JPL's Wireless Communication Reference Website

Chapter: Wireless Propagation Channels

New Directions in Propagation Research

Propagation research is a very old discipline. Over the years the frequencies of interest have move up, currently addressing the bands above 3 GHz, particularly 40 or 60 GHz. Infrared optical propagation is also being studied. Not only the pathloss, but also the (microscopic) fading and dispersion effects are relevant.

This interview with Daniel Davarsilvatham covers trends in propagation research. Dr Davarsilvatham is director of the Propagation and Planning Wireless Systems Research Lab at Bellcore.


Duration 3'07"
Propagation research is conducted for various reasons.
  • Precise understanding of the channel allows engineers to design better systems that can cope with multipath fading. Path loss, delay spreads, scatter plots etc. all affect system performance. If such systems are well designed according to accurate and reliable models, further measurements make no sense.
  • Planning and deployment, however, do require measurements.
References:
Cell planning.
Delay spread, Channel samples

Duration 2'25"
  • Once a system is designed and deployed, the service provision aspect comes in. For small startup operators, it is of critical business importance that their sales department can judge fairly reliably whether or not a certain location can be served by their wireless network. Unsuccessful attempts can break the economics of such companies.
References:
The last mile.

Duration 1'35"
Some scientists believe that frequency assignment for indoor systems can be done in future, relying on accurate models using high resolution data bases. More realistically, self-organizing systems will be deployed, adopting a set of "rules of thumb" for technicians in the field.

A challenging interesting new direction of propagation research is initiated by smart antennas and Space Division Multiple Access. Expertise in propagation, antennas and signal processing is combined.

References:
indoor, smart antennas.

 



JPL's Wireless Communication Reference Website 1999.