Indian Institute of Technology Bombay

Displaying 1-40 of 90 results

  • White Papers // Feb 2013

    Stochastic Model Based Opportunistic Spectrum Access in Wireless Networks

    The authors present a stochastic model based opportunistic channel access and transmission scheme for cognitive radio-enabled secondary users for single data channel. They refer to this scheme as RIBS (Residual Idle Time Distribution based Scheme). In this scheme, the SU uses residual white space distribution to estimate its transmission duration...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2012

    Symbiotic Cognitive Relaying with Mobile Secondary Nodes in Cognitive Radio Networks

    In a Symbiotic Cognitive Relaying (SCR) scenario, Secondary User (SU) nodes can act as multi-hop relays to assist communication between Primary User (PU) nodes in the case of a weak direct link. In return, the SU nodes are incentivized with the right to carry out SU-SU communication using licensed PU...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Oct 2012

    Analysis of Blocking Probability in a Relay-Based Cellular OFDMA Network

    Relay deployment in Orthogonal Frequency Division Multiple Access (OFDMA) based cellular networks helps in coverage extension and/or capacity improvement. In OFDMA system, each user requires different number of subcarriers to meet its rate requirement. This resource requirement depends on the Signal to Interference Ratio (SIR) experienced by a user. Traditional...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jul 2012

    Host-Bypass: Approximating Node-Weighted Connectivity Problems in Two-Tier Networks

    The authors focus on network design problems in those networks which have two distinct sets or tiers of network nodes: hosts and infrastructure nodes. For instance, wireless mesh networks are often composed of the infrastructure nodes which relay the data between the client nodes. Similarly, the switches (infrastructure) in data...

    Provided By Indian Institute of Technology Bombay

  • White Papers // May 2012

    On Throughput Performance of Decode and Forward Cooperative Relaying With Packet Combining and ARQ

    Cooperative Diversity can be used by wireless nodes to take the benefit of broadcast nature and inherent spatial diversity of wireless channel to relay messages for each others. This helps to propagate redundant signals over multiple paths, which can be used to combat the channel noise and fading effects. The...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Mar 2012

    Buffer-Based Channel Dependent Uplink Scheduling in Relay-Assisted LTE Networks

    The authors consider the problem of UpLink (UL) scheduling in relay-assisted Long Term Evolution (LTE) networks and propose a Buffer-based Channel dependent Scheduler (BCS) for the same. Their objectives are to minimize packet loss due to buffer overflow and increase resource utilization efficiency while ensuring fairness among users. This is...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2012

    Real Slepian-Wolf Codes

    The authors provide a novel achievability proof of the Slepian-Wolf theorem for i.i.d. sources over finite alphabets. They demonstrate that random codes that are linear over the real field achieve the classical Slepian-Wolf rate region. For finite alphabets they show that decoding is equivalent to solving an integer program. The...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2011

    On the Usage of FDLs in Optical Parallel Transmission to Support High Speed Ethernet

    Parallel transmission in the optical layer can enable a scalable network migration from low speed interfaces to high speed serial interfaces, such as 100Gbps Ethernet, as they become available. It is based on the principle of inverse-multiplexing which distributes high speed data stream into multiple low rate optical paths. The...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Sep 2011

    Performance Analysis of TCP and UDP-Based Applications in a IEEE 802.16 Deployed Network

    In this paper, the authors focus on various experiments conducted to analyze the performance of Transmission Control Protocol (TCP) and Universal Datagram Protocol (UDP) based applications in a IEEE 802.16 deployed network. They analyze the effect of Medium Access Control (MAC) and Physical layer characteristics on the performance of TCP...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Sep 2011

    Optimal Relay Placement for Coverage Extension in LTE-A Cellular Systems

    Third Generation Partnership Project (3GPP) Long Term Evolution-Advanced (LTE-A) has considered the deployment of Relay Nodes (RNs) for cost-effective throughput enhancement and coverage extension. The coverage extension (increase in cell radius) depends on the radial position of RNs in the cell. This is because the location of a RN affects...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Aug 2011

    On Theory of VM Placement: Anomalies in Existing Methodologies and Their Mitigation Using a Novel Vector Based Approach

