1
Energy-Neutral System-Level Analysis and Optimization of 5G Wireless Networks
(energy harvesting and wireless power transfer)
Marco Di Renzo
Paris-Saclay University Laboratory of Signals and Systems (L2S) – UMR8506
CNRS – CentraleSupelec – University Paris-SudParis, France
IEEE European Signal Processing Conference2016 IEEE EUSIPCO – Budapest, Hungary, Aug. 29 – Sep. 2, 2016
H2020-MCSA
Energy Neutrality – Part II
2
5G-PPP – 5G Network Vision
35G-PPP 5G Vision Document, “The next-generation of communication networks and services”, March2015. Available: http://5g-ppp.eu/wp-content/uploads/2015/02/5G-Vision-Brochure-v1.pdf.
5G-PPP – 5G New Service Capabilities
45G-PPP 5G Vision Document, “The next-generation of communication networks and services”, March2015. Available: http://5g-ppp.eu/wp-content/uploads/2015/02/5G-Vision-Brochure-v1.pdf.
5G-PPP in a nuthsell: To conduct research and innovation work that will form the basis of the 5G
infrastructure for the Future Internet for a wide range of applications
5G is a key enabler for the IoT, providing a platform to connect a massive numberof sensors, devices, actuators with stringent energy and transmission constraints
5G will be designed to be a sustainable and scalable technology
5G will bring drastic energy efficiency improvement and harvest energy fromeverywhere, solar, thermal, vibration and electromagnetic (RF) sources
Energy-Neutral Cellular Base Stations …
5
… and Beyond Cellular …
6S. Bi, C. K. Ho, and R. Zhang, “Wireless powered communication: Opportunities and challenges”, IEEECommun. Mag., vol. 53, no. 4. pp. 117–125, Apr. 2015.
The 5G (Cellular) Network of the Future
7
Buzzword 1: Densification
1. Access Points (Network Topology, HetNets)
2. Radiating Elements (Large-Scale/Massive MIMO)
Buzzword 2: Spectral vs. Energy Efficiency Trade-Off
1. Shorter Transmission Distance (Relaying, Femto, D2D)
2. Total Power Dissipation (Single-RF MIMO, Antenna Muting)
3. RF Energy Harvesting, Wireless Power Transfer, Full-Duplex
Buzzword 3: Spectrum Scarcity
1. Cognitive Radio and Opportunistic Communications
2. mmWave Cellular Communications
Buzzword 4: Software-Defined, Centrally-Controlled, Shared, Virtualized
1. SDN, NFV, Network Resource Virtualization (NRV)
Wireless Power Transfer & Energy Harvesting… Potential / Futuristic Scenarios based on Renewable Energy …
Y. Mao, Y. Luo, J. Zhang, and K. B. Letaief, "Energy Harvesting Small Cell Networks: Feasibility,Deployment, and Operation", IEEE Commun. Mag., June 2015.
Wireless Power Transfer & Energy Harvesting… Potential / Futuristic Scenarios based on RF Power Transfer …
A. Ghazanfari, H. Tabassum, and E. Hossain, "Ambient RF Energy Harvesting in Ultra-Dense Small CellNetworks: Performance and Trade-offs", IEEE Wireless Commun. Mag., Apr. 2015.
10
Wireless Power Transfer – RF Energy HarvestingSWIPT: Simultaneous Wireless Information and Power Transfer
Information + EnergyReceiver
Why Now? Is it Feasible?
115G-PPP 5G Vision Document, “The next-generation of communication networks and services”, March2015. Available: http://5g-ppp.eu/wp-content/uploads/2015/02/5G-Vision-Brochure-v1.pdf.
Why Now? Is it Feasible?
12Elia, Power generation, available online at http://www.elia.be/en/grid-data/power-generation.
SOLAR and WIND can provide the necessary electric power to Small Cells 100 W electric power can be generated by a 121 cm x 53.6 cm solar panel under
sunlight radiation or by a rotor with a 1 m diameter under an 8 m/s wind speed
They nicely complement each other over a short and a long term horizons
Solar Powered BSs Exist…
13V. Chamola and B. Sikdar, "Solar Powered Cellular Base Stations: Current Scenario, Issues and ProposedSolutions", IEEE Commun. Mag., May 2016.
