I had an Ubuntu 12.04 system which I recently upgraded to 13.04. I thought of trying to create a Wireless Hotspot that I could use to share my Mobile Broadband Connection with other devices. To that end, I went to the Network Settings -> Wireless Settings and pressed the Use a Hotpost button. But instead of asking me for a name of the hotspot connection and other details (as I had expected), the hotspot straight away asked me to turn the hotspot on. On doing so, I received a notification stating that I was now connected to the hotspot network and almost immediately afterwards it told me that I was disconnected from the network. The Wireless Network page still showed that I was connected to the specified hotspot. An idea on what might be going on with my system.
There is problem with Ubuntu 13.04. It is not connecting to other HotSpot.
But you can use
ap-hostspot instead. Read how-to-set-up-wireless-hotspot-access to install