Todd Mersch, General Manager of Software and Solutions at Radisys, is well placed to provide a high level view of the state of Small Cell product development. He travels the globe talking with many different designers and operators about all types of Small Cell products. We caught up with him recently and asked him whether he sees most activity in 3G or LTE, how significant TD-LTE will become and what part the larger RAN vendors are playing in the Small Cell market today.
Where is Radisys seeing most Small Cell development activity?
Our business today is a 50/50 mix between bleeding edge new development and practical day-to-day engineering. We've been heavily involved with the LTE Small Cell rollout in South Korea, probably still the most advanced in the world. At the same time, we continue to refine and enhance our proven 3G Small Cell platform.
For 4G/LTE products generally, the industry is now at the stage of widening the diversity of suppliers. Korea has been a tremendous proving out ground for LTE and especially from the Small Cell perspective. Both SKT and KT have used products with embedded Radisys software, allowing us to refine and perfect the system based on real-world experience. SKT has deployed both enterprise and residential LTE small cells. KT has also used the technology to enable indoor cellular access for coffee shops and similar public venues. They are now working on a residential LTE Small Cell solution and moving onto outdoor urban LTE Small Cells.
Overall, the most sought after LTE-Advanced feature today is Carrier Aggregation. This can be designed into a Small Cell but requires extra hardware for the two RF front ends that transmit in parallel. I've not heard of anyone considering Carrier Aggregation using both a macrocell and Small Cell simultaneously at this stage.
Our 3G small cell business is busy with a lot of second sourcing activity. We continue to be chipset agnostic, working across all the leading Small Cell silicon platforms.We are also seeing a number of opportunities for 3G outside of the mobile operator space including aerospace and defence applications.
How are the larger traditional RAN vendors positioned for LTE Small Cells?
If you look at the larger basestation equipment vendors, they all have a full range of high capacity LTE basestations. None apart from Alcatel-Lucent have anything that addresses less than 64 concurrent users. Most would offer a single sector picocell for larger buildings to fit the high end of the market. I can't see how this could be commercially competitive for the large number of smaller buildings that require simpler solutions. It may be that they could resell other vendors Small Cell products as part of their portfolio rather than investing in their own.
How mature are TDD Small Cell products?
Commercial TD-LTE service is still relatively new when compared with FDD mode. China Mobile's TD-LTE commercial launch on December 18th, with plans for 100 million users by the end of 2014, is substantial and significant.
TD-LTE Small Cells are still in the early design cycle. Few existing Small Cell vendors have added TDD mode into their products. Nobody is combining both FDD/TDD into the same box today. However we do see some initial operator interest. For example, Intel and Radisys have worked with Korea Telecom to demonstrate combined FDD / TDD small cells which will be on display at Mobile World Congress this February.
One example of a TD-LTE Small Cell is Airspan's AirSynergy which embeds our software. With FDD, TDD, LTE-Advanced and wireless backhaul capabilities the Airspan AirSynergy based on our software is one of the most advanced small cell products on the market. Another is ZCom in China. We see China as having huge potential, both for their internal market as well as many others worldwide. There's also a potentially sizable opportunity for residential home gateways with embedded femtocells.
When would you expect Dual-Mode 3G/LTE products to appear?
LTE rollout has been most visible in North America and a few Asian countries including South Korea and Japan. Europe will follow, albeit more slowly. In the majority of networks, we can expect voice to remain on 3G for some time, using CSFB (Circuit Switched FallBack). So where voice coverage is still an issue, it still makes sense to deploy 3G or a dual mode 3G/LTE Small Cell rather than LTE only.
It's possible to design a dual mode 3G/LTE product today. You don't have to do the full integration initially, but in future could look to add more value by co-ordinating the RRM (Radio Resource Management) between both 3G and LTE. This could make policy driven decisions when working with dual-mode smartphones. There would also be some software optimisation where we use consolidated hardware rather than completely separate circuitry. This would include collapsing some of the protocols on the network/backhaul side. Overall, integrated hardware would bring down both cost and power consumption.
Several chip vendors are (or will soon be) providing multi-mode chipsets that handle both 3G and LTE, and I'd expect we would see commercial products based on these during 2014.