WSNet

With its radio technology, our WSNet solution offers decisive advantages in the areas of range, interference immunity and power consumption. Physically, WSNet is based on LoRa™ technology, but represents a solution tailored by WSN for the respective application. In WSNet, only as much energy is used for sending and receiving data as is actually required.

The advantages of the IIoT solution at a glance:

Components of the WSNet solution

Component 1 - Radio network: WSNet base LoRa™

Thanks to the robust LoRa™ wireless technology, good coverage and penetration of even large production halls is achieved in an industrial environment. The radio technology is a development of the company Semtech Corporation. In contrast to WLAN, no large number of routers are required. A single LoRa™ gateway is capable of reliably and securely managing hundreds of sensors across thousands of square meters.

It is possible to use different virtual channels at the same time without the transmissions interfering with each other due to the “spread spectrum technology” (frequency spreading) used by LoRa™. The data rates, the frequencies and the transmission power of the end devices can be set individually. This technology is ideal for use inside buildings and radio-critical environments (e.g. in reinforced concrete buildings) due to the interference immunity and the excellent penetration.

The most important technical data and advantages in brief:

Use of the innovative LoRa™ radio technology as the physical basis for data transmission between end devices and base stations (gateways – cf. actuators further down in the article)
Long range (both inside and outside of buildings)
easy installation and commissioning of the network
Low installation costs as one-off costs, even for networks with large spatial coverage: Several thousand end devices can be networked with just a few gateways.
No further (non-administrable) repeaters are required

Use of free (ISM) tapes: No license fees, no ongoing usage costs
Star topology, with gateways typically acting as a transparent bridge between end devices and the message management center (MMC).
Bi-directional communication between end devices and gateways or applications
Central and optionally fully automatic integration and configuration of the end devices
Private network – data does not have to be transmitted over a public network

High data security against hacker attacks through double AES128 encryption (hardware and software) between end devices and gateway
SSL connections in the IP network
No consumption of private IP addresses by the end devices. Only the gateway occupies an IP address, end devices do not need their own IP addresses, but can be clearly addressed and localized.
Roaming without data loss on mobile devices

Component 2 - end devices:

The sensor technology of the solution consists, among other things, of mechanical or optical switches for shelves and roller conveyors, occupancy indicators for pallets and lattice boxes, level indicators for screw bunkers, etc. The battery-operated sensors are equipped with a low-power LoRa radio module and are characterized by their robustness and very long battery life.

Passive Sensor Nodes (PSN)

Send messages (event-driven) to the message management center (software – see later, component 3)
Are only available at preconfigured times to receive commands

This mode is the most battery-friendly operating mode with a battery life of up to 10 years
Product example:roller conveyor sensor

Active Sensor Nodes (ASN)

Use the “Wake on Radio” (WoR) functionality. Based on the configuration of the end device, it is permanently ready to receive for a preset interval.
These nodes accept commands from the message management center, for example to switch an LED.

Due to the frequent readiness to receive, this mode saves less energy than operation as a passive sensor node. In typical industrial applications, these endpoints can be used for appx. two years without battery change.
Product example: Call Button

Gateways

The gateways act as media converters and have at least two LoRa radio units (transceivers) and an IP connection via LAN/WLAN/mobile radio (depending on equipment). The LoRa radio units perform the following tasks:

Outbound Message Channel (OMC) – is used to send commands / information to end devices
Inbound Message Channel (IMC) – receives messages from end devices

By using a so-called “concentrator” module, up to 48 messages can be processed simultaneously.

All messages / commands follow the WSN Avro specification for the most efficient data transfer.

Component 3 – Software and Message Management Center

The Message Management Center (MMC) manages WSNet end devices and communicates with them via gateways. Communication with applications takes place via standard IP connections. It can be operated both on the gateway and independently on a PC.

The MMC has a so-called dashboard, i.e. a user interface for central monitoring and control of all end devices that are registered at the gateway. The dashboard allows direct communication with the end devices. It also logs all incoming data and events.

Our MMC supports the firmware update for the end devices via the dashboard. These can receive new firmware “over-the-air” either individually or via multicast. For security reasons, only signed firmware can be transferred to end devices.

Integration of Node-RED

Node-RED as a graphical tool for creating message histories

Node-RED Message Flow (example representation)

Another key part of the MMC is the use of Node-RED. A graphical tool for creating message threads. It allows end devices to connect to application interfaces, to send e-mails or tweets based on events or simply to conveniently monitor end devices. Node-RED supports MQTT, a real-time M2M message protocol.

Node-RED Message UI (example display)

All from a single source

The wireless IoT applications are connected to the respective operational systems and integrated into the company processes. For this purpose, an inventory is carried out on site in order to adapt the solution concept, the components and the software to the local requirements. The turnkey solution also includes installation, commissioning, training and support.