Hotspot

Hot Spot 2.0 (HS 2.0), also called Wi-Fi Certified Passpoint, is a new standard (IEEE 802.11u) for public-access Wi-Fi that enables seamless roaming among WiFi networks and between WiFi and cellular networks.

How does it all work?
1. The client sends an ANQP query to the AP.
2. In ANQP response, client gets list of Online Signup (OSU) providers that are reachable from this hotspot.
3. The list typically is displayed at client as an icon and operator friendly name.
5. Once the user selects an OSU provider from the list, client connects to the OSU WLAN (Open or OSEN).
6. Client then makes an HTTPS connection to the OSU server URI to finish registration/purchase.
7. On success full registration, security credentials are pushed to client.
8. Now client disassociates from the OSU WLAN.
9. And connects to the HS2.0 WLAN using the standard ANQP mechanism.

GAS => Generic Advertisement Service
ANQP => Access Network Query Protocol
Client uses GAS query (with ANQP IEs) to get ANQP Capability list from AP. This will enable client to identify AP’s network and service provider.

Software Hotspots
Wi-Fi adapters in computers could operate as hotspots.
1. Windows 7 have built in support for hotspot.
2. Third-party software vendors, offer applications to allow users to operate their own Hotspot.

How to Enable a Virtual WiFi in Windows

make sure "Microsoft Virtual WiFi Miniport Adaptor" is created.

http://www.wikihow.com/Enable-a-Virtual-WiFi-in-Windows

# netsh wlan set hostednetwork mode=allow ssid="Homewifi" key="passphrase" keyUsage=persistent

# netsh wlan start hostednetwork

Reference:
http://en.wikipedia.org/wiki/Hotspot_%28Wi-Fi%29
http://whatis.techtarget.com/definition/Hot-Spot-20-HS-20
http://www.theruckusroom.net/2014/10/hotspots-get-hotter-with-release-2-of-hotspot-20.html
http://www.arubanetworks.com/techdocs/ArubaOS_64_Web_Help/Content/ArubaFrameStyles/hotspot/predepoyment_overview.htm