Here at Metova, we strive to be on the cutting edge of technology. This means changing our proficiencies as new technology and tools come out. Most recently we have been concentrating on the Internet of Things (IoT), particularly embedded development and LoRa WAN. We see IoT as an enormous opportunity in multiple industries, ranging from utilities to agriculture to transportation. In July, Metova joined the LoRa Alliance to promote the use of LoRaWANTM (Low Power Wide Area Network) protocol as the leading open global standard for secure, carrier-grade IoT LPWA connectivity. That’s awesome, but what on earth does it all mean?
Learning enough to write about LoRa WAN and understand it had me going down a rabbit hole chasing information and definitions for the information and definitions I was learning about. So, in an effort to ease you into LoRa WAN and make understanding what it is and why it is so awesome, I am laying it all out, ELI5 style.
What is the Internet of Things?
Imagine if your smart fridge sent out a signal when you are low on milk. Your phone could pick that up and notify you or add it to your shopping list. Pretty cool, right? Think bigger. Expand that functionality out to every item you own. Now imagine it throughout a community: water and gas utility meters, parking sensors, equipment monitoring, et cetera, et cetera, et cetera. This interaction and communication is the basis for the Internet of Things.
Why LoRa WAN?
LoRa based signals can travel multiple miles. The devices are inexpensive and can run for years without needing a battery change. This creates the ability to monitor devices that are difficult to access or out of range for wifi or cell service.
The caveat to this wonderful technology is the limited amount of bandwidth it offers. In order to have such a long range and extended battery life, the frequency of a LoRa WAN transmission must be very low. The more data you want to transfer at a time, the less distance and more battery you use. While it may seem pointless if you can’t use it to stream Netflix, there are plenty of cases where range and reliability trump bandwidth.
How Does LoRa Work?
It is easiest to compare LoRa WAN to a cellular network. LoRa based devices have a module that communicates to a locally central location called a gateway. Think of how your phone uses a cell tower to send and receive information. The gateway is a go-between from the sensor to the server. The network server communicates with the gateway via the internet and tells it how to interact with the sensor.
LoRa WAN Communication Example
It might work something like this. A farmer has a herd of cattle, each has a collar that monitors when she was last milked. Bessie’s collar reads that she was milked at 4:00am. This information is sent, via LoRa WAN, to the gateway. The gateway uses the internet to notify the network server that Bessie was milked at 4:00 am. The network server then tells the gateway to send back a message-received type response. Next, the data is evaluated and sent to the dairy’s application server where the farmer can manipulate the data, create reports, and more.
LoRa WAN Uses
Resource management and knowing your fields and animals inside and out can make or break a farm. LoRa WAN sensors can be used to monitor the status of an area in real time which allows farmers to make decisions using the most accurate information. By measuring the moisture and minerals in the soil, water and fertilizer usage can be targeted. It reduces waste and puts the resources where they are needed most.
Pests are a huge challenge in growing crops. If a sensor can detect an otherwise indistinguishable increase in bug pheromones, farmers can create a plan to manage the pests sooner, saving more of their crops.
Water, gas, electricity, we all have utilities in our home or business whose use must be measured and billed. Currently, this role is filled by an individual who must go to every house and manually record the meter readings. If a LoRa WAN module is added to each meter, this information can be retrieved quickly, accurately, and on schedule. Tying the data into a database and billing system would aid in a faster and more accurate billing system.
Knowing I will have trouble finding a parking spot on a busy night in the city or at an event is almost enough to keep me home. What if each parking area or space had a LoRa WAN that could monitor whether the space was taken or not. That information could be displayed in a mobile app, making it easier to navigate tough traffic situations.
There are many, many more uses for LoRa WAN technology. If you need to monitor some basic information about a group of widely spaced items cheaply and reliably, LoRa WAN is the answer.
I am working on a long-range communication system ,which works about 100 km without any gateway .is it possible using Lora?
While LoRa has recorded extremely long range communications — in one instance, a 702km transmission, from a weather balloon 32km high — the more realistic everyday distances achieved would be closer to about 15km in an empty desert, 5-10 km in a more normal open environment (but still with some trees/hills/etc.), or 2-5km in more crowded/urban environments.
So – to answer your questions – it depends on your use case. If this is to track an object such as a weather balloon that will have a very straight line of sight with no interference, this becomes possible with the right equipment and power level. In most other use cases, this really isn’t the right communication method to achieve that kind of distance (100km) without gateways or other devices to transmit the information in between.
Thanks for your question!
If you want to talk further about your specific use case, we’d be glad to talk about possible solutions.
100km or more with ground-based transmitters is possible (I’ve done it myself https://faydrus.wordpress.com/2018/10/20/my-tapr-dcc-2018-paper-presentation/), but you need generally need more power and antenna gain than is typically used for LoRa/LoRaWAN setups.
If you’re transmitting between the tops of two fairly high hills or mountains, you have a decent shot at seeing that kind of distance, especially if you transmit at the regulatory max (in the US, it’s 4W EIRP, with 1W power and 6dBi antenna gain) and keep the datarate low.
If you have some knowledge of RF communications, Radio Mobile Online (http://www.ve2dbe.com/rmonline.html) does a good job modeling propagation distances you might be able to see with LoRa given where the stations are sited, the antennas used, power levels, etc.