Very Recent Developments: NB-LTE for IoT
14
Very Recent Developments: NB-LTE for IoT
15
WHAT’S THAT? NB-LTE is one of the proposed “clean slate” options for adapting LTE
technology to make it suitable for low cost, low power, wide area networksfor IoT applications
NB-LTE is one of the 4G LTE variants being looked at for IoT. Standardsbody 3GPP is studying no less than four possible ways to adapt 4G LTE tomake it suitable for low power wide area IoT networks
WHY THAT? NB-LTE is well-suited for the IoT market segment “because of its low
implementation cost, ease of use and power efficiency”
Cellular networks already cover 90 percent of the world’s population so itmakes sense to leverage this global footprint to support and drive IoTadoption through the standardization of NB-LTE
Very Recent Developments: Freevolt Technology
16
WHAT’S THAT? A patented technology developed by an international team from Drayson
Technologies and Imperial College London
Drayson Technologies claims to be the first to market this technology, whichwas recently commercially licensed (PA Consulting Group was granted it)
HOW IT WORKS? Freevolt harvests indoor & outdoor ambient RF waves across multiple bands
and uses the energy to power low energy electronic devices
Freevolt is able to pick up unused electro-magnetic energy from sources suchas mobile cellular networks and Wi-Fi without the need for charging by cableor a dedicated transmitter
Freevolt can harvest this energy without interrupting the data signal. The typeof devices it is able to power will depend the device’s energy budget, formfactor and the amount of available ambient radio energy
The range of possible applications is endless, but IoT sensors, beacons andwearables, such as fitness bands, clothing and medical garments, are obviousmarkets. The company has developed a commercially available personal airpollution sensor called CleanSpace Tag
Very Recent Developments: Freevolt Technology
17
18
SWIPT – System-Level Modeling and Optimization
M. Di Renzo and W. Lu, “System-Level Analysis of Cellular Networks with Simultaneous Wireless Informationand Power Transfer: Stochastic Geometry Modeling”, IEEE Trans. Vehicular Technol., IEEE Early Access.
Joint Statistical Characterization of Harvested Energy and Achievable Rate in the Presence of Other-Cell Interference
Major Difference: Information (rate) and harvesting (energy) requirements need to be jointly satisfiedSetup: LOS/NLOS, beamforming, etc.
Harvesting: Interference is GOOD Information: Interference is BAD
SWIPT – System-Level Modeling
19
Directional beamforming
Accurate channel modeling: LOS/NLOS links
Cell association criterion: smallest path-loss
maxBS BS
BS minBS BS
if 2
if 2
Gg
G
D
SWIPT – System-Level Modeling
20
Stochastic geometry is used for system-level analysis
Experimental validation with actual BSs and building deployments
Modeling (PPP)
Validation (OFCOM + OS in London, UK)
SWIPT – PPP + LOS/NLOS, etc…
21
… not an easy mathematical problem …
SWIPT – PPP + LOS/NLOS, etc…
22
… not an easy mathematical problem …
23
System-Level Modeling of Cellular Networks – IndustryThe NTT DOCOMO 5G Real-Time Simulator
DOCOMO 5G White Paper, “5G Radio Access: Requirements, Concept and Technologies”, July 2014.
24
Life of a 3GPP Simulation Expert (according to Samsung)
Charlie Zhang, Simons Conference on Networks and Stochastic Geometry, October 2015, Austin, USA.
Modeling Cellular Networks – In Academia
25
Conventional approaches to the analysis and design of cellularnetworks (abstraction models) are:
The Wyner model
The single-cell interfering model or dominant interferers model
The regular hexagonal or square grid modelD. H. Ring and W. R. Young, “The hexagonal cells concept”, Bell Labs TechnicalJournal, Dec. 1947. http://www.privateline.com/archive/Ringcellreport1947.pdf.
Modeling Cellular Networks – In Academia
26
Conventional approaches to the analysis and design of cellularnetworks (abstraction models) are:
The Wyner model
The single-cell interfering model or dominant interferers model
The regular hexagonal or square grid modelD. H. Ring and W. R. Young, “The hexagonal cells concept”, Bell Labs TechnicalJournal, Dec. 1947. http://www.privateline.com/archive/Ringcellreport1947.pdf.
Realityvs.
AbstractionModeling
The Conventional Grid-Based Approach
27
Probe mobile terminal
Macro base station
The Conventional Grid-Based Approach
28
Probe mobile terminal
Macro base station
w 211 1
0 01, B log 1 SINR ,i ir rrC r
The Conventional Grid-Based Approach
29
Probe mobile terminal
Macro base station
w 222 2
0 02, B log 1 SINR ,i ir rrC r
The Conventional Grid-Based Approach
30
Probe mobile terminal
Macro base station
w 233 3
0 03, B log 1 SINR ,i ir rrC r
The Conventional Grid-Based Approach
31
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The Conventional Grid-Based Approach
32
Simple enough… So, where is the issue?
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Nn
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The Conventional Grid-Based Approach
33
Simple enough… So, where is the issue?
