Polytechnic Institute of NYU

Displaying 1-32 of 32 results

  • White Papers // Feb 2012

    Dual-Band Femtocell Traffic Balancing Over Licensed and Unlicensed Bands

    Many cellular User Equipments (UEs) today are able to access both the unlicensed band (e.g., via Wi-Fi) and the cellular licensed band. However, in most regions of the world, they are not allowed to access both bands simultaneously for data communications - users can only choose either Wi-Fi or cellular....

    Provided By Polytechnic Institute of NYU

  • White Papers // Feb 2012

    Relaying Under Structured Interference

    An orthogonal components relay channel subject to structured interference is studied. Modeling interference as a structured signal is accurate for scenarios in which the interferer is another source communicating with its own destination. It is assumed that interference is known non-causally at the source and the relay is used for...

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2011

    On the Gaussian Z-Interference Channel With Processing Energy Cost

    This paper considers a Gaussian interference channel with processing energy cost, which explicitly takes into account the energy expended for processing when each transmitter is on. With processing overhead, bursty transmission at each transmitter generally becomes more advantageous. Assuming on-off states do not carry information, for a two-user Z-interference channel,...

    Provided By Polytechnic Institute of NYU

  • White Papers // Oct 2011

    Completion Time in Broadcast Channel and Interference Channel

    In a multi-user channel, completion time refers to the number of channel uses required for users, each with some given fixed bit pool, to complete the transmission of all their data bits. This paper extends the information theoretic formulation of multi-access completion time to broadcast channel and interference channel, enabling...

    Provided By Polytechnic Institute of NYU

  • White Papers // Apr 2011

    Inflight Modifications of Content: Who are the Culprits?

    When a user requests content from a cloud service provider, sometimes the content sent by the provider is modified inflight by third-party entities. To the author's knowledge, there is no comprehensive study that examines the extent and primary root causes of the content modification problem. The authors design a lightweight...

    Provided By Polytechnic Institute of NYU

  • White Papers // Mar 2011

    Energy-Neutral Source-Channel Coding in Energy-Harvesting Wireless Sensors

    This paper addresses the problem of energy allocation over source compression and transmission for a single energy-harvesting sensor. An optimal class of policies is identified that simultaneously guarantees a maximal average distortion and the stability of the queue connecting source and channel encoders, whenever this is feasible by any other...

    Provided By Polytechnic Institute of NYU

  • White Papers // Mar 2011

    Use of Devolved Controllers in Data Center Networks

    In a data center network, for example, it is quite often to use controllers to manage resources in a centralized manner. Centralized control, however, imposes a scalability problem. In this paper, the authors investigate the use of multiple independent controllers instead of a single omniscient controller to manage resources. Each...

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2010

    Relay Channel With Structured Interference Known at the Source

    The authors consider a relay channel in the presence of interference which is non-causally available only at the source. The interference signal may have structure, for example it could come from another source communicating with its own destination. However, the external interferer is not willing to adjust its communication strategy...

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2010

    Secure Device Pairing Based on a Visual Channel: Design and Usability Study

    Pairing is the establishment of authenticated key agreement between two devices over a wireless channel. Such devices are ad hoc in nature as they lack any common pre-shared secrets or trusted authority. Fortunately, these devices can be connected via auxiliary physical (audio, visual, tactile) channels which can be authenticated by...

    Provided By Polytechnic Institute of NYU

  • White Papers // Sep 2010

    Alternating-Offer Bargaining Games Over the Gaussian Interference Channel

    This paper tackles the problem of how two selfish users jointly determine the operating point in the achievable rate region of a two-user Gaussian interference channel through bargaining. In previous work, an incentive condition for two users to cooperate using a simple version of Han-Kobayashi scheme was studied and the...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jun 2010

    Understanding Peer Exchange in BitTorrent Systems

    Peer EXchange (PEX), in which peers directly exchange with each other lists of active peers in the torrent, has been widely implemented in modern BitTorrent clients for decentralized peer discovery. However, there is little knowledge about the behavior of PEX in operational systems. In this paper, the authors perform both...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jun 2010

    Waiting for Anonymity: Understanding Delays in the Tor Overlay

    Although Tor is the most widely used overlay for providing anonymity services, its users often experience very high delays. Because much of Tor usage is for Web applications, which are sensitive to latency, it is critical to reduce delays in Tor. To take an important step in this direction, the...

