CTIA: Nokia Siemens pours out Liquid Radio

At CTIA Wireless, Nokia Siemens Networks (NYSE:NOK, NYSE:SI) today officially unveiled the new Liquid Radio architecture it gave Connected Planet a sneak preview of at Mobile World Congress last month (CP: NSN, TI countering Alcatel-Lucent’s lightRadio with Liquid Radio). The new modular architecture builds on advancements its already made in its Flexi multi-radio line, incorporating adaptive array integrated heads to create a “liquid network”, which can distribute capacity as needed from cell to cell.

NSN executives said that the new architecture reflects the new reality of mobile networks and their ever-increasing peak capacity demands. Scaling networks so every individual cell site can meet the worst-case network congestion scenario is quickly becoming infeasible. “Liquids are unconstrained, streaming to fill any gap or space,” said head of NSN Network Systems product management Thorsten Robrecht in a statement. “In the same way, our Liquid Radio architecture removes the constraints of traditional mobile broadband networks to address the ‘ebb and flow’ of traffic created by users’ movements across the network.”

The architecture has three core components:

- Baseband pooling allows an operator to separate baseband processing from the cell site, creating a ‘cloud’ radio access network which dynamically allocates resources to whatever cell site needs it. Base station ‘hotels’ has been a concept in the industry for some time, but rather than simply separate the base station from the cell by location, the pooled architecture uncouples the base station from a specific cell entirely, created a shared pool of baseband processing resources. Stacking current Flexi Multiradio baseband units, NSN can create a baseband pool with 10 Gb/s of radio capacity, which can be allocated to hundreds of individual cells.
- A modular adaptive radio antenna integrated with the radio power amplifier becomes the only element deployed at the cell site. Each antenna has its own power amplifier, allowing antennas to be combined in active arrays. Those arrays support beamforming, which directs signals at specific users. Beamforming can increase signal gain by as much as 65%, NSN said, and will be a critical part of multi-layered heterogeneous networks and future coordinated multipoint (COMP) techniques in long-term evolution (LTE)-Advanced.
- Self-organizing network (SON) technologies will form the foundation of the new Liquid Radio management system, which will allow operators to meld multiple networks at the same frequencies and different cell sizes into a unified whole.

Combined, those three elements can build a network where capacity travels fluidly from site to site as users travel from cell to cell bringing their bandwidth demands with them, said Chris Ebert, head of 4G strategic marketing for NSN in North America. The new integrated antenna technology will allow operators to maximize the bandwidth each customer receives, while giving them the building blocks for building cells of different sizes on a common infrastructure platform, he said. The SON management system will tie all of those disparate cells together, allowing the network to dynamically decide the best path for a data payload, obviating the macro-cellular topology we know today, he concluded.

“We believe we’re heading to a point where we need to support 1 GB per user per day,” Ebert said. “In aggregate, that point might be four, five, six years ahead, but for the high-end user we’ll start seeing that kind of consumption in the next few years.” Dealing with those extraordinary data demands will require the industry to use every trick in the book to manage traffic and ever-increasing connection speeds without simply piling up capacity on every cell site, Ebert said. “You must have the ability to allocate capacity where it’s needed and when it’s needed.”

Alcatel-Lucent (NYSE:ALU) was the first operator to introduce a new modular architecture, announcing lightRadio just before Mobile World Congress in February (CP: Alcatel-Lucent’s new building block architecture does away with the base station and Freescale shrinks the base station down to a chip). Though the two architectures share a lot of the same conceptual design there are some key differences. Liquid Radio’s biggest distinction is that it is built on technology NSN offers commercially today, said Kai Sahala, head of mobile broadband marketing at NSN.

While ALU is launching a new baseband architecture using Freescale’s new system-on-a-chip (SoC) designs from Freescale, NSN has already using its second generation of SoC architectures from Texas Instruments (NYSE:TXN), Sahala said. Since NSN debuted its Multiradio platform in 2009 (CP: NSN releases multi-radio base station), it has been able to support baseband pooling configurations and the recent launch of its SingleRAN platform (CP: NSN prepping product line for LTE-Advanced) builds upon those capabilities by adding unprecedented levels of capacity to the baseband unit, Sahala said. The software defined radio architecture in those products allows an operator to designate whatever resources it chooses to a any given radio technology it, Sahala said.

From there it would be a simple step to remove the base stations itself from the site and pool them together at a central location, Sahala said. Operators simply chose not to do so as they’re still largely comfortable with their current dedicated base station deployments, Sahala said, but that’s starting to change. Operators such as China Mobile are exploring cloud RAN architectures, and NSN believes its ready to meet their goals with its current generation of equipment, Sahala said.

“We’ve been doing this for a while,” Sahala said. “It’s really at the heart of the Flexi architecture.”

On the integrated antenna front, Alcatel-Lucent may have the edge. ALU’s Cube radio antenna is the size of Rubik’s Cube and extremely low power—each radio consuming only 2 watts. The Cubes are intended to be modular stacked in arrays ranging in size from two to 32 cubes to form cells the size of femtos all the way up to full-fledged macro cell. NSN’s Flexi Multiradio Antenna System may beat the Cube to market—its’ already in trials but is scheduled for commercial availability later this year—but it’s still fairly large, intended for towers and building tops in a macro-cellular deployment. NSN, however, is developing the next generation of the antenna today, a highly miniaturized modular antenna called Race that will measure 20 cm on its longest axis, Sahala said.

Ericsson (NASDAQ:ERIC) and Samsung have both said they are both new RAN architectures for commercial release, though they have shared fewer details on their plans than NSN or Alcatel-Lucent. Ericsson, however, unveiled its new integrated antenna, AIR at Mobile World Congress (CP: Ericsson introducing new compact radio head)