Method for diverting an isup talkpath to an IP talkpath

Abstract

A method for improving the sound quality of voice signals transmitted during a call between two digital wireless telephones by diverting the call from a circuit switched network to a data network is disclosed. In accordance with the present invention, a call setup procedure using the circuit switched network is modified so that the calling party may determine the following information: I) whether the called party's digital wireless telephone is able to support one of the voice compression algorithms supported by the calling party's digital wireless telephone and 2) whether both wireless telephones have access to the same data network. If the called party's digital wireless telephone is able to support one of the voice compression algorithms supported by the calling party's digital wireless telephone and both wireless telephones have access to the same data network, the circuit switched network call setup procedure is abandoned before the called party answers the call and the call is completed using the data network. Completing the call by encoding voice signals using a common voice compression algorithm executed by the digital wireless telephones and by sending the encoded voice signals through a data network eliminates the drawbacks associated with the additional intermediate encoding which would have been required if the call had been completed using the circuit switched network.

Description

BACKGROUND[0001]The present invention relates to improving the sound quality of voice signals transmitted during a call between two digital wireless telephones. More particularly, the present invention relates to a method for diverting a wireless telephone call from a circuit switched network to a data network before the call is answered if the called party's digital wireless telephone is able to support one of the voice compression algorithms supported by the calling party's digital wireless telephone and if both digital wireless telephones have access to the same data network.[0002]Currently, many telephone calls from one digital wireless party to another digital wireless party are processed through a circuit switched network such as the public switched telephone network (PSTN). One example of such a telephone call may be illustrated by analyzing the process of completing a telephone call from a wireless party on the east coast of the United States to a wireless party on the west ...

AI Technical Summary

Benefits of technology

[0011]The present invention provides a method for improving the sound quality of voice signals transmitted during a call between two digital wireless telephones by diverting the call from a circuit switched network to a data network before the call is answered. In accordance with the present invention, a call setup procedure using the circuit switched network is modified so that the calling party may determine the following information: 1) whether the called party's digital wireless telephone is able to support one of the voice compression algorithms supported by the calling party's digital wireless telephone and 2) whether both wireless telephones have access to the same data network. If the called party's digital wireless telephone is able to support one of the voice compression algorithms supported by the calling party's digital wireless telephone and both wireless telephones have access to the same data network, the circuit switched network call setup procedure is abandoned before the called party answers the call and the call is completed using the data network.

Problems solved by technology

Unfortunately, there are drawbacks to the above-described method of transmitting voice signals through the PSTN from one digital wireless telephone to another digital wireless telephone.

First, the process of completing intermediate voice encoding slightly delays the transmission of the voice signals between the digital wireless telephones.

Third, decompressing and compressing the same voice signal two or more times while transmitting that voice signal from the sender to the receiver degrades the quality of the voice signal.

Finally, the cost of transporting voice signals through the PSTN can be relatively higher than transporting voice signals through a data network such as the Internet.

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