Charles I Okwudiafor

US Patent:

8605591, Dec 10, 2013

Filed:

Dec 14, 2010

Appl. No.:

12/968123

Inventors:

Shmuel Shaffer - Palo Alto CA, US
Charles I. Okwudiafor - Fremont CA, US
Sandeep J. Shetty - San Jose CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/28

US Classification:

370235, 370412

Abstract:

A method is provided in one example and includes receiving a first packet and a second packet that propagate in a mesh network and evaluating hop count metrics associated with the first packet and the second packet (e. g. , evaluate the number of hops traversed in the mesh network, hop characteristics, etc. ). The first packet is sent to a first queue, the second packet is sent to a second queue. The first queue is associated with a first hop count detected in the first packet, and the second queue is associated with a second hop count detected in the second packet. A buffer overflow condition can be identified. The method further includes discarding the second packet based on the second hop count being less than the first hop count. Discarding of the second packet may be performed in response to any type of congestion parameter detected in the mesh network.

US Patent:

20120147783, Jun 14, 2012

Filed:

Dec 14, 2010

Appl. No.:

12/968163

Inventors:

Shmuel Shaffer - Palo Alto CA, US
Charles I. Okwudiafor - Fremont CA, US
Sandeep J. Shetty - San Jose CA, US

International Classification:

H04L 12/28

US Classification:

370254

Abstract:

A method is provided in one example embodiment and includes receiving packets from a group of nodes configured to operate in a mesh network; referencing geographic information associated with the group of nodes; evaluating a subset of the group of nodes within a particular geographic area; determining a global positioning system (GPS) location and a relative location associated with the subset of the group of nodes; determining configuration data for the subset of the group of the nodes; and communicating the configuration data to the subset of the group of nodes.

US Patent:

20120155260, Jun 21, 2012

Filed:

Dec 17, 2010

Appl. No.:

12/971440

Inventors:

Jean-Philippe Vasseur - Saint Martin d'Uriage, FR
Shmuel Shaffer - Palo Alto CA, US
Charles Okwudiafor - Fremont CA, US
Sandeep Jay Shetty - San Jose CA, US

Assignee:

CISCO TECHNOLOGY INC. - San Jose CA

International Classification:

H04L 12/26

US Classification:

3702301

Abstract:

In one embodiment, a receiving node in a computer network may detect congestion, and also identifies a set (e.g., subset) of its neighbor nodes. In response to the congestion, the receiving node may assign a transmission timeslot to each neighbor node of the set based on the congestion, where each neighbor is allowed to transmit (synchronously) only during its respective timeslot. The assigned timeslots may then be transmitted to the set of neighbor nodes. In another embodiment, a transmitting node (e.g., a neighbor node of the receiving node) may receive a scheduling packet from the receiving node. Accordingly, the transmitting node may determine its assigned transmission timeslot during which the transmitting node is allowed to transmit. As such, the transmitting node may then transmit packets only during the assigned timeslot (e.g., for a given time). In this manner, congestion at the receiving node may be reduced.

US Patent:

20120155511, Jun 21, 2012

Filed:

Dec 17, 2010

Appl. No.:

12/971284

Inventors:

Shmuel Shaffer - Palo Alto CA, US
Sandeep Jay Shetty - San Jose CA, US
Charles Okwudiafor - Fremont CA, US
Jean-Philippe Vasseur - Saint Martin d-Uriage, FR

Assignee:

CISCO TECHNOLOGY INC. - San Jose CA

International Classification:

H04B 1/713

US Classification:

375133, 375E01033

Abstract:

In one embodiment, a management device determines a topology of nodes in a network. Based on the topology, frequency hopping sequences are assigned (and notified) to the nodes such that each particular node of a certain set of the nodes is assigned a frequency hopping sequence on which to transmit that is different than frequency hopping sequences of neighbors and hidden neighbors of that particular node. In another embodiment, a transmitting node first transmits a transmission indication signal on its particular frequency band based on its frequency hopping sequence, and then transmits a message on the particular frequency band. In a further embodiment, a receiving node listening to a plurality of frequency bands may detect the transmission indication signal on the particular frequency band. In response, the receiving node filters out all frequency bands other than the particular frequency band, and receives the following transmission on that particular frequency band.

