Primer: Follow the Signal Path

Speaker: 00:00:05

Welcome to

2

: 00:00:06

the business of LoRaWAN,

where we dive into this long range,

3

: 00:00:09

low power, wide area network

and its impact on your bottom line,

4

: 00:00:12

the latest sensors and proven real world

solutions.

5

: 00:00:14

I'm your host, Nik Hawks.

6

: 00:00:16

Since 2020,

7

: 00:00:17

when I stumbled into LoRaWAN via Helium

while hunting for a lost paraglider,

8

: 00:00:21

I've helped thousands

understand how it works and how to use it,

9

: 00:00:23

and I'm psyched to do the same for you.

10

: 00:00:25

I've installed everything

from soil sensors

11

: 00:00:27

to weather stations to retail foot

traffic counters.

12

: 00:00:29

Coming to the conclusion

that LoRaWAN is rad,

13

: 00:00:31

so I built the only show on the internet

fully dedicated to unlocking its potential

14

: 00:00:35

for your business. Let's dig in.

15

: 00:00:38

This episode is part of the LoRaWAN primer

series, recorded for those of us

16

: 00:00:42

who aren't wireless engineers and want to

understand more about how LoRaWAN works.

17

: 00:00:47

Today, we'll do this

by tracking the LoRaWAN signal

18

: 00:00:49

path, using and explaining

some of the specialized terminology.

19

: 00:00:52

You'll hear a bunch

as you listen in to other episodes.

20

: 00:00:56

The signal path is just

21

: 00:00:57

a path that signals take from the sensor

on the ground, all the way

22

: 00:01:00

to where you see that data,

whether it's on a dashboard for monitoring

23

: 00:01:03

or there's an action taken

like turning a valve on or off.

24

: 00:01:07

We'll start with the sensor.

25

: 00:01:09

Sometimes it's called an end device,

sometimes a node.

26

: 00:01:12

They all refer to the same thing.

27

: 00:01:14

They're all devices that

take a measurement from the real world.

28

: 00:01:17

So it could be a temperature sensor,

a water meter,

29

: 00:01:20

a tracker on a pallet,

anything that is measuring something.

30

: 00:01:24

The sensor will periodically wake up

and send a wireless message

31

: 00:01:27

called a payload, containing

whatever is measured,

32

: 00:01:30

for example, a temperature

reading or a GPS location.

33

: 00:01:34

This action of sending from the device to

the internet is called an uplink,

34

: 00:01:38

because LoRaWAN is low power,

the device is asleep most of the time

35

: 00:01:42

and transmit infrequently, which is why

the batteries can last for so long.

36

: 00:01:47

There are exceptions to this for devices

that are wired to mains power

37

: 00:01:50

and not on batteries, but most of the time

most devices are sleeping.

38

: 00:01:54

Once the sensor sends the message,

it has to be received,

39

: 00:01:57

and the thing that receives

it is called a gateway.

40

: 00:02:00

It's also called a hotspot

or a radio concentrator.

41

: 00:02:03

Most of the time on this podcast,

we'll call it a gateway.

42

: 00:02:06

A gateway is basically a LoRaWAN radio

43

: 00:02:08

antenna on a device

that's connected to the internet.

44

: 00:02:11

When it receives an uplink

45

: 00:02:13

payload from a sensor,

it forwards that payload to the next step.

46

: 00:02:17

A gateway does exactly what the name says.

47

: 00:02:19

It acts as a gateway between the sensor

and the internet.

48

: 00:02:22

A gateway can be bidirectional,

transmitting a downlinked payload

49

: 00:02:26

back to the sensor,

which gives it a command.

50

: 00:02:28

For now, we'll continue

to follow the signal path from the gateway

51

: 00:02:31

to the next step, which is called an LNS

or LoRaWAN network server.

52

: 00:02:36

The LNS is the brain in the system.

53

: 00:02:38

It authenticates devices, filters out

duplicate messages since multiple gateways

54

: 00:02:42

can hear the same sensor,

and if the device is expecting a response

55

: 00:02:46

like hey,

56

: 00:02:47

you told me to listen after I transmit,

do you have any instructions for me?

57

: 00:02:50

Then the gateway will send a downlink

back to the device.

58

: 00:02:53

Whenever you hear uplinks or down links,

they're in relation to the device.

59

: 00:02:58

The device sends

an uplink up to a gateway,

60

: 00:03:00

and it receives the downlink

down from the gateway.

