May 13 2016
By Eric J. Black, PhD,
Pivotal Communications

With TIA 2016 just around the corner, I want to kick-off a discussion about the importance of millimeter wave frequencies in 5G systems. In future posts, I will talk about Pivotal Communications’ solution for mmWave in 5G. I will also post about challenges MIMO is encountering in the field.

Last year, the FCC proposed four new mmWave bands for 5G: the 28 GHz band (27.5-28.35 GHz), the 37 GHz band (37-38.6 GHz), the 39 GHz band (38.6-40 GHz) and the 64 GHz to 71 GHz band. You can anticipate every US carrier pouncing on these while they continue to squeeze every last Hz out of what they have now.

Making full use of the new bands will require some innovative thinking from the wireless industry. Propagation loss generally becomes worse as frequency increases. To offset this, high gain antennas must be employed to keep wireless link budgets closed. This has historically relegated mmWave to fixed, point to point, solutions as no viable option existed for rapidly scanning the beam.

However, mmWaves are capable of much more than just fixed broadband links. If your antenna can quickly (less than 1 μs) point the mmWave beam in a desired direction, several interesting and important markets open up to the mmWave domain. We are working on three of these markets at Pivotal Communications.

The first market is backhaul. Every wireless network owner knows the pain of multiple truck-rolls with skilled technicians to install, alter or repair a fixed installation (this situation does not improve with densification). Software defined antennas (SDAs) with Directivity on Demand™ (DoD) reduce this to one truck roll made by a low-skill installer. With DoD, you simply mount the backhaul node, connect fiber and power, and turn it on. No precision alignment is needed. The new node electronically discovers its environment, locates existing nodes, establishes a connection and registers with your network operations center (NOC). Altering the network topology is easily done from the NOC. As more nodes enter the network, software can adjust the routing dynamically to optimize network throughput. These new SDA nodes are quite robust against classic disruptions such as misalignment due to heavy winds, obstructions or physical impacts.  The beam can easily repoint faster than any mechanical disturbance can move the antenna.

The second market is applying Access In Motion™. AIM is all about high throughput connections to planes, trains, automobiles and even ships where a high data rate signal needs to dynamically track a moving target. Ordinarily you would need a high performance phased array antenna for this. Phased arrays have high Cost, Size, Weight and Power (C-SWaP) requirements. Pivotal is offering a vastly lower C-SWaP alternative to phased arrays. We do this with a novel new technique, holographic beamforming, which requires no phase shifters, distributed amplification or distributed DACs. I will talk more about this in a future post and at TIA itself.

The third market is in Radio Access Networks (RAN). Given that current cellular bands are fully saturated, you can safely assume that future wireless devices will be including mmWave antennas and radios for 5G. DoD is still needed to close the link. AIM is still needed to follow your customers on the move. RAN also adds the need for cooperative operation between your antenna installations. With software defined antennas controlled by the NOC, such cooperative operation is possible. Your network will shift coverage where and when needed (daily commutes, sporting events, festivals, demonstrations, etc…) rather than sitting idle as customers move to adjacent cells. This cooperative coverage reduces the ultimate density (and cost!) of your network buildout.

You can be certain that 5G will make use of the mmWave domain. Using mmWave spectrum in your network requires RF beam formers (not digital). Even the US Government has been clear on this topic. FCC Commissioner Clyburn stated that industry is “finding ways to use short wavelengths to build dynamic beam-forming antennas to support high capacity networks” in the same release detailing the four proposed mmWave bands. Pivotal Communications is making that statement a reality.

Dr. Eric J. Black is the CTO of Pivotal Communications, Inc. He will speak at TIA’s Network of the Future conference on the 5G Densification and Enabling Technologies panel, taking place Monday June 6th at 4:00 p.m. Learn more about Pivotal Communications by visiting their and on LinkedIn


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