    Provided By Polytechnic Institute of NYU

  • White Papers // May 2010

    Interference Channel With a Half-Duplex Out-of-Band Relay

    A Gaussian Interference Channel (IC) aided by a half-duplex relay is considered, in which the relay receives and transmits in an orthogonal band with respect to the IC. The system thus consists of two parallel channels, the IC and the channel over which the relay is active, which is referred...

    Provided By Polytechnic Institute of NYU

  • White Papers // Apr 2010

    Coordination and Bargaining Over the Gaussian Interference Channel

    This paper considers coordination and bargaining between two selfish users over a Gaussian interference channel using game theory. The usual information theoretic approach assumes full cooperation among users for codebook and rate selection. In the scenario investigated here, each selfish user is willing to coordinate its actions only when an...

    Provided By Polytechnic Institute of NYU

  • White Papers // Mar 2010

    A Name-Centric Approach to Gender Inference in Online Social Networks

    Traditionally it has been laborious, via census or otherwise, to obtain a contemporary list of people's names. By crawling Facebook public profile pages of a large and diverse user population in New York City, the authors create a comprehensive and contemporary first name list, in which each name is annotated...

    Provided By Polytechnic Institute of NYU

  • White Papers // Feb 2010

    Diversity-Multiplexing Tradeoff for MIMO Wire-Tap Channels With CSIT

    In this paper fading multiple-antenna (MIMO) wiretap channels are investigated under short term power constraints. The secret Diversity-Multiplexing Tradeoff (DMT) is calculated analytically, when the destination and the eavesdropper have receiver side Channel State Information (CSI) and the source has Transmitter side CSI (CSIT). It is shown that the eavesdropper...

    Provided By Polytechnic Institute of NYU

  • White Papers // Feb 2010

    Error Resilient Video Multicast Using Randomized Distributed Space Time Codes

    In this paper, the authors study a two-hop cooperative transmission scheme where multiple relays forward the data simultaneously using Randomized Distributed Space Time Codes (R-DSTC). They propose to integrate this randomized cooperative transmission with layered video coding and packet level Forward Error Correction (FEC) to enable error resilient video multicast....

    Provided By Polytechnic Institute of NYU

  • White Papers // Feb 2010

    On Exploiting the Interference Structure for Reliable Communications

    Consider an additive Gaussian noise channel affected by an additive interference sequence, taken from a given codebook, which is known non-causally at the transmitter (e.g., via prior decoding). It is known that in this case optimal performance is attained by Dirty Paper Coding, which treats the interference signal as unstructured....

    Provided By Polytechnic Institute of NYU

  • White Papers // Jan 2010

    Understanding and Improving Incentives in Private P2P Communities

    Incentive mechanisms play a critical role in P2P systems. Private BitTorrent sites use a novel incentive paradigm, where the sites record upload and download amounts of users and require each user to maintain its upload-to-download ratio above a specified threshold. This paper explores in-depth incentives in private P2P file-sharing systems....

    Provided By Polytechnic Institute of NYU

  • White Papers // Jan 2010

    Waiting for Anonymity: Understanding Delays in Tor

    Although Tor is the most widely used system for providing anonymity services, its users often experience very high delays. Because much of Tor usage is for Web applications, which are sensitive to latency, it is critical to reduce delays in Tor. To take an important step in this direction, the...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jan 2010

    Oblivious Relaying for Primitive Interference Relay Channels

    Consider a relay node that needs to operate without knowledge of the codebooks (i.e., modulation, coding) employed by the assisted source-destination pairs. This paper studies the performance of relaying under this condition, termed oblivious relaying, for the Primitive Relay Channel (PRC) and the Primitive Interference Relay Channel (PIRC). "Primitive" refers...