US Patent:

20120320768, Dec 20, 2012

Filed:

Jun 20, 2011

Appl. No.:

13/164731

Inventors:

Shmuel Shaffer - Palo Alto CA, US
Charles Okwudiafor - Fremont CA, US
Sandeep J. Shetty - San Jose CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04W 24/00

US Classification:

370252

Abstract:

In one embodiment, hidden neighbor relationships are identified based on received neighbor information from a plurality of nodes in a communication network. Based on determining a number of hidden neighbors for a particular node at various node parameters, a cost function associated with the particular node may be determined and utilized. In another embodiment, a number of hidden nodes of the particular node is determined across a range of transmission powers, and a delay associated with the particular node reaching a root node in the network across the range of transmission powers is also determined based on the neighbor nodes reachable at respective transmission powers. A tradeoff is determined across the range of transmission powers between the number of hidden nodes and the delay, and then the transmission power of the particular node can be set based on an acceptable determined tradeoff.

US Patent:

7599398, Oct 6, 2009

Filed:

Jul 1, 2004

Appl. No.:

10/883550

Inventors:

Ching-Fang Shang - Fremont CA, US
Charles Okwudiafor - Fremont CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04J 3/06

US Classification:

370503

Abstract:

A root node sets wireless network timer values by using dynamic location information of a plurality of non-root nodes. In an embodiment, the root node and the non-root nodes are bridges, wherein the non-root bridges are connected to the root bridge in a point-to-point or point-to-multipoint manner. The locations of the nodes are determined by using a location system and locations receivers. The root node and each of the non-root nodes use this location information to determine the optimum timer values for the wireless network, thereby improving throughput on the wireless network. In one embodiment, the location system is the global positioning system (GPS). The location receiver is a GPS location receiver that is embedded in each of the nodes. In another embodiment, the GPS location receiver is external to the nodes, and the location information is determined remotely.

US Patent:

20160182121, Jun 23, 2016

Filed:

Feb 26, 2016

Appl. No.:

15/054512

Inventors:

- San Jose CA, US
Sandeep Jay Shetty - San Jose CA, US
Charles Okwudiafor - Fremont CA, US
Jean-Philippe Vasseur - Anchorage AK, US

International Classification:

H04B 1/7156
H04W 72/04

Abstract:

In one embodiment, a management device determines a topology of nodes in a network. Based on the topology, frequency hopping sequences are assigned (and notified) to the nodes such that each particular node of a certain set of the nodes is assigned a frequency hopping sequence on which to transmit that is different than frequency hopping sequences of neighbors and hidden neighbors of that particular node. In another embodiment, a transmitting node first transmits a transmission indication signal on its particular frequency band based on its frequency hopping sequence, and then transmits a message on the particular frequency band. In a further embodiment, a receiving node listening to a plurality of frequency bands may detect the transmission indication signal on the particular frequency band. In response, the receiving node filters out all frequency bands other than the particular frequency band, and receives the following transmission on that particular frequency band.

US Patent:

20140286377, Sep 25, 2014

Filed:

Jun 5, 2014

Appl. No.:

14/296728

Inventors:

- San Jose CA, US
Sandeep J. Shetty - San Jose CA, US
Charles Okwudiafor - Fremont CA, US
Jean-Philippe Vasseur - Saint Martin d'Uriage, FR

Assignee:

CISCO TECHNOLOGY, INC. - San Jose CA

International Classification:

H04B 1/713

US Classification:

375135

Abstract:

In one embodiment, a management device determines a topology of nodes in a network. Based on the topology, frequency hopping sequences are assigned (and notified) to the nodes such that each particular node of a certain set of the nodes is assigned a frequency hopping sequence on which to transmit that is different than frequency hopping sequences of neighbors and hidden neighbors of that particular node. In another embodiment, a transmitting node first transmits a transmission indication signal on its particular frequency band based on its frequency hopping sequence, and then transmits a message on the particular frequency band. In a further embodiment, a receiving node listening to a plurality of frequency bands may detect the transmission indication signal on the particular frequency band. In response, the receiving node filters out all frequency bands other than the particular frequency band, and receives the following transmission on that particular frequency band.