Todd Mersch, Director of Software and Solutions at Radisys, is seeing LTE small cell technology becoming deployed on a wider scale. He reports back some of the key learning points from real world field experience, shares which small cell roadmap features are most sought after and believes the number of small cell vendors is likely to continue to increase.
LTE (Long Term Evolution) has undoubtedly won the battle to become the world's 4th Generation radio access technology. It promises speeds of 100's of Mbit/s and includes many features to increase resilience, spectral efficiency and network performance. Small cells have been designed in from the outset, and will be a critical component providing the high speeds and capacity foreseen.
The first LTE small cells were developed independently from 3G products, and we have seen a number of new market entrants who had little or no involvement with earlier 3G femtocells. Chipset vendors such as Broadcom, TI, Fresscale and Cavium have been making great headway. Leading small cell vendors have included LTE in their roadmaps, but are cautious about bringing products to market too early while there remains strong demand for 3G.
The LTE system architecture differs from 3G, without mandating a small cell gateway. This puts more pressure on the core network, with every inter cell handover being handled directly by the core network. Some believe that for larger deployments, especially where indoor/residential is involved, a gateway will be required.
For some insight into what operators are thinking, I attended and reported on the Operator Mindshare session at LTE World Summit 2012, followed by the main LTE event itself.
We also looked at which vendors are developing LTE small cells.
One of the great things about GSM and 3G was the common set of frequency bands adopted worldwide. While there were a few exceptions, you'd find 2G GSM at 900 and/or 1800MHz with 3G at 2100MHz in almost every country. The US/Canada operated at 1900MHz. This meant that the industry could build and ship the same models of phones that worked everywhere, bringing huge benefits to the entire supply chain resulting in reduced costs, complexity and time to market.
However, the multiple variants of the iPhone 5 indicate a disturbing trend ahead due to fragmentation in LTE implementations.
The growing takeup of LTE, the new 4G radio technology, brings a major opportunity for a range of small cells. Last year saw major releases from both software and hardware components vendors, but there still seem to be relatively few generally available products today – will this change soon after forthcoming announcements made at Mobile World Congress?
There are so many different spectrum options for LTE (more than 50 are already standardized) combined with a choice of FDD and TDD modes. This is likely to lead to a two tier market for smartphones and mobile devices, but what will it mean for small cell vendors?
There is a lot of industry momentum building up for LTE femtocells. Much of this is from the vendor community, who have invested to create the chipsets and technology software platforms which enable it. For example, picoChip have already developed and proven an LTE femtocell prototype last year using the emerging standards.