TWIST
Short testbed description
The TKN Wireless Indoor Sensor Network Testbed (TWIST) is a multi-platform, hierarchical sensornetwork testbed architecture developed at the Technische Universität Berlin. One instance is currently deployed at TUB campus: a total of 204 sensor nodes (102 eyesIFX and 102 Tmote Sky nodes) are distributed in a 3D grid spanning 3 floors of an office building, resulting in more than 1500 m² of instrumented office space. Two nodes of each platform are deployed, while the larger ones (~28 m²) have four nodes. This setup results in a fairly regular grid deployment pattern with intra node distance of 3m. Within the rooms the sensor nodes are attached to the ceiling. The TWIST architecture introduces a layer of “super-nodes” (previous figure, right) between the sensor nodes and the testbed server, which manages sensor node reprogramming, configuration or accessing debug information over the serial connection. TWIST relies on COTS hardware and fully leverages the features of the USB 2.0 standard. The sensor nodes are connected to the super-nodes via USB hubs, which act as concentrators and also provide a power supply management capability. This enables active topology control and node fault injection modelling through selective powering on and off of nodes. TWIST is currently being extended by mobile robots which can be used for experiments that involve controlled mobility. At the end of CREW Year 1 (at the time of the first open call) one mobile robot can be used for local experiments.
Example experiments
Various experiments can be performed using the TWIST infrastructure, for example:
- Investigating different RF interference detection techniques, e.g. distributed vs. centralized detection.
- Exploring different interference mitigation techniques, such as frequency hopping or adaptive power control.
- Studying spatial distribution of RF interference in an office environment via RF interference maps.
Experimenters may also couple the TWIST testbed with mobile sensor nodes (carried on a human subject or by a mobile robot) or spectrum analyzers in order to, for example, investigate:
- Cooperation between fixed infrastructure and mobile body area networks (investigating network discovery, handover, etc.)
- Comparison of in-network interference detection with other (external) spectrum sensing equipment
Access information
TWIST is accessed via a web-interface. Experimenters can install their firmware on one or more sensor nodes, receive status information, download experiment traces, and interact with individual nodes during an experiment over an SSH connection. The mobile robot can only be accessed locally.
Demonstration
After applying for an account, a set of tutorials is offered to get you started right away.
