LoRaWAN
Architecture

LoRaWAN application areas

  • Energy resources

    Getting readings from gas, water, electricity, heat, and leaks meters.

  • Transport

    Monitoring of vehicles and cargo in the designated area, location determination, storage logistics, smart Parking.

  • Production

    Monitoring the condition of containers and containers in production with an oil or chemical purpose, as well as analyzing the operation of equipment, machines and equipment.

  • Smart city

    Monitoring and managing lighting, dumpsters, weather conditions, emissions, manhole control and facility security.

LoRaWAN Technology

LoRaWAN is a type of LPWAN network, which stands for Low-power Wide-area Network — “energy-efficient long-range network”.
LPWAN networks are wireless and have a wide coverage radius, the main advantage of such networks is low power consumption, and the amount of data transfer in such networks is measured in bytes, but this is enough to transmit the necessary telemetry from the end device to the dispatcher server. The lifetime of these end devices is several years on a single battery and depends on the data transfer schedule.
Basically, devices with LPWAN connection are typical microcontrollers with minimal power consumption and a wireless network interface. These devices usually communicate with their gateway (base station), which has an IP address for accessing the Internet.
LoRaWAN is a technology standard developed and supported by the Lora Alliance, which consists of international telecommunications companies and manufacturers, as well as integrators. The LoRaWAN technology platform can be segmented into two components:
* LoRa: Proprietary technology with LoRaWAN radio modulation that uses wireless connectivity to connect between end devices and gateways.
* LoRaWAN: an access control Protocol that uses MAC address identification (MAC-media access control ) to transmit and manage messages between the LoRaWAN Network Server and the end device.

Architecture

This diagram shows the final
LoRaWAN network architecture
The diagram shows four key elements of the network:
Devices: End IoT devices that send and receive messages in the LoRA wireless network.Gateways: the Gateway works as a relay and its task is to send all messages from the end devices and transmit them to the network server and back.
Network server: manages and maintains the LoRA network.
Application server: All devices send a message with payload to the client’s final application.The diagram shows that the network topology is a Star (Star — base topology of a computer network in which all computers/network devices connected to the Central node, forming a physical network segment.) with a network server connecting multiple gateways, which in turn connect to devices over the LoRA wireless network.
Communication is bidirectional, but the predominant type of communication is accepting data from end devices.
The diagram shows two LoRaWAN messages sent using two wireless devices, marked orange and green.
In the upper coverage area of the LoRA wireless network, the device sends LoRaWAN messages using the LoRA wireless network. This message is received by the gateway and sent to the network server. In the lower coverage areas, the device sends a similar LoRaWAN message that is received by two gateways, these two messages are forwarded to the network server.
We have shown two devices connected to two different application servers, i.e. in LoRaWAN, the application defines how the devices are connected to a specific backend server and all the devices are connected to a specific application.

Данные

Gateways send LoRaWAN messages over the wireless interface using the gateway Message Protocol defined in accordance with the LoRaWAN Gateway to Server interface specification. LoRaWAN messages and attached data are sent in JSON encoded format using UDP/IP
The image shows the control panel
network server
The LoRaWAN specification does not define or describe how the network server will interact with the application server (dispatcher). Typically, applications use Iso standards such as MQTT, AMPQ, HTTP, and others to exchange messages between the network server and the server.
 
LoRa Devices
End devices exchange LoRaWAN messages with gateways on different frequency channels and data rates, which are defined by The Alliance’s LoRa regional parameters document.
Currently, more than 100 countries use these LoRaWAN specifications, the main ones are presented below.

Региональные стандарты

Below is a table with recommended settings for the network server, in different regions.

 

ParameterEU868US902CN779RU868
Coding Rate4/54/54/54/5
RX1 Join Delay (s)5555
RX2 Join Delay (s)6666
RX1 Delay (s)1111
RX2 Delay (s)2222
Gateway Power16261216
Max EIRP (dBm)163012.1516
Max PowerMaxMaxMaxMax
Min PowerMax – 14dBMax – 20dBMax – 10dBMax – 14dB
Max Data RateSF7 125 kHzSF8 500 kHzSF7 125 kHzSF7 125 kHz
Initial Duty Cycle100%100%100%100%
Initial RX1 DR Offset0000
Initial RX2 DRSF12 125 kHzSF12 500 kHzSF12 125 kHzSF12 125 kHz
Initial RX2 Freq (MHz)869.525923.3786869.1
Initial Channels0-20-710-20-1

Optimization of data transfer

The speed of data exchange is determined by the modulation levels and the SF (Spreading Factor) coefficient in combination with the channel bandwidth. All these parameters affect the physical bit rate and time on the air.
Values: 7, 8, 9, 10, 11, 12 More number – more energy per bit and more capability processing, but more time on the air.
Consider the data transfer value for the ru868 frequency plan.
To maximize the battery life of your devices, LoRA uses the adaptive data rate (ADR) scheme. The ADR manages individual speeds for each connected device. End devices can transmit over any available channel at any time using any available ADR speed subject to the following rules:
The end device changes the channel in a pseudo-random way for each transmission, thus ensuring frequency diversity. The end device must comply with any transmission duty cycle restrictions defined by the range specification.