The answer: …this spatial expectation
cannot be computed mathematically…
0 0 0
0
,1
w 21
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1 B log 1 SINR ,
i
Nn
i irn
n
nN
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nr
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The Conventional Grid-Based Approach: (Some) Issues Advantages:
Dozens of system parameters can be modeled and tuned in suchsimulations, and the results have been sufficiently accurate as to enablethe evaluation of new proposed techniques and guide field deployments
Limitations: Actual coverage regions deviate from a regular grid Mathematical modeling and optimization are not possible. Any elegant
and insightful Shannon formulas for cellular networks? The abstraction model is not scalable for application to ultra-dense
HetNets (different densities, transmit powers, access technologies, etc…)
34
Let’s Change the Abstraction Model, Then…
35
Regulardeployment
Let’s Change the Abstraction Model, Then…
36
Regulardeployment
Randomdeployment
(PPP)
Stochastic Geometry Based Abstraction Model
37
A RANDOM SPATIAL MODEL for Heterogeneous CellularNetworks (HetNets): K-tier network with BS locations modeled as independent marked
Poisson Point Processes (PPPs)
The PPP model is surprisingly good for 1-tier as well (macro BSs):lower/upper bound to reality and trends still hold
The PPP model makes even more sense for HetNets due to lessregular BSs placements for lower tiers (femto, etc.)
Stochastic Geometry emerges as a powerful tool for theanalysis, design and optimization
of ultra-dense HetNets
An Emerging (Tractable) Approach
Beyond the PPP: Possible, but Math is More Complicated
38
Y. J. Chun, M. O. Hasna, A. Ghrayeb, and M. Di Renzo, “On modeling heterogeneous wireless networksusing non-Poisson point processes”, IEEE Commun. Mag., submitted. [Online]. Available:http://arxiv.org/pdf/1506.06296.pdf.
Matern Hard-Core PPTake a homogeneous PPP and remove any pairs of points that are closer to each other
than a predefined minimum distance R
PPP-based Abstraction
39
How It Works (Downlink – 1-tier)
Probe mobile terminal
PPP-distributed macro base station
PPP-based Abstraction
40
How It Works (Downlink – 1-tier)
Probe mobile terminal
PPP-distributed macro base station
PPP-based Abstraction
41
How It Works (Downlink – 1-tier)
Probe mobile terminal
PPP-distributed macro base station
PPP-based Abstraction
42
How It Works (Downlink – 1-tier)
Probe mobile terminal
PPP-distributed macro base station
Intended link
w 211 1
0 01, B log 1 SINR ,i ir rrC r
PPP-based Abstraction
43
How It Works (Downlink – 1-tier)
Probe mobile terminal
PPP-distributed macro base station
Intended link
w 222 2
0 02, B log 1 SINR ,i ir rrC r
PPP-based Abstraction
44
How It Works (Downlink – 1-tier)
Probe mobile terminal
PPP-distributed macro base station
Intended link
w 233 3
0 03, B log 1 SINR ,i ir rrC r
PPP-based Abstraction
45
0 0 0
0
,1
w 21
1E , ,
1 B log 1 SINR ,
i
Nn
i irn
n
nN
i
nr
n
rr r r
r
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CN
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PPP-based Abstraction
46
Are you kidding me? ... What makes it different?
0 0 0
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,1
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Nn
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nr
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PPP-based Abstraction
47
Are you kidding me? ... What makes it different?
The answer: …this spatial expectation
can be computed mathematically…
0 0 0
0
,1
w 21
1E , ,
1 B log 1 SINR ,
i
Nn
i irn
n
nN
i
nr
n
rr r r
r
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… On Abstraction Modeling …
48
George Edward Pelham Box (18 October 1919 – 28 March 2013)
StatisticianFellow of the Royal Society (UK)
Director of the Statistical Research Group (Princeton University)
Emeritus Professor(University of Wisconsin-Madison)
“…all models are wrong, but some are useful…”
Is This Abstraction Model Accurate?
49OFCOM: http://stakeholders.ofcom.org.uk/sitefinder/sitefinder-dataset/ORDNANCE SURVEY: https://www.ordnancesurvey.co.uk/opendatadownload/products.html
Methodology:
Is This Abstraction Model Accurate?
50OFCOM: http://stakeholders.ofcom.org.uk/sitefinder/sitefinder-dataset/ORDNANCE SURVEY: https://www.ordnancesurvey.co.uk/opendatadownload/products.html
Methodology: Actual base station locations from OFCOM (UK)
OFCOM:London“London
Bridge area”
Is This Abstraction Model Accurate?
51OFCOM: http://stakeholders.ofcom.org.uk/sitefinder/sitefinder-dataset/ORDNANCE SURVEY: https://www.ordnancesurvey.co.uk/opendatadownload/products.html
Methodology: Actual base station locations from OFCOM (UK)
Actual building footprints from ORDNANCE SURVEY (UK)
ORDNANCESURVEY:London“London
Bridge area”
Is This Abstraction Model Accurate?