    Provided By Polytechnic Institute of NYU

  • White Papers // Dec 2009

    BitTorrent Darknets

    A private BitTorrent site (also known as a "Bit-Torrent darknet") is a collection of torrents that can only be accessed by members of the darknet community. The private BitTorrent sites also have incentive policies which encourage users to continue to seed files after completing downloading. Although there are at least...

    Provided By Polytechnic Institute of NYU

  • White Papers // Dec 2009

    Achievable Rates for Multicell Systems With Femtocells and Network MIMO

    The uplink of a cellular system where macrocells are overlaid with femtocells is studied. Each femtocell is served by a Home Base Station (HBS) that is connected to the macrocell Base Station (BS) via a last-mile access link, such as DSL or cable followed by the Internet. Decoding at the...

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2009

    Collaborative Spam Filtering With the Hashing Trick

    User feedback is vital to the quality of the collaborative spam filters frequently used in open membership email systems such as Yahoo Mail or Gmail. Users occasionally designate emails as spam or non-spam (Often termed as ham), and these labels are subsequently used to train the spam filter. Although the...

    Provided By Polytechnic Institute of NYU

  • White Papers // Aug 2009

    Robust Communication Against Femtocell Access Failures

    A single macrocell serving a number of outdoor users, overlaid with a femtocell which includes several home users, is studied. The home users in the femtocell are served by a home base station (HBS) that is connected to the macrocell Base Station (BS) via an unreliable connection (e.g., DSL). The...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jul 2009

    Regulation Simulation

    A deterministic trading strategy by a representative investor on a single market asset, which generates complex and realistic returns with its first four moments similar to the empirical values of European stock indices, is used to simulate the effects of financial regulation that either pricks bubbles, props up crashes, or...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jul 2009

    Hardware-Assisted Secure Virtualization

    Securing Virtual Machines (VM) is a major concern in virtualizing commodity Operating Systems (OS). Virtual Machine Monitors (VMM) like Xen require a full-blown privileged OS, VM0 to manage guest VMs. Therefore VM0 becomes the single point of failure. For example, a malicious administrator may suspend a VM and read sensitive...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jun 2009

    Collaborative Email-Spam Filtering With the Hashing-Trick

    This paper delves into a recently proposed technique for collaborative spam filtering that facilitates personalization with finite-sized memory guarantees. In large scale open membership email systems most users do not label enough messages for an individual local classifier to be effective, while the data is too noisy to be used...

    Provided By Polytechnic Institute of NYU

  • White Papers // Apr 2009

    Queuing Network Models for Multi-Channel P2P Live Streaming Systems

    In recent years there have been several large-scale deployments of P2P live video systems. Existing and future P2P live video systems will offer a large number of channels, with users switching frequently among the channels. In this paper, the authors develop infinite-server queueing network models to analytically study the performance...

    Provided By Polytechnic Institute of NYU

  • White Papers // Mar 2009

    Layered Video Multicast Using Diversity Embedded Space Time Codes

    In traditional wireless multicast systems, the system is optimized to provide high reliability to users with the worst channel conditions. However this results in a waste of available bandwidth for users with a good channel conditions. In particular for transmission of video, this wasted bandwidth can be used to deliver...

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2008

    Layered Randomized Cooperation for Multicast

    Cooperation of wireless users is known to provide substantial improvements in channel reliability and in end-to-end distortion. User cooperation is especially attractive for multicast since the relays are also part of the intended recipients. In this paper, the authors consider a randomized distributed cooperation scheme for multicasting a source signal....

