Here Comes 5G—Whatever That Is

Here Comes

5G—Whatever

That Is

UNLIKE MOST EPOCHS, THOSE OF

the wireless age have come and gone with

convenient numerical designations. And

with each came marvelous new capabilities:

2G let us all text for the first time, for example,

and 3G empowered us to surf the Web.

So now, as phone makers and Internet

service providers begin hashing out the

details of what 5G will be and how it will work,

speculation is high about what new marvels

will be possible when carriers can deliver data to smartphones

at rates as high as

100 megabits per second.

Soon, we’ll start to find

out: This year, Verizon

and AT&T plan to deliver

broadband Internet

to select homes or

businesses using fixed

wireless networks built

with early 5G technologies.

These 5G pilot programs

will give the public its first

glimpse into a wireless

future that isn’t due to

fully arrive until the

early 2020s.

With 5G, carriers hope

to deliver data to smartphone

users at speeds

10 times as fast as on

today’s 4G networks, and

with only 1 millisecond

of delay. Right now, standards

groups including the

International Telecommunication

Union (ITU) are

in the middle of an eightyear

process to set technical

specifications and

performance parameters

for 5G that should be ready

around 2020. “At this time,

everything is open,” says

Colin Langtry, who oversees

5G for the ITU.

For many invested

in the 5G rollout, that

extended timetable

could be a problem. By

the time standards are

finalized in 2020, carriers

and governments will

have already poured

US $5 billion into 5G

development. With so

much cash on the line, and

facing pressure from datahungry

customers, carriers

are moving fast. Over the

past year, companies have  completed a flurry of lab

tests and trials to figure

out what types of radios,

antennas, and signal

processing techniques will

work best to deliver 5G in

hopes of bringing those

technologies and their

capabilities to market as

soon as possible.

“5G is really an amorphous

term,” says Thyaga

Nandagopal, a program

director for the National

Science Foundation who

oversees wireless initiatives.

“But it’s increasingly

going to become very narrowly

focused on a few

technologies, very fast.”

Both Verizon and AT&T

say their 2017 fixed wireless

networks will rely on

millimeter waves, which

are arguably the hottest

new 5G technology. Millimeter

waves are officially

defined as waves transmitted

at frequencies between

30 and 300 gigahertz,

and they are between

1 and 10 millimeters in

length. That’s much

shorter than traditional

cellular signals, which

have frequencies below

6 GHz, typically far below,

with wavelengths in the

tens of centimeters.

Millimeter waves could

solve a big problem for

today’s carriers: Customers

want to transmit more data

at once, but the traditional,

sub-6-GHz bands are more

crowded than they’ve

ever been. In contrast,

millimeter waves are part

of a wide-open section of

spectrum, which offers

intriguing possibilities.

In early tests, Verizon

homed in on one band in

particular—28 GHz, which

has become a clear favorite

for 5G after the U.S.

Federal Communications

Commission opened it and

a handful of other highfrequency

bands for commercial

use in July 2016.

AT&T, too, has tested millimeter

waves at 28 GHz and

on another popular band,

15 GHz, at its trial site in

Austin, Texas. In the lab,

AT&T has achieved peak

data speeds of 14 gigabits

per second at 15 GHz.

Other companies have

also had encouraging

results. Last year, Sprint

demonstrated peak

data speeds of 4 Gb/s—

good enough to stream a

virtual-reality demo for

spectators—on that same

15-GHz band at the 2016

Copa América Centenario

soccer tournament, in

Philadelphia. In Japan,

NTT Docomo has incorporated

another 5G technology

called MIMO

(multiple-input, multiple

output), in which dozens

of programmable antennas

are made to send and

receive signals at once

from a single base station,

to reach a blazing 20 Gb/s

at 15 GHz. At that speed,

a complete 2-hour, 1080p,

high-definition movie

can be transmitted in a

second and a half.

Now, Verizon and AT&T

are eager to share with

customers the speedy data

rates they have seen in

early tests, despite the fact

that comprehensive 5G

standards are still years

away. But though these

two companies may be the

first to bring millimeter

waves to customers, their

fixed wireless networks

will fall short of what

many experts consider

“true” 5G.

Unlike the networks

that connect smartphones,

fixed wireless

systems send a focused

beam to connect one stationary

point to another,

such as a base station

to a rooftop antenna.

From there, carriers run

Ethernet cables from the

antenna to deliver broadband

Internet to offices

or apartments within

a building.

To fully achieve 5G,

carriers and smartphone

manufacturers must

also figure out how to

deliver high-speed data

to mobile users who are

riding in cars or trains

or walking on sidewalks.

And the grandest vision

for 5G extends far beyond

mobile devices—to autonomous

cars, connected

appliances, and industrial

robots.

There are other problems,

too. Millimeter

waves don’t easily

penetrate obstacles

such as buildings, and

they are more readily

absorbed than traditional

microwave cell signals

by water and oxygen

molecules in the air.

So they require more

power to travel the

same distances as the

signals from today’s

smartphones. Given

these issues, using

millimeter waves to serve

mobile users will require

more sophisticated signal

processing and a greater

density of base stations

than are available today.

Some critics think fixed

wireless deployments are

an unfortunate distraction

at a time when companies

should be focused

on developing these other

capabilities. “Effectively,

that’s delaying mobile

5G,” says Paul Struhsaker,

chief technical officer for

the investment group

Carnegie Technologies.

Competitors also warn

that Verizon and AT&T

may have to forfeit their

early fixed wireless

investments if other

companies turn up even

better technologies in

time, and industry experts

fret about fragmentation

across carriers. “The

problem with prestandard

implementation has

always been you risk that

your investment after

three years is outdated,”

says Günther Ottendorfer,

Sprint’s chief operating

officer for technology.

Still, Sanyogita

Shamsunder, Verizon’s

director for network

planning, says the

company will press ahead

with its bold 2017 plan for

5G through fixed wireless.

“We see a reasonable use

case that we think we

can address with this

technology, so we’re

going to do it,” she says.