lpwan technologies for internet of things (iot) and m2m scenarios

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© Peter R. Egli 2015 1/11 Rev. 1.00 Peter R. Egli INDIGOO.COM OVERVIEW OF EMERGING TECHNOLOGIES FOR LOW POWER WIDE AREA NETWORKS IN INTERNET OF THINGS AND M2M SCENARIOS LPWAN LOW POWER WIDE AREA NETWORK

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Page 1: LPWAN Technologies for Internet of Things (IoT) and M2M Scenarios

© Peter R. Egli 20151/11

Rev. 1.00

LPWAN – Low Power Wide Area Network indigoo.com

Peter R. EgliINDIGOO.COM

OVERVIEW OF EMERGING TECHNOLOGIES FOR LOW POWER WIDE AREA NETWORKS IN

INTERNET OF THINGS AND M2M SCENARIOS

LPWANLOW POWER

WIDE AREA NETWORK

Page 2: LPWAN Technologies for Internet of Things (IoT) and M2M Scenarios

© Peter R. Egli 20152/11

Rev. 1.00

LPWAN – Low Power Wide Area Network indigoo.com

Contents1. The sweet spot for LPWANs

2. LPWAN requirements and characteristics

3. The need for long range wireless connectivity

4. LPWAN network topology

5. Link budget for LPWAN devices

6. Receiver sensitivity for LPWAN devices

7. Technologies for LPWAN

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LPWAN – Low Power Wide Area Network indigoo.com

1. The sweet spot for LPWANsDifferent wireless technologies cover different applications with regard to range and bandwidth.

Long-range applications with low bandwidth requirements that are typical for IoT and M2M

scenarios are not well supported by these existing technologies.

LPWAN technologies are targeted at these emerging applications and markets.

Long RangeShort Range

Low BW

High BW

Medium BW

Medium Range

LPWAN

BlueTooth

BLE

ZigBee /

802.15.4

802.11a

802.11b

802.11g

802.11ac

802.11ad

802.11n

RFID /

NFC

WBAN

802.15.6

2G

3G

4G

5G

VSAT

WPAN

802.15.3Key:

BW: Bandwitch

IoT: Internet of Things

M2M: Machine to Machine

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2. LPWAN requirements and characteristics (1/2)The needs of IoT and M2M applications pose some unique requirements on LPWAN

technologies as shown in the comparison with other wireless technologies:

RangePower

Consumption

Bandwidth

Radio Chipset

CostsRadio

Subscription Costs

Transmission

Latency

Number of

Base Stations

Geographical

Coverage, Penetration

LPWAN

3G/4G/5G

ZigBee

802.15.4

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2. LPWAN requirements and characteristics (2/2)

Characteristic Target Value for LPWAN Technologies

Long range 5 – 40km in the open field

Ultra low power Battery lifetime of 10 years

ThroughputDepends on the application, but typically a few hundred

bit / s or less

Radio chipset costs $2 or less

Radio subscription costs $1 per device and year

Transmission latencyNot a primary requirement for LPWAN. IoT applications are

typically insensitive to latency.

Required number of base

stations for coverage

Very low. LPWAN base stations are able to serve thousands

of devices.

Geographic coverage,

penetration

Excellent coverage also in remote and rural areas. Good in-

building and in-ground penetration (e.g. for reading power

meters).

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© Peter R. Egli 20156/11

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3. The need for long range wireless connectivityDevices in IoT applications (the “things”) are typically installed in the field on residential

premises, public places like restaurants or cafés or on industrial plant sites.

Using short range radio connectivity complicates the IoT setup due to the implications of

wired on-site connectivity (firewalls, NAT, port and protocol filtering).

Short range radio connectivity for IoT devices:

Direct long range connectivity (LPWAN) for IoT devices:

End Customer Premises

Wired

network

Access Network /

Internet

SRD

Gateway

Cloud, Apps

Cloud A

A

A

Short range radio devices (SRD)

such as ZigBee require using a

gateway for long-range backhaul.

The gateway is typically hooked

up to some on-site wired network

which is not under control of the

IoT provider.

End Customer Premises Access Network /

Internet

Cloud, Apps

Cloud A

A

ABase

Station

Long range connectivity allows

direct access to the devices in

the field.

The base station typically serves

a large number of devices thus

greatly reducing costs.

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© Peter R. Egli 20157/11

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4. LPWAN network topology (1/2)The wireless portion of LPWAN networks uses a star topology.

This obviates the need for complicated wireless mesh routing protocols which would greatly

complicate the implementation of end devices and drive up power consumption.

A. Direct device connectivity (base station):

A base station provides connectivity to a large number of devices.

The traffic is backhauled to servers (cloud) through TCP/IP based networks (Internet).

The base station is responsible for protocol translation from IoT protocols such as MQTT

or CoAP to device application protocols.

LPWAN Connectvitiy Access Network /

Internet

Cloud & Servers

Cloud

Base

Station

Star topology for long

range radio connectivity

Wired backhaul,

TCP/IP based

(e.g. MQTT)

Applications

A

A

A

A

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Short Range Conn.

4. LPWAN network topology (2/2)B. Indirect device connectivity through a LPWAN gateway:

In setups where devices cannot be directly reached through LPWAN, a local gateway

bridges LPWAN connectivity to some short range radio (SRD) technology (e.g. ZigBee,

BLE).

The gateway typically runs on mains power since it serves a larger number of devices

and must convert between LPWAN and SRD radio technologies and protocols.