    In this paper, the authors present the methodologies used in existing literature for Virtual Machine (VM) placement, load balancing and server consolidation in a data center environment. While the methodologies may seem fine on the surface, certain drawbacks and anomalies can be uncovered when they are analyzed deeper. They point...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jul 2011

    Implementation of WFQ in a Distributed Open Software Router

    There has been a considerable body of research devoted to the design and performance of PC based software routers running open source software. Most of the research on Open Software Routers (OSRs) has focused on improving the performance of single PCs with a few proposals for a distributed design. Modern...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jun 2011

    Automated Tagging to Enable Fine-Grained Browsing of Lecture Videos

    Many universities offer distance learning by recording classroom lectures and making them accessible to remote students over the Internet. A university's repository usually contains hundreds of such lecture videos. Each lecture video is typically an hour's duration and is often monolithic. It is cumbersome for students to search through an...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jun 2011

    A Self-Organized Resource Allocation Using Inter-Cell Interference Coordination (ICIC) in Relay-Assisted Cellular Networks

    In a multi-cell scenario, the Inter-Cell Interference (ICI) is detrimental in achieving the intended system performance, in particular for the edge users. There is paucity of work available in literature on ICI Coordination (ICIC) for Relay-Assisted Cellular Networks (RACN). In this paper, they do a survey on the ICIC schemes...

    Provided By Indian Institute of Technology Bombay

  • White Papers // May 2011

    An Optimized Energy Efficient Routing Algorithm for Wireless Sensor Network

    Wireless sensor network consists of thousands of individual nodes which collectively work as per application of the network. Each node made up of various parts which individually having a big research area. One of the upcoming research areas of it is its power consumption which in turn depends on energy...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Apr 2011

    Quantitative Synthesis for Concurrent Programs

    The authors present an algorithmic method for the quantitative, performance-aware synthesis of concurrent programs. The input consists of a non-deterministic partial program and of a parametric performance model. The non-determinism allows the programmer to omit which (if any) synchronization construct is used at a particular program location. The performance model,...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Apr 2011

    EMBANKS: Towards Disk Based Algorithms for Keyword-Search in Structured Databases

    In recent years, there has been a lot of interest in the field of keyword querying relational databases. A variety of systems such as DBXplorer, Discover and ObjectRank have been proposed. Another such system is BANKS, which enables data and schema browsing together with keyword-based search for relational databases. It...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Apr 2011

    Affinity-Aware Modeling of CPU Usage for Provisioning Virtualized Applications

    While virtualization-based systems become a reality, an important issue is that of virtual machine migration-enabled consolidation and dynamic resource provisioning. Mutually communicating virtual machines, as part of migration and consolidation strategies, may get co-located on the same physical machine or placed on different machines. In this paper, the authors argue...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Mar 2011

    Trapdoor one way functions associated with exponentiation

    This paper shows that if exponentiation b = Xk in groups of finite field units or B = [k]X in elliptic curves is considered as encryption of X with exponent k treated as symmetric key, then the decryption or the computation of X from b (respectively B) can be achieved...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Analyzing Fine-Grained Hypertext Features for Enhanced Crawling and Topic Distillation

    Early Web search engines closely resembled Information Retrieval (IR) systems which had matured over several decades. Around 1996 - 1999, it became clear that the spontaneous formation of hyperlink communities in the Web graph had much to offer to Web search, leading to a flurry of research on hyperlink-based ranking...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Static Program Partitioning for Embedded Processors

    Modern processors have a small on-chip local memory for instructions. Usually it is in the form of a cache but in some cases it is an addressable memory. In the paper, the user is required to partition and arrange the code such that appropriate fragments are loaded into the memory...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    WiFiRe: Rural Area Broadband Access Using the WiFi PHY and a Multisector TDD MAC

    The needs of Indian rural telecom, and the economics of currently available broadband access technologies, motivate a new system for rural broadband access, which the authors call WiFiRe (WiFi Rural Extension). The system leverages the widely available, and highly cost-reduced, WiFi chipsets. They, however, retain only the PHY from these...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Monitoring a Wireless Sensor Network

    In this paper, the authors propose two schemes to estimate the active sensor density and the residual power in a sensor network. They assume the sensor locations form a Poisson process and the communication region of each sensor is a circle with random radii, which are dependent on the available...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    A Cross Layer Congestion Control Algorithm in Wireless Networks for TCP Reno-2

