公开(公告)号：USRE49288E1

公开(公告)日：2022-11-08

申请号：US17104845

申请日：2020-11-25

Applicant: Cisco Technology, Inc.

Inventor： Michael A. Ramalho ,  Mihailo Zilovic

IPC: H04B1/709 ,  H04R1/34 ,  H04N21/422 ,  H04H20/30 ,  H04B1/707 ,  H04J13/10 ,  H04R3/00 ,  H04S7/00

Abstract: A first endpoint generates an acoustic spread spectrum signal including a pilot sequence and a data sequence representing a token synchronized to the pilot sequence, transmits the acoustic spread spectrum signal, and records a transmit time at which the acoustic spread spectrum signal is transmitted. A receive time at which a second endpoint received the acoustic spread spectrum signal transmitted by the first endpoint is received from the second endpoint along with an indication of a second token as recovered from the received acoustic spread spectrum signal by the second endpoint. A separation distance between the first endpoint and the second endpoint is computed based on a time difference between the transmit time and the receive time. The first endpoint is paired with the second endpoint when the token matches the second token and the computed distance is less than a threshold distance.

公开(公告)号：US10530417B2

公开(公告)日：2020-01-07

申请号：US15926720

申请日：2018-03-20

Applicant: Cisco Technology, Inc.

Inventor： Michael A. Ramalho ,  Mihailo Zilovic ,  David A. Benham

IPC: G10L19/02 ,  H04B1/69 ,  G10L19/16 ,  G10L19/022 ,  H04B1/66

Abstract: In a transmit method, a set of data eigenvectors that are based on a Prometheus Orthonormal Set (PONS) code construction and orthogonal to each other are stored, wherein the data eigenvectors are mapped to unique multi-bit words. A pilot sequence representing a pilot eigenvector that is based on the PONS code construction and orthogonal to each of the data eigenvectors is generated. Input data are grouped into multi-bit words and data eigenvectors among the data eigenvectors are selected based on the multi-bit words. A spread data sequence including the selected data eigenvectors and that is synchronized to the pilot sequence is generated. An acoustic signal including the synchronized pilot sequence and the spread data sequence is generated. The acoustic signal is transmitted.

公开(公告)号：US10141973B1

公开(公告)日：2018-11-27

申请号：US15631679

申请日：2017-06-23

Applicant: Cisco Technology, Inc.

Inventor： Michael A. Ramalho ,  Mihailo Zilovic

IPC: H04B1/709 ,  H04R1/34 ,  H04N21/422 ,  H04H20/30

Abstract: A first endpoint generates an acoustic spread spectrum signal including a pilot sequence and a data sequence representing a token synchronized to the pilot sequence, transmits the acoustic spread spectrum signal, and records a transmit time at which the acoustic spread spectrum signal is transmitted. A receive time at which a second endpoint received the acoustic spread spectrum signal transmitted by the first endpoint is received from the second endpoint along with an indication of a second token as recovered from the received acoustic spread spectrum signal by the second endpoint. A separation distance between the first endpoint and the second endpoint is computed based on a time difference between the transmit time and the receive time. The first endpoint is paired with the second endpoint when the token matches the second token and the computed distance is less than a threshold distance.

公开(公告)号：US20180091565A1

公开(公告)日：2018-03-29

申请号：US15275844

申请日：2016-09-26

Applicant: Cisco Technology, Inc.

Inventor： John Arsenault ,  Michael A. Ramalho ,  Mihailo Zilovic ,  Jonathan Rosenberg

IPC: H04L29/06 ,  H04W12/08 ,  H04L29/08

CPC classification number: H04L65/403 ,  G06F21/30 ,  G06F2221/2103 ,  H04L9/3271 ,  H04L63/08 ,  H04L63/10 ,  H04L67/02 ,  H04L67/104 ,  H04W12/08 ,  H04W88/02 ,  H04W88/08

Abstract: An access server communicates with a video conference device and a user device. The access server and the user device may access known mappings, including a default mapping. Each mapping is configured to map between tokens and symbols according to a distinct mapping relationship between the multi-bit tokens and the symbols. The access server instructs the video conference device to map an initial token to an initial symbol based on the default mapping and to transmit the initial symbol. The access server receives from the user device the initial token and a challenge mapping selected by the user device. The access server determines a challenge token that the challenge mapping maps to a challenge symbol, and instructs the video conference device to transmit the challenge symbol. The access server grants the user device access to an information carrying channel only if the challenge token is received from the user device.