Did your friend try to figure out which network the WiFi was running on?
There is a day I did NBO-MSA in a bus and was using Safaricom 3G and I'd either lose the signal or it would downgrade to EDGE at certain sections of the journey.
I am therefore pessimistic about "the signal was stable all through"portion of the experience.
Apparently free wifi on board MSA-NBI buses is the new trend. Oxygen bus has this too. A colleague managed do some fairly good video skype aboard one of them last Friday. Just as Wash says, we noticed that the signal died out at some points of the journey.
My guess is that they are using Safaricom 3G. I may be wrong.
Reason? : Queen bee is the only network I know that claims to have the full stretch of MSA-NBO highway covered by their 3G network. They used to blow their trumpet on that a few years back.
As for the hardware, any guess on what's involved? I'd go for the Orange-Domino-like cheap solution; but there's there's a constraint on the number of concurrent connected devices, leading to a need to have several of those dongles. If I had a bus on that route, I'd invest in a dirt cheap netbook/tablet (to make use of the battery life) + connectify (to weed out the limitation I pointed out earlier) + Mobile 3G data plan) :D
Anyone with a better poor man's bare-bones solution? I'm looking at the possibility of incorporating the Raspberry Pi on this....