52OFCOM: http://stakeholders.ofcom.org.uk/sitefinder/sitefinder-dataset/ORDNANCE SURVEY: https://www.ordnancesurvey.co.uk/opendatadownload/products.html
Methodology: Actual base station locations from OFCOM (UK)
Actual building footprints from ORDNANCE SURVEY (UK)
Channel model added on top (1-state and 2-state with LOS/NLOS)
Mobile terminal
Base station (outdoor)
Base station (rooftop)NLOS
LOS
NLOS
2-state: the location of MTs and BSsand the location/shape of buildingsdetermine LOS/NLOS conditions
1-state: all links are either in LOS orNLOS regardless of the topology
The London Case Study (1/7)
53
O2 + Vodafone O2 Vodafone
Number of BSs 319 183 136
Number of rooftop BSs 95 62 33
Number of outdoor BSs 224 121 103
Average cell radius (m) 63.1771 83.4122 96.7577
The London Case Study (2/7)
54
The London Case Study (3/7)
55
The London Case Study (4/7)
56
PPP Accuracy: 1-State Channel Model
O2+VODAFONE O2 VODAFONE
OFCOM: Actual base station locations, (actual building footprints), actual channels
PPP: Random base station locations, (actual building footprints), actual channels
The London Case Study (5/7)
57
PPP Accuracy: 2-State Channel Model
O2+VODAFONE
O2 VODAFONE
The London Case Study (6/7)
58
1-State vs. 2-State Channel Models: Only LOSWorse coverage, as interference is enhanced
Only NLOS In-between, as interference is reduced but probe link gets worse
LOS and NLOSMore realistic: we can model it with stochastic geometry
The London Case Study (7/7)
59
Omni-Directional vs. 3GPP Radiation Patterns
Why Is This Modeling Approach So Accurate?
60
O2 + Vodafone O2 Vodafone
Number of BSs 319 183 136
Number of rooftop BSs 95 62 33
Number of outdoor BSs 224 121 103
Average cell radius (m) 63.1771 83.4122 96.7577
Intrigued Enough?
61
W. Lu and M. Di Renzo, “Stochastic Geometry Modeling of Cellular Networks: Analysis, Simulation andExperimental Validation”, ACM Int. Conf. Modeling, Analysis and Simulation of Wireless and MobileSystems, Nov. 2015. [Online]. Available: http://arxiv.org/pdf/1506.03857.pdf.
… Further Information and Case Studies …
How It Works: The Magic of Stochastic Geometry (1/5)
62
… understanding the basic math …
0rir0BS
covP Pr SINR T
2
20
SINR o o
agg
P h rI r
0
20
\agg i i
i BSI r P h r
2
cov 20
P Pr ...o o
agg
P h rT
I r
is a PPP
iBS
How It Works: The Magic of Stochastic Geometry (2/5)
63
… understanding the basic math …
0 0
0 0
2
cov 20
2 2 10
2 10,
2 1 1
P Pr
Pr
E exp
E exp MGF
agg
agg
o o
agg
o agg o
agg oI r r
r o oI r
P h rT
I r
h I r P Tr
I r P Tr
P Tr P Tr
2 expoh
MGF
EX
sXX
s
e
How It Works: The Magic of Stochastic Geometry (3/5)
64
… understanding the basic math …
0 0
00
2 1 1cov
2 1 1
0
P E exp MGF
exp MGF PDF
agg
agg
r o oI r
rI r
T P r P Tr
T P P T d
How It Works: The Magic of Stochastic Geometry (3/5)
65
… understanding the basic math …
0 0
00
2 1 1cov
2 1 1
0
P E exp MGF
exp MGF PDF
agg
agg
r o oI r
rI r
T P r P Tr
T P P T d
Trivial so far… where is the magic?
