Thanks so much for being here.
It's my pleasure to introduce
Professor Douglas Sicker.
He is a professor and
Department Head of Engineering
and Public Policy in the
College of Engineering
at Carnegie Mellon University,
and has a joint appointment
there in the school of computer science,
and is also a chair in engineering.
He was previously a number of
art department 2000 to 2017,
before leaving to join
CMU and collaborating
with many of our faculty
here during that time.
He has had plenty of
other planets in academia,
industry and government,
including a stint as the Chief
Technology Officer at the FCC.
And Doug works the Intersection
of Network Technology
and Public Policy area rich
and technical challenges
and socially significant research topics.
Today he talk to us about
rethinking spectrum use
with softer smarter radio systems.
Please join me in welcoming Doug.
Thank you.
[audience clapping]
So it's a pleasure to be back.
I was just commenting, I
swear this room was bigger.
when I presented before.
[audience laughing]
So as Ken said, I'm
gonna talk about a number
of different things.
But I'm gonna mostly focus
on software defined radios
and some of the things
that can be done with them.
As Ken also mentioned,
I've had a lot of printing on the mic.
Is it on?
I've had a lot of leadership
activities recently.
But about three years
ago, I started ramping
up my research again, considerably.
And these are the kinds
of things that I'm running
now in the research space.
I don't have time to talk
about them at this point,
but I'll comment back as we go along
and talk about related research.
This is the newest one that I'm
leading with Kathleen Carly.
And this one we're
working on disinformation,
in particularly as it relates to how flows
are happening, and how
the dark web might be used
in some of the other
aspects of disinformation,
fake news.
And we have three
different grants right now
in this space just in
the last four months.
It's a very, very hot topic.
And really a great deal of
opportunity in that space.
So, I am gonna take a
little bit of time since
I won't be able to cover
the breadth of my research,
I wanna just kind of tell
you about a couple of areas
that I'm working in.
This is my main work,
which is looking at models
for dense wireless systems.
And in this space, I'm doing everything...
I just finished a lot of
work looking at new IDs,
new ID structures for wireless systems,
so you could have common IDs.
I'm not gonna get into that now,
but I'd be happy to talk
about it after the break.
One of the biggest
areas I'm working on now
is looking at mobility models
for terahertz communications,
and that's gonna be a lot of today's talk.
Another thing that I wanna call out,
that's up here is some interesting
work that we just started
a student of mine in me looking at privacy
implications of beamforming
and steerable networks,
which is gonna be all the rage and some
of the stuff that's coming down in 5G.
This is as I mentioned,
with the ideas, effort,
work that I'm doing and disinformation.
I spent most of the last
year and a half working,
looking at fake news as it
relates to science debates.
And I'm talking a little bit about that.
And I've also spent a lot of
time just in the last three
years looking at how you
might use AI tools to reform
the patent process.
And that's been a really
enjoyable set of research efforts.
And it's part of another
center that I'm directing,
and I'll talk a little bit about that.
Real quickly, these are
the these are the items
that I'm probably spending
most of my time on right now.
And these are the items
that I plan to be working
on going forward, and I'll
touch on a couple of them
as I go through.
But as I said, I'm not gonna
be able to cover the breadth
of the research that I'm doing,
I wanna jump down a little
more deeply into the spectrum
space and some of the
work that I've done across
the last 10 years in that area.
So here's a quick
overview of today's talk.
Again, I wanna get a little
context for radio and spectrum,
for those of you who may
not know much about that,
I'm gonna talk about
some radio use reform.
So that's policy, public policy.
I'm gonna talk about some
of the terahertz models
that we've developed,
and also what it means
this implication of the
advent of these smart radios.
I'm gonna do a deeper dive into some work
that I did a few years
ago on the 1755 megahertz.
And then some recent
work that extends that,
and looking at some of
the spectrum opportunities
that could be had there.
And then I'm gonna just
pitch some of the challenges,
but first since this is academia,
I'm gonna do a little test.
So some of you will know
this because you used
to sit down near me.
Does anyone know what this is?
I know Dirk knows what it is.
MAN: It's a really big bow tie.
A really big what?
MAN: Bow tie.
Bow tie, [laughing] I love.
GUY: It is a resonance cavity.
It is a resonance cavity, very good.
And you know the application of it?
It's an acoustic waveguide,
it used to be attached
to a candlestick phone.
Remember the old upright
phones that you would
see in the olden days, where
you'd lift up the thing?
You'd attach it here like this,
and you [mumbling] to
quiet your conversation.
So this device is called a hush a phone.
And the significance of
it is that the Bell System
spent millions and millions
of dollars fighting
to prevent this from being
attached to the network.
They said that linemen were gonna die,
people we're gonna fall
off of telephone poles
if you attach this, because
it was going to overload
the network, it was gonna
fry telephone switches,
all of these sorts of things.
It was all nonsense, of course.
Ironically, the FCC agreed with them,
and enrolled in their favor.
And it took 10 years and
a whole lot of lawyers
to fight to get this
attached to the network.
And if it hadn't been for this,
which was ushered in the
advancement of attached
devices to the network,
we would never have
had the acoustic modems
that many of us with gray
hairs used to get attached
to the early internet.
So it's pretty easy to
extrapolate to say without this,
we probably wouldn't have
had the commercial internet.
Now a that's a leap, but the point is,
is that there were years
and years and years
with the telephone system did
everything they could to fight
innovation and kind of attachment,
and as an a large
incumbent, they resisted.
That's a theme we're gonna
keep coming back to throughout
my talk, because that's
what incumbents tend to do.
If you wanna look at that and pass on.
