WalT - Wireless Testbed
Hover mouse over each platform component for details.
The WalT client software can be installed easily:
$ pip install walt-client
The client software only interacts with the WalT server. The server acts as a gateway allowing to manage the other elements of the platform.
Note: clients must reach the server through the external LAN. Connecting a client on one of the platform switches will not work.
The WalT server is the brain of the WalT platform:
Any amd64 machine may be installed as a WalT server (on this drawing this is an Intel NUC mini-PC) by using the dedicated USB image (see the Setup page for more info). We suggest a reasonably powerful CPU (intel core i5 or more) for a good experience with the most resource-consuming tasks (e.g. "walt image shell" involves emulation of the node's CPU architecture).
Important note: The WalT server must be connected on port 2 of the switch.
The switches used in a WalT platform need to provide the following features:
We recommend the Netgear ProSafe GS110TP switch that provides these facilities at a reasonnable price.
These black boxes are IEEE 802.3af compliant PoE splitters. They allow to:
Raspberry Pi nodes
These electronic boards are the nodes of the WalT platform. For now the WalT platform has only been tested with Raspberry Pi boards (type B or B+). More kinds of nodes should be added shortly.
The boot procedure of WalT nodes is made of 2 steps:
In order to setup a WalT node, you just need to flash its SD card (using dd or similar) with the dedicated SD card image (see the Setup page for more info).
The red cables on the drawing allow to bring power from the PoE splitter to the node. The connection to the PoE splitter requires a 5.5mm / 2.1mm 5V DC Jack connector. The connection to the Raspberry Pi node requires a micro-B male USB connector.
Such a cable may not be easy to find at a good price. Alternative options are:
The purple cables on the drawing are PoE cables (Power-Over-Ethernet), which means they bring both data and power signals to the nodes. They are standard Ethernet patch cables with RJ45 connectors. When installing a WalT platform in a building, you should be able to reuse the existing cabling material.
Troubleshooting: If you encounter problems such as node reboots, this may actually be due to power loss, especially if PoE cables are running over a long distance. In this case you may need:
The blue cables on the drawing are standard Ethernet patch cables with RJ45 connectors. When installing a WalT platform in a building, you can reuse the existing cabling material.
At first startup, the WalT server will:
As a consequence, this external LAN must provide:
Important note: The cable of the external LAN must be connected on port 1 of the main switch.
© LIG lab 2016 - 30 Nov 2016 - Funded by Université Grenoble Alpes, Grenoble INP / UJF, AGIR 2013-2014