WHITE PAPER

2016 LoRa

simulation using ATDI’s RF Solution

Three decades in radio

communications, software

tools in development for a

quarter of a century and

engineers who have

already overcome every

challenge the industry can

present. It makes ATDI

the world’s leading

authority on radio network

planning and modelling,

spectrum management,

dynamic spectrum and

network optimization

Yahya K

hale

d (

2016)

ATD

I South

Pacific

12A -

33 W

ate

rloo R

d

Macquari

e p

ark

NSW

, AU

STRALIA

ATDI The world’s leading authority on radio

network planning and modelling, spectrum

management, dynamic spectrum and

network optimization

LPWAN

Long rage is a key factor for large-scale

communication networks typically required in

Smart-City applications and IoT. Recently,

narrowband and spread-spectrum

technologies surfaced as cost-effective

candidate technologies to fulfill low

throughput and long-range communication.

LoRa physical layer

LoRa is a spread-spectrum modulation

scheme that that uses wideband linear

frequency modulated pulses whose frequency

increases or decreases over a certain amount

of time to encode information. The main

advantages of this approach are twofold: a

substantial increase in receiver sensitivity

due to the processing gain of the spread

spectrum technique and a high tolerance

to TX and RX frequencies misalign.

Outdoor and 3D in-building

LoRa coverage predictions for

Smart-City application and key

network performance

evaluation.

Network model

LoRa is simply a transmission modulation; the

technology can be applied to any network model

such as Mesh, P2P and P-MP such as star

topology. The network components are the

Gateway and Endpoints. The end points can be

sensors for different applications.

Key challenges

Regardless whether LoRa or NB wireless system

- there are RF limitations inherited from the use-

case itself. The End-points (EP) can be deep-

indoor, in the basement and even under-ground.

Most noticeable the EP and/or the gateway can

be as little as 2m height making additional

challenge to link-level predictions.

1) End-point installation location and height

2) building impact prediction

3) Link adaptation

4) Interference calculations and prediction

5) Co-existence with 2G/3G & 4G

ATDI’s approach

End-point location dependency

ATDI adopts a set of full 3D and

deterministic propagation models proven in

case-studies and validated by field

measurements for urban environment.

These models are described as path-

specific. Unlike classical models such as

Hata which is typically used for macro-

coverage predictions and street level mobile

receivers. Deterministic model such as ITU-

R P.525 + Deygout94 is governed by rules

of physics and require full descriptive RF

environment such as digital terrain model,

clutter and buildings.

Path specific models are the perfect

candidate for P-MP non-mobile scenarios

typically deployed for the IoT.

Figure 1: 3D coverage prediction

Building impact prediction

Buildings have two-fold impact; shadowing

and absorption. Thanks to our dedicated

building layer – the tool is able to distinguish

outdoor and indoor receivers and switch

accordingly. Signal crossing multiple buildings

can undergo diffraction on few buildings and

absorption on the last building where the EP

is installed. Such effect is only possible with

fully-deterministic model and separate

building layer model. See Figure 2 for full

predictions at every level. Separate clutter

classes can be defined for under-ground

installations. Also see Figure 4 for building

impact on outdoor signal level.

LoRa simulation

Link adaptation modeling

LoRa overcome some of the urban

challenges by adopting 7 different

spreading factors (SF) and 4 coding-rate

scheme (see AN1200.22). Varying SF result

in different SNR and packet duration. While

such scheme has its merits and de-merits –

it’s necessary to simulate this behavior

while trialing the network prior to the full-

scale deployment. Figure 3 shows coverage

ranges and adaptive link performance.

Figure 4 is a closer examination for link-

level on the street level and indoor.

3D outdoor to

indoor

predictions for

indoor P-MP

predictions

Figure 2: Outdoor to indoor signal level prediction for in-building End-Points

Figure 3: LoRa adaptive spreading factor coverage, Gateway install 10m above street level. 500m per ring. Building penetration and band interference taken into account

0.5 km

1.0 km

1.5 km

Key Offerings

Path specific 3D and urban propagation model

Advanced interference analysis engine

Technical expertly and professional consultation

services

3D digital maps

Key Clients

ATDI is key consultant and software provider in

mission-critical projects for

Cisco

Actility

KerLink

Contact Us ATDI South Pacific

12A - 33 Waterloo Rd

Macquarie park

NSW, AUSTRALIA

Telephone

Email Address

Website www.atdi.com

Closer view at

outdoor and

indoor LoRa link

performance when

predicted using

ATDI tool

Figure 4: Detailed path-specific analysis for LoRa in urban environment