Okay, so what I want to talk
about a little bit today,
for at least probably a half
an hour is some of the issues
that are going on with the radio spectrum
as a scarce resource,
and why it's in such huge demand.
What this messy figures
suppose to illustrate
is the advent of these
many, many wireless devices
that we're seeing kind of pop up.
And this speaks to a lot of
things that we're hearing about,
like the Internet of Things,
which is probably going to be a device
that's gonna be attached
wirelessly to the network,
as well as all of the things
that we have on our body.
I did a survey of my
home just a month ago,
and the first surprising
thing is that I found
45 MAC addresses in my home.
So 45 devices that are
have a network attachment
to the network.
And of those, almost half were wireless.
Now, I've never
experienced any significant
spectrum problems with these devices,
but a lot of them aren't
in use at the same time.
And what we're seeing is
this kind of rush toward more
and more devices.
And we're also seeing a rush
toward much higher data rates.
So on the wireless networks,
we're seeing superlinear growth in traffic
and the backhaul and
the core of the network.
So lots, lots more traffic.
That means we're going to get to a point
where we're gonna start really exhausting
the spectrum that we have,
and I'll talk about why that's the case.
So I think many of you
know when I say a radio
I'm talking about a transceiver
could be like my
telephone, it could be like
this device, could be like my laptop.
In this device, we have some antenna.
And that antenna is gonna be operating
on the electromagnetic
radiation that it can emit,
and receive.
And that electric magnetic
radiation is thought
of as the radio frequency spectrum.
That's the continuum of
spectrum that we can use
to communicate in the wireless space.
The thing that's amazing
about this spectrum
and he and I were just talking about it,
is that while it's something we can't see,
it's something we can't touch.
It's literally worth trillions of dollars
just in the United States,
which is a pretty remarkable thing.
So let's take a big step back.
And I hope somebody can can get this,
what happened in 1912?
Nope.
MAN: Titanic sank.
MUMBLING: titanic.
So the crash of Titanic into an iceberg
below Greenland, which I
think is one of the new US
territories, is one of the
reasons that we have a lot
of the spectrum policy
that we now exist with.
Prior to 1912, the only
regulation that existed
in the radio space was to
require ships that have radio
operators on board.
Before 1912 actually, before
1920s there was no allocation
of the spectrum for different uses.
And back in the day,
back in this time period,
we didn't have radio in the sense
that we think of, it wasn't AM radio,
it wasn't voice communication.
It was actually almost
entirely telegraphy.
So you were using the radio
space to do Morse code.
And unfortunately, what
happened when the Titanic crash,
all of these ships came to the rescue.
But there were a lot of people
on these different capes
and in these different
areas that were both trying
to participate in the rescue effort.
But there were also, and it was
found that there were people
who were purposely trying to subvert
and do kind of prankster sort of things,
trying to spoof communications.
And as a result, there
was this great contention
for a resource.
It led to all of this interference.
So we're pretty familiar
right with if you're using
your Wi-Fi network, and
somebody puts something
in the microwave and you just
see your wireless network
drop out of existence.
This is what we're talking about.
We saw some kind of interference
because of all of the use
of all of these different
spark gap sort of telegraphy
devices, and What happened
was congressional action,
because there are a lot of
people who are really pissed off,
because a lot of people die.
So the inquiry suggested
that hundreds of people
could have been saved if
there hadn't been this mishap
in terms of interference,
really led to a lot of the early
licensing an allocation of spectrum.
So if we jump ahead about 100 years,
we have this kind of crazy
hyper response to that through
assignment and allocation.
And this is what we have.
This is the spectrum table,
the spectrum allocation
table for the United States.
It goes from the upper
corner at three kilohertz
down to this bottom corner,
about 300 gigahertz.
And this is how the
spectrum is all chopped up,
given and assigned to different users.
As I mentioned before,
the spectrum is a very scarce resource,
and it's very valuable.
And as an example, we can
look at something I spent
a lot of time working on,
which was the AWS auctions
when I was in the federal government,
both at the FCC and when
I served at the Department
of Commerce, this is one of my charges.
And I'll come back to that in a bit.
If we look at this auction
and look at the slice
of spectrum that was involved,
if we if we zoom in here,
and you can see that little
line that's flashing right here.
And we continue to go in and we look again
at that spectrum.
And we do it one more time.
And that is just this
little area right in here.
That spectrum, take a guess
how much that spectrum
went up for an auction?
MAN: A hundred million
Hundred million?
GUY: Billion.
Closer.
Yeah 44 billion.
So 45 billion.
So this little tiny slice,
which is just this little tiny
area in here of spectrum
went for that much,
which if you really think about it,
that's pretty insane, right?
And, so it's very clear that
there's a lot of demand.
And unfortunately, there's
a lot, a lot of opportunity.
And then another unfortunate
thing, and this is opinion,
I'm doing a little soapbox in here,
it ends up in the hands
of AT and T and Verizon
and others like that.
So these big monopoly kind
of players get to continue
to control that spectrum.
So who owns this thing?
Well, the government actually...
So spectrum as we think
of it is actually owned
by the government, but it's
at least two companies.
So you're given a right to use.
Usually you want it as
an exclusive use right.
So you're given a little
slice of spectrum to use.
This spectrum, I believe
that went to AT and T,
I can't believe I can't remember now.
GUY] [MUMBLES: .
About
MAN: The previous price holder [mumbles]--
We'll talk about it, actually
and that's one of the case
studies that I talked about.
Turns out only about a
fifth of that was needed
to reallocate.
And it was a really contentious space.
Very interesting set of
interactions when I was working
with the government.
So don't know what that was.