How It Works: The Magic of Stochastic Geometry (3/5)
66
… understanding the basic math …
Trivial so far… where is the magic?Stochastic Geometry provides us with themathematical tools for computing, in closed-form,the MGF and the PDF of the equation above
0 0
00
2 1 1cov
2 1 1
0
P E exp MGF
e Mxp GF PDF
agg
agg
r o oI r
rI r
T P r P Tr
T P P T d
How It Works: The Magic of Stochastic Geometry (4/5)
67
… understanding the basic math …
0
20
\agg i i
i BSI r P h r
The aggregate other-cell interferenceconstitues a Marked PPP, where themarks are the channel power gains
0
2PDF 2 expr The PDF of the closest-distancefollows from the null probability ofspatial PPPs
0
MGF ...aggI r s
The MGF of the aggregate other-cell interference follows from theProbability Generating Functional(PGFL) of Marked PPPs
How It Works: The Magic of Stochastic Geometry (5/5)
68
… understanding the basic math …
200
2
0
2
0
2
,\
2
\
2
MGF E exp
E E exp
exp 2 1 E exp
agg i
i
i
i iI r hi BS
i ihi BS
i i i ihr
s s P h r
sP h r
sP h d
PGFL
available in closed-form in papers
So Powerful and Just Two Lemmas Need to be Used…
69
Stochastic Geometry: Advantages and Limitations
70
Advantages: “What the Lovers Say” Elegant mathematical formulation for network-wide performance metrics
Often closed-form and insightful
Provides utility functions for system design and optimization
…
Limitations: “What the Others Say” – MISCONCEPTION The PPP assumption may not be realistic for some tiers of BSs
Practical transmission technologies are more complicated than SISO
Practical path-loss models are bounded and different for LOS/NLOS
Practical channel models are more complicated than Rayleigh fading
Closed-form formulation only for specific parameters
In general, one or two integrals need to be accepted …
71
Three New and General Mathematical Tools
1. Average Rate: The MGF-Based Approach M. Di Renzo, A. Guidotti, and G. E. Corazza, “Average Rate of Downlink Heterogeneous
Cellular Networks over Generalized Fading Channels – A Stochastic Geometry Approach”,IEEE Trans. Commun., vol. 61, no. 7, pp. 3050–3071, July 2013.
2. Average Error Probability: The EiD-Based Approach M. Di Renzo and W. Lu, “The Equivalent–in–Distribution (EiD)–based Approach: On
the Analysis of Cellular Networks Using Stochastic Geometry”, IEEE Commun. Lett.,vol. 18, no. 5, pp. 761-764, May 2014.
M. Di Renzo and W. Lu, “Stochastic Geometry Modeling and Performance Evaluation ofMIMO Cellular Networks by Using the Equivalent-in-Distribution (EiD)-BasedApproach”, IEEE Trans. Commun., vol. 63, no. 3, pp. 977-996, March 2015.
3. Coverage Probability: The Gil-Pelaez-Based Approach M. Di Renzo and P. Guan, “Stochastic Geometry Modeling of Coverage and Rate of
Cellular Networks Using the Gil-Pelaez Inversion Theorem”, IEEE Commun. Lett., vol.18, no. 9, pp. 1575–1578, September 2014.
72
Many Tools/Results are Now Available… M. Di Renzo, C. Merola, A. Guidotti, F. Santucci, and G. E. Corazza, “Error Performance of
Multi–Antenna Receivers in a Poisson Field of Interferers – A Stochastic Geometry Approach”,IEEE Trans. Commun., vol. 61, no. 5, pp. 2025–2047, May 2013.
M. Di Renzo, A. Guidotti, and G. E. Corazza, “Average Rate of Downlink Heterogeneous CellularNetworks over Generalized Fading Channels – A Stochastic Geometry Approach”, IEEE Trans.Commun., vol. 61, no. 7, pp. 3050–3071, July 2013.
M. Di Renzo and W. Lu, “The Equivalent–in–Distribution (EiD)–based Approach: On theAnalysis of Cellular Networks Using Stochastic Geometry”, IEEE Commun. Lett., vol. 18, no. 5,pp. 761-764, May 2014.
M. Di Renzo and P. Guan, “A Mathematical Framework to the Computation of the ErrorProbability of Downlink MIMO Cellular Networks by Using Stochastic Geometry”, IEEE Trans.Commun., vol. 62, no. 8, pp. 2860–2879, July 2014.
M. Di Renzo and P. Guan, “Stochastic Geometry Modeling of Coverage and Rate of CellularNetworks Using the Gil-Pelaez Inversion Theorem”, IEEE Commun. Lett., vol. 18, no. 9, pp.1575–1578, September 2014.
M. Di Renzo and W. Lu, “End-to-End Error Probability and Diversity Analysis of AF-Based Dual-Hop Cooperative Relaying in a Poisson Field of Interferers at the Destination”, IEEE Trans.Wireless Commun., vol. 14, no. 1, pp. 15–32, January 2015.
M. Di Renzo and W. Lu, “Stochastic Geometry Modeling and Performance Evaluation of MIMOCellular Networks by Using the Equivalent-in-Distribution (EiD)-Based Approach”, IEEE Trans.Commun., vol. 63, no. 3, pp. 977-996, March 2015.
M. Di Renzo and W. Lu, “On the Diversity Order of Selection Combining Dual-Branch Dual-HopAF Relaying in a Poisson Field of Interferers at the Destination”, IEEE Trans. Veh. Technol., vol.64, no. 4, pp. 1620-1628, June 2015.
… and, Recently, Have Been Proposed M. Di Renzo, “Stochastic Geometry Modeling and Analysis of Multi-Tier Millimeter Wave
Cellular Networks”, IEEE Trans. Wireless Commun., vol. 14, no. 9, pp. 5038-5057, Sep. 2015.
