公开(公告)号：US11368236B2

公开(公告)日：2022-06-21

申请号：US16562598

申请日：2019-09-06

Applicant: Cisco Technology Inc.

Inventor： Huaiyi Wang ,  Matthew Aaron Silverman ,  Zhigang Gao ,  Evgeny Yankevich

IPC: H04W48/16 ,  H04J11/00 ,  H04L5/00 ,  H04L25/03 ,  H04W56/00

Abstract: A wireless node in a wireless communication network. The wireless node includes one or more interfaces configured to receive wireless transmissions, a memory comprising instructions, and a hardware processor. The wireless node samples a received wireless transmission into a plurality of time-based subdivisions for each subdivision of the wireless transmission the wireless node determines a cross-correlation between the subdivision and a local syncword. The local syncword is constructed to correlate to any primary synchronization signal, PSS, of a plurality of PSSs defined for synchronization in the wireless network. The wireless node, based on the cross-correlation, determines whether one PSS of the plurality of PSSs is present in the subdivision of the wireless transmission.

公开(公告)号：US20190028899A1

公开(公告)日：2019-01-24

申请号：US15657496

申请日：2017-07-24

Applicant: Cisco Technology, Inc.

Inventor： Evgeny Yankevich

IPC: H04W16/14 ,  H04W24/08

CPC classification number: H04W16/14 ,  H04B1/00 ,  H04W24/08 ,  H04W84/12

Abstract: In a shared radio frequency (RF) band, regulations or standards can stipulate that a device using an RF channel must vacate the RF channel if another device having priority to the channel is detected. It takes time, however, to move channels and this added time reduces the effective speed of the communication. In some cases, a received signal from the other device may be received on the channel when the other device is not, in fact, operating on the channel. These received signals can lead the device to move channels, thereby slowing communications unnecessarily. Accordingly, disclosed herein are a system and method for checking the characteristics of a received signal's spectrum to determine if the source of the received signal is on-channel or off-channel. This determination may be used to minimize the device from taking unnecessary interference avoidance measures, such as dynamic frequency selection.

公开(公告)号：US11695380B2

公开(公告)日：2023-07-04

申请号：US17654717

申请日：2022-03-14

Applicant: Cisco Technology, Inc.

Inventor： Matthew A. Silverman ,  Evgeny Yankevich ,  John M. Swartz

IPC: H03G3/30 ,  H03G3/00 ,  H04W28/02 ,  H04B1/10

CPC classification number: H03G3/3042 ,  H03G3/001 ,  H04B1/109 ,  H04W28/0268

Abstract: Dynamic automatic gain controller configuration in multiple input and multiple output receivers is provided by monitoring a given section of wireless spectrum for higher-priority signals using a first antenna set associated with a first Automatic Gain Controller (AGC) set while concurrently monitoring the given section of wireless spectrum for wireless packet-based traffic using a second antenna set associated with a second AGC set; in response to detecting a packet via the second antenna set: re-associating the first antenna set and the second antenna set to a third AGC set; receiving the packet via the first antenna set and the second antenna set using the third AGC set; and in response to the packet being received, re-associating the first antenna set to the first AGC set and the second antenna set to the second AGC set.

公开(公告)号：US11137475B2

公开(公告)日：2021-10-05

申请号：US16151466

申请日：2018-10-04

Applicant: Cisco Technology, Inc.

Inventor： Evgeny Yankevich ,  Matthew Aaron Silverman

IPC: G01S7/02 ,  H04W72/04 ,  H04L25/03

Abstract: A pseudo low intermediate frequency (IF) configuration is provided for a receiver having a zero IF radio architecture dedicated for radar detection, in order to reduce false radar detection. Energy from local oscillator leakage is shifted away from DC. After filtering out of the desired sub-channel, the local oscillator leakage energy is suppressed, reducing false radar detection.

公开(公告)号：US10405189B2

公开(公告)日：2019-09-03

申请号：US15657496

申请日：2017-07-24

Applicant: Cisco Technology, Inc.

Inventor： Evgeny Yankevich

IPC: H04W16/14 ,  H04W24/08 ,  H04W84/12

Abstract: In a shared radio frequency (RF) band, regulations or standards can stipulate that a device using an RF channel must vacate the RF channel if another device having priority to the channel is detected. It takes time, however, to move channels and this added time reduces the effective speed of the communication. In some cases, a received signal from the other device may be received on the channel when the other device is not, in fact, operating on the channel. These received signals can lead the device to move channels, thereby slowing communications unnecessarily. Accordingly, disclosed herein are a system and method for checking the characteristics of a received signal's spectrum to determine if the source of the received signal is on-channel or off-channel. This determination may be used to minimize the device from taking unnecessary interference avoidance measures, such as dynamic frequency selection.

公开(公告)号：US10237749B2

公开(公告)日：2019-03-19

申请号：US15802667

申请日：2017-11-03

Applicant: Cisco Technology, Inc.