I'm gonna really quickly go through this,
I showed a slide like this years ago.
For the most part, spectrum
policy kind of laid dead
for many decades.
One of the things that happened in the 80s
was a pretty novel idea of
using what was considered
real junk spectrum at 2.4
gigahertz a little bit,
and giving it to what's
called an unlicensed model.
And as a result of the
whole world of Wi-Fi,
and all of these other devices
that use the unlicensed bands
developed, that was a really
innovative and very big,
big positive impact on spectrum policy.
But for the most part, we
continued in this very command
and controlled regulation regulatory model
that really inhibited a lot of innovation.
That also because the
spectrum had been assigned
to all of these different uses,
like this chart here shows,
this one at the bottom.
It's all sliced up.
And this could be like television,
and this could be television,
some of these could be radio.
Some of these could be
radio location services,
very, very important services.
A lot of very important
DoD services are here.
But it's all been assigned.
So you can't just randomly go
in and start using spectrum.
So the result is that
you have this very locked
down limited use.
And the first time I spent
one time in the government
back in the 90s, where I
was running the FCC labs.
And what we were looking at,
we were finding that a lot
of the technology was
not being used in a lot
of these different bands.
And the commission generated this report,
about a year after I
left, that talked about,
hey, we need to start thinking differently
about how we're using and
characterizing spectrum.
So this idea of Whitespace came up.
And the idea of Whitespace
is radio spectrum
that's not being used either
in time or in frequency.
So if you looked at that model,
I mean that allocation table
I showed earlier, it looks
like it's just heavily,
heavily used.
That's not used, that's assignment.
So about 10 years later,
the second effort that, this
is what actually took me back
to the federal government.
We started looking at spectrum
for licensed operators.
And this led to trying to
clear a bunch of the TV bands,
the broadcast bands for
use for cellular service.
It took a long time, it
created a really interesting
auction mechanism called
an incentive auction,
bonuses reverse and forward auction.
And eventually the broadcaster's moved.
They made a bunch of money.
And, again the cellular
providers got more spectrum.
A few years later, based
on a big push from Google
and a few other companies,
the same kind of thought
was created through the White House.
And I worked on this report
too, and what we were working on
was trying to say, "Hey,
going forward spectrum
"should be shared.
"It shouldn't be used
exclusively for an exclusive
"use like the cellular companies want."
And it'd be really great
if we unlicensed it.
And it'd be really great
if we didn't have little
tiny slices like you saw on that chart.
If we had bigger, wider bands.
That's been kind of a goal.
Some of this is happening,
but it's been happening
very slowly, particularly
under this administration.
So, when we talk about
these smarter radios,
the question is what can we do?
I usually talk about three
things when I say this,
we can reallocate, we
can improve efficiency,
or we can share.
I'll come back to a fourth one.
When I say reallocate, what
I mean is I'm gonna take
somebody who's already sitting there,
I'm gonna move them somewhere else.
And I'm gonna put you in there.
Now, the problem with that
was highlighted up here
is it's gonna cost a
lot of money to do that,
and it costs a lot of time.
So while that works, and
while that's been the norm
for the last 15 years of
trying to get more spectrum
for 4G and 5G, it's very time intensive.
The next thing that kind
of goes along this lines
and I've done some work
in this space is looking
at how to improve efficiency.
And to do that you could get down
into the technical improvements.
How do you make a better
network architecture?
How do you get a smaller
cell architecture?
How do you improve the the
characteristics of the devices
that are talking to each other
in terms of the radio space?
So this gets down into the
nitty gritty of thinking about
the specifications of
how these communicate,
and how they modulate a signal,
and how they prevent
interference amongst them.
The third is getting to
this idea of sharing,
and I'm gonna come back to
that in much more detail.
The fourth thing that I
never used to talk about,
and this has been something
I've spent the last three years
working a lot on, is looking at spectrum
that hasn't been allocated.
What I mean by that is looking at spectrum
that's off of that table.
If you remember I said that table ends
at about 300 gigahertz.
What about the spectrum beyond that?
What about the spectrum
that goes up toward
the visible light range,
and can we use that?
So my first project in this
was a effort that was funded
by the Department of Commerce.
And what we were looking at
was trying to characterize
those spectrum bands above 300 gigahertz.
And this is where we get
into this what we call
terahertz communication.
So much of this I did actually on my own,
because I didn't have a grad student till
about two years ago to work on it.
And I started looking at,
okay what's the different
characteristics of this
frequency in the radio frequency
space that we think of down here?
Versus microwave, which is
what we think of is Wi-Fi
and a lot of those bands,
versus this stuff up here
that's up in the infrared, and beyond.
And what you see when you think about it
from a communications perspective,
is this spectrum down here,
radio frequency spectrum,
it's possible to get like
20 megahertz of spectrum,
and we think about 20
megahertz of spectrum.
If any of you have studied
Shannon or any of the other
gods of the the information theory space,
it dictates how many symbols per second,
or how many bits per second
you might be able to get
out of a hertz.
And what we see when we
look at possible bands
and possible uses down here,
is it's common you can probably
get about 20 megahertz,
and remember 25 megahertz
sold for 45 billion.
So, again keep that in mind.
And this spectrum is
down here is particularly
good at distance, you
can go about a kilometer
or more depending on
how far down here you go
with the spectrum, the
further down that tends
to be very good for propagation.
As we start moving up into these regions
and we start moving up into
here even more so the case
we find out we find less spectrum.
I mean, we find more spectrum available,
but it's characteristics
the physics of it means
that it doesn't propagate the same way.
