Hi Nemo,
In the USA and possibly other countries it would be a freedom of speech issue trying to prevent someone from using the airwaves they own (we all own them together and we let the FCC regulate them within limits). Or restricting the use of devices because the university wants to own the airwaves exclusively.
"(1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation." meaning that the parties operating such a device can not seek redress from other parties operating radio communication services.
See the FCC ruling in "MassPort" - "The genius of this unlicensed technology is that no central authority controls or manages how and where these networks spring up. Instead, any private or commercial operator who sees a need for a local Wi-Fi network may build and operate one." .... "When it comes to providing broadband over the unlicensed bands, the airwaves are truly the people's airwaves." Theres a weapon to use if you are having troubles at your university.
The principal that a unlicensed frequency can't be owned and controlled by anyone is clear.
The FCC recently opened up more frequencies in the 5 gigahertz range for unlicensed wireless networking services. Companies already make stuff for 5Ghz so students could move off the more popular frequencies at a reasonable cost (and get higher speeds as a bonus).
There are other frequencies that a group of smart students can use that allow communications of 1W or less without license. HAMs (amateur radio operators) have been known to use frequency multipliers or up/down converters to move existing equipment to different frequencies so it's possible to change the frequency of existing Wifi equipment (although quite technical, probably a good project for students). Most stuff under 100mW is unlicensed anyway.
Wifi Direct Sequence Spread Spectrum (DSSS) including special modulations with the chipping codes etc.. can allow more than one station to use the channel at the same time, although some will argue with this, you must consider that stations are not always at full strength or in direct contact with each other and that newer software attempts to prevent jamming. Also, stations may drop to a different speed, which can change the modulation.
802.11a (5GHz) and 802.11g (2.4Ghz) both at 54mb/s, use Orthogonal Frequency Division Multiplexing (OFDM) and should support more than one station at a time on the channel better than DSSS does and there are many more channels available (at 5Ghz).
With these technologies it's not always as simple as someone is transmitting on my channel so I can't talk.
There's articles on the net about "cantennas", where people use tin cans to make highly directional antennas. Students could use these to direct signals more narrowly and prevent interference possibly going from building to building through windows and at lower power. Make it a art project.
Now you've gotten rid of the too many stations on one channel problem and the "rogue AP" detection problem Nightwalker mentioned. It would also make spying and monitoring harder.
Students can add or cluster stations that repeat traffic at different frequencies, combining routers together including adding cabling to provide "service" to an entire dorm complex and adding Wifi stations that cover the dorm area from building to building. Then it's possible to have full LAN speeds some of the time.
It's probably better for overall security if the students mix it up since it would make it harder and more expensive for someone to try to block or spy on all the different modes.
There's also the option of going optical, for those situations where Wifi just won't do :)
FCC MassPort article (or use google)
http://www.wifinetnews.com/archives/007102.html
