LoRaWAN (Long Range Wide Area Network)

Viskubrunnurinn fallar um LoRaWAN og hvernig sú samskiptatækni gagnst fyrirtækjum og almenningi. Vista hefur nú þegar sett upp LoRaWan samskiptakerfi sem er notað til að stýra götulömpum með góðum árangri. Rétt er samt að skoða aðeins betur hvað LoRaWAN er og hvernig það getur nýst á hagnýtan máta.

LoRaWAN fellur undir frjálsatíðni og þarf ekki að sækja um notkunar/rekstrar-leyfi frá Póst og Fjarskiptastofnun.

What is LoRaWAN?

LoRaWAN is a low-power transmitting data network designed for wireless and fast data transfer. LoRaWAN networks are especially well-suited to transmitting small amounts of data. Two-way data connectivity, functionality, organizational structures, and ease of deployment are among their main features. LoRaWAN is a point-to-multipoint networking protocol based on the LoRa modulation scheme developed by Sem-tech. It’s built to let low-power devices connected with Internet-connected apps over long-range communication links. LoRaWAN-based IoT solutions are both cost-effective and long-lasting. Sensors for the collection of data are small and simple to install, and they don’t need any cables. Sensor batteries will last up to ten years, making the solutions virtually maintenance-free. In most cases, data is sent from the terminal computer (sensor) to the network. Messages are usually transmitted 15 times every 60 minutes. It’s not just about the radio waves; it’s about how they interact with LoRaWAN gateways to perform functions like authentication and recognition. There’s also a cloud aspect to which several gateways can link. The second and third layers of the OSI model can be converted to LoRaWAN. The LoRa Alliance defines the LoRaWAN protocols, which are documented in the LoRaWAN Specification, which can be downloaded from the LoRa Alliance website. Radio protocols like LoRaWAN are straightforward at their most basic level. LoRaWAN networks can be constructed with a local emphasis to cover a particular region or house, or they can be built to cover the entire country.

LoRaWAN network architecture

The star-of-stars framework is frequently used in LoRaWAN network architecture. This data transmission bridge connects the sensors, which are also known as terminal equipment, to the centralized network servers. LoRaWAN sensors send data to one or more gateways via wireless single-hop transmission, which are then linked to network servers via standard IP connectivity. Since LoRaWAN terminal devices do not use the IP protocol, they are connected to a network that is completely different from the internet. Three classes of LoRaWAN are active at the same time.

Figure: LoRaWAN network architecture

Class A

Symmetric communication can be achieved with class A terminal devices, so each communication is accompanied by two short retrieve windows. It is possible to specify the transmission time. It is focused on the ALOHA protocol, wherein the terminal system sends a packet when it is required to do so. Since their connectivity with servers has been minimized, class A terminal devices have the minimum energy usage. They just wait for a server to send them a confirmation message.

Class B

Using class B messages can be sent downward to battery-powered clusters. The gateway sends out a beacon every 128 seconds.  Since all LoRaWAN access points are slaves to one pulse-per-second clock, they all send beacon messages at the same time (1PPS). This implies that at the start of every second, each GPS satellite in orbit communicates a message, enabling time to be coordinated around the world. Inside the 128-second loop, all class B nodes are given a time slot and informed when to hear. For example, you can instruct a node to listen for any tenth-time slot, and when one appears, a downlink response can be sent.

Class C

When large volumes of data must be received rather than sent, this form of endpoint is ideal. Class C terminals operate in both directions and have a limited number of receive positions.

The use of LoraWan networks

  • LoRaWAN networks can be used in a variety of IoT (Internet of Things) solutions that involve low-cost, high-reliability data transmission.
  • LoRaWAN solutions are particularly well-suited to sending and receiving small amounts of data over lengths of tens of kilometres or more.
  •  Since encrypted data transmission is implemented in three separate network layers, LoRaWAN is a safe solution.
  • To ensure safe data transmission between both the sensors and the server, the remote computer, the program it uses, and the radio station all use their own specific encryption keys.