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: 7120453
    Abstract: Base stations on an Internet protocol (IP) network define a number of paging areas. An IP mobile host assumes one of (i) an active state, wherein the host informs other network nodes of a change in its point of attachment from one base station to another, and (ii) a standby state wherein the host informs other nodes only when a new point of attachment is a base station of a different paging area from a last point of attachment, thus conserving power at the mobile host. When data on the network is addressed to a standby mobile host, a page request is directed to a base station(s) in the host's current paging area for transmission. The host enters the active state and transmits a page response which is received by a base station in the current paging area, and network routing information for the host is updated accordingly.
    Type: Grant
    Filed: April 18, 2001
    Date of Patent: October 10, 2006
    Assignee: Lucent Technologies Inc.
    Inventors: Thomas F. La Porta, Li Li, Ramachandran Ramjee
  • Publication number: 20060092940
    Abstract: A SoftRouter architecture deconstructs routers by separating the control entities of a router from its forwarding components, enabling dynamic binding between them. In the SoftRouter architecture, control plane functions are aggregated and implemented on a few smart servers which control forwarding elements that are multiple network hops away. A dynamic binding protocol performs network-wide control plane failovers. Network stability is improved by aggregating and remotely hosting routing protocols, such as OSPF and BGP. This results in faster convergence, lower protocol messages processed, and fewer route changes following a failure. The SoftRouter architecture includes a few smart control entities that manage a large number of forwarding elements to provide greater support for network-wide control. In the SoftRouter architecture, routing protocols operate remotely at a control element and control one or more forwarding elements by downloading the forwarding tables, etc. into the forwarding elements.
    Type: Application
    Filed: June 8, 2005
    Publication date: May 4, 2006
    Inventors: Furquan Ansari, Martin Havemann, Tirunell Lakshman, Thyagarajan Nandagopal, Ramachandran Ramjee, Thomas Woo
  • Publication number: 20060092857
    Abstract: A dynamic binding protocol has three tasks that run in parallel: discovery, association, and operation. During discovery, control elements (CEs) and forwarding elements (FEs) learn about immediate neighbors and CEs in a SoftRouter network that has separate control and data planes. During association, FEs associate with CEs and are configured with basic parameters, such as IP interface addresses, hostnames, and the like. During operation, failover and packet tunneling between CEs and FEs is handled.
    Type: Application
    Filed: June 8, 2005
    Publication date: May 4, 2006
    Inventors: Furquan Ansari, Martin Havemann, Tirunell Lakshman, Thyagarajan Nandagopal, Ramachandran Ramjee, Thomas Woo
  • Publication number: 20060092974
    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: Application
    Filed: June 8, 2005
    Publication date: May 4, 2006
    Inventors: Tirunell Lakshman, Thyagarajan Nandagopal, Ramachandran Ramjee, Krishan Sabnani, Thomas Woo
  • Publication number: 20060092975
    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. There is a protocol failover mechanism for handling failovers initiated by FEs to transfer control from one CE to another CE.
    Type: Application
    Filed: June 8, 2005
    Publication date: May 4, 2006
    Inventors: Furquan Ansari, Tirunell Lakshman, Thyagarajan Nandagopal, Ramachandran Ramjee, Thomas Woo
  • Publication number: 20050221839
    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: Application
    Filed: March 31, 2004
    Publication date: October 6, 2005
    Inventors: Mun-Choon Chan, Martin Havemann, Ramachandran Ramjee, Sandra Thuel, Thomas Woo
  • Publication number: 20050053002
    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: September 9, 2003
    Publication date: March 10, 2005
    Inventors: Mun Chan, Ramachandran Ramjee
  • Patent number: 6842462
    Abstract: A General Packet Radio Service (GPRS) Accessed Extended Mobile Internet Protocol (EMIP) [G-EMIP] network is provided for wireless mobile device access to external packet data networks. Domains are defined to incorporate a subnet of standard GPRS and EMIP network entities accessed through a Domain Router. Packet access at the radio interface is provided using the base station portion of a GPRS network. Wireless link specific processing is relegated to this potion of the G-EMIP network. EMIP is utilized as a backbone network to provide mobility and service management and interconnection to external networks. A GPRS-IP Interworking entity (GII) interworks IP and GPRS protocols between GPRS and IP addressable network entities (i.e., translates messages of each protocol to corresponding messages of the other protocol). Mobility-related functionality is handled at the IP (network) layer.
