SCALING MOBILE BROADBAND

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Dec 12, 2013 (3 years and 8 months ago)

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

SCALING MOBILE BROADBAND

CAPACITY


A FRESH LOOK


IEEE
-
USA PRESENTATION TO FCC

NOVEMBER 6, 2012

Arogyaswami
Paulraj

Broadcom Corporation & Stanford University

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.


Headquartered
in Irvine,
CA


A
global leader in semiconductors
for wired
and
wireless
communications


~ 11,200 staff worldwide


75 design
centers globally


2011
net revenue
of $7.39
billion

Broadcom Corporation


Sr. Advisor to Broadcom Corp.


Professor
(
Emeritus), Stanford
University

Arogyaswami Paulraj

BROADCOM CORP. AND PRESENTER INFO

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

WIRELESS


CONNECTING EVERYTHING

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

MOBILE BROADBAND

DRIVERS


Richer Media


Lower Latency


Greater User Density


Service Criticality


Higher Availability Expectation


Greater
Geographic Penetration

Higher
Network Capacity

Higher
Areal
R
eliability

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.


MOBILE BROADBAND

DEMAND GROWTH

Industry Forecasts of Mobile Data Traffic

Traffic Relative to 2009

Cisco

Coda

Yankee Group

Average

Source:
FCC, October 2010

80% CAGR

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

Spectrum

(Hz
)

Spectrum

Efficiency

(BPS / Hz / Cell
)

No. of
Cells

/
Sq. Mile

Capacity

(BPS / Sq. Mile)

=

x

x

GROWING
NETWORK
CAPACITY

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

FCC Goal:

300 MHz by 2015 and additional 500 MHz by 2020 in the
“mobile” bands


optimistic ??


Allocating spectrum


Exclusively licensed


Shared Rights


Unlicensed

ADD MOBILE SPECTRUM

Spectrum

(Hz
)

Spectrum

Efficiency

(BPS / Hz / Cell
)

No. of
Cells

/
Sq. Mile

Capacity

(BPS / Sq. Mile)

=

x

x

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

WHAT CAN SPECTRUM BUY?


At low SNRs (typical), we cannot increase BPS / User by adding
bandwidth without proportionally adding power


Uplink:

Power in handsets already at Max (SAR)


so more spectrum mainly
buys more users, unless we shrink cell size
or add antennas


Downlink:

Power in BS is not at
max
(as yet) so

more
spectrum allows scaling BPS/user

and
number of
users

Bandwidth

(Hz
)

BPS /
User

=

x

Log (
1 + )

Signal
(Power per Hz)

Noise
(Power per Hz
)

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

Early MIMO

Better
reuse,
adaptive modulation

MORE SPECTRUM EFFICIENCY

Spectrum

(Hz
)

Spectrum

Efficiency

(BPS /
Hz / Cell)

No. of
Cells

/
Sq. Mile

Capacity

(BPS / Sq. Mile)

=

x

x

0.03

0.09

0.16
-
0.24

0.48

0.72

1.08
-
1.29

1.36
-
1.5

0.0
0.5
1.0
1.5
GPRS
EDGE
WCDMA
HSDPA,
Rel 5
HSPA,
Rel 6
HSPA,
Rel 7
LTE
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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

ADD CELLS

Spectrum

(Hz
)

Spectrum

Efficiency

(BPS /
Hz / Cell)

No. of
Cells

/
Sq. Mile

Capacity

(BPS / Sq. Mile)

=

x

x

Challenges in adding cells


High CAPEX
+ OPEX
costs

(
US cell growth 7
-
8% recent years)


Zoning /
access


Backhaul: Fiber is prohibitive

in
some areas, DSL/Cable do not

scale (
500 MBPS/Cell),
small cell radio back
haul faces many
technology issues

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

x10

capacity
growth


optimistic

MOBILE BROADBAND

CAPACITY GROWTH TO 2017

Cell

Type

Add Cells

Add Spectrum

(Low Band)

Add

Spectrum

Efficiency


Outdoor

Macro

+

50 %

+30%


+50%

-

MIMO

-

CoMP

-

Higher QAM

-

ICIC

Micro
-
Pico

+ 400%

Indoor


Covered

by Indoor Networks

12

A New Approach

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

FREQUENCY VS. RANGE (FIXED APERTURE)

Frequency

GHz

Tx

Aperture


Sq. cm

Rx Aperture

Sq. M

Range

Km.


