Patents by Inventor Christos Gkantsidis
Christos Gkantsidis 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).
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Publication number: 20100027424Abstract: Methods and algorithms for path estimation in a wireless mesh network are described. In an embodiment, each node calculates its cost for a packet flow based on the back-log at the node and the cost of downstream neighbor nodes for the flow. The cost is communicated to the upstream neighbor nodes for the flow. When a node has an opportunity to transmit a packet, a flow is selected by the node based on the back-log at the node and the costs received from each of the downstream neighbor nodes. These costs are then also used to select a downstream neighbor node is selected based on the costs received from each of the downstream neighbor nodes. A packet re-ordering algorithm is also described which intercepts packets received at a node and delays delivery of the packet to the IP layer if an earlier packet in the sequence of packets has not been received.Type: ApplicationFiled: July 30, 2008Publication date: February 4, 2010Applicant: Microsoft CorporationInventors: Bozidar Radunovic, Christos Gkantsidis, Dinan Gunawardena, Peter B. Key
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Publication number: 20090290491Abstract: An end-host based network management system and methods are described. The methods are performed independently at each end-host within the network based on data on local flows which is shared between end-hosts. In an embodiment, an end-host shares data on constrained local flows with other end-hosts and receives such data from other end-hosts. Based on this data, the end-host determines which flows from other nodes are competing for a shared resource with a constrained local flow and allocates the capacity of the shared resource between all the competing flows. This allocation is then enforced for the local flow by the end-host. Other end-hosts with competing flows perform similar methods and through an iterative process the contention for the shared resource is resolved and the utilization of the shared resource is optimized.Type: ApplicationFiled: May 22, 2008Publication date: November 26, 2009Applicant: Microsoft CorporationInventors: Thomas Karagiannis, Christos Gkantsidis, Peter Key, Elias Athanasopoulos
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Publication number: 20090265473Abstract: A topology management process is implemented in peer-to-peer content distribution clouds using tracker nodes. Tracker nodes have information about available peers and assist peers in finding other peers to connect to. Various algorithms for use at the tracker nodes are described for selecting which peers to return as potentials for forming connections to. In addition, architectures and algorithms to allow efficient scaling of tracker nodes in peer-to-peer clouds are described.Type: ApplicationFiled: January 26, 2007Publication date: October 22, 2009Inventors: Aamer Hydrie, Anders E. Klemets, Christos Gkantsidis, John Miller, Pablo Rodriguez Rodriguez, Rebecca C. Weiss
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Publication number: 20090248898Abstract: The invention provides methods of encoding content for distribution over a network and methods for decoding encoded content which has been distributed over the network. In a first example in which the content is divided into a plurality of segments and each segment comprising a plurality of blocks of data, the method comprises selecting a segment from the plurality of segments and selecting at least two blocks of the selected segment from a store of blocks. A new encoded block is created from a linear combination of the selected blocks.Type: ApplicationFiled: December 4, 2006Publication date: October 1, 2009Applicant: Microsoft CorporationInventors: Christos Gkantsidis, John Miller, Manuel Costa, Pablo Rodriguez, Stuart Ranson
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Publication number: 20090198825Abstract: Managing content by influencing its distribution in the form of blocks or other units is crucial to the performance of a peer-to-peer content distribution system. We provide a content management module at each peer node to achieve this. The content management module implements a content request/response cycle in order to negotiate about blocks of content with other peer nodes. This cycle comprises an offer request, offer reply and a block request. These steps are preferably followed by data exchange and verification. The negotiation protocol used by our content management module provides a generic method that is advantageously used in conjunction with different encoding schemes such as full network coding and group network coding. In one embodiment we use group network coding and add information to the offer request and offer reply to facilitate efficient content distribution. Block request messages are selected to promote the use of on-the-fly decoding where possible.Type: ApplicationFiled: April 5, 2007Publication date: August 6, 2009Applicant: Microsoft CorporationInventors: John L. Miller, Armando Garcia-Mendoza, Christos Gkantsidis, Pablo Rodriguez Rodriguez, Stuart Ranson
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Publication number: 20090190599Abstract: Sampling rules for information dissemination are described which may be applied in a system containing a number of nodes arranged into groups. A target address is selected using one of two methods: selection of an address from the entire address space of the system and selection of an address from a part of the address space which corresponds to set of groups of nodes. The set of groups of nodes is updated when information is successfully disseminated to a node at a target address selected using the first of the two methods. Rules to determine which of the two methods are used for any particular selection operation are also described.Type: ApplicationFiled: January 30, 2008Publication date: July 30, 2009Applicant: Microsoft CorporationInventors: Milan Vojnovic, Varun Gupta, Thomas Karagiannis, Christos Gkantsidis
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Publication number: 20090138486Abstract: The invention describes a control node for a content distribution network and a method of automatically verifying content distributed over a network at a node in the network. In the method, a content description is received which comprises a content identifier, a publisher identifier, publisher authorisation information and content checking information. The integrity and validity of this information are checked and if both the checks are passed, the content description is stored.Type: ApplicationFiled: February 8, 2007Publication date: May 28, 2009Applicant: Microsoft CorporationInventors: Aamer Hydrie, John Miller, Anders E. Klemets, Christos Gkantsidis, Pablo Rodriguez Rodriguez, Rebecca C. Weiss