    Type: Grant
    Filed: December 17, 1999
    Date of Patent: January 11, 2005
    Assignee: Lucent Technologies Inc.
    Inventors: Ramachandran Ramjee, Thomas F. La Porta, Kannan Varadhan, Luca Salgarelli, Mark Haner, Arun Narayan Netravali, Gerard Terence Foster
  • Publication number: 20040215753
    Abstract: Techniques and systems for managing transmissions from a TCP source by regulating the flow of acknowledgement signals to the TCP source are described. An acknowledgement signal regulator monitors a data queue used to buffer data packets received from the TCP source and an acknowledgement signal queue used to store acknowledgement signals to be transmitted to the TCP source. An acknowledgement signal release manager determines the available space in the data queue and the expected number of data packets arriving at the data queue, and manages the release of acknowledgement signals from the acknowledgement signal queue to the TCP source so as to prevent an undesired overflow of the data queue resulting from the arrival of an excessive number of data packets from the TCP source.
    Type: Application
    Filed: March 31, 2003
    Publication date: October 28, 2004
    Applicant: Lucent Technologies, Inc.
    Inventors: Mun-Choon Chan, Ramachandran Ramjee
  • Patent number: 6763007
    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 13, 2004
    Assignee: Lucent Technologies Inc.
    Inventors: Thomas F. La Porta, Kazutaka Murakami, Ramachandran Ramjee, Sandra R. Thuel, Kannan Varadhan
  • Publication number: 20040052210
    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: Application
    Filed: September 12, 2002
    Publication date: March 18, 2004
    Inventors: Sneha Kasera, Ramachandran Ramjee, Danny Raz, Yuval Shavitt, Prasun Sinha
  • Publication number: 20030228878
    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: Application
    Filed: June 10, 2002
    Publication date: December 11, 2003
    Inventors: Thomas F. LaPorta, Ramachandran Ramjee, Krishan K. Sabnani
  • Patent number: 6654359
    Abstract: Domains are defined to incorporate a subnet including a plurality of base stations and routers. 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. Local mobility between domain base stations is provided by including and updating routing table entries at domain routers and base stations for forwarding packets having a mobile device's address as a destination address to the mobile device. Packets are delivered to the mobile device regardless of the domain base station to which the mobile device is attached. When a mobile device is attached to a base station included within a foreign domain, a care-of address is assigned, and packets are tunneled for delivery of packets to the mobile device. Only one care-of address is required per mobile device per foreign domain.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: November 25, 2003
    Assignee: Lucent Technologies Inc.
    Inventors: Thomas F. La Porta, Kazutaka Murakami, Ramachandran Ramjee, Sandra R. Thuel, Kannan Varadhan
  • Patent number: 6496505
    Abstract: A tunneling optimization is described in which packets are forwarded from a home agent to a mobile device by co-locating a foreign agent corresponding to a mobile device at the mobile device. When a mobile device acquires a new foreign agent, the mobile device notifies the home agent as to the corresponding foreign agent address. A packet received at the home agent having the mobile device as a packet header destination address is parsed and the foreign agent address is substituted for the mobile device address, and the packet is forwarded to the foreign agent. The foreign agent, upon receiving the packet, removes the foreign agent address and replaces the mobile device address as the packet header destination address. The packet is then forwarded to the mobile device.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: December 17, 2002
    Assignee: Lucent Technologies Inc.
    Inventors: Thomas F. La Porta, Ramachandran Ramjee, Kannan Varadhan
  • Patent number: 6434134
    Abstract: The number of packet routing addresses utilized within a wired subnet offering wireless services via subnet base stations is reduced by assigning a packet routing address to a wireless device accessing a wired subnet upon power up of the wireless device. A Dynamic Host Configuration Protocol (DHCP) server is utilized to assign the packet routing addresses, and supplies addresses either directly or indirectly via a node acting as a DHCP relay for a DHCP server. If the assigned packet routing address is a care-of address for a foreign domain, the address is released upon wireless device power down or upon handoff of the wireless device to a new domain. If the assigned packet routing address is an address for the wireless device within a home domain, the address is released upon wireless device power down.
