Latency, clouds, and how the telcos hope to take over

The 1 ms latency frequently touted will be available to less than 2%, probably much less. 300-600 million homes will be able to connect at 15-25 ms through carrier edge cloud networks. Most will be in China. (This and the other predictions are well-researched but of course not guaranteed.)

Deutsche Telekom is rapidly building a network to connect all Germans to servers within 20-25 milliseconds. Multi-player Pokemon has a great demo. DT is working with rivals. Timotheus Höttges and team have decided a project like this needs to reach the largest audience and are including rivals. 

Carriers have monopolies on reaching their own customers. Many expect to charge a high price to use their edge clouds, which will be 10 ms to 30 ms faster than other choices such as CDNs. It is totally unclear whether the market for that kind of service will be large. I am more sceptical than most but very unsure.

They are already making deals, such as China Unicom with Tencent. Verizon is building game servers. The partnerships are logical, if and only if the terms work.

Telcos dream of a wireless umbilical cord between your phone or autonomous car and their servers

Verizon CEO Hans Vestberg is generally a straight shooter, so I was surprised by his comment

"5G network equipment and devices will consume only 10% of the energy consumed by 4G network equipment and devices,"

Almost everyone expects 5G to use more energy. It takes enormous calculating power to keep up with the speeds and complex calculations. The phone may need 10X the number of transistors as basic LTE. The base station energy demand is not as extreme. MIMO and Massive MIMO do not require major increases in power. But many network builders are warning about the expense of energy. In November, Iain Morris reports,  

Guiqing Liu, the executive vice president of China Telecom, grumbled during a keynote presentation about the high power consumption of 5G basestations. His complaints were echoed and amplified by Orange's Arnaud Vamparys, a senior vice president of radio networks with the French incumbent. 

5G at Verizon and AT&T is delivering latency around 10 ms. Mei Meiyuan writes, "For 4G mode, the best round-trip radio latency is about 10ms for FDD and about 13ms for TDD model2). In theory, With short TTI, the best round-trip radio latency is about 2ms（FDD,2 OFDM symbols 8ms(TDD, 7 OFDM symbols under planning，model2)." 

(Editor's note: Those measures are from the base station to the receiver. To reflect the real user experience, you must add the latency from the base station back to the relevant server. That's 20-50 milliseconds or much more. In the future, edge clouds will often reduce the combined latency to 20-30 ms total.)

Many politicians and salesmen still think 5G latency is much better than 4G latency. As the new equipment reaches the field, people will discover the difference in latency is only a few

milliseconds.

Neville Ray's central justification for the merger is that in 5G  "mid-band spectrum will achieve a 52 percent improvement" over 4G. That is not an appropriate figure today.

One reason for the improvement was that 5G allows 100 MHz bands compared to the 20 MHz bands of 4G. Sprint and China Mobile both have blocks of over 100 MHz at 2.6 GHz. The new 4G SuperBAND from Huawei effectively coordinates 100 Mhz of spectrum for a similar result. T-Mobile's vendors, Nokia and Ericsson, should soon be able to do similar.

Ray in a footnote points out he doesn't know whether his claim is accurate. "The spectral efficiency improvements are derived from equipment vendor simulations, internal T-Mobile analysis, and ITU requirements." Those equipment vendors are trying to sell him 5G equipment and have the incentive to make inflated claims. They are not a reliable source. It's easy to imagine testing that produces a preferred result.

There was no test data available when Ray (a first-rate engineer) wrote in June 2018. Fortunately, several vendors can now provide the equipment to provide more accurate figures. I have data from T-Mobile's parent company, Deutsche Telekom, that 5G speeds in 100 MHz of mid-band spectrum are 350-850 megabits. That's slower than the 4G starting to be deployed. 

SuperBAND 4G performance undermines the primary engineering argument for the deal. The early results from 5G suggest the actual testing of 5G will show less benefit than the T-Mobile claim. 

Gordon Mansfield of AT&T "told [management] that I want every day that’s left in the year ... The equipment is literally coming off production lines and going into the field — we are not even using normal shipping channels.” AT&T is the first in the world to use 39 GHz, a remarkable achievement.

AT&T has one of the best and most experienced senior engineering teams in the world, but the first efforts are struggling. It claims the supplier - probably Ericsson - isn't ready with the equipment in the 39 GHz band. They refuse to provide information on network speed. It may be as low as 250 megabits, half the LTE speed at T-Mobile in Manhattan.

Lessons learned:  

 “Now, in mmWave, it’s a new frontier.  Sometimes you expect the signal to be there and it isn’t, so you have to adjust. As you move through the coverage area, you will be served by different beams, and you have to understand transitions between beams,” said Hristov. “RF engineers have to be hyper-accurate about placing and facing nodes … [because] if you don’t land on the right beam, you won’t get maximum performance.”

MIMO antennas extend the easily usable frequencies well beyond the 4.9 GHz band. The FCC took the first step with a Notice of Proposed Rulemaking. Claus Hetting of Wi-Fi Now kindly allowed me to reprint his report.

The FCC wants to introduce four new unlicensed subbands aptly named U-NII-5 to U-NII-8. In the case of U-NII-5 and U-NII-7 (a total of 800 MHz) a new scheme called AFC (‘Automated Frequency Control’) will protect some incumbent 6 GHz users (mostly point-to-point microwave links) from harmful interference, the FCC says. In these two subbands the FCC wants to allow the operation of ‘standard-power access points’ equivalent to current rules for U-NII-1 and U-NII-3 subbands.

Four new subbands and (some) new rules 

Sharon White at OFCOM is leading Europe to spectrum sharing, setting aside 3.8 GHz to 4.2 GHz, enough to make an enormous difference in carrier capacity. For monopoly spectrum, she is proposing buildout requirements to 90% of the land mass (not population), more rural towers (500), a limit on the maximum spectrum one company can own (37%), and using spectrum auctions to make these happen. The result will be better broadband at a (relatively) modest cost.

She's launched a consultation on 700 MHz & 3.6-3.8 spectrum auctions, including the buildout and tower-building requirements. The goal is an auction in the spring. Mark Jackson reports 

The 700MHz Coverage Obligation

The binding coverage rules mean that up to two winning bidders would each have to, within 4 years of the award:

1. Extend good, outdoor data coverage to at least 90% of the UK’s entire land area within four years of the award.

It's great that AT&T announced 5G and is moving forward. Unfortunately, information is so restricted that Mike Dano put quotes around "5G." If AT&T really were ready, they would be shouting from the rooftops. They aren't. Update 12/19 AT&T told Mike Dano they were using only 100 MHz of spectrum and two antennas. That will be much slower than good LTE. Also, people nor businesses can order the service even if they live in the right location. Consumers can only "express interest" and only businesses selected by AT&T qualify.

It refused to give any information about typical performance or basic details like how many homes are covered. I'm inferring that the performance is disappointing, although many are working to change that.

There is no charge for "at least 90 days," guaranteeing no angry customers will ask for their money back. Then they want US$70 for 15 gigabits, as expensive as LTE.

"The $500 hotspot will mostly be run on 4G LTE," Kellen writes. $500 is hundreds more than an LTE hotspot.