By Morgan Kurk…
As 2014 rolls in, the continued implementation of LTE and the ongoing data boom mean that for most wireless operators, modernizing and enhancing the capacity of their networks with the most efficient architectures and equipment possible will be a major focus. Increasing network capacity intensifies the focus on metrocells and indoor coverage. With this in mind, let’s take a look at what will be the biggest and most important wireless infrastructure trends of the next 12 months.
The newest focus in the wireless industry globally is LTE. GSMA Intelligence expects the number of LTE connections worldwide to pass one billion by 2017. As the world’s population begins to access the Internet at the speeds available on LTE, there will be no turning back. Operators will be forced to quickly update and fortify their networks. Operators must ensure that their network evolution is well architected and accurately implemented to provide the exceptional experience that is 4G LTE to their customers.
Prior generation systems such as GSM were designed in a voice-only era and have aged as much as 20 years. As such they are not very efficient when delivering data. Forward-looking operators who are not deploying LTE yet will use 2014 to update their network equipment and architecture, preparing their networks for the arrival of 4G. Central to this preparation will be shifting to a remote radio architecture that will put much of the radio function on the top of the tower. This design replaces traditional coaxial runs with hybrid fiber optic and power cable, which is used to connect the remote radio heads at the tower top to the baseband units that remain at ground level. Advanced multiband and multi-technology capable antennas will be connected to the radio heads, improving performance and increasing power efficiency while servicing 2G, 3G and 4G simultaneously.
Implementing such technologies to modernize the wireless network is a sound investment for improving operating expense in all of its forms, from energy efficiency to maintenance, while improving reliability and preparing for an LTE rollout.
Bigger focus on small cells
Wireless operators will continue to increase their focus on “small cells” in 2014. This term is defined as everything that is not the macro cell. We further break it down into the metro (or micro) and indoor layers of the network. These layers are designed to significantly increase capacity by moving closer to the mobile device, working in conjunction with rather than in competition to sector splitting on the macro layer. The indoor layer of small cells may include pico and femto radios, distributed antenna systems and low power remote radio heads, while the metro layer is made up of microcells and medium power remote radio heads. Operators will place more focus in 2014 on how to most efficiently deploy and integrate small cells in more buildings and urban centers where increased use is dramatically slowing the network. With the proliferation of data intensive devices like smartphones and tablets, focusing on how to offload traffic from the macro site will become increasingly important in 2014.
Inside becomes the new outside
The increased focus on indoor coverage may ultimately compel operators to trial a whole new approach to their network, which I call the “inside-out approach.” Historically, operators deployed wide area macro sites and eventually worked their way indoors on an ad-hoc basis, starting with the most heavily used areas such as airports and arenas. With the recognition that more than 70 percent of mobile sessions occur indoors, operators will take a fresh look at how best to architect their networks. The inside-out approach will likely start in the heavy traffic areas indoors, where the exception rather than the rule is being on the macro network. The first trials of using indoor sites to cover outdoor areas as part of an inside-out architecture could occur in a large city in 2014.
Morgan Kurk is senior vice president, Wireless, CommScope.
The future of small cells, at least those with remote radio heads, will depend on a new networking concept known as “fronthaul,” according to a white paper by iGR. In 2014, the lion’s share of small cells will use remote radio heads, iGR said, which will be connected, or “fronthauled,” via fiber-optics to baseband units located in a central location that are then backhauled to the telephone network.
“The importance of providing a quality fronthaul/backhaul connection to a small cell cannot be overemphasized. The success, or failure, of the het‐net and small cell architecture depends on the operator’s ability to deploy fronthaul and backhaul that is appropriate to both the immediate data demand and what is forecasted,” according to iGR.
The move to a fronthaul-type architecture should be executed as a carrier deploys LTE, Iain Gillott, principal of iGR, told DAS Bulletin, but not every site is a candidate for fronthaul.
“There is a limit to how far the baseband can be away from the radio,” he said. “There can also be logistical reasons for avoiding fronthaul architecture.”
Fronthauling the baseband, which represents the virtualization of the radio access network, will save carriers millions of dollars in OpEx and CapEx globally, Gillott said.
“The cost to implement this architecture is not insignificant, but when you are putting in LTE you have a ton of work to do anyway. Especially with small cells, why not deploy fronthaul and get the benefits?” he said.
Fronthaul Fuels Deployment of SK Telecom Small Cell Network
The white paper goes on to highlight a system deployed by South Korea’s SK Telecom, which used SOLiD networking equipment and existing fiber to fronthaul an LTE small cell system.
Across South Korea, which is a small densely populated country, SK Telecom deployed 12,000 base station nodes and 80,000 remote radio heads in one year, using SOLiD’s fronthaul architecture. Since then the network has grown to 200,000 remote radio heads.
“SK Telecom is widely recognized as an innovator using the latest wireless technology. Because the South Korean market is in the forefront of technology it sheds some light on how the U.S. market is going to approach new technologies, such as small cells and RRH in order to fill in the holes and achieve network densification,” Mike Collado, SOLiD spokesman.
