Advanced wireleSS Environment Research Testbed (ASSERT)
Formerly Texas Networking Testbed (TNT)
Overview
Advanced wireleSS Environment Research Testbed (ASSERT) is a device-independent platform for developing and testing wireless network protocols. The system contains hardware and software facilities to conduct wireless experiments that are:- Repeatable
- Realistic
- Accurate
- Cost Effective
- Scalable
- Ability to support many types of nodes.
- A remote user interface for network configuration, experiment monitoring and data retrieval.
- Capability to automatically map a given topology to available hardware.
- The ability to scale up to 1,000 sites.
Advantages
Advantages of conducting wireless experiments on ASSERT:- Cheaper
- Less time consuming
- Mobility and distance
- Shielded from weather
- Concurrently run multiple experiments
- Concurrent support of heterogeneous units under test
- Eliminates need for user license to conduct experiments in licensed frequency bands
Concept of Operation
We use coaxial cables between the antenna ports of two nodes to emulate an over-the-air link between them. By changing signal attenuation level, using programmable attenuators and amplifiers on the path between nodes, we emulate the formation/disruption of wireless links and node mobility. Using power dividers/combiners we can emulate complex, multi-hop wireless networks. As all communication is over coaxial cables, the network is immune to interference from other wireless networks. It is also possible to inject the desired amount of noise into the links.
How to Use
The testbed is designed to be a device indpendent platform for conducting wireless experiments. The testbed will be provisioned with a basic set of wireless sensor nodes as the Unit Under Test (UUT) for conducting wireless sensor networking experiments. If an experimenter does not wish to use this technology ASSERT allows the UUT to be interchanged with any other wireless device as long as it falls within the supported frequency band and transmission power range. If the user's UUT must receive control signals, it can be connected to the site using the RS-232 serial port on the site. Other digital interfaces may be available if required by a UUT.
Status & Goals
Hardware
As of December 2008 the custom site hardware for ASSERT has been manufactured and tested. Evaluation and verification experiments are in progress using revision 1 hardware. By July 2009 UTD expects to have 50 sites of revision 1 and 2 hardware connected and running.
Update: As of June 2009, we have 48 sites available, 40 of which are already mounted on two separate racks. Four sites can be seated in 6U of a standard rack. Each site has a separate isolated space for the Unit Under Test (UUT), which can be connected to the digital board through an internal connector.
Software
Design and implementation of critical software functions for the testbed are largely complete. These functions include control of the attenuators, diagnostics of the RF links, reservation of site hardware for an experiment and control of the experiment flow. We are in the process of creating a more sophisticated control graphical user interface for setting up experiments, software for controlling a Unit Under Test and automated mechanisms for experiment supervision and data retrieval. Currently we gather all data recieved from the UUT from the serial port and collect it as text files for the end user. This data can be processed by the final user to gather their desired output.
Press & Related Publications
- ASSERT Product Summary
- Testbed capabilities poster PDF Version (6MB file)
- Burchfield, R., Nourbakhsh, E., Dix, J., Sahu, K., Venkatesan, S., Prakash, R. 2008. "RF in the Jungle": Effect of Environment Assumptions on Wireless Experiment Repeatability to appear in Proceedings of The IEEE International Conference on Communications 2009.
- Paul Johnson, Ehsan Nourbakhsh, Ryan Burchfield, Jeff Dix, Ravi Prakash, S. Venkatesan, Neeraj Mittal, and Lee McFearin, Demo Abstract: ASSERT - An Advanced Wireless Environment Research Testbed, Demo in SenSys'09.
- Texas Networking Testbed: Press Release
Testbed Information Contacts
To obtain more information about the testbed or inquire about using it for your wireless experiments please contact Professor Prakash (ravip@utdallas.edu) or Professor Venkatesan (venky@utdallas.edu).
