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This access gateway application scenario describes an Internet enhancement to call waiting service. The call waiting functionality is extended to calls to the subscriber's number when the subscriber is connected to an Internet service provider. Currently, the telephone subscriber deactivates the call waiting service before calling the Internet service provider. As a result, while the subscriber is connected to the Internet provider, incoming calls do not activate the subscriber's call waiting service. In other words, for the typically long hold times associated with Internet calls, the subscriber is not aware of any subsequent calls. However, by integrating the capabilities of the telephone network and the Internet, the subscriber can be aware of incoming telephone calls while connected to the Internet. In addition, the information about the caller can be displayed on the subscriber's computer screen. Figure 7 shows a network diagram of this access gateway application scenario. The access gateway is again used as the connection point between the telephone network and the Internet and is important because of its ability to translate between the Internet and the varied protocols used in the telephone network.
Figure 7. Call Waiting with Internet Enhancement
When the telephone subscriber calls the Internet service provider, the telephone services of the subscriber must be prepared for this application scenario. Specifically, when the subscriber successfully connects to the Internet provider, the provider sends a message to the access gateway informing it of the connection. The access gateway then uses the information in this message to activate the "call terminate—busy" trigger in the telephone switch serving the subscriber. As a result, any subsequent calls to the subscriber cause an AIN query message to be sent within the telephone network. In other words, when a call is made to the subscriber's telephone number, the "call terminate—busy" trigger will fire because the subscriber is busy on the Internet call. The firing of this trigger causes the telephone switch serving the subscriber to send an IN query message to the SCP in the telephony network. Upon receiving this query, the SCP will perform a lookup in the "calling subscriber's name" database. The result of this lookup will be the name of the calling subscriber as text. The SCP then sends a message to the access gateway that contains the called subscriber's telephone number, the calling subscriber's telephone number, and the calling subscriber's name. The access gateway sends this information in a message to the Internet provider. Upon receipt of the information, the Internet provider informs the subscriber of the call by displaying the caller's name and telephone number on the subscriber's computer screen. When the subscriber disconnects from the Internet, the Internet provider will inform the access gateway. The access gateway uses this information to deactivate the "call terminate—busy" trigger in the telephone switch serving the subscriber.
As an extension of this application scenario, Internet telephony can also be used to deliver the telephone call to the subscriber. As in the previous example, the call to the subscriber's number is indicated by displaying the caller's telephone number and name on the subscriber's computer screen, but this application also provides options for handling the call. For example, the subscriber can accept the call, decline the call, or send the call to voice mail. If the subscriber accepts the call, Internet telephony functionality is used to deliver the call to the subscriber from the SN while the subscriber is still connected to the Internet provider (see Figure 8).
Figure 8. Call Waiting with Internet Enhancement
