System for real time voice quality measurement in voice over packet network
Granted: March 27, 2007
Patent Number:
7197010
In assessing the capability of an IP based network to support toll telephony service, objective measurements of Speech Quality are taken. A module is used with Voice over Packet equipment that allows performance of voice quality measurements in real-time without using any external test equipment. A reference signal that includes a marker and a voice test signal is sent through the network from one Voice over Packet equipment containing or connected to the module to another. The received…
Flexible SONET access and transmission system
Granted: July 27, 2004
Patent Number:
6768745
A SONET network interface for interconnecting at least one high speed unit (HSU) with at least two low speed interface units (LSUs) to enable transmission of signals therebetween. The interface having: a common bus of predetermined bit width for interfacing the HSU unit with each of the LSU units to enable transmission of signals from each of the LSUs to the HSU, and reception of the signals from the HSU to each of the LSUs; a first partition bus of the predetermined bit width for…
Acoustic echo processing system
Granted: June 1, 2004
Patent Number:
6744887
A system and method of Acoustic Echo Cancellation includes a digital filter used to estimate the echo path is split into 2 filters: one fixed infinite impulse response (IIR) filter and one adaptive finite impulse response (FIR) filter. The fixed filter models the composite frequency response of the loudspeaker, its cabinet enclosure and the direct coupling path between the loudspeaker and the microphone(s). The adaptive filter models the time varying characteristics of the indirect…
Mechanism for 1:1, 1+1, and UPSR path-switched protection switching
Granted: February 10, 2004
Patent Number:
6690644
A mechanism for 1:1, 1+1, and UPSR path-switched protection switching, particularly for optical interface units in synchronous optical network (SONET) multiplexer equipment. A working unit and a standby unit pair protect each other in the event of a failure of the working unit or the failure of the span connected to the working unit if both the working and standby units are connected to different spans. Each unit is made responsible for detecting failures of the span that it…
Flexible SONET access and transmission systems
Granted: December 23, 2003
Patent Number:
6667973
A SONET network interface for interconnecting a high speed unit (HSU) with low speed interface units (LSUs) to enable transmission of signals therebetween. The interface including: a bus for interfacing the HSU with each of the LSU units to enable transmission of signals from each of LSUs to the HSU, and reception of the signals from the HSU to each of the LSUs; and a backplane connected to the bus and having at least two time slots for performing full time slot interchange between the…
