As one of the most anticipated network technologies, Voice over LTE (VoLTE) has been discussed by operators for years. The expectation was that deployments would start in 2013, but roll-outs in North America were delayed.
Operators have faced a series of issues that include poor voice quality and long call establishment times. Once these problems are solved, it is expected that VoLTE will allow operators to provide voice and data services using an integrated packet network. As the problems described show, the implementation of VoLTE presents challenges for the entire LTE ecosystem including microwave backhaul.
We have produced a white paper to describe some of the VoLTE requirements that must be met in order to overcome these technical challenges, which must encompass a flexible microwave backhaul as a key factor for a successful transition to all-packet voice and video VoLTE networks. A brief introduction to VoLTE is presented and then different VoLTE backhaul requirements are described with possible solutions.
Click here to download a white paper on this subject titled “VoLTE and the IP/MPLS Cell Site Evolution”.
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.
Technical Marketing Manager, South Africa
85 mobile operators were selected and surveyed globally, including a good cross-section from both developed and emerging markets. The respondents were screened to ensure that they all had a stake in microwave-specific backhaul: 93 percent had deployed microwave and the rest had plans to deploy it. In fact, 45 percent were categorized as heavy microwave users—those where more than 50 percent of their cell sites were served by microwave backhaul.
So we asked this select group, which consisted of mostly planners, engineers and strategy leaders, “What is the biggest challenge your company faces regarding the future development and deployment of microwave backhaul?”
The results were interesting in that “total cost of ownership” actually eclipsed “increasing capacity” as their biggest challenge, as shown in the pie chart of survey responses below.
Wireless backhaul operators, both mobile phone networks and others carrying dedicated traffic, face the constant issue of maximizing the functionality of their systems.
In the emerging markets around the world, the pressure can be most intense. Wireless network reliability, availability and capacity all need to be increased. Customer expectations are on the rise, and operators must take the appropriate steps to meet and exceed them.
In working with MTN Ghana, Aviat Networks recently completed an implementation to increase network visibility (i.e., intelligence) by close to one-third. Aviat’s professional services experts designed the mobile operator’s backhaul links for high capacity and resiliency. Using ProVision, Aviat’s leading network management software, MTN Ghana can now administer its wireless backhaul efficiently and effectively with a reduced level of manpower.
Because of need for higher capacities, the trend toward shorter link distances for mobile backhaul and declining product costs, 70/80GHz (i.e., E-band) solutions are gathering significant interest for mobile backhaul and enterprise access applications. However, because these frequencies are new to most people, there is little understanding of costs and other issues related to licensing the 70-80GHz spectrum.
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:
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:
These five priorities are closely interrelated. For more details, download the complete article.
Stuart D. Little
Director Corporate Marketing
Last year in August, Aviat Networks presented its argument for why fiber optics technology isn’t everything where backhaul of wireless networks is concerned. If anything, this point has only been reinforced by analyses and anecdotal stories showing that fiber can be overkill for the mobile backhaul requirements of LTE wireless. Plus, there is the simple truth that fiber cannot be deployed to every cell site due to financial and topological issues. That’s why microwave technology remains the world’s first choice for backhauling wireless networks. So let’s look at last year’s FierceWireless webinar slide presentation and refresh our memories.
These slides present the findings of an Ovum survey of North America’s largest backhaul players to understand their strategies regarding media types used to supply cell-site backhaul.
Ovum found that demand for wireless backhaul equipment in North America will continue to grow as mobile operators upgrade their networks to support higher-speed LTE networking technologies. The most common backhaul strategy for mobile operators in the region comprises leasing services over fiber combined with owning and operating microwave-based facilities. Microwave has a distinct advantage vis-a-vis leased services over the long-term due to the opex associated with leasing.
If you would like to see more, you may register for the on-demand replay of the full webinar. It will also present the latest trends and advancements in microwave transmission technology that support the evolution of mobile backhaul networks to all-IP.