Patents by Inventor Ramachandran Ramjee

Ramachandran Ramjee has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7778170
    Abstract: Each node or link of an ad hoc network assists in the distributed allocation of a data channel to increase fairness, even in a multi-hop network, by tracking a measure of link weight for itself and sharing this information over a control channel with neighboring nodes. The metric can be provided over a dedicated control channel, added as a header to data communication on a data channel, or inferred by monitoring data traffic from the neighboring node. The link weight can be adjusted by a link quality factor based on provided or inferred metrics such as transmission rates, ratio of transmission errors, idle time, etc. For multiple flow queues at a subject node, one with a higher transmission rate can be selected for increased fairness. When a packet is received, medium access includes allocating bandwidth, including bonding multiple frequencies that are determined to be available to both nodes.
    Type: Grant
    Filed: November 14, 2007
    Date of Patent: August 17, 2010
    Assignee: Microsoft Corporation
    Inventors: Bernard D. Aboba, Paramvir Bahl, Miguel Oom Temudo de Castro, Gopala S. Narlanka, Jitendra D. Padhye, Bozidar Raduvic, Ramachandran Ramjee, Kun Tan
  • Publication number: 20100195548
    Abstract: Embodiments of the claimed subject matter provide an approach to managing the power state of wireless network devices in a wireless network. Embodiments include a process for modifying the scheduling of data distribution device by referencing the data buffer in an access point for data intended for a wireless network client operating under a power-saving mode, and re-arranging the distribution queue of the access point to be granted priority for a time which coincides with the delivery of a polling beacon to the power-saving wireless client. Other embodiments include a method to create virtual access points for a particular usage, and to leverage access points in a wireless network for particular usages of devices in range.
    Type: Application
    Filed: January 30, 2009
    Publication date: August 5, 2010
    Applicant: MICROSOFT CORPORATION
    Inventors: Vishnu Navda, Ramachandran Ramjee, Venkata N. Padmanabhan, Shravan Rayanchu
  • Patent number: 7715382
    Abstract: The SoftRouter architecture separates the implementation of control plane functions from packet forwarding functions. In this architecture, all control plane functions are implemented on general purpose servers called the control elements (CEs) that may be multiple hops away from the forwarding elements (FEs). A network element (NE) or a router is formed using dynamic binding between the CEs and the FEs. The flexibility of the SoftRouter architecture over conventional routers with collocated and tightly integrated control and forwarding functions results in increased reliability, increased scalability, increased security, ease of adding new functionality, and decreased cost.
    Type: Grant
    Filed: June 8, 2005
    Date of Patent: May 11, 2010
    Assignee: Alcatel-Lucent USA Inc.
    Inventors: Tirunell V. Lakshman, Thyagarajan Nandagopal, Ramachandran Ramjee, Krishan K. Sabnani, Thomas Y. Woo
  • Publication number: 20090192688
    Abstract: A traffic sensing system for collecting information on traffic conditions is provided. A traffic sensing system includes a traffic sensing server and a mobile traffic sensing device that sends traffic reports to the traffic sensing server. An MTS device may use an accelerometer integrated into a smart phone to detect potholes, to detect when the vehicle is braking, to detect whether the MTS device is being transported via a vehicle or a pedestrian, to detect horns sounding, and so on. The MTS device reports the various conditions to the traffic sensing server for accurate assessment of traffic conditions at stretches of road through which vehicles transporting MTS devices travel.
    Type: Application
    Filed: June 26, 2008
    Publication date: July 30, 2009
    Applicant: Microsoft Corporation
    Inventors: Venkata N. Padmanabhan, Ramachandran Ramjee, Prashanth Mohan
  • Publication number: 20090187673
    Abstract: Described is transparently compressing content for network transmission, including end-to-end compression. An end host or middlebox device sender sends compressed packets to an end host or middlebox device receiver, which decompresses the packets to recover the original packet. The sender constructs compressed packets including references to information maintained at the receiver, which the receiver uses to access the information to recreate actual original packet content. The receiver may include a dictionary corresponding to the sender, e.g., synchronized with the sender's dictionary. Alternatively, in speculative compression, the sender does not maintain a dictionary, and instead sends a fingerprint (hash value) by which the receiver looks up corresponding content in its dictionary; if not found, the receiver requests actual content.
