15 / 96
xxxxxx xxx
supported completely by Wi-Fi and other
unlicensed spectrum, without requiring
licensed spectrum access.
Coming 5G networks also will make
available device access that is virtual
in another sense, automatically using
frequency agile radios to select from a
wide range of available frequencies to
support any session, including licensed
and unlicensed, plus shared spectrum.
All of those approaches virtualize the
access network in one or more ways.
Virtualization might also be possible for
in-building access infrastructure that
could be shared by any number of sup-
pliers, using a “neutral host” concept.
Ruckus Wireless, for example, be-
lieves its OpenG platform would allow
any number of providers access to a
single indoor access platform using
shared 3.5 GHz spectrum, avoiding
the need to duplicate “outdoor” mobile
infrastructure by each carrier when
inside buildings.
Distributed antenna systems and
traditional small cells can address those
indoor environments, but arguably are
more costly than a neutral-host solution,
assuming competitors would agree to
use it. The point is that such neutral-
host systems also represent one more
way access virtualization could happen.
But LTE-U is among the first efforts
to virtualize access “at scale.” Never
before tried, LTE-U allows LTE network
operators to use some portions of the 5
GHz Wi-Fi spectrum as though it were
simply part of the licensed spectrum
used by LTE.
LTE-U allows mobile operators to
use some unused Wi-Fi spectrum in the
U-NII-1 band (5150-5250 MHz) and U-
NII-3 band (5725-5850 MHz) as those it
were part of a licensed spectrum asset.
Some devices support LTE-U in
hardware, including those using Qual-
comm’s X16 LTE modem (Snapdragon
820 chip and newer designs). That in-
cludes smartphones such as the Galaxy
S7/S7 Edge, LG V20, and Google Pixel.
Existing T-Mobile phones probably will
need a software update to enable LTE-U
functionality.
Verizon has been working toward
LTE-U since at least 2015. And T-Mobile
U.S. has announced deployment of
LTE-U capabilities in its LTE network,
following FCC certification of equipment
from Ericsson and Nokia.
T-Mobile U.S. expects to begin com-
mercial LTE-U functions in the spring of
2017. Basically, LTE-U gives T-Mobile
U.S. customers the ability to bond
some Wi-Fi spectrum (20 MHz) with
CBRS Introduces a 3-Tiered Shared Spectrum
Source: Qualcomm
Source: Nokia Networks
LTE-U Leverages Wi-Fi Spectrum
Opens up 150 MHz spectrum while incumbents are still using it
Incumbents are protected
from int rference from
PAL and GAA
Tier 1
Incumbents
Tier 2
Priority Acces
Licenses (PAL)
Tier 3
General Auth rized
Access (GAA)
PAL has priority over GAA
licensed via auction, 10 MHz
blocks, up to 7 licenses
GAA can use any spectrum
not used, yields to PAL and
incumbents
3550
3600
3650
3700 MHz
Navy radar
FSS RX
WISPs
PAL
GAA
Wi-Fi
Wi-Fi 5GHz
Channel 149
DL
LTE-U 5GHz,
Channel 136, DL
Lic DL
Lic UL
LTE-U
March - April, 2017
|
Channel
Vision
15