© 2013 InterDigital, Inc. All rights reserved.
19th European Wireless Research Conference
University of Surrey, Guildford, UK
April 16-18, 2013
Future Wireless Opportunities for
Millimetre Wave Systems
Douglas Castor
Principal Engineer, Innovation Labs
2 © 2013 InterDigital, Inc. All rights reserved.
InterDigital Snapshot • Approximately 200 engineers developing fundamental technology used in
every cellular wireless device
• Innovations and Technology development ahead of the curve, examples • 1985: First digital wireless call
• 2000+: Leading contributor to LTE and HSPA architectures
• Almost 20,000 issued and pending patents at year-end 20111
• History of successful technology development partnerships (e.g. Infineon, Nokia, Siemens, Sony, etc.)
___________________________ 1. As of June 30, 2012, Not pro forma for pending $375 million patent sale to Intel Corporation announced on June 18, 2012
All trademarks are the sole property of their respective owners.
R&D, Montreal, Canada
Headquarters, Wilmington, DE
R&D, San Diego, CA R&D, King of Prussia, PA
R&D, Melville, NY London, UK (2013)
3 © 2013 InterDigital, Inc. All rights reserved.
mmW Background
Propagation and Channel
Use Cases and Opportunities
4 © 2013 InterDigital, Inc. All rights reserved.
What is mmW?
• Electromagnetic radiation /
Spectrum Band • Frequencies: 30GHz to 300GHz
• Wavelengths: 1cm to 1mm
5 © 2013 InterDigital, Inc. All rights reserved.
Today’s mmW Wireless Applications
Security Screening
Inter-Satellite Car-to-Car Radar
In-room high speed
connectivity
Source: WiGig Alliance
6 © 2013 InterDigital, Inc. All rights reserved.
A Conjecture on year 2020 spectrum requirements…
Average
Speeds1
Population
Density
Devices/
Person
Busy
Hour
Required Area
Capacity
2013 0.8Mbps x 4984/km2 x 1.20 x 15% 0.7 Gbps/km2
2016 2.9Mbps x 5191/km2 x 1.40 x 20% 4.2 Gbps/km2
2020 30Mbps x 5477/km2 x 1.70 x 25% 70 Gbps/km2 London
1Cisco VNI 2012 2 3GPP TR 36.913 (Microcellular model: 2.6b/s/Hz/Cell, ISD=500m, 4x2MIMO) – Assumes perfect trunking efficiencies
Assuming only the performance of LTE-A today2 at 500m cell size
• In 2016 we might need 317MHz of spectrum
• By 2020 we might need more than 5GHz!
• Only mmW bands can support this demand
The “Bandwidth Crunch” – How much BW is needed?
100X by 2020, and will keep growing
7 © 2013 InterDigital, Inc. All rights reserved.
Emerging solutions to combat “Bandwidth Crunch”
• But...
• Higher risk in solution deployments compared to certainty of data demand
• Other complications: What about small cell backhaul? Interference problems?
• Reaching to 1000x will take significantly more spectrum
0
1
2
3
4
5
6
500m 400m 300m 200m Sp
ectr
um
Req
uir
emen
ts (
GH
z)
Intersite Distance(meters)
Simple model showing
benefits of small cells
2.6b/s/Hz/cell (LTE Only)
• United States
• PCAST: share 1,000MHz of federal spectrum with cellular providers
• European Commission • Licensed Shared Access (LSA)
concept • 1,200 MHz additional identified
by 2015 for wireless broadband
Small Cells Spectrum Sharing
~ 10X more spectrum
~ 5X spatial reuse
~ 2X spectral efficiency
= 100X x x
8 © 2013 InterDigital, Inc. All rights reserved.
Main driver of capacity
growth last 50 years1
Microcell
Femto Cellular Broadcast
Picocell
WiFi
Nano
mmW
Hotspots
It has always been about making the network more efficient
Millimeter Wave: The Next Frontier for Spectrum Utilization
This is unlikely to change anytime soon
• Next step: ultra-dense and hotspot technology using
sophisticated wireless access and backhaul
• Falling device cost & wealth of spectrum will drive
millimeter wave (mmW) use for dense wireless
networks
(3.5GHz5GHz10GHz20GHz 60Hz )
1 Source: Agilent, 2008 (Coopers Law)
2000x Number of cells
25x More Spectrum
20x Radio Design
Denser topologies are synergistic with mmW
Small Cells and Personal Area Communications
Ultra-dense
Device to Device
9 © 2013 InterDigital, Inc. All rights reserved.
mmW Spectrum Opportunities
30GHz of candidate spectrum unlicensed or lightly used
Ava
ilab
le
ban
dw
idth
6
27.5
3
1.2
38.6
40
45.5
4
6.9
57
66
71
76
81
86
92
95
10
0 G
Hz
0.5
GH
z
1.3
GH
z
1.4
GH
z
1.4
GH
z
9 G
Hz
5 G
Hz
5 G
Hz
2.9
GH
z
6 – 23 GHzFrequently used fixed
point-to-point, smaller
BW allocations
LMDS
Wireless cable TV (point-to-multipoint), competitive local
exchange carriers (CLEC) for
businesses, non-contiguous band.
