Q: Iphone 4s Hotspot Functionality Problem

When trying to use my iphone 4s as a hotspot, other devices (all non-apple) can not see the iphones 'hotspot' for anywhere from 10 minutes to never, or until after rebooting phone, and/or cycling hotspot setting off and on (often, trying that multiple times before it works). I ususally wait up to five minutes after any attempt to see if hotspot has become available. My other devices have no problems connecting to other hotspots. It appears that my iphone does not properly broadcast it's availability consistently. Any ideas for resolving this? And is this a common problem between iphones and non-apple phones and laptops?

NOTE: I updated last week from ver 6.x to ver 7.x       There has been no change in this issue.