    In this paper, the authors discuss a cross layer congestion control technique of TCP Reno-2 in wireless networks. In this both TCP layer and PHY layer jointly control congestion. The PHY layer changes transmission power as per the channel condition, interference received and congestion in the network, whereas the TCP...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Architecting Protocol Stack Optimizations on Mobile Devices

    Applications using traditional protocol stacks (e.g. TCP/IP) from wired networks do not function efficiently in mobile wireless scenarios. This is primarily due to the layered architecture and implementation of protocol stacks. Cross layer feedback is one of the mechanisms to improve the performance of a layered stack, in mobile wireless...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    M2MC: Middleware for Many to Many Communication Over Broadcast Networks

    M2MC is a new distributed computing middleware designed to support collaborative applications running on devices connected by broadcast networks. Examples of such networks are wireless ad hoc networks of mobile computing devices, or wired devices connected by a local area network. M2MC is useful for building a broad range of...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Entropy-Optimal Generalized Token Bucket Regulator

    The authors derive the maximum entropy of a flow (information utility) which conforms to traffic constraints imposed by a generalized token bucket regulator, by taking into account the side information present in the randomness of packet lengths. Under constraints of maximum aggregate tokens and maximum aggregate bucket depth, information utility...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Discrete Rate Scheduling for Power Efficient Transmission Over Wireless Link

    While scheduling transmissions in a wireless communications system can result in significant power savings, a realistic scheduling scheme must take into acvount practical constraints that apply to wireless transmitters. Here, the authors examine scheduling actions for power efficiency under the constraints that physical transmission may be carried out at a...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    PTC : Proxies That Transcode and Cache in Heterogeneous Web Client Environments

    Advances in computing and communication technologies have resulted in a wide variety of networked mobile devices that access data over the Internet. In this paper, the authors argue that servers by themselves may not be able to handle this diversity in client characteristics and intermediate proxies should be employed to...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    RF Energy Harvesting System From Cell Towers in 900MHz Band

    An experimental RF energy harvesting system to harvest energy from cell towers is presented in this paper. An electromagnetically-coupled square microstrip antenna is designed and fabricated for deployment in the presented system. Antenna gain of 9.1dB and bandwidth from 877 MHz to 998 MHz is achieved. A Schottky diode-based single...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    Acoustic Features for Detection of Aspirated Stops

    Aspiration is an important phonemic feature in several Indian languages. Unlike English, languages such as Marathi have lexicons in which words with different meanings differ only in the aspiration feature of the initial voiced or unvoiced stop. Thus the reliable discrimination of aspirated stops from their unaspirated counterparts is important...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    IPv6 in WiMAX Networks - Challenges for Broadband Wireless

    Broadband wireless access is one of the ways to enable widespread broadband Internet access in India. Worldwide Interoperability for Microwave Access (WiMAX) is a proven technology choice for providing broadband wireless access. An Indian operator offering broadband in India today, by default, uses an IPv4 network. However, country-wide wireless broadband...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    Exact Error Analysis for the Piecewise Linear Combiner for Decode and Forward Cooperation with Two Relays

    Exact expressions are obtained for the Bit Error Rate (BER) for coherent and non-coherent Decode and Forward (DF) cooperative systems with two relays. The Piecewise Linear (PL) combiner, a close approximation to the Maximum Likelihood (ML) detector, is employed at the receiver. BER analysis is done using a contour integral...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    On Achieving Marton's Region for Broadcast Channel Using Feedback

    The authors consider a two user Discrete Memoryless Broadcast Channel (DMBC) with perfect feedback from both the receivers. The best known achievable region for the general DMBC without feedback is known as the Marton's region, where the achievable strategy employs random coding. By effectively using the available feedback, they construct...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    On Achieving Marton's Region for Broadcast Channel Using Feedback

    The authors consider a two user Discrete Memoryless Broadcast Channel (DMBC) with perfect feedback from both the receivers. The best known achievable region for the general DMBC without feedback is known as the Marton's region, where the achievable strategy employs random coding. By effectively using the available feedback, they construct...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    Improving the Consistency of Vocal Tract Shape Estimation

    Estimation of the vocal tract shape has applications in articulatory synthesis, speech recognition, and speech-training aids. LPC based analysis can be used to obtain the vocal tract shape during speech segments produced with glottal excitation and with fixed as well as transitional tract configurations. During the stop closures of Vowel-Consonant-Vowel...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    Extensions to Orthogonal Matching Pursuit for Compressed Sensing