39 GHz
Fixed point-to-point links for backhaul.
46 GHz
Vehicle radars and
cordless phones in small portions of the
band, otherwise
unallocated.
60 GHz
Unlicensed mmW
band (actual
allocations vary
by country)
E-Band
Lightly licensed
spectrum for
directional point -to-point links (specific
rules vary by
country)
Currently these bands
are lightly used.
0
2 G
Hz
40.5
4
2.5
40 GHz
Currently unallocated
for terrestrial
communications ,
adjacent to radio astronomy band.
10 © 2013 InterDigital, Inc. All rights reserved.
mmW Background
Propagation and Channel
Use Cases and Opportunities
11 © 2013 InterDigital, Inc. All rights reserved.
mmW Propagation: Misconception about pathloss
• “Pathloss is too high for mmW data” - incorrect
• Free space pathloss equation for isotropic antennas
• No additional pathloss if multiple antennas are packed into equivalent area, as frequencies increases
• An advantage over lower frequencies if higher order directivity mechanisms are employed (e.g. highly directive beams)
• However, impact from environment is more severe
kfdc
dfPL log20log20
4log20
Spreading of energy over sphere – not dependent on frequency
Assumes antenna proportional to λ2
12 © 2013 InterDigital, Inc. All rights reserved.
mmW Propagation Challenges compared to 2GHz
• 2GHz
• Negligible rain and air
• 8dB shadow losses
• mmW
• dB’s of rain and air losses higher at
1km
• ~20dB shadow losses
• What does this tell us?
• Opportunities at shorter ranges (<1km)
• Need mitigation against foliage losses • More antenna gain
• Mesh architectures
2GHz 60GHz
Environmental Losses 2GHz 40Ghz 60GHz
Oxygen + water vapor (per km)
0.007dB .1dB 15dB
Rain (per km) 0.003dB 7dB 10dB
Foliage 8dB 20dB 22dB
Oxygen absorption band
13 © 2013 InterDigital, Inc. All rights reserved.
mmW Propagation NLOS Studies
• Very few NLOS measurements
made until recently
• LMDS band studied in [1],
showing ~50% coverage for
<1km radius at 28GHz.
• NYU Poly (T. Rappaport)
• “5G Cellular” pathloss and
channel measurements at mmW
(28GHz, 38GHz, 60GHz, 70GHz)
• Demonstrated ~200m coverage
with no outage is possible using
steerable antennas •Measurements in New York City and
College Campus (Texas)
•~25dB gain antennas
[1] S.Y. Seidel and H.W. Arnold, "Propagation measurements at 28 GHz to investigate the performance of local multipoint distribution service (LMDS)," in IEEE Global Telecommunications Conference (Globecom), Nov. 1995, pp. 754-757.
T. Rappaport, “The Renaissance of Wireless Communications in the Massible Broadband Era”, IEEE VTC, 5 Sep 2012
14 © 2013 InterDigital, Inc. All rights reserved.
mmW Background
Propagation and Channel
Use Cases and Opportunities
15 © 2013 InterDigital, Inc. All rights reserved.
• Consumer video device connectivity • Tablets, portable media players and smartphones
• Uncompressed video supported with data rates of 10-28 Gbps
• 3D over WirelessHD
• Standardized through Wireless HD and IEEE 802.15.3c
mmW Personal Area Network (PAN)
16 © 2013 InterDigital, Inc. All rights reserved.
• “Wireless Office” connectivity
• High Speed Wireless Networking
• Broad range suitability for mobile devices and computing
• Standardized through WiGIG and IEEE 802.11ad:
• Up to 7 Gbps.
• Triband Wi-Fi support over 2.4 GHz, 5 GHz and 60 GHz
mmW Local Area Network (LAN)
• New 802.11aj (China mmW) considering new use cases
• Proposed data rates of > 10 Gbps in 45 GHz (Chinese allocation)
• Rapid Download Mass Data from Fixed Devices (e.g. Kiosk)
• Wireless access and backhaul
• Cloud Computing /Storage & Mass Data Synchronization
Source: WiGig Alliance Whitepaper, 2010
17 © 2013 InterDigital, Inc. All rights reserved.
Future opportunities for mmW PAN and LAN
Opportunity & Challenges
Current state-of-the art Next Step
Increased mmW Spatial Multiplexing
• Only analog beamforming, limited spatial multiplexing
• Multiple RF front-ends are expensive
• mmW multi-stream MIMO (single user through multi-users)
• Multiple RF front-end with digital beamforming
Adaptive Beamforming
• Lengthy beam training procedures create excess overhead
• Fast adaptation can provide robustness to dropouts
Range extension • Simple 1-hop relay • Full mesh architecture
Multi-band operation • Fast session transfer in 802.11ad allows full transfer between bands
• Partition control and data into separate bands
18 © 2013 InterDigital, Inc. All rights reserved.