So, when we think of a television
of broadcast televisions
channel, we think of
these great big antennas
that will be up on a mountain somewhere,
and it will reach 20 3040 miles,
it'll go through walls to get inside
and light up your television.
Whereas Wi-Fi tends to
hit one or two walls
and stop propagating,
especially walls like this.
This would be an enemy
to a lot of the microwave
and millimeter wave.
Now, the work that I started
working on a few years ago
was this terahertz spectrum.
What's interesting about
that is that a sheet of paper
can block it.
Your breath can block it.
Now, there's advantages
and disadvantages of that.
First of all, one of the
advantages is that there's tons
and tons of spectrum up there
that hasn't been allocated
anybody for anything, so
you can use it, potentially.
However, you can't use
it to create a radio link
of 10 miles outside.
And you really couldn't use
it to create a radio link
in like San Francisco, where
you have high humidity, right?
'cause it just isn't gonna work,
the radio signals not gonna propagate.
So we started characterizing
what we might be able
to deal with some of
the spectrum as we move.
Again, this is a spectrum that's here.
If you continue this column right here,
you get into terahertz.
I'm not gonna cover these,
but this is some of the work that I did.
I took measurements from the
weather service and from NOAA.
And that measured penetration
rates through different
humidities for these different bands.
And I flipped them to
look at them from a comms
perspective, and looked at
them at different things.
I looked at one gigahertz band,
I looked at a 10 gigahertz band.
I looked at achievable data rates
and ran these different
studies looking at humidity
and other path loss.
The bottom line from
this is that there's tons
and tons of spectrum that you could use,
but you're not gonna get
much distance out of this.
This spectrum is particularly
good for within a room.
So with that work, and when
I finally got a PhD student
who can do some of the work in this space,
and I got two that are
working in terahertz now,
we came up with what we called
RUTH because acronyms matter.
RUTH is reliable ultra
high speed data service
in the terahertz space.
And we produce both an indoor strategy
and an outdoor strategy.
I'll talk a little bit
about the indoor strategy
and some of the work that we're done here.
We came up with three different models.
The first model was looking
at outage scenarios.
And what we could do in
terms preventing outages,
this really focused on looking
at human use models first,
and I'll come back to that in a second.
The second thing that
we worked on was looking
at how if you have a
mobility model for indoor
terahertz use, how might
that model together
with information about the
beam width of an access point,
when I talk about the beam width,
if we think of a Wi-Fi access point,
which I'm sure there are
some in here, thank you.
That things radiating out pretty generally
across the whole space in here.
These antennas that we're working with,
tend to be patch panels,
and they tend to radiate
in a certain direction.
And we just got newer
ones that are actually
steerable patch panels.
So I can actually take a
thing that's about this big
and I can direct the
beam, and while we call it
a pencil beam, it's not
really a pencil beam,
it turns out it's a beam about this big
as it gets further out.
But what we're dealing there
is we're actually directing
the beam to one individual at a time.
And we can generate
multiple of these things
with multiple antennas.
Very different model,
but then it has impact
on what you can do with the MAC layer.
When I say MAC layer, I'm
talking about the media
access control layer.
This is the data link layer
in networking protocols
that says how you share
access to a resource.
So that everybody can get fair access.
And so we came up with a beam selection.
This we just finished
this, we just actually sent
this off, this work is
published some of it
and been published.
This is just sent off.
I'm gonna go into a
little more detail on it.
Sorry, the last one is just,
this is work that's just started.
And what we're looking at here is how...
Given that we know what
you might be able to do
with the characteristics of the spectrum,
and what you might be able
to do with the protocol,
we kind of flipped between these two
and started thinking about well,
we probably need more
than one AP in a room.
So it's no longer the case where you could
just have a single access
point serving the room,
you're probably gonna have
multiple access points.
And it might even be
that in a room like this
you could have 10, or more
terahertz access points.
We're looking at what
these handoff strategies
might look like.
And we're also looking at weird things.
So I'll come back to it in a moment.
But as I implied earlier,
as you start moving toward
terahertz communication,
you're actually moving very
close to visible light.
And as you go to visible light,
you can start thinking about terahertz,
in that domain.
So, one of my students is
looking at and borrowing
from the literature in the
lighting design community,
to inform how you might
think about terahertz
lighting up a room.
And it's been kind of
cool because he's sitting
there reading all these
Architectural Digest on lighting,
and trying to learn from it.
We're not sure that the analogy holds,
but we think it's pretty strong.
The one thing we have
tested, and we have shown
is that pretend this is a cellphone.
Pretend I'm talking on it.
And using terahertz communication,
which makes no sense
by the way, because you
would never need terahertz
of bandwidth, but let's
just say that's the case.
If the access points over
here and I'm talking,
it's fine, but if I was to turn this way,
that would kill my connection,
it would never go through my head.
What we were able to do though,
is we were able to put
a reflective surface,
a mirror on the other wall,
and actually bounce the terahertz directly
to the phone, and this was like something
we had to mess around
with a monkey with it,
it worked the first time.
We put put a reflective
surface on one of the walls,
and we were able to able to
support a more dynamic range.
So these are the kinds of things
that we're looking at in ETF.
So we've got clever
acronyms for each of these.
This was something that
I've spent a lot of the last
from about 18 months ago
until about a year ago.
And this has been accepted
for publication too.
As you can imagine, as you
start moving toward terahertz
communications, you're now
in a world where you might
not have the same mobility
model that we assumed
for Wi-Fi working.
So it's not like the
humans moving differently,
but it's how the access point
interacts with the human.
So we started looking at all
of these different dimensions
of high Mobility, low mobility,
the movement of the body,
the movement and the height,
and build up a set of nine
categories buckets of use.
