this. Additionally wireless chipset manufacturers such as Atheros, Broadcom, Intel and others, may add the capability for certain Wi-Fi NICs, usually used in a client role, to also be used for hotspot purposes. However, some service providers, such as AT&T, Sprint, and T-Mobile charge users for this service or prohibit and disconnect user connections if tethering is detected. Third-party software vendors offer applications to allow users to operate their own hotspot, whether to access the Internet when on the go, share an existing connection, or extend the range of another hotspot. Hotspot 2.0 Hotspot 2.0, also known as HS2 and Wi-Fi Certified Passpoint, is an approach to public access Wi-Fi by the Wi-Fi Alliance. The idea is for mobile devices to automatically join a Wi-Fi subscriber service whenever the user enters a Hotspot 2.0 area, in order to provide better bandwidth and services-on-demand to end-users and relieve carrier infrastructure of some traffic. Hotspot 2.0 is based on the IEEE 802.11u standard, which is a set of protocols published in 2011 to enable cellular-like roaming. If the device supports 802.11u and is subscribed to a Hotspot 2.0 service it will automatically connect and roam. Supported devices Apple mobile devices running iOS 7 and up Some Samsung Galaxy smartphones Windows 10 devices have full support for network discovery and connection. Windows 8 and Windows 8.1 lack network discovery, but support connecting to a network when the credentials are known. Billing The "user-fairness model" is a dynamic billing model, which allows volume-based billing, charged only by the amount of payload (data, video, audio). Moreover, the tariff is classified by net traffic and user needs. If the net traffic increases, then the user has to pay the next higher tariff class. The user can be prompted to confirm that they want to continue the session in the higher traffic class. A higher class fare can also be charged for delay sensitive applications such as video and audio, versus non time-critical applications such as reading Web pages and sending e-mail. The "User-fairness model" can be implemented with the help of EDCF (IEEE 802.11e). An EDCF user priority list shares the traffic in 3 access categories (data, video, audio) and user priorities (UP). Data [UP 0|2] Video [UP 5|4] Audio [UP 7|6] See Service-oriented provisioning for viable implementations. Legal issues Depending upon the set up of a public hotspot, the provider of the hotspot has access