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2008

    Resource Allocation in Wireless Networks With Multiple Relays

    A cooperative network where transmission between two nodes that have no direct link, but assisted by many relays is considered. The authors assume a broadband system, such as OFDM, modeled by multiple parallel Gaussian subchannels between the source and each relay, and also between each relay and the destination. They...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jun 2009

    Collaborative Email-Spam Filtering With the Hashing-Trick

    This paper delves into a recently proposed technique for collaborative spam filtering that facilitates personalization with finite-sized memory guarantees. In large scale open membership email systems most users do not label enough messages for an individual local classifier to be effective, while the data is too noisy to be used...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jul 2009

    Hardware-Assisted Secure Virtualization

    Securing Virtual Machines (VM) is a major concern in virtualizing commodity Operating Systems (OS). Virtual Machine Monitors (VMM) like Xen require a full-blown privileged OS, VM0 to manage guest VMs. Therefore VM0 becomes the single point of failure. For example, a malicious administrator may suspend a VM and read sensitive...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jul 2009

    Regulation Simulation

    A deterministic trading strategy by a representative investor on a single market asset, which generates complex and realistic returns with its first four moments similar to the empirical values of European stock indices, is used to simulate the effects of financial regulation that either pricks bubbles, props up crashes, or...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jan 2010

    Understanding and Improving Incentives in Private P2P Communities

    Incentive mechanisms play a critical role in P2P systems. Private BitTorrent sites use a novel incentive paradigm, where the sites record upload and download amounts of users and require each user to maintain its upload-to-download ratio above a specified threshold. This paper explores in-depth incentives in private P2P file-sharing systems....

    Provided By Polytechnic Institute of NYU

  • White Papers // Apr 2009

    Queuing Network Models for Multi-Channel P2P Live Streaming Systems

    In recent years there have been several large-scale deployments of P2P live video systems. Existing and future P2P live video systems will offer a large number of channels, with users switching frequently among the channels. In this paper, the authors develop infinite-server queueing network models to analytically study the performance...

    Provided By Polytechnic Institute of NYU

  • White Papers // Mar 2009

    Layered Video Multicast Using Diversity Embedded Space Time Codes

    In traditional wireless multicast systems, the system is optimized to provide high reliability to users with the worst channel conditions. However this results in a waste of available bandwidth for users with a good channel conditions. In particular for transmission of video, this wasted bandwidth can be used to deliver...

    Provided By Polytechnic Institute of NYU

  • White Papers // Feb 2010

    Error Resilient Video Multicast Using Randomized Distributed Space Time Codes

    In this paper, the authors study a two-hop cooperative transmission scheme where multiple relays forward the data simultaneously using Randomized Distributed Space Time Codes (R-DSTC). They propose to integrate this randomized cooperative transmission with layered video coding and packet level Forward Error Correction (FEC) to enable error resilient video multicast....

    Provided By Polytechnic Institute of NYU

  • White Papers // Feb 2010

    Diversity-Multiplexing Tradeoff for MIMO Wire-Tap Channels With CSIT

    In this paper fading multiple-antenna (MIMO) wiretap channels are investigated under short term power constraints. The secret Diversity-Multiplexing Tradeoff (DMT) is calculated analytically, when the destination and the eavesdropper have receiver side Channel State Information (CSI) and the source has Transmitter side CSI (CSIT). It is shown that the eavesdropper...

    Provided By Polytechnic Institute of NYU

  • White Papers // Oct 2011

    Completion Time in Broadcast Channel and Interference Channel

    In a multi-user channel, completion time refers to the number of channel uses required for users, each with some given fixed bit pool, to complete the transmission of all their data bits. This paper extends the information theoretic formulation of multi-access completion time to broadcast channel and interference channel, enabling...

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2011

    On the Gaussian Z-Interference Channel With Processing Energy Cost

    This paper considers a Gaussian interference channel with processing energy cost, which explicitly takes into account the energy expended for processing when each transmitter is on. With processing overhead, bursty transmission at each transmitter generally becomes more advantageous. Assuming on-off states do not carry information, for a two-user Z-interference channel,...

    Provided By Polytechnic Institute of NYU

  • White Papers // Feb 2012

    Relaying Under Structured Interference

    An orthogonal components relay channel subject to structured interference is studied. Modeling interference as a structured signal is accurate for scenarios in which the interferer is another source communicating with its own destination. It is assumed that interference is known non-causally at the source and the relay is used for...