W. Lu and M. Di Renzo, “Stochastic Geometry Modeling and System-LevelAnalysis/Optimization of Relay-Aided Downlink Cellular Networks”, IEEE Trans. Commun., vol63, no. 11, pp. 4063-4085, Nov. 2015.
M. Di Renzo and P. Guan, “Stochastic Geometry Modeling, System-Level Analysis andOptimization of Uplink Heterogeneous Cellular Networks with Multi-Antenna Base Stations”,IEEE Trans. Commun., IEEE Early Access.
M. Di Renzo and W. Lu, “System-Level Analysis/Optimization of Cellular Networks withSimultaneous Wireless Information and Power Transfer: Stochastic Geometry Modeling”, IEEETrans. Vehicular Technol., IEEE Early Access.
F. J. Martin-Vega, G. Gomez, M. C. Aguayo Torres, and M. Di Renzo, “Analytical Modeling ofInterference Aware Power Control for the Uplink of Heterogeneous Cellular Networks”, IEEETrans. Wireless Commun., IEEE Early Access.
Y. Deng, L. Wang, M. Elkashlan, M. Di Renzo, and J. Yuan, “Modeling and Analysis of WirelessPower Transfer in Heterogeneous Cellular Networks”, IEEE Trans. Commun., IEEE EarlyAccess.
73
… and, Recently, Have Been Proposed
A Complete Mathematical Framework for System-Level Analysis
M. Di Renzo, W. Lu, and P. Guan, “The Intensity MatchingApproach: A Tractable Stochastic Geometry Approximation toSystem-Level Analysis of Cellular Networks”, IEEE Trans.Wireless Commun., IEEE Early Access.
Realistic path-loss model with LOS/NLOS conditions
Arbitrary shadowing and fading
General antenna-array radiation pattern
Multi-tier topology with practical cell association
Realistic traffic load models as a function of the densities ofBSs and MTs
…
74
IM Approach: Why So Many Details are Needed?
75
... Impact of LOS/NLOS …
Mobile terminal
Base station
NLOS
LOS
3GPP
IM Approach: Why So Many Details are Needed?
76
... Impact of LOS/NLOS …
IM Approach: Why So Many Details are Needed?
77
... Impact of LOS/NLOS (fully-loaded) …
0 100 200 300 400 500 600 700 800 900 10000.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Rcell [m]
Rat
e [b
ps/H
z]
3GPP link stateonly LOSonly NLOS
Current assumption
(for tractability)in stochastic
geometry modeling(99.99%
of papers)
IM Approach: Why So Many Details are Needed?
78
... Impact of Load of Base Stations …
Resource Blocks Resource Blocks
Inactive for these resource blocksBlocked
IM Approach: Why So Many Details are Needed?
79
... Impact of Load of Base Stations …
2 5 10 25 50 1000
0.5
1
1.5
2
2.5
3
Rcell [m]
Rat
e [b
ps/H
z]
full loadpractical load, NRB=1
practical load, NRB=4
practical load, NRB=8
IM Approach: Why So Many Details are Needed?
80
... Impact of Antenna Directionality …
-180 -150 -120 -90 -60 -30 0 30 60 90 120 150 180-15
-10
-5
0
5
10
Azimuth in degrees
Gai
n in
dB
Omni-directional3GPP antenna pattern
Omni-directional antennas
Directional antennas
IM Approach: Why So Many Details are Needed?
81
... Impact of Antenna Directionality …
2 5 10 25 50 1000
1
2
3
4
5
6
7
8
9
10
Rcell [m]
Rat
e [b
ps/H
z]
Omni-directional3GPP antenna pattern
IM Approach: Why So Many Details are Needed?
82
... Sub-Linear Trend of the Area Spectral Efficiency …
RATE ASE
Intrigued Enough? On Experimental Validation…
83
W. Lu and M. Di Renzo, “Stochastic Geometry Modeling of Cellular Networks: Analysis, Simulation andExperimental Validation”, ACM Int. Conf. Modeling, Analysis and Simulation of Wireless and MobileSystems, Nov. 2015. [Online]. Available: http://arxiv.org/pdf/1506.03857.pdf.W. Lu and M. Di Renzo, “Stochastic Geometry Modeling of mmWave Cellular Networks: Analysis andExperimental Validation”, IEEE Int. Workshop on Measurement and Networking (M&N) – SpecialSession on Advances in 5G Wireless Networks, Oct. 12-13, 2015.