Gateways may help to improve security since more powerful security algorithms can be

implemented on the gateway than is possible on the constrained devices.

LPWAN Connectvitiy Access Network /

Internet

Cloud & Servers

Cloud

Base

Station

Star topology for long

range radio connectivity

Wired backhaul,

TCP / IP

(e.g. MQTT)

Applications

A

A

A

A

Gateway

Short range

local connectivity

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© Peter R. Egli 20159/11

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SRx

[dBm]

5. Link budget for LPWAN devicesLink budget:

As in most radio systems, the link budget is an important measure for power calculation.

The link budget calculates the power received at the receiver and accounts for gains and losses

along the transmission path.

PTX

[dBm]

+dB

-dB

GTX

[dBi]

LTX

[dB]

0dBLFS

[dB]

LM

[dB]

GRX

[dBi]

LRX

[dB]

Transmission

Path

𝑷𝑹𝑿 = 𝑷𝑻𝑿 + 𝑮𝑻𝑿 − 𝑳𝑻𝑿 − 𝑳𝑭𝑺 − 𝑳𝑴 + 𝑮𝑹𝑿 − 𝑳𝑹𝑿𝑷𝑹𝑿 = 𝑹𝒆𝒄𝒆𝒊𝒗𝒆𝒅 𝒑𝒐𝒘𝒆𝒓 𝒅𝑩𝒎𝑷𝑻𝑿 = 𝑺𝒆𝒏𝒅𝒆𝒓 𝒐𝒖𝒕𝒑𝒖𝒕 𝒑𝒐𝒘𝒆𝒓 𝒅𝑩𝒎𝑮𝑻𝑿 = 𝑺𝒆𝒏𝒅𝒆𝒓 𝒂𝒏𝒕𝒆𝒏𝒏𝒂 𝒈𝒂𝒊𝒏 𝒅𝑩𝒊𝑳𝑻𝑿 = 𝑺𝒆𝒏𝒅𝒆𝒓 𝒍𝒐𝒔𝒔𝒆𝒔 𝒄𝒐𝒏𝒏𝒆𝒄𝒕𝒐𝒓𝒔 𝒆𝒕𝒄. 𝒅𝑩𝑳𝑭𝑺 = 𝑭𝒓𝒆𝒆 𝒔𝒑𝒂𝒄𝒆 𝒍𝒐𝒔𝒔 𝒅𝑩𝑳𝑴 = 𝑴𝒊𝒔𝒄. 𝒍𝒐𝒔𝒔𝒆𝒔 𝒎𝒖𝒍𝒕𝒊𝒑𝒂𝒕𝒉 𝒆𝒕𝒄. 𝒅𝑩𝑮𝑹𝑿 = 𝑹𝒆𝒄𝒆𝒊𝒗𝒆𝒓 𝒂𝒏𝒕𝒆𝒏𝒏𝒂 𝒈𝒂𝒊𝒏 𝒅𝑩𝒊𝑳𝑹𝑿 = 𝑹𝒆𝒄𝒆𝒊𝒗𝒆𝒓 𝒍𝒐𝒔𝒔𝒆𝒔 𝒄𝒐𝒏𝒏𝒆𝒄𝒕𝒐𝒓𝒔 𝒆𝒕𝒄. 𝒅𝑩𝑺𝑹𝑿 = 𝑹𝒆𝒄𝒆𝒊𝒗𝒆𝒓 𝒔𝒆𝒏𝒔𝒊𝒕𝒊𝒗𝒊𝒕𝒚 𝒅𝑩𝒎

PRX

[dBm]

Gain

Loss

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© Peter R. Egli 201510/11

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6. Receiver sensitivity for LPWAN devicesReceiver sensitivity:

The required receiver sensitivity for a LPWAN device is derived from the calculated link budget.

The wireless link can be closed (communication between sender and receiver is possible) if the

receiver sensitivity SRX equals or is lower than (numerically in dB) the received power PRX.

Due to the long transmission paths that are typical for LPWAN systems, free space loss (path

loss) is the dominant factor that greatly reduces the received power at the receiver.

Therefore it is essential that LPWAN receivers, particularly device nodes, have a very good

receiver sensitivity (<= -140dBm), i.e. are able to receive signals levels that are 7 orders of

magnitude or more smaller than the transmission level at the sender.

𝑺𝑹𝑿 <= 𝑷𝑹𝑿

Page 11: LPWAN Technologies for Internet of Things (IoT) and M2M Scenarios

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LPWAN – Low Power Wide Area Network indigoo.com

7. Technologies for LPWANIn the still evolving IoT and M2M markets, a few competing radio technologies are emerging.

Common to these technologies is the use of lower frequencies than 2.4GHz or 5.8GHz to

achieve better penetration into buildings or underground installations.

Work is still in progress in most of these technologies.

LPWAN

Technology

Standard /

SpecificiationRange Spectrum

ETSI LTN ETSI GS LTN 001 - 003 40 km in open fieldAny unlicensed spectrum such as

ISM (433MHz, 868MHz, 2.4GHz)

LoRaWANLoRa Alliance

LoRaWAN

2-5km in urban areas

<15km in suburban

areas

Any unlicensed spectrum

868MHz (Eu)

915MHz (US)

433MHz (Asia)

Weightless-N Weightless SIG<5km in urban areas

20-30km in rural areas800MHz – 1GHz (ISM)

RPMA

Proprietary (On-Ramp

Wireless), planned to

become an IEEE

standard

<65km line of sight

<20km non line of

sight

2.4GHz