Infrastructure

Server

The data base for the collection and archival of sensor data, the resources for their processing and the TDRM website are hosted by a professional ISP on a root server operated by FIfF e.V.

Sensor data are rooted to this server. A MySQL data base is the kernel of the TDRM server. All incoming sensor data are registered by the data base and deployed for web publishing as well as for retrospective evaluation. The data base is encapsulated by a ReST API. By means of the ReST API sensor data can be transmitted end-to-end encrypted via common router ports which are open by default. Vice versa the website accesses the data base to fetch the data required for presentation on its pages via the ReST API.

The server supervises the operation of all sensor stations and informs, by email, the administrator as well as the host of the respective station about changes of its state of operation.

Transmission of sensor data from sensor station to server

Once every minute every sensor station generates a data string representing the current dose rate. The string is completed by a time stamp and the station's ID, encrypted and transmitted, via ethernet cable, to the router at the premises of its host. Via Internet the router passes the string to the server. For security reasons a sensor station cannot be addressed from the outside.

DSC00844sAt locations which are not supplied with internet access we will prospectively apply the novel LoRaWAN wireless technology. LoRaWAN facilitates a narrow-band transmission over up to 10km in the 868 MHz band. This technology is employed, among others, for public open networks of internet gateways which are built up and operated by the TTN community—the acronym TTN standing for The Things Network. A project group of Karel-de-Grote Hogeschool, Campus Hoboken, Antwerpen has developed a hardware module and appropriate software extensions for TDRM sensor stations to transmit their sensor data via TTN gateways to the TDRM server.

Local website

Current and past sensor data can be retrieved locally within the local network to which the station is connected. For this purpose the operating system of sensor stations contains an own local web server. Local web pages can be accessed by the web browser of any computer connected to the same local network.

PiGI 4a

Source: Openresource project PiGI

The home page of the local web server is to be addressed by its local URL or by its IP number:

  • The local URL of a sensor station reads http://tdrmNN (occasionally http://tdrmNN.local, http://tdrmNN.lan or http://tdrmNN.fritz.box). NN is the unique identification number of the station.
  • Unfortunately routers which resolve the local URL of connected devices are quite rare. Alternatively the local home page can be adressed by the stations IP number. The IP number which the router 'leased' to the station (e.g. 192.168.1.234) can be found on the administartion pages of the router on the page 'connected devices'.

Please ignore "Websocket Error" messages!