Hotspot 2.0 is an industry-wide initiative aimed at facilitating and automating secure and trusted connection with the ability to use a variety of user/device-based credentials. Hotspot 2.0 will provide WiFi with cellular-like security and user experience. Given the explosion of data traffic on cellular networks and the desire of operators to offload this traffic to WiFi networks, Hotspot 2.0 is widely viewed as a critical component to accelerating the adoption of WiFi as a complementary technology to high-mobility broadband cellular networks.
Hotspot 2.0 is built around a set of a few IEEE specifications:
- IEEE 802.11u (new standard approved in 2011): network discovery and selection 802.11u was developed to effectively automate how devices connect to available WiFi networks, a process that up till now has been manual and cumbersome. 802.11u enables WiFi hotspots to advertise their capabilities and then allows devices to connect to them automatically rather than requiring the end user to manually select an SSID.
- IEEE 802.11i: encryption (using WPA2-enterprise) In Hotspot 2.0 only server-based authentication is allowed, a notable change from ‘Open’ and ‘Pre Shared Key’ (PSK) methods supported today. AES 128 bit is used for encryption of the air link.
- IEEE 802.1x: authentication (using SIM/USIM device credentials with new Extensible Authentication Protocol – EAP additions)
Four EAP types are supported in the specifications: EAP-SIM, EAP-AKA, EAP-TLS and EAP-TTLS. The cellular convergence comes in with the new additions of EAP-SIM and EAP-AKA. It will now be possible to authenticate a mobile device with the operator AAA server through an AP using the SIM/USIM card in the device. The following steps are performed to discover and select the appropriate network:
- AP beacons/advertises Hotspot 2.0 support
- User device probes with Hotspot 2.0 support
- Device selects AP and request information to determine what providers are supported, services, capabilities of the AP, etc.
- AP responds to device query with requested information
- Device compares provisioned profile information against Hotspot 2.0 data from AP’s and associate with the best SSID Note that both the device and the AP have to support 802.11u for Hotspot 2.0 to work. While the WiFi Alliance Passpoint certification process started in 2012 it will take another two years before we see mass adoption.
In summary, Hotspot 2.0 promises to automate network discovery, registration, provisioning and network connectivity, which are manual steps today when a user connects to a given WiFi hotspot. It also helps the wireless operator in facilitating unified security architecture using the AAA server in the EPC to authenticate users connected via WiFi and/or LTE. Ultimately, 802.11u and Hotspot 2.0 promise to make connecting to WiFi services as easy, seamless and secure as today's cellular experience.