UPLINK

1.0


1

1

1

2.0



0.25

0.25

0.5

0.25

1

1

1

1

2

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

FREQUENCY VS. CAPACITY (FIXED APERTURE)

Frequency

GHz

No. of Tx

Antennas

No. of Rx
Antennas

Capacity

Mbps


UPLINK

1.0


1

1

1

2.0



1

4

4

4

4

8

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.


Current (Small) Aperture

Higher
Frequency
Band


Current (Low)
Frequency Band
Larger Aperture

HYPER MIMO (H

MIMO)

Adding Antennas

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

ATTENUATION LOSS


HIGH BAND

Attenuation
Loss
from
Atmosphere
,
Rain
and
Foliage
is
Acceptable
in
Small Cells

Atmospheric

Rain

Weissberger’s

Mode

Foliage

where,

L = The loss due to foliage (dB)

f = The transmission frequency (GHz)

d = The depth of foliage ‘’’along’’’ the path (m)

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

H
-
MIMO PROPAGATION


HIGH BAND


High shadowing and low diffraction


so only LOS or
Near LOS propagation will work


ball parks


F
oliage loss is manageable with “look down” rather than
“look through” deployments


Small cells keeps atmospheric and rain loss manageable


Handset antennas can be switched to avoid hand / head
shadowing

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

H
-
MIMO: ANTENNA AND RF HARDWARE


Long history in military radar
applications


Wi
-
Fi 802.15c and .11ad already
building multi element arrays


Broadcom, IBM, Cybeam, …
have built low
-
cost integrated
array modules


Low band large aperture arrays
need multi
-
use models


bill
boards, architectural structures

Low cost
high band RF
array technology
is possible

16 element Active Array

802.15c

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

H
-
MIMO: BASEBAND AND NETWORK COMPLEXITY


With Multi
-
User(MU)
-
MIMO, a 50 user baseband
complexity is lower than Single
U
ser 4x4 MIMO






Other layer 2 and 3 technologies are no different from
current systems


data rates are just scaled up


But strong shadowing will require rapid multi
-
cell
coordination

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

Use Case:
Elevated
base station antenna array, small cell,
for high density
outdoor pedestrian
subscribers

H
-
MIMO: SMALL APERTURE


HIGH BAND


Scale up frequency by
K
f



No. of BTS antennas up by K
f
2


No of handset antennas 1 (or more)


Technology


MU
-
MIMO


Capacity scales by K
f
2


Range unaffected

(ignoring absorption loss)

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

Use Case:
Large
array
base stations for nomadic

and
vehicular subscribers

H
-
MIMO: LOW BAND


LARGE APERTURE


Aperture = K
a

times wider and taller


No. of BS antennas up by K
a
2


No. of handset antennas 1 (or more)


Technology


MU
-
MIMO


Capacity scales by K
a
2


Range “doublings” = log (K
a
2
)

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

LOW BAND


LARGE APERTURE

(MOBILE STATION)

Use Case:
Vehicular subscribers
in macro cell environment


No of vehicular antennas = N


Technology


Up Link
and
Down
Link beam forming


Range “doublings” = log (N)


Technology


MU
-
MIMO / COMP


Capacity scale up by x10 ?

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

H
-
MIMO REGULATORY ISSUES


New
s
pectrum allocation in high bands for “mobile” use


Spectrum licensing models in high bands


exclusive,
shared, unlicensed


RF bio
-
safety in high and low bands


High gain beam forming increases EIRP


Multi
-
User MIMO


multiple beams


Near field


Base station zoning in low bands (for physically large
arrays)

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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

x500

capacity

Cell

Type

Add Cells

Add Spectrum

Add

Spectrum

Efficiency

Outdoor

Low

band

High Mobility

+

50 %

+30%

+100%

Vehicular

Backhaul

High

band

Low Mobility

+ 50%

150%

+10,000%

H
-
MIMO

MOBILE BROADBAND POTENTIAL

CAPACITY GROWTH 2017


2022




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Broadcom Proprietary and Confidential. © 2012 Broadcom Corporation. All rights reserved.

SUMMARY


Mobile broadband capacity will severely lag demand if
we rely only on current approaches


Huge capacity gains can come from H
-
MIMO


Needs significant spectrum, regulatory and technology
initiatives

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Thank You