henningFCC Chief Technologist Henning Schulzrine startled the engineers at a high level 5G wireless event by predicting a complete turnaround in spectrum policy and licensing.

Instead of "licensing" monopoly use of spectrum, "All new spectrum would be shared." That corresponds to the opinions of nearly all impartial top engineers, but of course is heresy to lobbyists in the EU and U.S.

Shared spectrum is better, but I fear Henning is being optimistic about what the politicians will do.

In the EU, Ottinger is talking instead about lengthening the monopoly terms. Across the globe, regulators are designating 3.5 GHz mostly for monopoly use. In the U.S., the FCC is planning more auctions and possibly rolling back the rules for sharing.

"Share everything" (Henning)

Henning asked me to clarify an earlier version of this article. Sharing does not necessarily mean completely unlicensed, like Wi-Fi. The 3.5 GHz band combines a variety of models. If I have this right, the 3.5 GHz band is divided between "unlicensed," "lightly licensed,' and a limited number of more restrictive licenses. (As well as certain locations and bands that continued to be reserved for the military.) Wi-Fi is good evidence sharing can work, given enough spectrum, but not the only way to share. His comment shouldn't be interpreted to mean it is all going to be like 2.4/5.8 GHz.

No one disputes that some spectrum should be reserved for monopoly use, at least on a regional level. That's important for public safety and (at least for many years) control channels. No one has studied this in depth; my guess is that completely reserved spectrum could be reduced to 20-50 MHz/company, half what most major telcos have today. Beyond that, the carriers can explore for unused spectrum and in almost all likely cases find plenty.

At least 50% of the usable spectrum is fallow today, even in congested cities. See Dennis Roberson's work. This isn't news; I remember Dave Farber holding up an amazing chart more than a decade ago. 

That's exactly what AT&T intends to do with LAA later this year in the Wi-Fi band. Their radios would "listen" to make sure a band is empty, "before talking" on that band.Verizon and Qualcomm testing convinced every engineer I've discussed this with that will work. The current 3GPP rules have problems, including an inappropriate noise floor. That needs to be solved. 

This very open and free sharing is just starting to deploy. It would take 10-15 years to upgrade the networks fully. It would also require some modest "rules of the road." In particular, neither Wi-Fi nor anything else should commonly use 80 MHz or 160 MHz, unless it's clearly free. Stanford Professors Cioffi & Goldsmith in 2014 pointed out the greed in 802.11 ac. LTE-U can have the same problem.

Efficient sharing normally at least doubles wireless capacity and often increases capacity 500% or more.  

dave askOn Oct 1, Verizon turned on the first $20B 5G mmWave network. It will soon offer a gigabit or close to 30M homes. Thousands of sites are live in Korea; AT&T is going live with mobile, even lacking phones. The hype is unreal. Time for reporting closer to the truth.

The estimates you hear about 5G costs are wildly exaggerated. Verizon is building the most advanced wireless network while reducing capex. Deutsche Telekom and Orange/France Telecom also confirm they won't raise capex.

Massive MIMO in either 4G or "5G" can increase capacity 4X to 7X, including putting 2.3 GHz to 4.2 GHz to use. Carrier Aggregation, 256 QAM, and other tools double and triple that. Verizon sees cost/bit dropping 40% per year.

Cisco & others see traffic growth slowing to 30%/year or less.  I infer overcapacity almost everywhere.  

Believe it or not, 80% of 5G (mid-band) for several years will be slower than good 4G, which is more developed.


5G Why Verizon thinks differently and what to do about it is a new report I wrote for STL Partners and their clients.

STL Partners, a British consulting outfit I respect, commissioned me to ask why. That report is now out. If you're a client, download it here. If not, and corporate priced research is interesting to you, ask me to introduce you to one of the principals.

It was fascinating work because the answers aren't obvious. Lowell McAdam's company is spending $20B to cover 30M+ homes in the first stage. The progress in low & mid-band, both "4G" and "5G," has been remarkable. In most territories, millimeter wave will not be necessary to meet expected demand.

McAdam sees a little further. mmWave has 3-4X the capacity of low and mid-band. He sees an enormous marketing advantage: unlimited services, even less congestion, reputation as the best network. Verizon testing found mmWave rate/reach was twice what had been estimated. All prior cost estimates need revision.

My take: even if mmWave doesn't fit in your current budget, telcos should expand trials and training to be ready as things change. The new cost estimates may be low enough to change your mind.