    Type: Application
    Filed: January 18, 2008
    Publication date: July 23, 2009
    Applicant: MICROSOFT CORPORATION
    Inventors: Ramachandran Ramjee, Ranjita Bhagwan, Venkata N. Padmanabhan, Manveer Singh Chawla
  • Patent number: 7554967
    Abstract: Portable and/or mobile IP hosts desiring to connect to the Internet can dynamically acquire a home address and other configuration information through DHCP when powering up in a foreign network. A two-stage configuration procedure is used. First, the mobile host uses the M-IP protocol to establish contact with an addressing element, referred to as a bootstrapping agent, that is usually co-located with a M-IP Home Agent, and that allocates a temporary home address for the mobile host. The temporary address is used to create a temporary tunnel. Second, this temporary tunnel is used as the communication vehicle over which standard DHCP transactions take place. The present invention is thus arranged to use a) M-IP as the signaling mechanism for reaching the home network and dynamically allocating a temporary home address for the mobile host; and b) DHCP to allocate a permanent home address and any other configuration state for the mobile host.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: June 30, 2009
    Assignee: Alcatel-Lucent USA Inc.
    Inventors: Kannan Varadhan, Thomas F La Porta, Ramachandran Ramjee, Luca Salgarelli, Sandra R Thuel
  • Publication number: 20090122700
    Abstract: Each node or link of an ad hoc network assists in the distributed allocation of a data channel to increase fairness, even in a multi-hop network, by tracking a measure of link weight for itself and sharing this information over a control channel with neighboring nodes. The metric can be provided over a dedicated control channel, added as a header to data communication on a data channel, or inferred by monitoring data traffic from the neighboring node. The link weight can be adjusted by a link quality factor based on provided or inferred metrics such as transmission rates, ratio of transmission errors, idle time, etc. For multiple flow queues at a subject node, one with a higher transmission rate can be selected for increased fairness. When a packet is received, medium access includes allocating bandwidth, including bonding multiple frequencies that are determined to be available to both nodes.
    Type: Application
    Filed: November 14, 2007
    Publication date: May 14, 2009
    Applicant: MICROSOFT CORPORATION
    Inventors: Bernard D. Aboba, Paramvir Bahl, Miguel Oom Temudo de Castro, Gopala S. Narlanka, Jitendra D. Padhye, Bozidar Radunovic, Ramachandran Ramjee, Kun Tan
  • Publication number: 20090124205
    Abstract: A communication device cognitively monitors interference signals across a communication band so that adaptations for physical and medium access control (MAC) of data packet transmissions are appropriate for a particular interference signal. Characteristics of an interference signal of interest (e.g., bandwidth, power and/or duration relative to an average data packet transmitted over a communication channel of the communication device) are sensed for an appropriate adaptation (e.g., forward error correction, modulation technique, back off, request to send/clear to send protocol, etc.). Patterns for known types of interference sources can be compared so that when recognized an associated adaptation can be used.
