I too have a Samsung ativ pro. I upgraded to 8.1 when it was released, I have had the issue since. the Samsung works fine at work, but not at home, all other devices are fine. With the Samsung I get 10-30 minutes before it all stops.
I have tried all the advice on this thread, those worked with my 2 other 8.1 devices, but nothing works for my ativ pro. I have downloaded Samsung and Intel s software to detect if there are any upgrades needed, there were, but it did not stop the issue.
I guess the moral of the story is that if it's not broken, don't try to fix it. I learned from this bad experience with upgrading to 8.1, that I will *not* upgrade my husband's computer. I was thinking about doing it, but I am glad I tried it on my tablet first. He would go ballistic if he faced the same problem so many have reported here and on other threads. What I have gathered is that in the upgrade , MS replaces manufacturer's drivers with their own. I even went to the original drivers website, but they had so many drivers and I couldn't find the exact driver I needed. Did a search for Win 8.1 Broadcom drivers and they had 0 results. At any rate.. I am back to using Win 8 on the tablet and in the process of re-installing software and devices, trying to get my tablet back to where it was before the 8.1 disaster occurred.
Good Luck with getting yours up and running. Please let everyone know when you do and how you did it. Also wonder if MS is planning on sending out release notes if they ever get the connectivity fixed.