By Brian Porter, American Tower
The network challenges facing mobile operators change over time. At the onset of digital cellular (PCS), carriers purchased spectrum and then focused on building their networks, deploying tens of thousands of cell sites. As subscriber rates rose and capacity constraints emerged, carriers secured additional spectrum and augmented existing sites to support both new technologies and increased subscriber bandwidth needs. In parallel, they deployed additional sites, splitting cells. This era of network deployment supported the 2G and initial 3G networks from rollout to a state of manageable growth. It lasted 12 years in the United States; from 1997 to 2009.
The challenges operators faced during this era were predictable and the carriers had the luxury of addressing major challenges one at time in a linear fashion as they arose.Then things changed quickly. Operators began offering aggressively priced data plans, LTE and new versions of HSPA provided significantly higher data rates, smartphone and tablet adoption rose rapidly, and subscribers consumed data at a faster rate than anticipated. Traffic and congestion on the network increased rapidly, and the carriers faced two major challenges simultaneously; both of which required significant planning, time and capital to resolve. First, they had to address backhaul demand in a more creative way other than continuing to order expensive T1s/ E1s by the thousands from the incumbent providers or face a large increase in transport costs. Secondly, the operators had to find a macro network offload solution to separately support in-building users to alleviate capacity constraints on nearby outdoor cell sites.
This is where we were a year or two ago with some carriers in the United States and the direction things are headed currently with others. Several major carriers have all but solved the backhaul problem in the urban areas with fiber-based solutions, and those that have not, plan to do so this year and next. Additionally, most operators have extensive Distributed Antenna System (DAS) rollout plans.Why is this pertinent to Latin American operators? Because the market is evolving rapidly and these same two issues are now arising in the region. The time has arrived for the operators to define and implement their 3G backhaul strategies and develop data offload strategies. American Tower is working with several operators to help with both of these initiatives. The company is leveraging its experience as the leading shared wireless infrastructure provider in the region to implement approaches that enable or accelerate the delivery of high speed backhaul to its own cell sites and customers’ cell sites. The availability of competitively priced capacity at the sites will help customers provide a more profitable and robust service while making the sites more attractive to additional tenants. Further, at the request of its customers, American Tower is developing a Latin American DAS Program to support the increased demand and need for a neutral-host DAS operator in the market. The remainder of this article will focus on backhaul needs and solutions. A later article will provide details on the Latin American DAS market.
Backhaul- Market and Options
Latin American operators, just as their U.S. counterparts, prefer a fiber-based, managed service purchasing 20-50 Mbps per site. Future bandwidth forecasts range from 100-150 Mbps eventually reaching 300 Mbps per site as the LTE market matures. As in the U.S., several major carriers have initiated extensive programs to obtain fiber-based services at a majority of their urban cell sites, but others have not and need to quickly as it takes time to plan and deploy these networks.
The primary challenge many operators face is based on one simple fact: Although their current 2G backhaul networks, dominated by large scale, multi-hop microwave links, were adequate to support voice-centric 2G services, they were not designed to support data-centric 3G and 4G services. Microwave may still be the logical choice to carry 2G traffic and 3G network traffic in rural areas where capacity requirements are lighter, but in metropolitan areas, fiber remains the logical long-term solution if available.
To prepare for this bandwidth onslaught, operators need to develop plans to inject more fiber into their existing networks or build parallel 3G backhaul networks.Operators have several options at their disposal. They can engage partners to purchase lit fiber service at on-net or near-net sites and aggregate microwave traffic at these locations. This approach is a step in the right direction and a viable interim solution as operators work to obtain fiber at additional 3G sites. Another choice is to work with partners to finance new fiber deployments to additional cell sites and then purchase lit services.
This route can greatly increase an operator’s fiber density in a market. A third option is to build or lease dark fiber at the sites. This option can be a very cost-effective long-term solution as bandwidth needs rise and carriers are willing to take on the responsibility for operating an internal backhaul network. Other tools exist including installing Optical Wireless Broadband (OWB) links. OWB technology, formally known as free space optics, is maturing rapidly and can be deployed quickly and cost effectively.
In summary, next-generation networks will not behave like their predecessors. People are using their eyes more than their ears to communicate as video, photos, text and multimedia messages, as well as web browsing and email access, become primary device features and preferred communications options. To address this increased network traffic, operators need to consider securing fiber-based services at as many cell sites as possible to avoid capacity problems in their networks and lower their cost of bandwidth. Given the resources, planning and time it takes to address long-term backhaul needs and other network issues, operators should engage partners and suppliers to assist with addressing this critical need.
