The Small Cell Forum recently released numbers showing that more than 10 million small cells have shipped to date. Analyst Stefan Pongratz of Dell’Oro Group said that small cells saw a “modest ramp” at the end of last year and are expected to gain further momentum this year, doubling to become about 2% of overall Radio Access Network spending.
What are the top factors to consider for the small cells business case? RCR Wireless News explored the small cell market in a recent special report on small cells and testing. The Small Cell Forum has documented the small cells business case as part of its release program, examining the potential arguments for deployments in urban, residential, and rural and remote applications. The following are the top five factors that need to be considered in small cell deployment:
Ease of deployment. According to the most recent numbers from Mobile Experts, more than 75 mobile operators around the world are already using small cells – and the most popular deployment approaches are in enterprise or public buildings (70 operators) and in the home (47 operators). Those two options offer an easier road in terms of solving power and backhaul issues, which are among the commonly cited barriers to small cell deployment. Compared to the urban, public small cell use case, where both power and backhaul may need to be run to a site – requiring a significant investment of time and money – indoor small cells offer an environment in which the in-building location helps to mitigate interference from neighboring macros.
The enterprise deployment of small cells appears to be picking up. Small cell provider ip.access is partnering with Amdocs to roll out enterprise small cells on a large-scale basis, while SpiderCloud announced in December that it will supply 4G small cell systems to Verizon Wireless business customers.
Return on investment. Enterprise small cell deployments offer the possibility of a business either taking on some of the costs, such as power and backhaul, or potentially even paying for the equipment itself, depending on the arrangement. In-home deployments offer similar benefits and has been one of the first areas where small cells have been deployed in significant numbers – albeit typically operating from user white-lists.
ROI considerations also include the potential services and benefits that are enabled by a small cell deployment. Voice and data coverage are the obvious answers there, with the aim of reducing churn – but Signals Research has also noted that home-zone pricing and macro cellular traffic offload are also benefits to be considered. Signals’ white paper on the femtocell business case can be read here.
Impact to the overall network. Interference and interoperability are two of the major factors that can influence how well a small cell works in a live network, and the industry is still working out how to deal with those in a cost-effective way. ETSI and the Small Cell Forum have hosted an ongoing series of small cell plugfests, and the test results show that while some features and functions are working quite well in a multivendor environment, others still have bugs to be worked out.
Interference can be a major issue to address in small cell deployments, and is one of the reasons that outdoor urban small cell deployment is still considered by many to be in its infancy. Handovers are a critical piece of the puzzle, and can get particularly tricky when dealing with cells with comparatively small radii – handovers always offer an opportunity for disruption, and ping-ponging among cells is undesirable.
“This is one of the most frequent questions that we get – how does the handoff happen? Is it happening correctly? Is there some delay, or some problem with the handoff protocol?” said Vijay Kulkarni, CEO of GL Communications, which provides emulation for small cell testing purposes.
Timing of deployment. Mobile operators, particularly in the U.S., have spent the last few years putting most of their time and effort into their LTE networks, but the small cell marketplace has until recently been dominated by 3G offerings – perhaps one reason that the investment in small cells has been slower to ramp than initially expected.
“One of the drivers for small cells is to solve the capacity crunch, and as you build a well-provisioned LTE network, it adds a lot of capacity to the network, so it postpones that need for that 3G small cell,” noted Petter Blomberg of Ericsson.
Rethink Technology Research recently found that while operators increasingly do have a deployment roadmap for small cells, 35% of surveyed operators had built-in flexibility of six to 12 months in their plans, 32% stretched that to one to two years, and 5% said they could delay their deployments by up to three years if the conditions weren’t right.
Indoor vs. outdoor focus. Mike Schabel, VP of small cells for Alcatel-Lucent, said that in terms of the mix he sees between indoor and outdoor small cells, it’s roughly half and half on a global basis.
“Any one operator is generally focused on one first, then the other – largely driven by their customer base and where any problems are that they have. For example, if an operator has high bands, then they may not penetrate as well into deep buildings,” Schabel said.
“I think the outdoor small cell market feels more like an extension of what the industry knows how to do well, which is macro,” he said.
In general, “the indoors is a more naturally segregated environment,” said Josh Adelson, director of product marketing for small cell company Airvana. “Even if there are windows, it does provide some RF isolation and typically you have entrance ways in a few known places, so you can deal with that.”
Overall, the expectations for small cells continue to be rosy, as operators seek to deepen their LTE capacity and fill in coverage gaps both indoor and out.
“The trend is positive,” said Alan Law, chairman of the Small Cell Forum. “I’d say there’s more and more confidence in the market, and I’d say that there is strong appreciation by the operators that small cells are functioned to drive significant capacity in their networks.”