And from those we build up
a model to emulate that,
so that we could in simulation
start looking at what kind
of terahertz communications
was gonna work best?
What kind of beam width?
What kind of placement of antennas?
What kind of power
levels would be required
to actually work for
any of these scenarios.
I've gotten some money from
Microsoft for this work.
And that's because they're
interested in AR and VR.
Jumping ahead, I'm gonna
try to move more quickly.
The beam alignment strategy,
if this is the access point,
and that's a poorly drawn
VR headset or AR headset,
the scenarios that
you're gonna wanna be in
is where the access point is
pointing toward the headset,
and the headset is pointing
toward the access point.
So in situation A and situation B the,
the delta, small delta is wide
enough that in this scenario
they're overlapping and
you have connectivity.
However, you can have a
change in beam direction
where you're actually fixed
in movement in location,
but you changed your direction and you go
into a failed state,
because the AP can be heard
by the headset, but the headset
can't talk back to the AP.
And this situation where
you actually have a change
in the movement of the headset.
So in both of those scenarios
they're failure modes,
and you wanna get out of them.
We looked at again and antenna placement,
multiple antenna placement
based on like perimeter models,
based on center the other room models,
based on a light fixture model.
We also looked at mirrors
designed into the wall.
And by the way, when I
say mirrors the terahertz
can reflect off of other
surfaces not classically
a mirror like we think would
be required for visible light.
There's other things that will reflect
that terahertz signal.
It's whether you want your
walls to be made out of that.
So we put together this
strategy and we looked
at a whole bunch of these different things
that I just talked about,
how the beam forming occurs,
how the movement of the human occurs,
whether you adjust your beam
before you have a failure
so that you have some predictive notion
that you're gonna go to a failure mode,
or whether you do it after failure.
And what we were able to
find was not surprisingly
because this kind of finding
was found in the Monet space
and some of the other
directional antenna space.
It's best to try to
adjust before you fail,
because you can get in
scenarios where you can fail
and not reconnect.
We also found strategies
that align mobility models
with steering and beam width.
I mentioned beam width and
I didn't really cover that,
which is this delta here.
If this had a wider, let's say this one,
if this had a wider delta here,
it could probably talk and
probably hit the antenna.
And if this was pointing
out and it had a cone,
which none of these are cones actually,
but it could actually
encompass that headset
and this could work.
But there's a trade off
between how much power
and how much potential
interference to other players
in the space.
So we modeled that and we've come up with,
as I said, a paper that's
looking at media access control.
The last one that I wanna talk to,
before I jump in change
direction was this idea
of lighting up the room.
And I already talked a
little bit about this,
which is just trying to
think about terahertz
as these beam forms
and steerable antennas.
And in this, sorry, in this bottom corner,
what we have represented is a heat map
where this is the dimensions
of a room, a square room.
This is a placement of
a central model an AP,
that's probably at the top of the ceiling.
And the resulting data
rates were at the edge,
these blue patterns are
where you're not getting
much data rate at all.
Read patterns and being
the well lit up space.
We looked at different scenarios in terms
of how you could deploy
and what we did was,
we measured one of these, and
then we measure two of these.
Then we measured four
of these in real life
and then we started modeling them.
And we started putting them
in all these different places,
and thought about how you
might wanna optimize it.
Now the problem with
any of this is we found
these very constrained,
convoluted approaches,
that would probably be
the best deployment.
But at the end of the day,
that's not what you want.
You want it to probably be
wherever the light bulb is,
or you want it to be wherever
the current access point is,
whatever it might be.
You don't wanna have to
go back and then wire up
your whole infrastructure
for antenna deployment.
So we think we can find
some really interesting
deployment strategies in
terms of where the APs
could be placed optimally.
But we don't know that it makes any sense
in anything other than
a Greenfield deployment.
Shifting back to the
allocation problem, as I said,
there's four things that
we could talk about,
about improving radio
networks and radio efficiency,
with the spectrum, we could reallocate,
we could improve
efficiency, we could share,
or we could get new spectrum.
This is going back to
the allocation problem.
I've presented this, I
think in this room before
the next couple of slides.
But I think it's illustrative.
I mentioned that, hey there's
this allocation table,
and it sure when you look at
it looks like it's packed.
And it is from an assignment perspective.
But if we look at a particular
band, and this is a band
that I've been pushing really
strongly to get allocated
for other uses particularly
5G from three gigahertz
to six gigahertz, it looks
crowded, but when you measure it
this is the band from three to six.
This is a gathering of
different measurements across.
So on the on the X axis,
we're talking gigahertz of spectrum.
On the Y axis, we're seeing power signal.
So this is received signal
that was ambient in the area
when a test was being
made of this spectrum.
This was actually a gathering
of spectrum measurements
in Chicago, as well as
integrated with some made in DC,
actually Virginia.
And what you see is, down here
there's a whole lot of power.
All this blue means that
there's probably being used.
Up here, you're seeing
much less of the case.
And one would ask, well,
what is this person
doing right here?
Why aren't they using the spectrum?
They might be using it, but
they just might not be using it
right there, or right
then when it was measured,
we did long measurements,
but we measured it in a city,
and it has implications on us.
So we wanted to look at
and we got a bunch of us
started working on this
stuff about 15 years ago,
thinking about how do
you use this spectrum
that's been assigned but isn't being used,
and that again is called
Whitespace spectrum.
So here are some of the
opportunities, you can have a hole.
And again on this chart,
what we see in this graph
on the X axis is frequency,
and on the Y axis is power levels.
So across the spectrum, again,
just like the last chart,
we see there's this opportunity.
Well, it looks like there's
20 megahertz of spectrum
right here that could be used.
