| 摘要 |
A wireless terminal (1) capable of handling voice and data traffic is configured to use an internet connection (3) when available and a connection to a cellular network (7) otherwise. To allow handover between the systems, voice calls using the VoIP protocol are tunnelled to a bridging point (74) between the internet (3) and cellular network (7). However, to avoid the need for data to be routed by way of the cellular network and then back into the internet, the tunnelled connection between the hub and the mobile access bridge (74) is replaced with two separate tunnels (14, 47) respectively connecting the user (1) and MAB (74) with an intermediate breakout point, such as is a VoIP network controller (4). From this breakout point a third connection (46) is made to the internet, for carrying non-voice data traffic by way of a network access control proxy (5). This arrangement provides the ability to transfer not only VoiP traffic but all other application traffic through the first tunnelled connection (14) to the network controller (4), from where voice traffic can be identified and forwarded over the second tunnelled connection (47), whilst other, data, traffic can be routed to the internet 6 over the third link (46). This configuration allows high speed data applications to be carried over the link (14) concurrently with VoIP traffic. This arrangement allows a single wifi connection to be used between the handset (1), the access point (2), and the broadband connection (3) to the network controller (4), using the same single IPSec tunnel (14) to provide the ability to have a voice call in progress via a handsfree device, whilst receiving a streaming data application such as a remote camera transmission Alternative breakout points are discussed in the specification.
|
