LPWAN Tutorial: Features, Architecture, and Benefits

This tutorial covers the basics of LPWAN (Low Power Wide Area Network) technology, its architecture, and the benefits it offers. LPWAN systems include technologies like LoRa, Sigfox, EC-GSM, NB-IoT, LTE-M, DASH7, Weightless, and NB-Fi.

What is LPWAN?

LPWAN is a type of wireless network designed for applications requiring low power consumption, long range, and low bandwidth. These characteristics are particularly well-suited for IoT (Internet of Things) and M2M (Machine-to-Machine) communication scenarios.

LPWAN finds application in various areas such as:

• Smart tracking
• Smart grids
• Smart parking
• Smart cities
• Smart agriculture
• And more

Figure 1 illustrates various LPWAN standards:

Figure 2 compares LPWAN with other wireless technologies based on key system parameters like bandwidth, latency, range, power consumption, coverage penetration, costs, and the number of base stations needed. LPWAN typically operates in the sub-GHz frequency band.

As illustrated, LPWAN excels in providing longer range, low power consumption, deeper penetration, and wide coverage. It’s worth noting that LPWAN generally supports longer transmission latency, which isn’t typically a primary concern for its intended applications.

LPWAN Features and Characteristics

Here are the key features and characteristics that define LPWAN networks:

• Long Range: Offers a typical range of approximately 5 to 40 Km in open field conditions.
• Ultra-Low Power Consumption: Extends battery life to around 10 years for connected devices.
• Low Throughput: Provides throughput of a few hundred bits per second (bps) or less.
• Low Chipset Cost: Radio chipsets can cost $2 or less.
• Fewer Base Stations: Requires fewer base stations, as a single base station can serve thousands of LPWAN devices or sensors.
• Excellent Coverage: Provides excellent coverage, including good in-building and in-ground penetration.

LPWAN Architecture

The LPWAN network architecture typically consists of the following components:

• LPWAN End Devices: These are the sensors or devices collecting and transmitting data.
• Base Stations: These receive data from end devices and forward it to the network.
• Gateways: These can act as intermediaries, especially for short-range devices.
• Access Network/Internet: This provides the backbone for data transport.
• Cloud Servers: These store and process the data received from the network.

LPWAN networks often utilize a star topology. This choice avoids the complex routing algorithms associated with mesh topologies, simplifying implementation and reducing power consumption.

End Devices

Two types of devices typically connect to an LPWAN network:

• Long-Range Devices: These devices (e.g., using LoRa, NB-Fi) connect directly to the Base Station.
• Short-Range Devices: These devices (e.g., using Zigbee or Bluetooth) connect to the Base Station via an LPWAN gateway.

Base Station (BS)

The Base Station connects to end devices or gateways on one side and to the Access Network or internet service provider on the other. A single BS can handle a large number of devices. TCP/IP is commonly used to transport traffic between the BS and cloud servers.

The BS handles protocol translation between IoT protocols and application protocols. Common IoT protocols include MQTT and CoAP.

LPWAN Gateway

The Gateway provides network connectivity for short-range devices using standards like BLE (Bluetooth Low Energy) and Zigbee. It manages the conversion between LPWAN and short-range device radio technologies and their respective protocols.

Gateways often run on mains power due to the need to handle a large number of end devices. They are typically equipped with encryption algorithms for end-to-end security.

Cloud Server and Apps

Cloud storage refers to a service where user data is remotely maintained, managed, backed up, and stored. Users access this service over the internet to store files on external servers maintained by cloud storage service providers.

Cloud storage delivery models include:

• Public Cloud
• Private Cloud
• Hybrid Cloud
• Community Cloud

LPWAN Benefits

Here’s a summary of the benefits offered by LPWAN technology:

• Longer range
• Long device life cycle
• Low cost of gateways/BSs/Sensors
• Fewer BSs required
• The sub-GHz frequency band facilitates operation under complex channel conditions.
• Deeper penetration through walls and building basements.
• Simple network installation and easy network management
• Secured data communication between nodes and Gateways due to encryption algorithms.

LPWAN Technologies

LoRa

Sigfox

EC-GSM

NB-IoT

LTE-M

DASH7

Weightless

NB-Fi