 

Regional parameters document LoRaWAN v 1.0.3
LoRaWAN regional settings document v 1.1

Terms and definitions

Activation by Personalization

Activation by pre-recording personal settings in the device before enabling the device in the network

AppEUI

(8-byte, EUI64) globally unique application ID for routing received data by the network server to the application server (AppServer)

AppKey

a unique (16-byte, AES-128) encryption key generated by the app Server for this particular device

AppServer

client application server

DevEUI

(8-byte, EUI64) globally unique device identifier (End-device identifier). It can be assigned by the device manufacturer (similar to the MAC address), it can be obtained in a limited number from an available pool of operator IDs, or it can be obtained by the node owner as part of a pool in the IEEE

DevAddr

A 32-bit (four-byte) network address for addressing packets at the network level has a unique value within the operator’s network (you can draw an analogy with the MAC address, which also provides addressing at level 2 of the OSI model in Ethernet networks, but the way to get DevAddr with OTAA is similar to getting a dynamic IP address received from a DHCP server in TCP/IP networks). The highest 7 bits of DevAddr contain the network address of the NwkID operator. this value must be unique for nearby networks and for networks that have overlapping coverage zones. Most often, a four-byte sequence is used to denote DevAddr (for example: 02:D1:D2:01), in which the highest byte is the network address NwkID

End-node

end user device in the LoRaWAN network

LoRa®

physical layer Protocol that describes a connection in LoRaWAN networks

Long Range wide-area networks

a long-range global network allows you to connect devices with a battery life of up to ten years, transmit data over long distances, and so on. Unlike mobile networks, LoRaWAN networks are hybrid and can be both private and public

Network ID

A 7-bit network ID that is part of the network address (DevAddr) is used to identify networks that operate on the same territory

NwkSKey

network session key [128 bit] used for calculating and checking the MIC (message integrity code) field) messages exchanged between the terminal device (end-node) and network Server (Network Server), AS well as for Mac-level message encryption

AppSKey

session key [128 bit] used for encrypting data at the application level (between the endpoint device and the application server)

LoRaWAN Classes A B C

The device can operate according to three different communication profiles, known as class A, B, and C. Each class is optimized for energy efficiency and latency requirements, the profiles are shown in the table below.
Class
Class description
A
A battery-powered device where the outgoing transmission from each end device is accompanied by two short incoming receiving Windows RX1 and RX2, minimizing the time needed to listen. (an example of class A usage is a water meter that sends its own tariff once a day)
B
The destination device, in addition to sending an outgoing message, also goes on the air on a schedule, to receive an incoming message from the network server (rarely used, the device must have a built-in clock)
C
An end device that constantly listens to incoming messages (example of an electric meter application)

Devices and software

LoRa Gateways

 

Gateways act as a bridge between the LoRA wireless network and the IP network. Gateways work as wireless base stations for various devices and resemble GSM base stations. The base station can cover either a local object/house, or a district or block. The deployment of multiple base stations in the street version can provide coverage of an area or city.

 

Since the gateway has a LoRA wireless interface, it must meet the communication requirements (in Russia, the unlicensed power of the transmitter is 25 mW with a frequency plan of 864-870 MHz), channel distribution, and data transfer speed defined by the corresponding range specification.

 

LoRaWAN network server
A network server with all end devices that is configured as an integral part of the application (top-level Software) and connected to the base stations (LoRaWAN gateway). A network server can be embedded in a gateway or located on a dedicated server along with the Dispatcher SOFTWARE.

 

The network server provides three key functions:
Device authentication and authorization
        Network management and optimization
        Interaction with higher-level application servers

 

The network server receives messages from devices, manages their authentication, data routing, and gateway management. The network server independently selects the best gateway for routing data from the device, as well as eliminates duplicate messages and optimize the radio airwaves using ADR.

Security in LoRaWAN

Device authentication:
The LoRaWAN network server supports two methods of authentication and activation described in the specification.
A) activation personalized ABP Activation By Personalization (no connection procedure required, encryption keys and DevAddr address are written to the device in advance (device personalization))
Devices are configured using network and application session keys, as well as a pre-allocated 32-bit network address of the device, similar to static IP address allocation.
B) OTAA over-the-Air Activation (you need to go through the join procedure, during which session encryption keys and the DevAddr address are generated).
OTAA requires devices to send a connection request to the network server, and when authenticating, the network server allocates an address to the device and a token to retrieve session keys. The network and app session keys are output during the connection procedure from the shared app key that was previously prepared on the device. OTAA activation is provided with a high level of security, and addressing is similar to IP address allocation via DHCP.

Network management and optimization

If the end device supports it, the network server can perform adaptive data transfer rate (ADR) settings based on the received SNR (signal-to-noise ratio). SNR is a dimensionless value equal to the ratio of the power of the useful signal to the noise power.) each device. When using ADR, devices spend less time on the air, increasing the efficiency of radio resources, as well as managing the reliability of message delivery.
Devices will use the port parameter in LoRaWAN messages to detect MAC control messages from app messages. When sending a control message, fport will be set to zero.

In conclusion

The purpose of any LoRaWAN network implementation is to provide messaging from devices and devices to the application server. The Telemetric software package is such an application and covers all parts of the operation of the LoRaWAN network and ensuring data delivery to the client.

Installing on your own server

The Telemetric Local version is a solution that allows you to deploy a software package that includes the LoRaWAN V 1.03 network server and the personal account of the Telemetric Manager.

 

Collecting and storing data from your objects on a completely proprietary infrastructure.
logo-white

Разработка IIoT систем