When it was further divided
this this bleep right here
at 2050 actually wasn't always on.
So if we think about it, with
frequency across the X axis
and time on the Y axis now,
what we see is not only are there holes
in the frequency domain,
but there's also holes
in the frequency of the time domain.
That means that there was
a user of the spectrum
at a certain time period,
but not the rest of the time.
Wouldn't it be cool if we could figure out
a way of accessing that spectrum?
And what would that mean?
I will come back to some of the economics,
one could argue pretty easily
that if you could figure out
how to do sharing, all
those spectrum bids,
and all those auctions would
plummet into nearly nothing.
And there'd be a lot of people
who'd be upset about it,
but it might be a better
allocation of resources
for the public.
Because remember, the spectrum
is being managed for us
as a public resource.
And ultimately, it's one of those things
where the government wants to protect
certain high priority uses.
A high priority use
might be public safety,
it might be national defense,
might be communications.
But there's a lot of priority uses.
But there's a whole lot
of uses where we could
probably rethink this model.
The Treasury, the US
Treasury would be pissed
that that would happen,
because I mean this has been
a significant contribution to
the Treasury over the years.
They get Very happy when the
FCC auctions off spectrum.
Okay.
Yes.
MAN] [MUMBLES: .
Yeah, that's a great question.
And there's a little
bit of it and a number
of different ways.
Probably be best to have that conversation
'cause I'll go on for half an hour.
But it's been fairly failed as a model.
The government has tried to
make it a little more accessible
so that you could do that.
But the models of renting
spectrum or using it for different
uses has really not caught on
in the way that we've hoped.
One of the places where
Google's doing some cool stuff
and they've been watching
and they'll just in the last
few months, I was just talking their head
of their wireless group.
They've made a database, and
the database has been approved
because you could well
imagine one of the ways
of sharing spectrum would
be for me to ask Bobby,
"Bobby, are you using your spectrum?"
And you would say, "No."
And I would say, "Okay,
here's my Paypal account."
Right?
Or it could be that there's a third party
who's a proxy for Bobby.
And maybe Bobby doesn't
get any of the money,
maybe the money goes
to the Treasury again.
But there's models where this could work.
And there's some party that
could be in charge of that.
So there's some hope that
this is going to happen.
But for the most part,
still in the radio space,
and I'll come back to this hopefully,
and I have to get moving.
Nobody wants to use the
technology that's out there.
And it's been 20 years of this.
There's all kinds of stuff that
could be done in this space.
A lot of work that was
done here years ago,
that could be implemented.
That's not the novel stuff.
The novel technology has not been adopted.
A lot of the neat things in
terms of sensing the spectrum
and trying to find out
whether it's being used,
and then using it when
when the primary user
is not using it.
It's really fallen kind of on deaf ears.
For the most part, people
want spectrum assigned to you,
it's mine, I wanna simple
control model about how I get it.
And that's it.
The one thing that I think
will force the change
is as we start running
out of usable spectrum,
and I hope you do get the
understanding that I'm not saying
that terahertz is going to solve anything,
aside from being a huge
pipe inside a room.
And it's one of those things
where I started working on it,
I thought, oh this could be
really cool for point-to-point
outside communication.
Now, you can't use it,
you can't do it for that.
At some point, we need more
spectrum in the lower bands.
And you would want more of
these models of sharing.
But it's a great question.
So this was a lot of
work that was done here
by a bunch of people even in this room,
over the years looking at
moving from what a legacy
radio looked like, which
was very constructed
through hardware in a bunch of circuitry,
and tended to have a fixed
behavior to more flexible
architecture is based on
some kind of processor,
general processor that
allows for reconfiguration
and well as a flexible behavior.
And when you have this kind
of software defined radio
that has allowed for a flexible behavior,
you could start thinking
about what a term that came
into vogue about 20 years
ago called a cognitive radio.
And some of my friends from
the Institute of Cognitive
Science don't like when that word is used
in the radio space, because
it's not that cognitive.
But it's getting more
and more, at some point
we're actually getting
some cool intelligence,
at least some simple machine
learning into these things.
The idea is that in this device up here,
it would operate on a certain band,
and would operate in a certain behavior.
Down here, you might have
a radio that not only
can operate across different bands,
but it could also
reconfigure itself as a radio
to operate across those different bands.
And it could start learning and listening
to the spectral components,
and maybe even get database
updates to say, "Hey,
there's nobody operating
"in your space, so on and so forth."
And you could have this
much more dynamic radio,
the problem is that these
radios come at a cost.
And that again goes back
to the issue that a lot
of the smarter technology
is not being adopted.
Nobody wants to build something
that's gonna cost more,
they want to adopt
something that costs less.
So slowly some of this
stuff is starting to happen.
Here's where I want to take a step back.
I implied that radios are getting smarter.
And that is the case and
we, with another PhD student
of mine, we started looking
at what we might be able
to do in terms of looking at
the spectrum that's available,
and understanding what might
be mined out of the spectrum
use, so we took a data set
that IIT in Chicago created
and started just looking at
what bands might be available
and when, and mining it
across those two dimensions
and we found..
Oh oh, low battery.
We found a lot of opportunities,
and we've just written that up.
The other thing that we're
working on is looking at
how you might be able
to apply some simplistic
machine learning
techniques to spectrum use.
There's a big DARPA challenge
that's been underway
and it's gonna be happening,
I think it's this month
or might have just happened
actually, now I think about it.
That's looking at the application
of ML to spectrum use.
One of the funny things that
came out of that from a couple
years ago when they first started,
was the work was kind of
scratched the surface ML.
