Ramanathan T Jagadeesan

6801622, Oct 5, 2004

Oct 31, 2000

09/703336

Ramanathan T. Jagadeesan - San Jose CA

Cisco Technology, Inc. - San Jose CA

H04M 100

379386, 379283

Devices, software and methods are provided for encoding DTMF signals for telephone connections between digital voice communication systems that use compression, such as wireless connections or network connections. First the twist of the DTMF signals is determined, and then it is determined whether the twist is within a mapped range of a remote decoder. If not, the signal is first balanced to change the twist, and then the balanced signal is encoded.

6836804, Dec 28, 2004

Oct 30, 2000

09/702193

Ramanathan T. Jagadeesan - San Jose CA

Cisco Technology, Inc. - San Jose CA

G06F 1516

709236, 709203, 709246, 709227, 714 4, 370394, 370473, 370476

Devices, software and methods are provided for encoding voice data to conceal packet loss in Voice over Internet Protocol applications. The voice data of each frame is split into two groups, one of a low frequency band and one of a high frequency band. The two groups are transmitted through a network as separate packets. The high frequency group of one frame can be paired with the low frequency group of the next frame.

6888808, May 3, 2005

Sep 15, 2003

10/664984

Ramanathan T. Jagadeesan - San Jose CA, US
Bich T. Nguyen - Los Altos CA, US
Kamaldip Toor - San Diego CA, US
Sudhakar S. Valluru - San Jose CA, US
Christopher E. Pearce - Dallas TX, US

Cisco Technology, Inc. - San Jose CA

H04Q007/00

370328, 455432

A method is provided that includes receiving a request from a communication device to establish a communication session with a mobile station, the mobile station being operable to roam between a private and a public network. The mobile station is signaled via a cellular data network that a call is being initiated for the mobile station. Signaling information may be exchanged with a voice gateway such that one or more voice circuits are established. A signaling pathway may be established between an Internet protocol private branch exchange (IP PBX) and the mobile station via the cellular data network. The establishment of the signaling pathway is substantially concurrent with the establishment of one or more of the voice circuits. One or more features associated with a private network are delivered to the mobile station during the communication session as an end user moves between the public and private networks.

6930982, Aug 16, 2005

Dec 12, 2000

09/735429

Ramanathan T. Jagadeesan - San Jose CA, US

Cisco Technology, Inc. - San Jose CA

H04L012/26
H04L012/56

370252, 370394, 370474, 370476, 714761, 714762, 714776

Devices, software, and methods measure a burstiness of packet loss episodes in transmissions of voice data through networks. At least one burstiness statistic is determined to quantify how the lost packets are distributed with respect to the received packets within the sequence. The burstiness statistic is optionally used to determine a figure of merit, which in turn can be used to give a grade for predicting how well a packet loss concealment scheme will work.

6999417, Feb 14, 2006

Nov 30, 2001

09/998866

Philip R. Graham - Milpitas CA, US
Ramanathan T. Jagadeesan - San Jose CA, US
Bich Tu Nguyen - Los Altos CA, US

Cisco Technology, Inc. - San Jose CA

H04J 1/16
H04J 3/14

370230, 370235

Devices, software, and methods quantify a burstiness quality of the packet loss in the node of a path. The quantified burstiness becomes a metric for determining the Quality of Service (QoS) offered by a node in retransmitting data through a network. Network routing and rerouting decisions are made according to the improved QoS. The burstiness statistic is determined by counting lengths of episodes of sequentially discarded packets at the node. The burstiness statistic is incorporated as a metric with the other metrics of the QoS of the node.

6999560, Feb 14, 2006

Jun 28, 1999

09/340987

Kevin J. Connor - Sunnyvale CA, US
Michael E. Knappe - San Jose CA, US
Ramanathan T. Jagadeesan - San Jose CA, US

Cisco Technology, Inc. - San Jose CA

H04M 1/24
H04M 3/08
H04M 3/22

379 3, 37940601, 379392

A test system measures performance of telephone network echo cancellers using a primary criterion of estimated user annoyance due to audible returned echo. The invention generates live telephone calls, uses real speech samples as stimulus signals and provides tail-circuit emulation using actual measured telephone tail-circuit impulse responses. These features provide better ‘real-life’ test conditions for the echo canceller system under test than current ITU standard test methods. Two methods are employed for echo canceller performance evaluation via metrics of estimated user annoyance due to echo. Energy-based method employs point-by-point comparison of talker speech and talker echo signal energy envelopes and uses variable energy thresholds for estimation of echo audibility. A perceptual-model based method uses a Perceptual Speech Distortion Metric (PSDM), such as ITU P. 861, in an unique configuration to estimate user annoyance due to audible echo.

6999763, Feb 14, 2006

Aug 14, 2003

10/641190

Michael A. Ramalho - Wall Township NJ, US
Ramanathan T. Jagadeesan - San Jose CA, US
Bich Tu Nguyen - Los Altos CA, US

Cisco Technology, Inc. - San Jose CA

H04Q 7/20

4554351, 4554323, 4555521, 4555531, 455526

A mobile device supports concurrent registrations of different wireless personalities with one or more service provider networks. Potentially using a single wireless interface, the mobile device can register and maintain multiple personalities and monitor for notifications targeted to any one of these personalities.

7003298, Feb 21, 2006

Feb 28, 2002

10/086673

Ramanathan T. Jagadeesan - San Jose CA, US

Cisco Technology, Inc. - San Jose CA

H04Q 7/20

455442, 455436, 455437, 455445, 370331, 370352, 370353, 370354, 370355, 370356, 370493

Devices, softwares methods hand off a live call from an original leg of a first modality (such as Circuit Switched Voice) to an alternate leg of another modality (such as Voice over Internet Protocol). An original leg of a call is established using the first modality. Then the alternate leg of the call is established using the second modality, while the first leg is still established. Then the call is handed off from the original leg to the alternate leg, while the connection is active.