    Provided By Polytechnic Institute of NYU

  • White Papers // Feb 2012

    Dual-Band Femtocell Traffic Balancing Over Licensed and Unlicensed Bands

    Many cellular User Equipments (UEs) today are able to access both the unlicensed band (e.g., via Wi-Fi) and the cellular licensed band. However, in most regions of the world, they are not allowed to access both bands simultaneously for data communications - users can only choose either Wi-Fi or cellular....

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2009

    Collaborative Spam Filtering With the Hashing Trick

    User feedback is vital to the quality of the collaborative spam filters frequently used in open membership email systems such as Yahoo Mail or Gmail. Users occasionally designate emails as spam or non-spam (Often termed as ham), and these labels are subsequently used to train the spam filter. Although the...

    Provided By Polytechnic Institute of NYU

  • White Papers // Mar 2011

    Use of Devolved Controllers in Data Center Networks

    In a data center network, for example, it is quite often to use controllers to manage resources in a centralized manner. Centralized control, however, imposes a scalability problem. In this paper, the authors investigate the use of multiple independent controllers instead of a single omniscient controller to manage resources. Each...

    Provided By Polytechnic Institute of NYU

  • White Papers // Dec 2009

    BitTorrent Darknets

    A private BitTorrent site (also known as a "Bit-Torrent darknet") is a collection of torrents that can only be accessed by members of the darknet community. The private BitTorrent sites also have incentive policies which encourage users to continue to seed files after completing downloading. Although there are at least...

    Provided By Polytechnic Institute of NYU

  • White Papers // Apr 2011

    Inflight Modifications of Content: Who are the Culprits?

    When a user requests content from a cloud service provider, sometimes the content sent by the provider is modified inflight by third-party entities. To the author's knowledge, there is no comprehensive study that examines the extent and primary root causes of the content modification problem. The authors design a lightweight...

    Provided By Polytechnic Institute of NYU

  • White Papers // Mar 2010

    A Name-Centric Approach to Gender Inference in Online Social Networks

    Traditionally it has been laborious, via census or otherwise, to obtain a contemporary list of people's names. By crawling Facebook public profile pages of a large and diverse user population in New York City, the authors create a comprehensive and contemporary first name list, in which each name is annotated...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jun 2010

    Understanding Peer Exchange in BitTorrent Systems

    Peer EXchange (PEX), in which peers directly exchange with each other lists of active peers in the torrent, has been widely implemented in modern BitTorrent clients for decentralized peer discovery. However, there is little knowledge about the behavior of PEX in operational systems. In this paper, the authors perform both...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jan 2010

    Waiting for Anonymity: Understanding Delays in Tor

    Although Tor is the most widely used system for providing anonymity services, its users often experience very high delays. Because much of Tor usage is for Web applications, which are sensitive to latency, it is critical to reduce delays in Tor. To take an important step in this direction, the...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jun 2010

    Waiting for Anonymity: Understanding Delays in the Tor Overlay

    Although Tor is the most widely used overlay for providing anonymity services, its users often experience very high delays. Because much of Tor usage is for Web applications, which are sensitive to latency, it is critical to reduce delays in Tor. To take an important step in this direction, the...

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2010

    Relay Channel With Structured Interference Known at the Source

    The authors consider a relay channel in the presence of interference which is non-causally available only at the source. The interference signal may have structure, for example it could come from another source communicating with its own destination. However, the external interferer is not willing to adjust its communication strategy...

    Provided By Polytechnic Institute of NYU

  • White Papers // Sep 2010

    Alternating-Offer Bargaining Games Over the Gaussian Interference Channel

    This paper tackles the problem of how two selfish users jointly determine the operating point in the achievable rate region of a two-user Gaussian interference channel through bargaining. In previous work, an incentive condition for two users to cooperate using a simple version of Han-Kobayashi scheme was studied and the...