84
… the approach (e.g., 3-ball case) … Practical link-state models are approximated using a multi-ball model
The related parameters are computed using the “intensity matching” criterion
d1
d3
d2
1 1
1
3, ,
,1 LOS,NLOS,...
with 1 1,2, ,n n n n
n n
Nd d d d
S S Sd dn S
p r q r q n N
1
0 0
2
actual approx, max , max
LOS,NLOS, LOS,NLOS,minimize ln 0, ln 0,r S r S
S SF
x x
Rationale of IM Approach: Multi-Ball Approximation
Rationale of IM Approach: Multi-Ball Approximation
85
Why Matching the Intensity Measures ?
Consider the general association criterion as follows:
Ф is a (non-homogeneous) PPP of BSs with density λ(r) = λ*p(r)
l(r) denotes the path-loss function
Υ is a random variable that accounts for all random variables that are takeninto account for cell association except for the distance (e.g., shadowing)
Based on the displacement theorem of PPPs, the set Ψ is a PPP in R+ whoseintensity measure is the following:
0BS is chosen as the of the set minimum ,n
n
l rn
0
0
0, 2 Pr 0,
2 E Pr 0,
l rx x p r rdr
l r x p r rdr
86
Since the intensity measure is now known and Ψ is still a PPP, the coverageprobability can be formulated, after some algebra, as follows:
LOS
NLOS
2
,LOS LOScov LOS NLOS LOS LOS2
LOS
2
,NLOS NLOSLOS LOS NLOS NLOS2
NLOS
2
,LOS
2
P E Pr Pr
E Pr Pr
Pr
o
lagg
o
lagg
o
agg
P h lT l l l l
I l
P h lT l l l l
I l
P h xT x
I x
NLOS LOS
LOS NLOS
0
2
,NLOS
20
CCDF PDF
Pr CCDF PDF
l l
o
l lagg
x x dx
P h yT y y y dy
I y
LOS LOS LOS NLOS NLOS NLOSmin minl l r l l r
Rationale of IM Approach: Multi-Ball ApproximationWhy Matching the Intensity Measures ?
87
void probability th.
CCDF exp 0, PDF CCDFSS S Sl l ld d
2,
2,
2,
,LOS,
2
, , ,,
2
, , ,
PGF
N OS
L
,
, L
2
MGF ; MGF ;MGF ;
E exp
E E e
MGF ;
xp
exp 1 E exp
agg
QQ k Q
agg ag
Q Q
g
k
Q
g
Q
k
a gI SI Q S
k Q k Q k Q Skh
k Q k Q k Q Sk h
k Q
S I
h
I Sw l
w P h l l l
w P h l l l
w P l
l
h
w l w l w
1
1
1
0,
0,Q
S
Q
l
d dl l
l dl
Rationale of IM Approach: Multi-Ball ApproximationWhy Matching the Intensity Measures ?
Intrigued Enough? On Mathematical Modeling…
88M. Di Renzo et al., “The Intensity Matching Approach: A Tractable Stochastic Geometry Approximation toSystem-Level Analysis of Cellular Networks”, IEEE Trans. Wireless Commun., IEEE Early Access.
The Intensity Matching Approach: Main Takes
89
2 5 10 25 50 100 300 10000
0.5
1
1.5
2
2.5
3
3.5
Rcell [m]
Rat
e [b
ps/H
z]
Very Dense
Dense SparseVery Sparse
M. Di Renzo et al., “The Intensity Matching Approach: A Tractable Stochastic Geometry Approximation toSystem-Level Analysis of Cellular Networks”, IEEE Trans. Wireless Commun., IEEE Early Access.
The Intensity Matching Approach: Main Takes
90M. Di Renzo et al., “The Intensity Matching Approach: A Tractable Stochastic Geometry Approximation toSystem-Level Analysis of Cellular Networks”, IEEE Trans. Wireless Commun., IEEE Early Access.
The Intensity Matching Approach: Main Takes
91
2 5 10 25 50 100 300 10000
0.5
1
1.5
2
2.5
3
3.5
Rcell [m]
Rat
e [b
ps/H
z]
Depends on the density of blockages
Depends on the base station load
M. Di Renzo et al., “The Intensity Matching Approach: A Tractable Stochastic Geometry Approximation toSystem-Level Analysis of Cellular Networks”, IEEE Trans. Wireless Commun., IEEE Early Access.
92
SWIPT – System-Level Modeling and Optimization
M. Di Renzo and W. Lu, “System-Level Analysis of Cellular Networks with Simultaneous Wireless Informationand Power Transfer: Stochastic Geometry Modeling”, IEEE Trans. Vehicular Technol., IEEE Early Access.
Joint Statistical Characterization of Harvested Energy and Achievable Rate in the Presence of Other-Cell Interference
Major Difference: Information (rate) and harvesting (energy) requirements need to be jointly satisfiedSetup: LOS/NLOS, beamforming, etc.