    Type: Application
    Filed: November 13, 2007
    Publication date: May 14, 2009
    Applicant: MICROSOFT CORPORATION
    Inventors: Bernard D. Aboba, Paramvir Bahl, Gopala S. Narlanka, Jitendra D. Padhye, Bozidar Radunovic, Ramachandran Ramjee, Kun Tan, Miguel Oom Temudo de Castro
  • Publication number: 20090010234
    Abstract: A routing protocol, according to one embodiment of which a first station of a wireless network monitors its outgoing transmissions corresponding to a traffic flow for occurrence of multi-tier signals and for ability to achieve a specified minimum transmission rate. Based on the monitoring, the first station may transmit an outgoing solicitation message that identifies the monitored traffic flow as a candidate for rerouting. Upon receipt of the solicitation message, a second station of the wireless network evaluates whether rerouting of the monitored traffic flow through the second station is capable of increasing data throughput for that traffic flow without decreasing data throughputs for other traffic flows presently handled by the second station. Based on this evaluation, the second station may transmit to the first station an offer to reroute the monitored traffic flow. The first station, in turn, evaluates this offer, e.g.
    Type: Application
    Filed: May 21, 2008
    Publication date: January 8, 2009
    Applicant: LUCENT TECHNOLOGIES INC.
    Inventors: Li Li, Harish Viswanathan, Ramachandran Ramjee
  • Publication number: 20090010216
    Abstract: A medium-access-control (MAC) scheduler, according to one embodiment of which a station of a wireless network evaluates data throughputs corresponding to three different transmission configurations for transmission of a packet over a first of that station's wireless links. The first and second of those transmission configurations have the packet encoded in the first and second tiers, respectively, of a two-tier signal. The third transmission configuration has the packet encoded as a conventional single-tier signal. For each of the first and second transmission configurations, the station selects a second of that station's wireless links for transmission of at least a second packet, with the first and second packets encoded in different respective tiers of the two-tier signal.
    Type: Application
    Filed: May 21, 2008
    Publication date: January 8, 2009
    Applicant: LUCENT TECHNOLOGIES INC.
    Inventors: Li Li, Harish Viswanathan, Ramachandran Ramjee
  • Publication number: 20080267106
    Abstract: The present invention demonstrates how network-coding can be applied to a deterministic broadcast approach, resulting in significant reductions in the number of transmissions in the network. We propose two algorithms, that rely only on local two-hop topology information and make extensive use of opportunistic listening to reduce the number of transmissions: 1) a simple XOR-based coding algorithm and 2) a Reed-Solomon based coding algorithm that determines the optimal coding gain achievable for a coding algorithm that relies only on local information.
    Type: Application
    Filed: April 24, 2007
    Publication date: October 30, 2008
    Inventors: Milind M. Buddhikot, Li Li, Scott C. Miller, Ramachandran Ramjee
  • Publication number: 20080159299
    Abstract: Novel, Internet-related architectures, methods and devices are proposed that are based on a fundamentally different philosophy: hosts (e.g., source and destination nodes) are given the ability to specify their access control policies to the network they are a part of, and the network enforces these policies. The architecture proposed is mobility friendly to the ever increasing number of mobile hosts and is scalable as well.
    Type: Application
    Filed: December 29, 2006
    Publication date: July 3, 2008
    Inventors: Tian Bu, Li Li, Ramachandran Ramjee
  • Publication number: 20080144509
    Abstract: The amount of TCP/IP packets which can be sent from an Internet network to a wireless network is maximized by modifying a receive window value of an acknowledgment (ACK) before the ACK is sent on to a source of data packets within the Internet network. The receive window value is modified to take into consideration delay and rate variations which occur in the wireless network.
    Type: Application
    Filed: February 5, 2008
    Publication date: June 19, 2008
    Inventors: Mun Choon Chan, Ramachandran Ramjee
  • Publication number: 20080137608
    Abstract: The transmission of data from base stations to users (and their devices) in a wireless network is made using proportional fairness without sacrificing throughput by taking in to account fairness considerations at the time the devices are associated with a base station.
    Type: Application
    Filed: December 8, 2006
    Publication date: June 12, 2008
    Inventors: Tian Bu, Li Li, Ramachandran Ramjee
  • Patent number: 7352700
    Abstract: The amount of TCP/IP packets which can be sent from an Internet network to a wireless network is maximized by modifying a receive window value of an acknowledgment (ACK) before the ACK is sent on to a source of data packets within the Internet network. The receive window value is modified to take into consideration delay and rate variations which occur in the wireless network.