Inventor： Evgeny Yankevich ,  Jack Chuang

IPC: H04W16/14 ,  H04B17/336 ,  H04K3/00 ,  H04W84/12

Abstract: Dynamic frequency selection (DFS) is often a requirement for a wireless local area network (WLAN) apparatus to prevent the apparatus from interfering with other systems that have a priority to a radio frequency (RF) channel. When DFS is executed, the WLAN apparatus ceases WLAN operations on the channel and searches for an open channel to resume WLAN operations. Often a WLAN apparatus misinterprets signals from another system as operating on the channel when actually the received signals are signals leaked into the channel from a system transmitting on a different channel. Presented herein are methods and apparatuses for preventing unnecessary DFS operations resulting from misinterpreted signals through the use of a signal to noise ratio determined from a pulse spectral density of the received signal.

公开(公告)号：US09877251B2

公开(公告)日：2018-01-23

申请号：US14449763

申请日：2014-08-01

Applicant: Cisco Technology, Inc.

Inventor： Paul J. Stager ,  Tak Ming Pang ,  Evgeny Yankevich ,  Arnab Sengupta

IPC: H04W36/18 ,  H04W36/32 ,  H04W36/00 ,  H04W36/30 ,  H04W84/00 ,  H04W48/16

CPC classification number: H04W36/18 ,  H04W36/0061 ,  H04W36/0083 ,  H04W36/0088 ,  H04W36/30 ,  H04W36/32 ,  H04W48/16 ,  H04W84/005

Abstract: Access points and a wireless client device, such as a workgroup bridge, are configured to optimize a roaming algorithm of the client device for a high-speed vehicle scenario, such as a high-speed train. A static/dynamic neighbor list is generated and used to improve scanning efficiency. An improved parent access point selection procedure, metrics, and thresholds are provided to optimize client roaming along the vehicle's path, e.g., the train track.

公开(公告)号：US20240345200A1

公开(公告)日：2024-10-17

申请号：US18300247

申请日：2023-04-13

Applicant: Cisco Technology, Inc.

Inventor： Samer M. Salam ,  Matt Silverman ,  Taha Hajar ,  Salvatore Valenza ,  Evgeny Yankevich

IPC: G01S5/02 ,  H04B17/327 ,  H04W16/18

CPC classification number: G01S5/02528 ,  H04B17/327 ,  H04W16/18

Abstract: A method includes determining a 2D DEM for a physical environment, determining a viewshed for an access point in the physical environment using the DEM, and identifying, at the end terminal, at least one obstacle that is visible from the access point. For each point in space within the physical environment that is on a same side of the at least one obstacle as the access point: a respective first RSSI is determined, the respective first RSSI being associated with a direct LOS ray from the access point to a point in the space. A respective second RSSI for each of the at least one obstacle is determined to yield at least one second RSSI. A respective RF power based on the respective first RSSI and the at least one second RSSI is also determined, the respective RF power being used for generating a 3D heatmap for the physical environment.

公开(公告)号：US20240267852A1

公开(公告)日：2024-08-08

申请号：US18163448

申请日：2023-02-02

Applicant: Cisco Technology, Inc.

Inventor： Evgeny Yankevich ,  Brian Hart ,  Matt Silverman

IPC: H04W52/26 ,  H04L5/00

CPC classification number: H04W52/265 ,  H04L5/0073 ,  H04W52/267

Abstract: Increased channel availability may be provided. A computing device may receive radio channel information comprising a radio channel to operate within and an incumbent indication indicating whether an incumbent is using the radio channel. Next, power to operate a radio at may be determined based on the incumbent indication. When the incumbent indication indicates an incumbent is present on the radio channel, determining the power to operate the radio based on the incumbent indication comprises: i) determining a first power level for subcarriers in the radio channel that are non-overlapping with a portion of the radio channel used by the incumbent; and ii) determining a second power level for subcarriers in the radio channel that are overlapping with the portion of the radio channel used by the incumbent wherein the first power level is greater than the second power level. The radio may then be operated at the determined power.

公开(公告)号：US20230126483A1

公开(公告)日：2023-04-27

申请号：US17512098

申请日：2021-10-27

Applicant: Cisco Technology, Inc.

Inventor： Fred J. Anderson ,  Paul Jeffrey Stager ,  Evgeny Yankevich ,  Matthew Aaron Silverman

IPC: H04W72/08 ,  H04W72/04 ,  G01S7/02

Abstract: Methods and systems for distinguishing between radar signals and Wi-Fi signals are provided. When a set of electromagnetic signals are received, various tests are performed on the signals to determine if the signals are associated with radar pulses or if the signals are more likely to be associated with stray WI-Fi signals or other non-radar interference. One such test relies on the relatively small variance of frequencies used by radar pulses when compared to the high variation of Wi-Fi signals. Another test relies on the relatively low peak to average power ratio of signals associated with radar pulses when compared to Wi-Fi signals. The tests described herein are an improvement on existing methods for distinguishing radar signals from Wi-Fi signals and result in less switching of Wi-Fi channels due to erroneously detected radar signals.