not limited to these applications, he says. Burchell sees its applicability in uses as diverse as health care, government and utilities.

Some considerations are common to all microwave networks—low latency and all others, according to Burchell. Proper path planning and network engineering must be executed in order to have the most fully functional wireless point-to-point  backhaul possible, he says.

In general, Burchell sees microwave as the best choice where telecommunications have to be rolled out quickly and cost effectively. There are many other points to consider. The complete interview is available online in Engineering News.

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4G Upgrade Path Drives Backhaul Migration in Kenya

Safaricom's Internet Broadband Dongle (with SI...

Burgeoning WiMAX and 3G data traffic from subscriber devices such as Safaricom’s Internet Broadband Dongle (with SIM Card) are driving the mobile operator to migrate from TDM to hybrid microwave backhaul. (Photo credit: whiteafrican via Flickr)

Migrating legacy mobile backhaul networks that were designed for TDM traffic to add support for high-speed Ethernet data for 3G and 4G mobile technologies is one of the biggest challenges for operators worldwide. Each case is unique and poses its own quirks and potential pitfalls. Mobile operators must juggle new technologies, cost pressures and the need to maintain existing services or risk driving customers to the competition.

For Safaricom, the leading mobile operator in Kenya and one of largest in all Africa, the case involved preserving its E1 capacity for voice calls and simultaneously adding Ethernet/IP bandwidth for burgeoning 3G and WiMAX data traffic. As many mobile operators have done in the past, Safaricom built its network over time. Many parts of the network are still legacy 2G TDM technology. However, things are changing rapidly, with 3G subscriber numbers up 85 percent in 2011 year over year.

Many of these subscribers are consuming ever-increasing amounts of data bandwidth. Safaricom’s TDM based backhaul, making use of Ethernet-to-E1 converters, is finding it hard to keep up with demand. To help resolve the situation, the operator called on Aviat Networks, one of its incumbent solution providers. Using its market leading hybrid radio solution, the modular Eclipse microwave networking platform, Aviat Networks enabled Safaricom to add IP data capacity as necessary while keeping E1 capacity for voice calls.

In addition, the stage has been set for Safaricom to make the eventual migration to all-IP backhaul. With the modular Eclipse platform, it can transition on its own schedule. For more information, read the complete Safaricom case study in the frame below or download the PDF:

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Mobile Network Modernization in Africa

Africa Mobile Penetration Rates

Total African Mobile Connections and Penetration Rate (million, percentage penetration). Source GSMA Africa Mobile Observatory 2011

Throughout Africa a wind of change is blowing as mobile network operators ponder, and in many cases implement, a wave of network modernization. The trigger for this is multi-faceted. Booming subscriber growth, introduction of new data services and arrival of new undersea fiber optic cable links are combining to strain existing network infrastructure to the breaking point.

Booming Mobile Subscriber Growth
According to the GSMA , as of September 2011 Africa has overtaken Latin America with 620m mobile connections, making it the second largest mobile market in the world after Asia-Pacific. The number of connections has more than doubled over the past four years, with growth expected to continue at the fastest rate of all global regions over the next four years.

First Voice, Now Increasingly Data
Most networks across Africa were built many years ago to serve the initial rollout of 2G/GSM mobile networks that were designed to provide basic voice services. Many operators have since introduced data services using EDGE, 3G WCDMA, and, more recently 3G HSPA, putting an incredible strain on these networks. These data services can be vital for the operator, as they are often supporting premium, prepaid subscribers or new fixed line data services being offered for small and medium-size businesses.

One example of network modernization in action is in East Africa, where a mobile network operator saw subscriber numbers increase 9 percent in 2011, with 3G customers increasing more than 85 percent. This operator was also offering fixed data services to private and corporate customers through the deployment of WiMAX base stations collocated with the existing mobile sites. All this new data traffic was growing exponentially and fast outstripping the legacy backhaul network capacity. The operator also had to ensure that existing voice traffic was protected.

Priorities Driving Network Upgrades
Today, several priorities are driving network operators to upgrade their networks including the need for:

  • Increased capacity
  • More efficient use of backhaul spectrum resources
  • Support for increasing volume of Ethernet/IP-based traffic
  • Network Simplification
  • Reduction in Capital and Operational Expenses

These five priorities are closely interrelated. For more details, download the complete article.

Stuart D. Little
Director Corporate Marketing
Aviat Networks

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