    Compressed Sensing (CS) provides a set of mathematical results showing that sparse signals can be exactly reconstructed from a relatively small number of random linear measurements. A particularly appealing greedy-approach to signal reconstruction from CS measurements is the so called Orthogonal Matching Pursuit (OMP). The authors propose two modifications to...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    Effective Data Association Scheme for Tracking Closely Moving Targets Using Factor Graphs

    Effectiveness of tracking closely moving targets depends on the capability to resolve the ambiguity in associating measurements-to-tracks. Joint Probabilistic Data Association (JPDA) has been shown to be very effective in tracking closely moving objects, but the approach is susceptible to track coalescence. The Factor Graph (FG) based association scheme developed...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    Azimuth-Dependent Spatialization for a Teleconference Audio Display

    This paper proposes a novel scheme for the spatial rendition of audio in a teleconferencing situation. Several researchers have examined and established that there is a substantial improvement in intelligibility by the use of spatialization in such a multitalker environment, over monaural rendition. The authors provide experimentally obtained values for...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    Proportionally Fair Resource Allocation in Multi-Rate WLANs

    Since IEEE has standardized 802.11 protocol for WLANs, significant work has been done in developing rate adaptation algorithms. Most of the rate adaptation algorithms proposed till now are heuristic, suboptimal and are competitive in nature. Even though these algorithms have advantage of implementing in distributed fashion, their throughput performance will...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Mar 2011

    Trapdoor one way functions associated with exponentiation

    This paper shows that if exponentiation b = Xk in groups of finite field units or B = [k]X in elliptic curves is considered as encryption of X with exponent k treated as symmetric key, then the decryption or the computation of X from b (respectively B) can be achieved...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Nov 2009

    Estimating Network Link Characteristics Using Packet-Pair Dispersion: A Discrete Time Queueing Theoretic View

    Packet-dispersion based measurement tools insert pairs of probe packets with a known separation into the network for transmission over a unicast path or a multicast tree. Samples of the separation between the probe pairs at the destination(s) are observed. Heuristic techniques are then used by these tools to estimate the...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Analyzing Fine-Grained Hypertext Features for Enhanced Crawling and Topic Distillation

    Early Web search engines closely resembled Information Retrieval (IR) systems which had matured over several decades. Around 1996 - 1999, it became clear that the spontaneous formation of hyperlink communities in the Web graph had much to offer to Web search, leading to a flurry of research on hyperlink-based ranking...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Static Program Partitioning for Embedded Processors

    Modern processors have a small on-chip local memory for instructions. Usually it is in the form of a cache but in some cases it is an addressable memory. In the paper, the user is required to partition and arrange the code such that appropriate fragments are loaded into the memory...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Mar 2010

    A Practical Perspective on the Design and Implementation of Enterprise Integration Solution to Improve QoS Using SAP NetWeaver Platform

    Most of the enterprise operations require information from several systems within and outside the enterprises. The past few years have seen explosive growth in direct program to program interaction for application integration, removing manual steps yielding tremendous improvements in reliability and efficiency. This paper addresses the practical approach for the...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2009

    Dynamic CPU Share Allocation and Server Consolidation in Virtualized Data Centers

    Data centers owners all over the world are facing the complex problem of reducing the cost of management without violation of SLAs. Virtualization as a technology for server consolidation is used and will continually get used since it reduces number of physical servers and hence, cost in the data center...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Apr 2011

    Affinity-Aware Modeling of CPU Usage for Provisioning Virtualized Applications

    While virtualization-based systems become a reality, an important issue is that of virtual machine migration-enabled consolidation and dynamic resource provisioning. Mutually communicating virtual machines, as part of migration and consolidation strategies, may get co-located on the same physical machine or placed on different machines. In this paper, the authors argue...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Apr 2010

    Balancing Response Time and CPU Allocation in Virtualized Data Centers Using Optimal Controllers

    The cloud computing paradigm proposes a flexible payment model, where a cloud user pays only for the amount of resources used. Thus, the cloud provider must only allocate as many resources to a user, as are to meet client performance requirements. In this paper, the authors present a control-theoretic approach...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2009

