Table of Contents
Lora / LoraWAN / Things Network
Gateway Pledges - Pledge your ££££ to build the infrastructure
The Things Network is coming to Edinburgh and the first gateway has been installed on Leith Walk. This is a free, open source IoT network project which allows for ultra low power electronics to send and receive small amounts of data over large distances (up to 20km).
Lora is a spread spectrum wireless technology, typically operating on the license free 868Mhz ISM band in the UK. A network stack called LoraWAN sits on top of this providing encrypted messaging to and from devices from gateways.
The Things Network provide a backbone for the gateways, allowing applications to be created to allow devices to connect to an open network worldwide. This is an entirely free and distributed service. Clients can then authenticate to TTN using MQTT to receive data from their devices and display it on dashboards or otherwise act on it.
Want to see how many people push a big red launch button attached to a lamppost? This is the network for you! In more serious applications, it is being used for temperature monitoring, remote lighting control, car and bike counting, stolen bike tracking, hedgehog crossings and flood warnings. There are plenty of other applications out there.
The nodes are low cost and low power. An ESP8266 with an RMF95W module is enough for a node at a cost of about £5. A LoraWAN stack called LMIC is used to provide the network layer. This will also run on the larger Arduinos such as the Leonardo or similar. For a little more, Microchip have a transceiver which is easier to use and builds in the stack. Complete boards exist from PyCom, BadgerBoard and others.
Gateways require more complex electronics as a Concentrator chip is used - this runs multiple virtual Lora receivers in a DSP so that it can work across 10 frequencies and all Spreading Factors (which control the bandwidth and distance). Using GPS synchronisation they may also offer time based geolocation from multiple gateways. Whilst there are commercial gateways and The Things Network will soon offer a gateway, the most versatile and cheap option is to build your own. This consists of a Raspberry Pi and a Concentrator board with (ideally) a mezzanine PCB to connect the two. An example gateway build is here
To start using the network, we need gateways. The University of Edinburgh are building a dual homed network in the town centre which is primarily for their commercial clients but will likely also connect to TTN. There is one gateway in the Leith Walk area run by Gary Martin and Tim Kerby is planning a gateway in Portobello. There is an opportunity for the Hacklab to host a gateway in Summerhall and also potentially at the Observatory on Blackford Hill using Hubs as a data provider.
Each gateway is likely to be about £250 to £350 (depending on config) to build so we need to raise some funds to enable the network. Once we have a few gateways and coverage, we can look at IoT applications and try to get funding for further Gateways. Edinburgh Council may help here (they have IoT bins using GSM so why not a free open network instead).
Please pledge your contributions to the gateways here: Gateway Pledges