I went and I talked to
some of my colleagues
including Tom Mitchell,
in machine learning about
some of the methods that were being used,
and he kind of chuckled and
Tom's not one to chuckle
about things like that.
He's a gentleman.
But the approaches that many
of us were using it wasn't ML,
some of it was like expert
system, like first generation AI.
And even in the ML approaches have been...
Some of it's gotten
more and more advanced.
There's some pretty cool
three layer convolution,
neural nets and all this other stuff,
and random forests work and other things
that's happening.
Some of that I know
some of it I don't know.
This isn't my field.
But what we applied were
some pretty simple models.
And we found that you could,
surprisingly improve how
you might access spectrum,
or how you might be able to share spectrum
compared to even the best models
for database managed spectrum sharing.
So there's a whole lot
of stuff that's going on.
One of the other things that
I'm working on right now,
so I just published a
paper about six months ago
on blockchain for Spectrum Management.
I did that really just because
I didn't want anyone else
to do it.
So I worked with a few friends.
I don't think it has any legs
at all, but it's out there.
Some of the cooler stuff
that we're working on,
and this is something I'm
doing actually on my own.
So when I mentioned 5G or is
this next generation network
that's gonna up our bandwidth,
and give us tons and tons
of spectrum and super
ultra or high reliability,
low latency kind of network connectivity.
A part of that is this
new radio access network.
Radio access network is what
we refer to as the antenna
and the smarts behind the
antenna that run the network,
and back toward the core.
There's an effort underway
looking at decomposing
this radio access network.
So you can create a bunch
of modular components
and the interfaces amongst them.
There's some concern
that that might open up
a whole bunch of security vulnerabilities.
And my view is that I don't believe it.
I believe that you may be
increasing the attack surface
but I believe that that's
just a smokescreen.
Because the big companies
don't want this modularize
because it's a threat to their ownership.
So the Huawei's and Nokia's
and others don't wanna
open it radio access network,
they want to sell the whole thing.
So interesting work in that space,
kind of moving between
looking at radio design
and security vulnerability.
I'm gonna move beyond that.
So I'm going to get to this test case.
What time do we have?
I'm way over.
Let me tell you about a
study that we did in 2012.
This is one of the things
that I was handed when I first
came into the Federal Government.
I was told that there was a
spectrum band called 1755.
This is one that I
mentioned at the beginning,
that what sold for 45 billion.
And I was handed this document
about this thick that said,
"Hey, we can't possibly use that,"
and this was the draft
report that was given to me,
because it was going to cost $18 billion
to move the people who were
in it, and 10 years to do it.
And most of these were DoD.
There was also covert
surveillance and some other things
in that space.
They also wanted the broadcast spectrum.
This is the claim of how
the use of the spectrum
is in that in that band, and you can see
that it's everywhere, but
like North Dakota and Montana.
So it's very, very, very covered in use.
What I did was I asked the
boulder labs right down here
to do measurements.
So there's a group within
the NTIA that does radio
measurements, and they
have a band that can go out
and do these sorts of things.
And they went out to the primary use sites
and did all a whole bunch of measurements.
And this is that band.
And by the way, this is
a little bit that sold
for 45 billion.
You can see that there's
pretty much nothing
going on in this space.
Again, across the X axis we have frequency
and on the on the Y axis we have power.
This represents services,
this represents services,
but for the most part
this is fairly unused.
So therefore, it looks like
a poster child for sharing.
And sharing could be implemented
through a whole bunch
of pretty simple approaches,
which is what actually happened.
When they figured this out, it took,
I'm just going to pop ahead.
It took a whole bunch of meetings,
and a whole lot of negotiation.
But at the end of the day,
this reallocation cost about
five years and $4 billion,
not these numbers in the
auction already said two.
So what I started doing as
I started looking at this,
the rather simplistic
approach that they took,
which how they did this
sharing is through antenna
placement, they said that the incumbents
couldn't be proximal to any
of the users of the spectrum.
They also tilted the
antennas in the way that they
were being used.
They put an exclusion zone saying,
"You can't use this
certain area near a fort."
Which makes sense, near
an army base, DoD base.
And then they reallocated
some that's why it cost money
that was the 5 billion or whatever it was.
But this is pretty simplistic.
This is low tech across the board.
So work that I just finished is looking
at what you could do.
And what was clear is that
even with a simple database
model where the DoD would
agree to participate and say,
"Hey, don't use this now in this area,
"that you could turn on and off antennas
"in a way that could
free up tons of megahertz
"of spectrum in certain areas."
The only thing that refutes
some of these findings
is for the most part, and
this is why I don't know
if it's a publishable result.
For the most part, while
I could show you could use
this...
My computer died.
[audience laughing].
Sorry.
There's only a few more
things and I can talk
about those off the top of my head.
While you can get more spectrum,
it's not where you really want it.
So it doesn't matter.
It's not New York City it's
somewhere where a basis.
So some of the other things
that I didn't get to,
I have a whole list of ML
based things that I think
could be really interesting to work on.
I talked a little bit about
the work that I'm doing
in natural language
processing as patent space.
And I can't wait to talk to
Martha and Jim about that.
The other thing, and this
ties back to my little
hush a phone, which somebody
has somewhere else we can,
I don't trust that one.
So the app for any of
this to move forward,
we need to start thinking
about trust models.
And there, they're about seven elements
of that I've that I've highlighted,
that I think really have
to be worked through.
And if we can't convince the incumbents,
that we're not going to
screw up their spectrum,
none of this will matter.
And they'll actually
have the ability to pull
a hush opinion on us and
say the sky is falling.