    Provided By Polytechnic Institute of NYU

  • White Papers // Apr 2010

    Coordination and Bargaining Over the Gaussian Interference Channel

    This paper considers coordination and bargaining between two selfish users over a Gaussian interference channel using game theory. The usual information theoretic approach assumes full cooperation among users for codebook and rate selection. In the scenario investigated here, each selfish user is willing to coordinate its actions only when an...

    Provided By Polytechnic Institute of NYU

  • White Papers // Mar 2011

    Energy-Neutral Source-Channel Coding in Energy-Harvesting Wireless Sensors

    This paper addresses the problem of energy allocation over source compression and transmission for a single energy-harvesting sensor. An optimal class of policies is identified that simultaneously guarantees a maximal average distortion and the stability of the queue connecting source and channel encoders, whenever this is feasible by any other...

    Provided By Polytechnic Institute of NYU

  • White Papers // Feb 2010

    On Exploiting the Interference Structure for Reliable Communications

    Consider an additive Gaussian noise channel affected by an additive interference sequence, taken from a given codebook, which is known non-causally at the transmitter (e.g., via prior decoding). It is known that in this case optimal performance is attained by Dirty Paper Coding, which treats the interference signal as unstructured....

    Provided By Polytechnic Institute of NYU

  • White Papers // Dec 2009

    Achievable Rates for Multicell Systems With Femtocells and Network MIMO

    The uplink of a cellular system where macrocells are overlaid with femtocells is studied. Each femtocell is served by a Home Base Station (HBS) that is connected to the macrocell Base Station (BS) via a last-mile access link, such as DSL or cable followed by the Internet. Decoding at the...

    Provided By Polytechnic Institute of NYU

  • White Papers // Jan 2010

    Oblivious Relaying for Primitive Interference Relay Channels

    Consider a relay node that needs to operate without knowledge of the codebooks (i.e., modulation, coding) employed by the assisted source-destination pairs. This paper studies the performance of relaying under this condition, termed oblivious relaying, for the Primitive Relay Channel (PRC) and the Primitive Interference Relay Channel (PIRC). "Primitive" refers...

    Provided By Polytechnic Institute of NYU

  • White Papers // May 2010

    Interference Channel With a Half-Duplex Out-of-Band Relay

    A Gaussian Interference Channel (IC) aided by a half-duplex relay is considered, in which the relay receives and transmits in an orthogonal band with respect to the IC. The system thus consists of two parallel channels, the IC and the channel over which the relay is active, which is referred...

    Provided By Polytechnic Institute of NYU

  • White Papers // Aug 2009

    Robust Communication Against Femtocell Access Failures

    A single macrocell serving a number of outdoor users, overlaid with a femtocell which includes several home users, is studied. The home users in the femtocell are served by a home base station (HBS) that is connected to the macrocell Base Station (BS) via an unreliable connection (e.g., DSL). The...

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2010

    Secure Device Pairing Based on a Visual Channel: Design and Usability Study

    Pairing is the establishment of authenticated key agreement between two devices over a wireless channel. Such devices are ad hoc in nature as they lack any common pre-shared secrets or trusted authority. Fortunately, these devices can be connected via auxiliary physical (audio, visual, tactile) channels which can be authenticated by...

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2008

    Resource Allocation in Wireless Networks With Multiple Relays

    A cooperative network where transmission between two nodes that have no direct link, but assisted by many relays is considered. The authors assume a broadband system, such as OFDM, modeled by multiple parallel Gaussian subchannels between the source and each relay, and also between each relay and the destination. They...

    Provided By Polytechnic Institute of NYU

  • White Papers // Nov 2008

    Layered Randomized Cooperation for Multicast

    Cooperation of wireless users is known to provide substantial improvements in channel reliability and in end-to-end distortion. User cooperation is especially attractive for multicast since the relays are also part of the intended recipients. In this paper, the authors consider a randomized distributed cooperation scheme for multicasting a source signal....

    Provided By Polytechnic Institute of NYU