Use a signal Jammer on exam days (Score 1)

If your only concern is networking and not inbuilt memory then you can just use a signal jammer on exam days and let your students know that they will not have any networking capabilities on exam days. 3 issues i can think of with this approach- 1. People using translators that speak to a server in the cloud. (But if they really require a translation device that bad, they probably have one that does everything on the device itself) 2. No access to important phone calls. This is probably a bigger issue, as students may not be able to receive urgent phone calls. But then again, exams only last for an hour or two so that is not a huge amount of time to be without a phone. Furthermore, the probability of someone needing to tend to a life threatening accident is rather low. 3. Might end up disrupting reception on phones of people passing by the classroom in the corridor outside. This, again, isnt a big deal as anyone on AT&T can tell you, you can learn to live with losing signal from time to time.