1ABI reports that by 2017 80% of all small cells will have a wireless backhaul solution
Millimeter Wave Use Cases for 5G Cellular
Access •Access link capacity needs to grow to
support 80% CAGR in data demand
•Radio integration into devices has
already begun, enabling mmW bands
for small cell access
• Initially for cable replacement in 2013,
longer term for access
• By 2016, mmW will be in 1/3 of 802.11
shipments1
Backhaul • Backhaul is a top priority for small cell
deployments
• 80% of small cells will have wireless backhaul
• Cost of fiber is ~4x greater than wireless
(cumulative CAPEX/OPEX)
• Small Cell mesh inter-connectivity over
~150m
• Large indoor and outdoor public spaces
Small Mesh
60-80 GHz
19 © 2013 InterDigital, Inc. All rights reserved.
Higher frequency backhaul and access solutions to solve the future wireless capacity problem
- Capacity growth above 100x !
Extend mmW MAC/PHY
and add directional
mesh networking to
provide high capacity,
low cost backhaul
solution
Enable wireless backhaul
Full mmH
Architecture
Leverage mmW radios
which are becoming
commercially available
mmW for Small Cell Capacity Relief
mmWave Hotspots (mmH)
Extend support to Access links
and integrate with 3GPP
Adapt 3GPP RAN
Architecture to support
multi-RAT mmW
Next G
eNB
mmW
backhaul
mmW
access Traditional
Cellular
Link
20 © 2013 InterDigital, Inc. All rights reserved.
mmH Architecture
802.11
• Interfaces with Core Network using
standards based WLAN/3GPP
interworking
• Mesh extension of existing mmW
MAC/PHY
• Shared mB equipment for backhaul and
access
• Multi-band (2.4/5/60 GHz) support for
enhanced coverage
3GPP
• mB underlay integrated with RAN
architecture, with no Core Network
impact
• Control plane functions provided by
eNB
• Additional data capacity provided by
local mB
• Impact limited to RAN nodes, with no
impact to core
Options for Network Integration
3GPP 802.11
mB = Millimeter Wave Basestation mBA = mB Aggregator
21 © 2013 InterDigital, Inc. All rights reserved.
More than 500x over today’s small cell capacity
Campus Deployment
Ray tracing software computes power, delay,
and AoA information for each grid point
15
0m
• Goal of 70 Gbps/km2 can be met, with excess capacity useable for wireless backhaul • 90% coverage demonstrated in most scenarios (Campus, Urban and Munich) • 150m inter-site distances is reasonable
Foliage
22 © 2013 InterDigital, Inc. All rights reserved.
Challenge! - Human Blockage
• How significant is human blockage
(20dB penetration)?
• Statistical simulations performed to
analyze probability and impact of
blockages
• Steerable directional antenna
solutions are essential for robust
networks
Blockage from Other People
Self Blockage
0.5 blockers / m2 No blockers
No Self Blockage
Self Blockage
Impact of ~45% cell TP
Impact of ~15% cell TP
Simulation Assumptions • Probabilistic model of multiple paths to each terminal • 730 people/km2, randomly oriented • Beamwidth: 30deg (Tx), 60 deg (Rx)
23 © 2013 InterDigital, Inc. All rights reserved.
Challenge! - Directional Mesh (for Backhaul)
• Existing MAC solutions have limited directional neighbor support • 802.11s: Mesh extension for .11 omni-
directional transmissions
• 802.11ad: single-hop relay mode, no multi-hop
• Traditional 802.11 CSMA techniques are limited to time domain scheduling
• Requirements • Scheduling approach to address
deafness
• Simultaneous directional data transmissions
• Accommodations for Traffic QoS prioritization and buffer occupancy must be build into design
Interference Management
Forwarding
Scheduling / Qos
Prioritization
Mesh Management
Directional-Mesh MAC
24 © 2013 InterDigital, Inc. All rights reserved.
0
0.5
1
1.5
2
2.5
3
3.5
4
5 GHz 60 GHz
Challenge! - Interference Mitigation • Co-linear spaced deployments in urban canyons suffer significant
interference from LOS and multi-path
• Uncoordinated 60GHz can also be impacted by interference
• Solutions to consider
• Receiver interference cancellation techniques
• Scheduling and Radio Resource management (centralized vs. distributed controls)
• Measurements and interference mapping
Perfect Interference Cancellation
Gb
ps
With Interference
10th Percentile Link Throughput
25 © 2013 InterDigital, Inc. All rights reserved.
Summary
• mmW is the next frontier in mobile broadband spectrum • Satisfies exponential data demand
• mmW devices will be available
• Viable candidate for 5G Mobile
• 2012 saw increasing research interest in mmW • 3GPP R12 and beyond planning
• NSF AIR Project & NYU-Poly
• IWPC “MoGiG”
• IEEE 802.11aj (China mmW)
• More research collaborations are needed • RF Phased Arrays
• MAC & PHY for directional links
• Network integration
26 © 2013 InterDigital, Inc. All rights reserved.
Thank You!
Doug Castor Principal Engineer, Innovation Labs InterDigital Communications, LLC King of Prussia, PA 19406 +1 610.878.5674 [email protected] www.linkedin.com/in/douglasrcastor
18
April