SK Telecom and SOLiD’s architecture used the existing legacy transport system complemented by two fiber rings for the LTE deployment. LTE remote radio heads were connected to SOLiD’s Infinity ACCESS RT and, in this deployment, the RRHs acted as small cells that were mounted on towers.
A single fiber ring simultaneously supports 2G/3G, 4G and Wi-Fi traffic: CPRI/OBSAI is used to support LTE traffic, Ethernet supports Wi-Fi, and E1/T1 is used for the legacy 2G/3G network. Up to 30 remote radio heads can be supported per base station node.
The base station nodes were located in a central office terminal. The transport system then provided connectivity back to the base station controller/radio network controller (BSC/RNC) and to the IP core, maximizing the re-use of existing fiber infrastructure.
SK Telecom deployed its initial network in about 12 month, which was half of the expected time. Operating expenses were reduced 5 percent in the first year and by 2014, SK Telecom expects 50 percent savings through reduced building lease and rental costs, reduced utilities, reduced maintenance and fewer truck rolls.
A copy of the iGR white paper can be downloaded directly from iGR’s website.
A five-mile test of rural small-cell wireless system has been completed by CoverageCo, a wholesale service provider. The Vermont Telecommunications Authority (VTA) has provided funding for CoverageCo to build nearly 90 miles of wholesale cell service in a number of the state-designated target corridors where little or no service currently exists.
VTA is purchasing the necessary equipment, which CoverageCo will lease. The company has expressed the intention to invest its own capital in building 125 additional service miles beyond the 90-mile VTA project.
The test is a standard process before commercially launching a new network, and the technology passed for voice, text and data.
CoverageCo works with existing cellular providers through industry-standard roaming agreements, and its network offers compatibility with both the major technologies, CDMA and GSM, in use today through existing consumer phones.
An alternative to the traditional model of cell towers, the CoverageCo net and is made up of micro sites, unobtrusive, low-power base stations mounted about a mile apart on utility poles already in place along roadways or other existing structures.
CoverageCo, which is a subsidiary of Vanu Inc. uses latest generation of Vanu products, the CompactRAN, which is a complete cellular base station in a sealed all-weather outdoor enclosure the size of a ream of paper. A software-defined radio that uses Internet Protocol, the CompactRAN is software upgradeable to future technologies can use an Internet connection for backhaul to the core network.
The next step is building additional service on this and other Corridors for commercial launch within the next two months. Expansion will continue throughout the year.
Mobile Experts has released a small-cell market forecast, which predicts more than 5 million metrocells to be shipped in 2017. The company predicts slow growth for residential femtocells at only 12 percent per year, based on weak shipment data during 2012. As mobile operators push hard for high-capacity small cells, faster growth will come from capacity upgrades.
The research company predicts that outdoor metrocells and indoor capacity nodes will overtake residential femtocell shipments in the 2016 time frame. More than 100,000 public small cells are already deployed in Korea and Japan. “The Asian market is stretching the femtocell into areas where small cells are handling capacity effectively for operators like KT, SKT and NTT DoCoMo. Other operators around the world will follow this example as the LTE macro rollout is completed and capacity tightens up in North America, China, Latin America, Europe and the Middle East,” explained Joe Madden, principal analyst at Mobile Experts. According to Madden, the bottom line is that small cells are 65 percent less expensive than macro base stations, for adding mobile capacity.
Eight different types of small cells, by architecture and by power level, are identified in the forecast. In this year’s analysis, Mobile Experts included low-power remote radio head units, multiband small cells, and carrier aggregation into the forecast, with 33 band combinations identified for interband CA. The report breaks down small-cell shipments by frequency band and identified 38 frequency bands for small-cell deployment.
The latest report from MRG examines how the development of small cells is providing solutions for last-mile backhaul. “Small Cells Provide New Opportunities in Last Mile Backhaul” addresses the changing nature of mobile networks and provides a comprehensive count of small cells (including femtocells) and last-mile backhaul.
MRG estimates there are as many as 11 backhaul mediums: five wireline technologies and six wireless technologies. Last-mile mediums include copper E1/T1 lines, Ethernet over copper, Ethernet over cable, fiber, and fiber using CRAN or distributed antennas. Wireless technologies include microwave, millimeter microwave, non-line-of-site radios, WiMAX, Wi-Fi and satellite.
The small-cell form factors forecasted include femtocells, enterprise femtocells, indoor picocells, outdoor metropolitan picocells and microcells. The information provided about each form factor includes new shipments, the retail value of each device, and the installed base. Last-mile backhaul for small-cell and macro base stations is presented in the report by access points shipped, last-mile CAPEX costs for mobile operators, installed base and total capacity. The report also features forecasts for 2011-2017, which are broken down by data for North America, Europe (Eastern and Western), Central and Latin America, Middle East and Africa, and the APAC.
In 2011, small cells only had about 3 percent of the capacity that macro base stations had. By 2017, with the prevalence of outdoor metropolitan picocells, small cells will have roughly 19 percent of the overall capacity of macro base stations.
Microwave radios are still the most popular last-mile backhaul medium, but by 2016, there will be more macro base stations connected by fiber than by microwave radios.