Standalone cellular small cells had a slower ramp up than the initial industry hype indicated, but the technology is starting to gain momentum that is expected to continue. RCR Wireless News explored the small cell testing arena in a recent special report and webinar, and out of the related interviews has summarized some of the current small cell market trends that are shaping the ecosystem. These include:
• The rise of the enterprise small cell. Initially deployed for coverage extensions in residences, small cells usage is beginning to ramp up in enterprise environments. AT&T recently announced its Small Site solution for businesses, which can either be installed as Wi-Fi only or as a combination of Wi-Fi and LTE. Small cell provider ip.access is partnering with Amdocs to roll out enterprise small cells on a large-scale basis, and SpiderCloud Wireless will be supplying 4G small cell systems to Verizon Wireless business customers; Cisco is also reselling SpiderCloud’s small cells, which will be used by Vodafone to offer small cell enterprise solutions. The most recent market report commissioned by the Small Cell Forum puts the overall small cell market at 10.2 million units shipped, and predicts that most of the small cell growth between now and 2019 will come from the enterprise space.
• Continued progress in multitechnology, multiband support. A few of the recent signs of momentum include: Galtronics, which supplies antennas for SpiderCloud’s small cells, is adding new quad-band antennas for DAS and small cell applications, and Alcaltel-Lucent recently expanded its outdoor small cell lines with a new, particularly compact line of metro cells that support LTE for up to 200 users (60 MHz capacity), with a Wi-Fi option. It will be used in deployments with JCDecaux, which has a partnership with Vodafone to deploy small cells in street furniture. Mike Schabel, VP of small cells for Alcatel-Lucent, said the inclusion of Wi-Fi as a feature gives operators the potential to leverage Wi-Fi in deals with cities that want to expand public Wi-Fi offerings while smoothing the path for cellular small cell deployments – which can definitely run into site acquisition, zoning and placement issues.
• Management and interoperability remain challenges. Many consider Self-Optimizing Networks to be in their early days, and the SON standard is still evolving. ETSI plugfests have shown that there are still kinks being worked out. Two of the most basic aspects of SON are Physical Cell Identification and Automatic Neighbor Relations – essentially the abilities of a site to identify itself to the network and to determine the identity of neighboring cells and what its relationship to them should be.
“What you see right now is very simple SON, where you have ANR and that kind of thing going on,” said Jim Zik, product manager for the RF solutions group at PCTel. “I’ve not seen a lot of very complicated activity in SON because of the interoperability issues.”
The Next Generation Mobile Alliance’s Work Stream 2 document on SON best practices noted several potential areas where interoperability is key – for example, handover timescales can differ between vendor equipment. If handover configuration updates are triggered for one vendor’s equipment, that can reduce the opportunity for updates by a second vendor, leading to uneven levels of issues depending on the direction of the handoff; or it can mean that small cells from one vendor might make multiple adjustments in the same amount of time that another vendor’s equipment makes only one.
• Evolving small cell architectures. Some see a larger evolution at play for infrastructure beyond individual LTE-A features. Joe Madden, principal analyst for Mobile Experts, said in a blog post that rather than the much-vaunted “heterogeneous network” approach of small cells, macro sites, DAS and Wi-Fi, he believes that, particularly for in-building coverage, connectivity systems are converging. “In-building mobile solutions are migrating from DAS to IP-based networks with a controller that can ‘route’ the traffic and perform the features of LTE-Advanced. DAS meets Cloud RAN,” he wrote.
Madden cited a number of vendors with approaches in this vein, including Ericsson’s Radio Dot; Huawei’s LampSite; Commscope and Axell Wireless’ dynamic DAS; and small cell vendors including SpiderCloud and Airvana. Some of those include Wi-Fi integration as well as cellular connectivity, as does ALU’s solution mentioned above.
“It’s remarkable that all of these players are converging on something that looks pretty similar. All of these roadmaps end up with an inexpensive system to be shared by three or four mobile operators,” Madden added. “All of them will eventually include Wi-Fi and Ethernet traffic. All of them lead to radio processing features that sound a lot like LTE-Advanced: combined cells, multi-user MIMO, and joint processing which basically offer improved performance and capacity.”
• Cost pressures. The industry is still figuring out how to deploy small cells at a price point that operators consider acceptable, but that account for the complexity of the radio frequency environment and maintaining quality of experience and continuity in interactions with the macro network and other small cells. Cari Shyiak, president of professional services for Goodman Networks, said that one of the biggest challenges of small cells is meeting the cost targets for what operators believe they should be paying while supporting the sometimes-complex demands of the design, installation and testing process.
“It’s not economical to do a dozen revisions in a build with three to four small cells,” Shyiak said. “What they’re willing to pay vs. the work required right now – it’s a mismatch, especially if you’re missing features like SON.”
