L a u r e n t M a v i e l , Yo a n n C o r r e

2 8 t h S e p t e m b e r 2 0 2 1

B R AV E – C l o s u r e e v e n t

SubTHz networ k s imulat ion

2

Solut ions for subTHz network simulat ion

Applications

• Radio channel characterization

• Production of channel samples (some are

available on an open data repository

http://www.brave-

beyond5g.com/index.php/publications/)

• Link-level simulations

• Network design

3

Hotspot based on subTHz OOK

• Network dimensioning study for the OOK + energy detection system

• Scenario: hotspot area into a large venue (e.g. an airport, railway station, shopping mall…)

Scenario #1

Scenario #2

17.75 m

4

FWA scenario & challenges

• FWA deployment use-case in a North American residential area

o Key 5G scenario today

o Where beyond-5G capacity will obviously be beneficial

• Ambitious FWA+backhaul network using sub-THz frequencies

o FWA access: Connect a significant amount of houses at 150 GHz (D-band)

o Backhaul: Provide backhaul connectivity in same D-band frequency with a limited

number of fiber points of presence (PoP)

• Study based on a realistic PHY-layer simulation & optimization techniques

Key challenges in real

environments?

Required

infrastructure?

How deployment or link

budget settings influence

the network?

5

Leveraging innovations

Industry-standard

propagation modelSub-THz polar-QAM Automated Cell Selection

Coverage @3.5GHz

Coverage @28GHz

Upgraded to sub-THz

Robust to Phase Noise

Performance characterized

as SE vs. SNR

Simulation and optimization of

dense access+backhaul topologiesS. Bicaïs, et al., “Optimized Single-

Carrier Transceiver For Future Sub-

TeraHertz Applications“, ICASSP 2020

6

• Typical North-American environment

(Houston) – 0.52 km²

• 341 node candidates at the lamppost

and power line pole locations

• Network antennas: 4 m above ground

• CPE antennas: At the building façade

Setup

670 m

78

0 m

7

Environment

Propagation

Link performance

Network design

Simulation methodology

8

Environment & Propagation

Accurate 3D representation from aerial LiDAR dataRadio unit antenna orientation (best-power path)

… -115 dBm

-200 dBm

Ray-path power (dBm)

w/o antenna impact

9

Parameter Backhaul FWA

Carrier 150 GHz 150 GHz

Channel bandwidth 1 GHz 1 GHz

Tx power 100 mW 100 mW

Tx antenna gain 32 dBi 28 dBi

Rx antenna gain 32 dBi 5 dBi

Implementation loss 3 dB 3 dB

Noise figure 8 dB 10 dB

Phase noise Medium Medium

Parameter Backhaul FWA

Modulation scheme Polar-QAM Polar-QAM

Rainfall 10 mm/h 10 mm/h

Min. required data rate 1024 Mbps 384 Mbps

Min. required SNR 5.9 dB -0.8 dB

Confidence level 99 % 95 %

Error margin 14 dB 9.9 dB

Link performance

Scenario #1: Sub-THz baseline design

More details on Budget Link for Scenario #1 & other scenarios → See BRAVE Deliverable 3.1

10

Network definit ion

Backhaul Unit

Relay Site

Last-mile

backhaul

Access

Access Point (AP) Point of Presence (PoP)

Customer Premise Equipment (CPE)

Access LinkBackhaul Link

Core

11

• Joint Access and Backhaul automated algorithm

o Target: X % of buildings covered (throughput 384 Mbps)

o Minimization of the number of radio nodes

• Estimation of number of 1-GHz channels required for capacity

o Base on a DL demand of 150 Mbps; 50 % suscription rate

• Pre-design analysis

o Coverage target: 55 %

o May be later complemented, for instance with 5G units

Network design

Valid (LOS / NLOS Vegetation) Not valid

13.5 % 86.5 %

12

Scenario #1: Low-cost CPE (5 dBi)

5

1

Nb required

channels

at FWA AP’s

1

Nb required

channels

at backhaul

links

7

Fiber PoP

Backhaul relay

DL Peak Throughput (Mbps) for 1 GHz channel

Total Access Backhaul

#Sites #AP #channels #PoP #Site #Units #channels

Med. Max Med. Max

57 35 2 3 4 22 112 1 5

13

Alternative scenarios

5

1

Nb required

channels

at FWA AP’s

1

Nb required

channels

at backhaul

links

7

Scenario 4: 5G designScenario 2: Greater CPE gain Scenario 3: Antenna@6m

14

Alternative scenarios

15

Focus on Scenario 4) comparison to 5G

• Budget link main differences

o FWA at 3.5 GHz (BW: 100 MHz)

o Backhaul at 28 GHz (BW: 800 MHz)

o MAPL almost identical between 5G and sub-THz

o Assumption: single-user MIMO beamforming

• Different design approaches

o Sub-THz with buildings and vegetation → coverage-constrained design

o 5G with easier propagation and limited bandwidth → capacity-

constrained design

• Result: denser network at 5G frequencies

o 2 times more sites

16

PoP locations variation

#5.2

#5.1#1

#5.3

17

Conclusion

• A FWA network with higher data rates than possible today looks

feasible based on 150 GHz devices, even if it comes with challenges in

hardware and radio-propagation

o Link budgets will have to be refined along with hardware innovations

• Hybrid complementary 5G/subTHz look like promising approaches

o Full coverage target may be very costly at 150 GHz

o Capacity targets are costly with 5G frequencies

• Joint optimization of the access and backhaul layer → required for

operators designing high-frequency FWA network

Laurent Mav ie l , Yoann Corre

lmavie l@siradel .com

+33 (0)2.23.48.05.00

This work was supported by

Thank you for your attention