600 MHz Incentive Auction Spectrum: 5G or Not 5G, That’s a Big Question

Peter Jarich
Peter Jarich – VP, Consumer Services and Service Provider Infrastructure

Summary Bullets:

  • Among the unknowns surrounding the 600 MHz incentive auction, the question of what technology will get deployed in the spectrum is dividing the industry.
  • Technology providers need to settle on a consistent, external message in order to ensure the industry moves forward along with their own priorities.

Not surprisingly, the FCC’s ongoing, 600 MHz incentive auction was a frequent topic of conversation at CTIA’s Super Mobility Week this year. Where any operator actively involved in the auction wasn’t allowed to talk about it, everyone else was free to discuss anything from how long it might go on to who might win and how much they’d end up paying. One question, however, seemed to generate more debate than any other: what technology – LTE or 5G – would eventually get deployed in the spectrum?

It’s not a trivial question. Every spectrum winner will want to pick the technology that aligns best with their own priorities and assets. Yet, if the market isn’t aligned behind one or the other, ecosystem scale will necessarily be limited. And, to be fair, there are good arguments for each.

The Case for 5G

Timing. Combining a 39-month repack timeline (the period when broadcasters vacate their spectrum and allocations get re-arranged to support non-interfering services) with the need for multiple stages, we’re looking at winners getting their hands on spectrum in the 2020 timeframe. That aligns pretty well with 5G standardization and commercialization expectations.

Need for Low-Band 5G. Yes, initial 5G activity in the U.S. has been focused on high-band (above 10 GHz) spectrum. Still it’s well understood that 5G will also need to be deployed in low-band spectrum if there’s an interest in delivering broad 5G coverage. Chairman Wheeler even called this out in his Super Mobility Week keynote.

Massive IoT. Since massive IoT connectivity is one of the key use cases for 5G, the importance of coverage – supported by low-band spectrum deployment – cannot be ignored.

Latest & Greatest. Nobody wants to invest in yesterday’s technology. This might be a corollary of the timing point above, but if 5G solutions are commercially available when 600 MHz spectrum gets deployed, it’s only natural for any carrier interested in maximizing the lifespan of its investments to look there first.

The Case for LTE

Early Use Case Priorities. As 5G standards get completed, there’s a consensus that enhanced mobile broadband (including fixed access) use cases will dominate initial releases. The broad-reaching propagation characteristics and comparatively limited bandwidth available at 600 MHz, on the other hand, lend themselves more to the other two key 5G use cases: broad-scale IoT and critical communications.

Massive MIMO. One of the key technologies expected to play into 5G deployment is massive MIMO. Unfortunately, physics dictates that massive antenna arrays are more difficult with low-band spectrum given the realities of antenna siting (i.e., larger antennas at lower frequencies).

Massive Spectrum Bandwidth. To effectively be deployed in high-band spectrum, the 5G air interface (5G New Radio/5G NR) is being designed to operate in wide swaths of spectrum more effectively than LTE can. That’s a benefit in spectrum allocations that are measured in the hundreds of MHz. It’s less important in the 600 MHz space where the allocations will be more constrained.

NB-IoT. Low-band spectrum may be a prerequisite for delivering on 5G massive IoT use cases. 5G, however, is not a requirement for supporting IoT market demands. NB-IoT promises to support IoT before 5G arrives. And given the expectation of NB-IoT commercialization next year, there should be a solid ecosystem in place when 600 MHz spectrum finally gets deployed (while the 5G ecosystem will still be in its infancy).

To call this an industry debate is no exaggeration. It’s not that there are open arguments or battles around the topic. Worse, industry leaders – think silicon vendors, network vendors, the carriers willing to talk abstractly – are proclaiming that the path forward and eventual use of 600 MHz spectrum in the U.S. is clear. Yet, they’re not in agreement. In fact, some actually presented one story in conference sessions while their colleagues told a different story when catching up with them afterwards. In other words, there’s not even agreement within companies.

Everyone’s position will, naturally, be shaped by their own assets and strengths (including solutions and IPR). As much as it might be too much to hope for the entire industry to get behind one viewpoint, it’s not unreasonable to expect every mobile network solution vendor to formulate and message one…and just one. Given the size of the opportunity, it’s foolish not to begin shaping opinion in the here and now.

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