| 摘要 |
A station (114,116,404,800) makes a unidirectional announcement (that is, an indication, notification or advertisement) of types of services that are available to devices in or via a wireless network, for example, a wireless local area network 'WLAN' (104, 106). The announcement is receivable by mobile devices (102, 108,110,402,900) within radio communication range of the wireless network that are in the pre-associated state, because the announcement is conveyed using low-level layer 2 frames. A mobile device that receives such a layer 2 frame may determine the announced service type or types from the received layer 2 frame. The mobile device may determine whether it can make use of any of the announced service type or types. The mobile device may provide results of the determination to a network selection algorithm implemented at the mobile device. |