Harvesting: Interference is GOOD Information: Interference is BAD
93
SWIPT – The Math in Simple Terms…
M. Di Renzo and W. Lu, “System-Level Analysis of Cellular Networks with Simultaneous Wireless Informationand Power Transfer: Stochastic Geometry Modeling”, IEEE Trans. Vehicular Technol., IEEE Early Access.
94
SWIPT – Trends and Insight
Feasibility Regions: Rate and Energy Targets are BOTH Achieved
(a)
(b)
95
SWIPT – Trends and Insight
System-Level Optimization & Importance of Channel Modeling
(a)
(b)
96
SWIPT – Trends and Insight
Impact of Cellular Network Density: Network Densification
97
SWIPT – Trends and Insight
Impact of Multi-Antenna Transmission: Massive MIMO
R0 [Mbits/sec]
Q0 [d
Bm
]
0 50 100 150 200 250-65
-60
-55
-50
-45
-40
-35
-30
1x12x1
4x1
8x1
16x1
32x1
64x1
128x1
256x1
512x1
1024x1
98
SWIPT – Trends and Insight
Impact of Multi-Antenna Transmission: Massive MIMO
99
SWIPT – If The Receiver is NOT Adaptive
Impact of Parameter Setups: Two Receive Antennas (MRC, SC)
100
SWIPT – If The Receiver is Adaptive
Impact of Parameter Setups: Adaptation as a function of ρ
101
SWIPT – If The Receiver is Adaptive
Impact of Parameter Setups: Two Receive Antennas (MRC, SC)
102
SWIPT – How Much Power Can We Harvest?
0 1 2 3 4 5 6 7 8 9 10-80
-70
-60
-50
-40
-30
-20
-10
0
Directive Antennas (ULA: Nq = 16)
Q* [d
Bm
]
log2(Nt)
SWIPT – Main Takes
103
Takeaway messages for system-level analysis (proofs in the paper): Optima power splitting and time switching ratios exist and are unique
Power splitting outperforms time switching if they operate at theirrespective optima
Impact of directional beamforming: reducing the other-cell interferenceleads to the optimum
Impact of base stations density: existence of an optimal deploymentdensity
Wireless power transfer: Densification of base stations and antennas ismandatory for (possibly) making it a reality Energy-Neutral design
Design RuleNetwork densification: To bring the access points closer to the users
Directional beamforming: To reduce the other-cell interference generated by network densification and to enhance the power gain of the intended link
The System-Level Side of 5G – YouTube Video
104https://youtu.be/MB8IvOYYvB0
105
Some Reference Papers… M. Di Renzo and W. Lu, “System-Level Analysis/Optimization of Cellular Networks
with Simultaneous Wireless Information and Power Transfer: Stochastic GeometryModeling”, IEEE Trans. Vehicular Technol., IEEE Early Access.
Y. Deng, L. Wang, M. Elkashlan, M. Di Renzo, and J. Yuan, “Modeling and Analysis ofWireless Power Transfer in Heterogeneous Cellular Networks”, IEEE Trans.Commun., IEEE Early Access.
T. Tu Lam, M. Di Renzo, and J. P. Coon, “System-Level Analysis of SWIPT MIMOCellular Networks”, IEEE Commun. Lett., IEEE Early Access.
T. Tu Lam, M. Di Renzo, and J. P. Coon, “System-Level Analysis of Receiver Diversityin SWIPT-Enabled Cellular Networks”, IEEE/KICS J. Commun. & Networks, IEEEEarly Access.
W. Lu, M. Di Renzo, and T. Q. Duong, “On Stochastic Geometry Analysis andOptimization of Wireless-Powered Cellular Networks”, IEEE GLOBECOM, Dec.2015.
T. Tu Lam, M. Di Renzo, and J. P. Coon, “MIMO Cellular Networks withSimultaneous Wireless Information and Power Transfer”, IEEE SPAWC, July 2016.
Thank You for Your Attention
Marco Di Renzo, Ph.D., H.D.R.Chargé de Recherche CNRS (Associate Professor)Editor, IEEE Communications LettersEditor, IEEE Transactions on CommunicationsDistinguished Lecturer, IEEE Veh. Technol. SocietyDistinguished Visiting Fellow, RAEng-UK
Paris-Saclay UniversityLaboratory of Signals and Systems (L2S) – UMR-8506CNRS – CentraleSupelec – University Paris-Sud3 rue Joliot-Curie, 91192 Gif-sur-Yvette (Paris), France
E-Mail: [email protected]: http://www.l2s.centralesupelec.fr/perso/marco.direnzo
ETN-5Gwireless (H2020-MCSA, grant 641985)
An European Training Network on 5G Wireless Networks
http://cordis.europa.eu/project/rcn/193871_en.html (Jan. 2015, 4 years)