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Publication number: 20090088089Abstract: A dual mode communication device utilizes a control channel to exploit diversity, history, and context in advance of establishing a broadband data exchange session on a broadband but shorter range wireless data channel, maximizing productive use of such a session. Appropriate diversity for the negotiated session further enhance data transfer, including path diversity, radio technology diversity (e.g., WiMax, Wi-Fi, ultra wideband, Bluetooth), antenna diversity (e.g., MIMO), modulation diversity (e.g., rate selection for 802.11, or symbol length selection to combat multi-path fading), and frequency diversity (e.g., 2.4 GHz versus 5 GHz). Historical information about channel characteristics optimize the selection of channel parameters with respect to the diversity choices. In addition, context information such as location and speed can be used to categorize the historical information that is collected to further optimize channel parameters.Type: ApplicationFiled: October 2, 2007Publication date: April 2, 2009Applicant: MICROSOFT CORPORATIONInventors: Ranveer Chandra, Christos Gkantsidis, Ratul Mahajan, Antony Ian Taylor Rowstron, Alastair Wolman, Yongqiang Xiong
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Publication number: 20090003216Abstract: A method of transmitting data across a wireless mesh network is described which uses network coding at each of the intermediate nodes between the source node and the destination node. Each intermediate node also controls the rate at which it broadcasts packets based on link congestion and the backlog of packets at each of the possible next-hop nodes for the data flow.Type: ApplicationFiled: June 27, 2007Publication date: January 1, 2009Applicant: Microsoft CorporationInventors: Bozidar Radunovic, Christos Gkantsidis, Peter B. Key, Dinan Gunawardena, Wenjun Hu, Pablo Rodriguez
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Publication number: 20080320300Abstract: The invention relates to content distribution over a network and provides methods of controlling the distribution, of receiving the content and of publishing content. The method of controlling distribution of content over a network includes receiving a content description and location information for a source of the content from a publisher, where the content description comprises authorisation details associated with the publisher.Type: ApplicationFiled: December 4, 2006Publication date: December 25, 2008Applicant: MICROSOFT CORPORATIONInventors: Christos Gkantsidis, John Miller, Stuart Ranson, Aamer Hydrie, Tan See-Mong, Pablo Rodriguez Rodriguez, Manuel Costa
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Publication number: 20080301246Abstract: A wire protocol is described which implements connection management and other methods to give enhanced peer-to-peer content distribution. Connections between nodes can be placed in a “notify” state when they are idle but may soon yield useful content. This notify state is also used together with a content request/response cycle to allow a peer to evaluate content available at a neighbour. If no suitable content is available a notify state is entered. When new content is later received at the neighbour it is able to inform the requesting node to allow it to restart the content request/response cycle.Type: ApplicationFiled: December 4, 2006Publication date: December 4, 2008Applicant: Microsoft CorporationInventors: Christos Gkantsidis, John Miller, Manuel Costa, Pablo Rodriguez Rodriguez, Stuart Ranson
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Publication number: 20080294779Abstract: A topology management process is implemented which involves removing or “tearing down” connections between nodes in certain situations in order to try to replace those connections with more optimal ones. Idle connections are torn down unless those are in a “notify” state; a notify state being one in which a request for content has been made to a neighbour but that neighbour has no available content as yet. Idle connections in a notify state are torn down only if they remain idle for a longer time than that required before an idle connection is torn down. To avoid problems caused by clusters of node forming and of loners being unable to join the cloud, network churn algorithms are taught. These involve requiring nodes to drop connections when specified conditions are met. Relative content distribution between connections is monitored and this information used to influence selection of those connections to drop.Type: ApplicationFiled: December 4, 2006Publication date: November 27, 2008Applicant: Microsoft CorporationInventors: Christos Gkantsidis, John Miller, Manuel Costa, Pablo Rodriguez Rodriguez, Stuart Ranson
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Publication number: 20070150596Abstract: Publishing content using a peer-to-peer content distribution system is described. A publisher is required to request authorization to publish from an authorization body. Resources such as tracker and seed nodes are allocated in a peer-to-peer content distribution system and pre-processing of content to be published is carried out. For example, a content description is generated for each item of content as well as a set of checksums or other items for validating blocks of content. Publication can be terminated in a variety of different ways. For example, by using expiry methods, by active revocation of publishers, authorization bodies, or individual items of content.Type: ApplicationFiled: June 27, 2006Publication date: June 28, 2007Applicant: Microsoft CorporationInventors: John Miller, Aamer Hydrie, Anders Klemets, Armando Garcia-Mendoza, Christos Gkantsidis, Pablo Rodriguez Rodriguez, Rebecca Weiss
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Publication number: 20060282677Abstract: A content distribution mechanism that relies on cooperative desktop PCs to distribute content is disclosed. The mechanism distributes content in a robust manner by allowing at least one intermediate network node (i.e., between a source and client) to generate and send packets that contain a linear combination of the portions of content available at the node. Such linear combinations may be created by the source and client using at least a portion of the original content file in either encoded or unencoded form. After the client has received enough linearly independent combinations of packets, the original content may be reconstructed. Further, security for network coding file distribution may be employed to maintain the efficiency and security of the content distribution mechanism. A security server may generate security information using a hashing algorithm including the property of producing security information for each block which survives the process of creating encoded blocks.Type: ApplicationFiled: July 28, 2005Publication date: December 14, 2006Applicant: Microsoft CorporationInventors: Pablo Rodriguez, Christos Gkantsidis, Stephane Ubeda
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Publication number: 20060020560Abstract: A content distribution mechanism that relies on cooperative desktop PCs to distribute content is disclosed. The mechanism distributes content in a robust manner by allowing at least one intermediate network node (i.e., between a source and client) to generate and send packets that contain a linear combination of the portions of content available at the node. Such linear combinations may be created by the source and client using at least a portion of the original content file in either encoded or unencoded form. After the client has received enough linearly independent combinations of packets, the original content may be reconstructed.Type: ApplicationFiled: June 13, 2005Publication date: January 26, 2006Applicant: Microsoft CorporationInventors: Pablo Rodriguez, Christos Gkantsidis