Evaluation of the voice delivery system used by Bluetooth

Information communication between individuals is now frequently performed because of the spread of cellular phones and the Internet. However, when disaster and traffic congestion occur over a wide area, network access using a cellular phone (wireless) might be concentrated in one area and immediate communication might thereby become impossible. At that time, user's necessary information is the same. This study uses MOS evaluation of the voice when it is assumed that an ad-hoc network is constructed to alleviate the network congestion when disaster and congestion occur. Delivery of voice (streaming delivery) information is evaluated. Results show that MOS evaluations of MP3 and of CELP reverse as the communications distance lengthens. Therefore, in a communication environment and the sound bit rate of a trade-off is connected with each other.