    Type: Grant
    Filed: September 9, 2003
    Date of Patent: April 1, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Mun Choon Chan, Ramachandran Ramjee
  • Patent number: 7340253
    Abstract: A system that enables end-to-end networking within CDMA oriented networks. Several base stations operating within the CDMA oriented network simultaneously receive data from the same mobile unit. A distributed algorithm operating within each of the base stations monitors the reception of the data from the mobile unit, as well as commands/instructions from other base stations. One of the base stations is appointed as a dominant base station. The appointment of a dominant base station can be done randomly or based on the quality of data being received by the base station. When the dominant base station detects a decrease in the quality of received data from the mobile unit, the dominant base station instructs the remainder of the base stations to forward any data received from the mobile to the dominant base station.
    Type: Grant
    Filed: June 10, 2002
    Date of Patent: March 4, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Thomas F. LaPorta, Ramachandran Ramjee, Krishan K. Sabnani
  • Patent number: 7317686
    Abstract: A network node computes a fair share data rate for the sharing of a shared communication channel in a local area network. The network node determines the required information for computing the fair share by snooping the network, by receiving the required information from other network nodes, or a combination of the two techniques. Alternatively, instead of computing the fair share data rate, the network node may receive the fair share data rate which was computed by another network node. The fair share data rate is enforced by the network node in a network protocol stack layer above the media access control layer. In one embodiment, the network protocol stack layer above the media access control layer is the link layer.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: January 8, 2008
    Assignee: Lucent Technologies Inc.
    Inventors: Sneha Kasera, Ramachandran Ramjee, Danny Raz, Yuval Shavitt, Prasun Sinha
  • Patent number: 7257409
    Abstract: A base station controller (BSC) of a radio or wireless telecommunications network base station includes a director. A BSC includes multiple central processing units (CPUs), with each CPU running a call-processing application for one or more connections. The director is a logical entity that intercepts wireless call-setup signaling and assigns each corresponding connection to a CPU according to a centralized load-balancing algorithm. The centralized load-balancing algorithm distributes connections to less loaded CPUs to i) prevent individual CPUs from overloading, ii) utilize otherwise unused system resources, and iii) increase overall system performance. The director hosts cell components that manage code division multiple access (CDMA) downlink spreading codes for a base station, providing centralized allocation of spreading codes by the base station.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: August 14, 2007
    Assignee: Lucent Technologies Inc.
    Inventors: Mun-Choon Chan, Martin Havemann, Ramachandran Ramjee, Sandra R. Thuel, Thomas Y. Woo
  • Patent number: 7239618
    Abstract: Local mobility within a subnet is supported by classifying wireless base stations, and the routers used to forward packets to those base stations, within defined domains. Domains are defined to incorporate a subnet having a plurality of base stations. Base stations are used by mobile devices to attach to the wired portion of a packet-based network, such as the Internet, and exchange packets thereover with a correspondent node. Packets sent from the correspondent node to the mobile device have a packet destination address corresponding to the mobile device. The mobile device retains this address for the duration of time it is powered up and attached to the Internet via any base station within a given domain. Host-based routing is utilized to update routing table entries corresponding to the mobile device at routers incorporated within a single domain.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: July 3, 2007
    Assignee: Lucent Technologies Inc.
    Inventors: Thomas F. La Porta, Kazutaka Murakami, Ramachandran Ramjee, Sandra R. Thuel, Kannan Varadhan
  • Publication number: 20070070933
    Abstract: Estimates are provided for the number of links needed in a Internet Protocol-Radio Access Network (IP-RAN) to ensure the IP-RAN is resilient to base station and radio network controller type failures.
    Type: Application
    Filed: September 28, 2005
    Publication date: March 29, 2007
    Inventors: Mun-Choon Chan, Ramachandran Ramjee, Tian Bu