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: August 13, 2002
    Assignee: Lucent Technologies, Inc.
    Inventors: Thomas F. La Porta, Ramachandran Ramjee
  • Publication number: 20020057657
    Abstract: A tunneling optimization is described in which packets are forwarded from a home agent to a mobile device by co-locating a foreign agent corresponding to a mobile device at the mobile device. When a mobile device acquires a new foreign agent, the mobile device notifies the home agent as to the corresponding foreign agent address. A packet received at the home agent having the mobile device as a packet header destination address is parsed and the foreign agent address is substituted for the mobile device address, and the packet is forwarded to the foreign agent. The foreign agent, upon receiving the packet, removes the foreign agent address and replaces the mobile device address as the packet header destination address. The packet is then forwarded to the mobile device.
    Type: Application
    Filed: December 11, 1998
    Publication date: May 16, 2002
    Inventors: THOMAS F. LA PORTA, RAMACHANDRAN RAMJEE, KANNAN VARADHAN
  • Publication number: 20020046287
    Abstract: Base stations on an Internet protocol (IP) network define a number of paging areas. An IP mobile host assumes one of (i) an active state, wherein the host informs other network nodes of a change in its point of attachment from one base station to another, and (ii) a standby state wherein the host informs other nodes only when a new point of attachment is a base station of a different paging area from a last point of attachment, thus conserving power at the mobile host. When data on the network is addressed to a standby mobile host, a page request is directed to a base station(s) in the host's current paging area for transmission. The host enters the active state and transmits a page response which is received by a base station in the current paging area, and network routing information for the host is updated accordingly.
    Type: Application
    Filed: April 18, 2001
    Publication date: April 18, 2002
    Inventors: Thomas F. La Porta, Li Li, Ramachandran Ramjee
  • Patent number: 6298039
    Abstract: A method of delivering highly-reliable, fault-tolerant communications services in a telecommunications network of distributed call processing systems. The method advantageously identifies a set of objects within the telecommunications network requiring checkpointing; checkpoints the objects; and subsequently restores the checkpointed objects in the event of a failure. Various aspects of the method are disclosed, including restoration strategies.
    Type: Grant
    Filed: January 31, 1998
    Date of Patent: October 2, 2001
    Assignee: Lucent Technologies Inc.
    Inventors: Richard Wayne Buskens, Thomas F. La Porta, Yow-Jian Lin, Kazutaka Murakami, Ramachandran Ramjee
  • Patent number: 6198941
    Abstract: A method of effectuating a change in the operation of a portable communication device such as a laptop or palmtop computer, a personal digital assistant (PDA), or a cellular telephone. The device can communicate with a remote host or server using one of two or more different communication arrangements. Various signals indicative of the environment in which the device is operating are monitored, to anticipate or predict a change or transition from one communication arrangement to the other. If the change is determined to be both imminent and significant, the operation change is effected substantially simultaneously, by changing parameters in the transport and/or application protocol layer in the device.
    Type: Grant
    Filed: August 7, 1998
    Date of Patent: March 6, 2001
    Assignee: Lucent Technologies Inc.
    Inventors: Alfred Vaino Aho, Richard Dennis Gitlin, Ramachandran Ramjee, Thomas Yat Chung Woo
  • Patent number: 6192250
    Abstract: A “cluster mobile switching center” (cMSC) is arranged to perform the switching and control functions of a conventional mobile switching center (MSC), including, if desired, the additional functions of a conventional visitor location register (VLR). The cMSC is implemented on distributed processors using modular software. Advantageously, a specific instance of middleware, known as Common Object Request Broker Architecture (CORBA), is used as the communications middleware. Functionally, the cMSC is arranged to have two classes of servers: (1) Interworking managers (IMs) that act as gateways and provide interfaces to external network elements, and (2) core servers that perform call processing (registration, location updates, incoming and outgoing call processing) functions and communicate with each other using CORBA. IMs terminate standard protocols with the external elements and use CORBA to communicate with the core servers.
    Type: Grant
    Filed: September 1, 1998
    Date of Patent: February 20, 2001
    Assignee: Lucent Technologies Inc.
    Inventors: Richard Wayne Buskens, Michael P. Deitz, Thomas F. La Porta, Yow-Jian Lin, Kazutaka Murakami, Ramachandran Ramjee