Sivers and Ampleon partner in hope of an open 5G BTS chip market

One of the great hopes for 5G is that it will usher in a wider, more open ecosystem of chip and base station makers, which will boost innovation and competition, and lower the cost of 5G deployment. The hopes rest on the extensive work being done on open interfaces and frameworks for next generation base stations, especially virtualized ones; and on the presumption that 5G will, over time, become very dense. That means it will rely far more heavily than 4G on small cells, a nascent sector in which there are lower barriers to entry – in terms of cost or powerful incumbents – for new entrants.

Independent small cell vendors like Parallel Wireless are already highly active in open RAN initiatives like Telecom Infra Project (TIP). Such vendors will generally want to use a merchant chip solution for their small base stations, rather than incur the cost and time to market of an inhouse development. A general shift towards a more WiFi-like ecosystem could provide significant opportunities for new or independent suppliers of baseband processors, access point system-on-chip (SoC) products and related components like FPGAs (field programmable gate arrays) and RF front ends. In time, these may succeed in moving up the chain into larger base stations, especially if backed by a large operator.

Some companies may move in on an expanded base station opportunity from other sectors. Intel is trying this via Cloud-RAN processors and also with its purchase of FPGA maker Altera. But smaller firms will often move more quickly. One example is a new joint development between Sivers IMA, a Swedish company which has been working on millimeter wave products, and RF power specialist Ampleon. The two companies will develop a 5G base station chip, initially for small cells and CPE (customer premises equipment), but in time targeting larger 5G hardware. The first offering should come to market by the end of this year.

Ampleon will invest SEK3.5m ($400,000) in the project, which will be led by Sivers IMA. Ampleon will then be the main sales channel, targeting Tier 1 OEMs, some of which already buy its existing RF power solutions for 4G and 5G base stations. The company said it sees an enhanced opportunity to move into other parts of the base station chip sector, mainly because of the demand from large vendors for advanced mmWave solutions. One of the distinguishing features of 5G is that it will run in high frequency spectrum bands as well as those below 6 GHz, boosting capacity and speeds. However, commercial wireless technology in these high bands is immature and entails engineering and cost challenges, so there is perceived to be more chance for innovation – not necessarily by the usual suspects – than in 5G in familiar spectrum.

Anders Storm, CEO of Sivers IMA, said that it has been working with Ampleon for a year already, mainly within a 5G consortium with Fujikura and other partners. This group has already produced a 28 GHz 5G transceiver chip, the TRX BF02, which is now ready for customer testing. It will be targeted at small cells, CPE and fixed wireless (the latter the main sector in which early 5G mmWave deployments are actually happening). The new Sivers/Ampleon project will build on that transceiver but expand it to a full 5G base station chip.

Sivers IMA has also been working in the most mature mmWave band in the wireless market, 60 GHz, in which the WiFi-like standard WiGig operates. It said its TRX BF01 WiGig chip is now ready for volume production and will initially target fixed wireless and mesh backhaul use cases. Sivers IMA claims this is the only chip available that can use the entire band from 57 GHz to 71 GHz, which has been made available for unlicensed use in the USA, UK and some other markets. This chip is being used by UK-based Cambridge Communication Systems (CCS) for its Metnet 60 GHz mmWave wireless platform, which is being used in a 5G testbed based in the UK city of Bath, supporting high speed small cell backhaul for applications such as virtual reality.

Sivers IMA has also been working, via its UK-based photonics unit CST Global, on a technology called analog Radio over Fiber (RoF), which aims to overcome the limitations of an all-digital approach in order to maximize the bandwidth capacity in mmWave. CST Global recently demonstrated the feasibility of 60 GHz RoF transmission at a 1,270nm wavelength. It says there is a natural synergy between fixed optical and mmWave technologies, easing spectrum constraints and allowing multiple coax cables to be replaced with a single fiber optic link for backhaul and fronthaul.

RoF will also enhance cell coverage, says the team. It supports very high bandwidth and also reduces latency because it does not require digital-to-analog conversion (DAC). These factors are the most critical ones for fronthaul.

The feasibility study was part of an EU Horizon 2020 research project called iBROW (innovative ultra-broadband ubiquitous wireless communications through terahertz transceivers), led by the University of Glasgow. The project’s aim is to develop an energy-efficient and compact ultra-broadband short-range wireless transceiver technology.

According to CST, it is now working with Sivers IMA to optimize a combined RoF, optical and mmWave solution targeted at 60 GHz and 5G. “Although more development work is needed, I see CST Global’s achievement as confirmation that we are on track to establish a commercially viable solution in this area,” said Storm.