Patent ID: 6970467
Filing Date: 2005-11-29
Classification: H04J,H04L,H04Q

Abstract:
1. A transfer method for transferring speech and voice band signals and ISDN (Integrated Services Digital Network) digital signals between an ATM (Asynchronous Transfer Mode) network and an STM (Synchronous Transfer Mode) network, the transfer method comprising the steps of: (a) obtaining a silence information by detecting silence sections in input signals entered from the STM network; (b) obtaining a signal type information for each input signal by judging whether each input signal is a speech and voice band signal or an ISDN digital signal, and further judging a signal type of each input signal that is judged as the speech and voice band signal; (c) dynamically changing a compression scheme of each input signal into a most appropriate compression scheme selected from a plurality of different compression schemes with different compression rates, which is determined by using the silence information obtained at the step (a) and the signal type information obtained at the step (b), and compressing each input signal using the most appropriate compression scheme; (d) assembling variable length packets each having a length shorter than that of an ATM cell from signals compressed at the step (c) by using the silence information obtained at the step (a) and the signal type information obtained at the step (b); (e) assembling ATM cells by multiplexing a plurality of the variable length packets assembled at the step (d), and transferred the ATM cells to the ATM network; (f) receiving input ATM cells from the ATM network and disassembling the input ATM cells into received packets; (g) disassembling the received packets obtained at the step (f) into received, and obtaining a silence section information by detecting positions at which silence sections are to be inserted in the receiving signals entered from the ATM network; (h) judging a signal compression scheme of each received signal obtained at the step (g); (i) expanding each received signal by using the silence section information obtained at the step (g) and the signal compression scheme judged at the step (h); and (j) reproducing silence sections in signals expanded at the step (i) by using the silence section information obtained at the step (g) so as to generate STM signals, and transferring the STM signals to the STM network.