So some of this, almost
all of the elements
that I've described, and
again, there are about seven
of them are actually technical
issues, proof models,
trust models that could be different.
Up out of proofs on the
tech on the technology.
And this is one of those
things where I think,
again, a center or an institute
around that space in the,
moving toward very high
density use of spectrum
could be very beneficial.
I apologize again, I
didn't think this machine
was gonna was gonna croak.
But I'll be happy to share
my slides with you all.
And that's it.
Thank you.
[audience clapping]
Be happy to take some talks.
I think I'm it's fairly near.
Yes, sir.
Yep, they have it harder than we do,
for the most part, but they're
a little more organized.
They don't have as
powerful incumbent users.
So there's a little more flexibility
I didn't talk at length about this.
But I hinted at it when I said,
remember I said, I talked
about three gigahertz
to six gigahertz being essential.
So the whole world and
clicked including Europe
has allocated what's
called mid range spectrum
for 5G that's going to
be really sweet spectrum.
And that's 3.5 to six
gigahertz, that's going to allow
for a much lower dense
deployment of antennas.
why that matters is a denser
deployment of antennas
comes with a big cost.
And I'm talking like a
fifth as much or a 10th
as much infrastructure.
If you have that.
We have people that are sitting
on it and they won't budge.
And we have a government
that won't move it along.
So and I feel a little
torn right because I'd like
to beat up on AT and T and Verizon,
but I also like them to have
the spectrum and give me
my good 5G services.
There is no 5G, by the way
that by G that you're getting
is not 5G.
That's 4G ish at best.
So there's more there's a
the one problem is right.
The nationality issue is
there's all nation issues,
they're all on top of each other.
So they have to coordinate
in a much closer way,
but they know how to coordinate.
And they do that.
But they have actually
access to reallocate spectrum
a little more quickly.
It's not, but don't think
that it's any cheaper spectrum
is still a valued resource there.
And in England is what a
great model where England has,
UK, I should say, has kind
of an island effect, right?
So, it can it doesn't have
to worry about it's neighbors
we worry about Mexico in Canada,
we worry about between states we worry
about between providers
and in the United States.
England still sells markets
a spectrum for outrageous
amounts of money.
Same situation.
Yes sir.
SIR] [MUMBLING: .
So you can take a bigger picture,
which is what does
enforcement look like at all?
So I'm an amateur radio guy and I have
been for a long time.
And there used to be kind of
like a radio enforcement group
within radio operator
within the ham amateur
radio operators.
And that was to augment
what was being done
by the Federal Government.
The FCC used to have field
offices all over the country,
and its job was to look
for as well as enforce
interference issues.
Now, as you could well imagine,
that's not something
that's going to scale.
You can't have some government agency
that's going to be able to
go out there and monitor
and catch the catch the interference.
So what it turns out to
be is that it's incumbent
upon us by the by being spectrum owners,
if I'm AT and T for
example, to be able to know
that I'm being interfered with
and then be able to report
it and then be able to take an action.
That whole process is
is very, very lengthy
and it doesn't, it
doesn't happen in any kind
of meaningful time period.
So what you'd want,
right you'd want again,
throw technology at this problem.
You want to have some
kind of sensor network
that would say, who's being problematic
is going to use a more descriptive word.
And, but that's also
requires infrastructure.
So maybe there's a model where the phones
or the other devices that
exist could start picking up
who's who's interfering, and in what way.
But a lot of this has been
discussed from a technology
perspective and shown to be
able to be pretty powerful,
but it doesn't exist.
So at this point, the field
offices have shrunk by one 10th,
or one 10th of what they
were just 30 years ago.
And they, they've closed a lot of them.
And what they really
do anymore is a couple
of things they go out when
they get when they get assigned
a complaint from one
provider to another provider,
they go out and they do the measurement.
And it's usually like a
rusty bolt or some weird
thing like that.
It's usually not people purposely being,
pranksters or anything like that,
but that there was something
wrong with the infrastructure,
they still do have a group.
And by the way, those guys
are actually they go train
it lenco they train it,
they become federal agents.
They don't get to carry guns.
They have a badge lately,
like the love their badge,
but they're kind of ineffectual.
But they're they'll,
they'll go and they'll get the sheriff's
or they'll get the marshals
like to stop pirate radio.
And the pirate radio is still a thing,
which is kind of funny.
Like I find I find it amusing
now that we have the internet,
why do you care to broadcast when you can
just do whatever you want
on the internet, right?
But it's really not where
enforcement could be so much more.
And when I say enforcement, it's paulist.
It's the policies, it's the policing,
and then it's the punishment side of it.
How do you how do you wrap that together?
I can't imagine it
being done any way other
than through technology going forward?
It's the only way that I
think you could scale it.
Yes, sir.
MUMBLING: range, Wi-Fi,
present a meaningful
model going forward.
And it has panned out in certain areas.
There were there were a number
of stumbles along the way.
So one of the things that happened.
So if you have a device and this gets back
to the trust models that
I talked about before,
so we were getting DFS mode.
So this is this is an approach to saying
how you might how you might
might listen to spectrum
before you use it and
use it if you don't have
users in that space.
There were there was
equipment being manufactured,
where they when they
were tested by the FCC,
or by a third party and operated properly.
But when it was actually
shipped, it wasn't turned on.
So it actually lit up and
caused all this interference
up and down the East Coast.
So that's been resolved.
I think it's a powerful model.
One thing I will say like
I love these convoluted
cool technology approaches,
the simpler the model,
the better it's going to,
the better it's going to roll
out and if it's something
that the incumbent doesn't
get pissed off about,
it's even more likely to to be adopted.
Thank you.
[audience clapping].
