Wireless lab

When researching or developing products or solutions that will be used over wireless networks, or designing the protocols that drive these wireless networks, experimentation is a crucial aspect in determining the reliability of a solution.  Small-scale experiments with a limited number of wireless devices may already be helpful to discover certain functional, stability or performance issues with a solution under test, caused by the unpredictable behavior of the error-prone wireless environment. However, the behavior of the same solution in a larger, more realistic and more complex wireless environment, characterized by a diversity of interfering wireless technologies and devices may be completely different.  Furthermore, the repeatability of wireless experiments that are carried out on top of a temporary set-up of wireless devices is limited.

The w-iLab.t testbed provides researchers and developers with the hardware and with software tools to develop and test their wireless solutions (or their solutions that rely on wireless connectivity) in a time-effective way in small and large-scale set-ups. Experimenters are provided with the tools to install and configure firmware and software on (a selection of) wireless nodes, schedule automated experiments, and collect, visualize and process results.

 

Two test locations

w-iLab.t Office

The w-iLab.t Office is located in the IBBT office building in Ghent (Belgium) and is equipped with a wireless Wi-Fi and sensor network testbed infrastructure. 

 

w-iLab.t Zwijnaarde

A second w-iLab.t deployment is found in Zwijnaarde located approximately 5 km away from the w-iLab.t Office. The w-iLab.t Zwijnaarde is an unmanned utility room were hardware is hosted at another 60 spots. 

 

Shielded wireless experiments and mobility emulation

For those cases where the experimenter expects full shielding from external interference, and/or wants to emulate mobility, the iLab.t offers access to the Qosmotec Air Interface Simulator  environment.

Four shielded boxes are available in the Qosmotec set-up (see figure below). Wireless devices can be placed in one of four shielded boxes. Their antenna is decoupled and the wireless signals are carried over coax connectors to a central combiner/splitter unit, also equipped with remotely configurable variable attenuators. As such, various wireless networking topologies can be set up, such as a simple bidirectional wireless link between two devices, a handover experiment where a single wireless client travels between different access points, or a wireless mesh set-up.

 

Example use cases

As the w-iLab.t nodes and their interfaces are fully configurable, the w-iLab.t can be used for a wide range of experiments.  Example experiments include:

  • Development of routing protocols for wireless sensor nodes or Wi-Fi nodes, for example to build city-mesh networks.
  • Development and analysis of load balancing algorithms for spreading the client load over different Wi-Fi access points. In this case, the Wi-Fi interface of some of the nodes is configured as a Wi-Fi access point. A large number of the other nodes’ Wi-Fi interfaces are configured as Wi-Fi clients.
  • Deploy your mobile application on the embedded nodes in the testbed – see how your mobile application reacts when 100 Wi-Fi clients use your application at the same time.
  • Test the stability of your (improved) wireless driver for Wi-Fi cards.
  • Evaluate the scalability of your solution for Wi-Fi access in hotels – see what happens when 10 customers simultaneously connect to a single access point.
  • Use the shielded emulation set-up to verify the performance of your wireless device under perfect interference-free conditions in a simple 2-device set-up. Verify the behaviour of your device as the received signal power drops.
  • Determine the feasibility of a remote surveillance solution by transmitting live webcam video over a multi-hop wireless path.
  • Determine the accuracy of your positioning solution based on Wi-Fi or sensor networks by letting mobile robots travel along a predetermined repeatable path. Determine the effects of (controlled) interference on the accuracy.

 

The above list is by far a full listing of possibilities. For an overview of selected projects during which the w-iLab.t testbed has been used, please consult the Projects page.

 

Access info and more information

The w.iLab.t testbed is centrally managed for control and monitoring purposes, and is accessible through a secured OpenVPN connection. It supports easy configuration and deployment, including installation of new software, protocols and middleware components via an intuitive web-based interface.

The w-iLab.t testbed is part of the CREW [Cognitive Radio Experiment World] federated experimentation facility. As part of the CREW project, detailed information on w-iLab.t is provided via http://www.crew-project.eu/portal/wilabdoc .

Finally, the figures below present an overview of the most important hardware available in the w-iLab.t testbed, and of the most important testbed functionality.