61

: 00:03:04

Once the LNS has received the payload

from the gateway,

62

: 00:03:07

it runs it through a codec,

which is basically a tiny translator

63

: 00:03:10

that turns the ones and zeros

64

: 00:03:12

the sensor sends into something

you could read on a dashboard.

65

: 00:03:15

When encoded, the messages are very short,

just a couple of bytes.

66

: 00:03:20

The LNS sends

the decoded payload to an application.

67

: 00:03:24

The application is what we would use

as humans, either

68

: 00:03:27

displaying the data in a dashboard

or actuating some valve like turning off

69

: 00:03:30

a hose bib

70

: 00:03:31

when soil moisture is saturated,

or turning down the heat

71

: 00:03:33

if the temperatures

are too high in a room.

72

: 00:03:36

And that's how a LoRaWAN works,

it's pretty straightforward.

73

: 00:03:38

Sensor or device to gateway.

74

: 00:03:40

Gateway to LNS illness to application.

75

: 00:03:44

The only variation to this

is with the global LoRaWAN run by helium.

76

: 00:03:48

It's a big network with multiple LNS.

77

: 00:03:51

Médio scientific runs

one of those illnesses, and because helium

78

: 00:03:54

is powered by cryptocurrency incentives

and all of the data is paid

79

: 00:03:58

for in more or less real time,

an extra step is required.

80

: 00:04:02

That step is called the HPR or Helium

Packet Router.

81

: 00:04:06

The HPR lives between the gateway

and the LNS.

82

: 00:04:09

Let me walk you through the modified

signal path for helium.

83

: 00:04:12

A device sends its payload to a gateway.

84

: 00:04:14

The gateway sends that payload

onto the helium packet router,

85

: 00:04:18

and the helium packet router finds the

correct LNS, conducts the cryptocurrency

86

: 00:04:22

transaction and delivers

that payload to the correct LNS.

87

: 00:04:26

While cryptocurrency

may sound scary for most users,

88

: 00:04:28

if you were to try helium today

on the Médio Scientific Airlines,

89

: 00:04:32

you just buy data credits and dollars

or euros

90

: 00:04:34

and all of the cryptocurrency transactions

would happen behind the scenes.

91

: 00:04:38

Helium makes it really easy

for anyone to use LoRaWAN

92

: 00:04:40

because the coverage is almost everywhere.

93

: 00:04:43

Both traditional and the helium models

have the same end result.

94

: 00:04:47

Sensor data gets to your application.

95

: 00:04:49

The only thing that's different

is the path and the business model.

96

: 00:04:52

Okay, so now we've used all of the common

LoRaWAN terms, and we've described

97

: 00:04:56

the signal path in both traditional

and the helium networks.

98

: 00:05:00

From the sensor or device a payload is

sent on an uplink to a gateway.

99

: 00:05:04

The gateway forwards it to an LNS,

where the tiny payload

100

: 00:05:07

gets decoded by a codec

and is then sent to an application.

101

: 00:05:11

If any action is required, the LNS sends

the command to the correct gateway,

102

: 00:05:14

which forwards the payload on a downlink

103

: 00:05:16

back to the device,

and the device conducts the action.

104

: 00:05:20

If you need to listen to this a few times

for it to sink in, that's totally normal.

105

: 00:05:23

There's a lot of meat on the bone here.

106

: 00:05:26

That's it for the business of LoRaWAN.

107

: 00:05:27

Thanks for listening.

108

: 00:05:29

If you enjoyed the show and want to learn

more, the podcast home on the web

109

: 00:05:32

is metsci.show That's metsci.show.

110

: 00:05:38

There you'll find calculators to estimate

the impact of IoT usage on your business.

111

: 00:05:42

Be able to make guest suggestions.

112

: 00:05:44

If you know someone who you think

113

: 00:05:45

should come on the show

and easily get in touch with me.

114

: 00:05:48

If you think the show is useful

for LoRaWAN, please leave a review

115

: 00:05:50

wherever you listen to this.

116

: 00:05:52

Ratings

interviews really help podcast grow.

117

: 00:05:55

Finally, an enormous

thanks to our sponsor, the IoT

118

: 00:05:57

working Group at the Helium Foundation,

for supporting this show.

119

: 00:06:01

If you want to try LoRaWAN out

for yourself

120

: 00:06:03

without asking anyone permission,

you can sign up for a

121

: 00:06:06

MeteoScientific account

at console.meteoscientific.com,

122

: 00:06:10

and get your first 400 data credits

for free.

123

: 00:06:12

That's enough to run a sensor for

about a year if you're sensing once a day.

124

: 00:06:16

Right on. See you on the next show.