At it’s most basic level, any LoRaWAN gateway’s job is to receive messages from sensors over radio signals and forward these to a LoRaWAN network server. The network server then decides what to do with these messages – more than likely store the data from them so someone or something can analyse them later on.
The gateway needs to be programmed to talk to your LoRaWAN network server, whether that’s something like The Things Network, Loriot or your own server (the LorixOne supports all of these systems), the gateway talks to a Network Server over an IP connection.
The LorixOne gateway has a single RJ45 connection to plug into a network. It comes with a passive-PoE adaptor which is used to provide both an IP connection and power down a single Ethernet cable to the gateway. It doesn’t support 802.3af/802.3at Power-over-Ethernet standards, so you need to use the passive-PoE injector supplied even if you already have a PoE capable network switch.
It doesn’t matter how the gateway reaches the Network Server as long as it can. So you can simply connect it up to your IP network, or you can connect it to a converter such as a 3G/4G router or a Wifi bridge for back-haul to the LoRaWAN network server. Just how much bandwidth is required will depend on how many sensors will talk via this gateway and how often they will talk. However, LoRaWAN uses minuscule amounts of data, each message being a few bytes in size only. Just looking at the console in my own ThingNetwork account at the last few messages my LorixOne gateway received, I can see that two of them were 14 bytes and one of them was 20 bytes.
So doing some pretty crude estimations as an example, lets say we have 100 sensors sending messages every ten minutes (which is actually quite a lot for most use cases) and the average message size is 16 bytes. UDP & IP overhead adds about 30 bytes (more for IPv6, TTN seems to be IPv4 only at the moment). So lets say that each message uses 46 bytes on the wire, it could be more depending on how your gateway is talking to the network but this probably isn’t a million miles off:
- In one hour, one sensor will send 276 bytes (46×6)
- In one hour, all 100 sensors will send 27.6 kilobytes (276×100/1000)
- In one month (lets just say 30 days), we will require 19.87 megabytes (30 days is 720 hours, 720×27.6bytes / 1000 to get MB)
Even if you had 10,000 sensors doing this you’re using less than 2GB a month.
Radio Capabilities
The LoRa radio in the LorixOne gateway is based on the Semtech SX1301 chip. This is an 8-channel radio which means the gateway can receive 8 messages from sensors at once. How many sensors it can handle is hard to answer as it depends on many factors. These include: how often the sensors are sending messages, how much data the messages contain and the signal strength between sensors and the gateway. Sensors that have a weaker signal will increase their transmit time in order to send data, this means a receive channel on the gateway is tied up for longer.
When it comes to sending data from the gateway back to sensors, there is only a single channel for this. In addition, the regulations for use of ISM band radio devices states that you can only send data for 5% of the time (depending on exactly which channel is being used though) in Europe.
LoRaWAN (in common with many other low power wide area networks) is asynchronous, it’s not quite one way only but it’s not far off. If you are wanting to send data back to your sensors, you need to be careful how you manage this and ensure you don’t break the regulations.
The gateway should easily be able to handle several thousand sensors sending small pieces of data periodically.
Software and Configuration
The LorixOne gateway is an embedded computer running a Linux based operating system (based on Yocto).
Configuration is done by command line only, you need to ssh in to it. Use the ‘ssh’ command on a Mac or Linux PC, download the Putty program on Windows.
We can help with configuration and can pre-configure gateways before shipping them.
Get in touch if you are interested in this (contact@alliot.uk)
Gateway Variants
There are two product codes you can order for the LorixOne gateway.
LORIXONEIP65O: this is the outdoor IP67 rated version of the gateway
LORIXONEIP43I: this is the indoor IP43 rated version of the gateway
In reality the only difference is the antenna which is supplied with the unit.
The outdoor version contains a fixed position 500mm 4.15dBi antenna. This will give the longest range, the gateway needs to be installed vertically.
The indoor version contains a variable position (as in the angle of it can be adjusted so the gateway can be installed horizontally or vertically), 200mm 2dBi antenna.
Both are currently the same price.
Verdict
Things I like about this gateway are:
- it’s really small! The body of the unit is a cylinder of approximately 200mmx45mm diameter. This helps make it easy to install without looking messy
- Very easy to mount. Just strap it to a pole
- Outdoor rated. IP67 dust/water ingress rating means it can be sited wherever you want
- The price. We have retail and trade pricing. For an IP67 gateway, I haven’t found anything cheaper
- Quality. The gateway looks & feels very high quality, it’s made of tough ABS plastic, it feels like it will last a long time. The software is running off NAND flash, not an SD card or similar
Limitations:
- passive PoE instead of 802.3af/at. I think it’s a shame it needs an injector and power supply, although both are included in the box
- Ethernet only. I would like to see versions that include an integrated 3G/4G modem and a SIM card slot, perhaps a wifi version too. I wouldn’t want a single gateway with them all, it will become too expensive. You can of course connect it to a 3G/4G router or Wifi bridge
Given the price and that those limitations are either not much of an issue or easily solvable, this gateway is just about the best thing I’ve seen so far for building a LoRaWAN network.