    Network Bandwidth Configuration Tool for Xen Virtual Machines

    Performance differentiation has always been a requirement in virtualized environments, especially in case where virtualization is used in high-end data center applications. In this paper, the authors present a command-line tool for network bandwidth differentiation in Xen, which is an open source solution for virtualization. Though the CPU credit scheduler...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Oct 2009

    Energy-Aware Contour Covering Using Collaborating Mobile Sensors

    Environmental sensing systems are useful in the area of disaster management where the system can provide alerts as well as remediation services in the event of a disaster such as pollutant spills. Recent advances in robotics technology have led to the development of sensors with the ability to sense, move,...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2009

    Comparative Performance of Hierarchical Fault Tolerance Protocol for Mobile Agent Systems

    A Mobile Agent (MA) is autonomous and identifiable software process that travels through a network of heterogeneous machine and act autonomously on behalf of user. Improving the survivability of MA in presence of various faults is the major issue concerns with implementation of MA. This paper presents a brief introduction...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Mar 2009

    Contour Estimation Using Collaborating Mobile Sensors

    A mobile wireless sensor network may be deployed to detect and track a large-scale physical phenomenon such as a pollutant spill in a lake. It may be called upon to provide a description of a contour characterized by an isoline of a specific concentration value. In this paper, the authors...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2010

    Optimal Relay Placement for Cellular Coverage Extension

    In this paper, the authors address the problem of optimal relay placement in cellular networks for maximum extension of coverage area. They present a novel definition of the coverage radius after the introduction of relays. Using this, they determine the optimal relay positions to maximize the coverage radius and estimate...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Nov 2010

    On Delay-Constrained Scheduling in Multi-Radio, Multi-Channel Wireless Mesh

    In this paper, the authors consider the goal of scheduling the maximum number of voice calls in a TDMA-based multi-radio, multi-channel mesh network. One of main challenges to achieve this goal is the difficulty in providing strict (packet-level) delay guarantees for voice traffic in capacity limited multi-hop wireless networks. In...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Apr 2009

    Modeling Finite Buffer Effects on TCP Traffic Over an IEEE 802.11 Infrastructure WLAN

    The network scenario is that of an infrastructure IEEE 802.11 WLAN with a single AP with which several STAtions (STAs) are associated. The AP has a finite size buffer for storing packets. In this paper, the authors consider TCP-controlled upload and download file transfers between the STAs and a server...

    Provided By Indian Institute of Technology Bombay

  • White Papers // May 2011

    An Optimized Energy Efficient Routing Algorithm for Wireless Sensor Network

    Wireless sensor network consists of thousands of individual nodes which collectively work as per application of the network. Each node made up of various parts which individually having a big research area. One of the upcoming research areas of it is its power consumption which in turn depends on energy...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    WiFiRe: Rural Area Broadband Access Using the WiFi PHY and a Multisector TDD MAC

    The needs of Indian rural telecom, and the economics of currently available broadband access technologies, motivate a new system for rural broadband access, which the authors call WiFiRe (WiFi Rural Extension). The system leverages the widely available, and highly cost-reduced, WiFi chipsets. They, however, retain only the PHY from these...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Feb 2009

    PIP: Reliable Bulk Data Transfer In Wireless Sensor Network

    The authors present PIP (Packets In Pipe), a novel solution to bulk data transfer intended for wireless sensor networks. PIP is a TDMA protocol with primary emphasis on efficiency and reliability. It strives to achieve high throughput by operating at highest degree of parallelism (in transmissions) along the path. Use...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Monitoring a Wireless Sensor Network

    In this paper, the authors propose two schemes to estimate the active sensor density and the residual power in a sensor network. They assume the sensor locations form a Poisson process and the communication region of each sensor is a circle with random radii, which are dependent on the available...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    A Cross Layer Congestion Control Algorithm in Wireless Networks for TCP Reno-2

    In this paper, the authors discuss a cross layer congestion control technique of TCP Reno-2 in wireless networks. In this both TCP layer and PHY layer jointly control congestion. The PHY layer changes transmission power as per the channel condition, interference received and congestion in the network, whereas the TCP...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2009

    A Robust Active Queue Management Algorithm for Wireless Network

    Active Queue Management (AQM) techniques play an important role in controlling congestion in Transmission Control Protocol (TCP) networks. Random Early Detection (RED) was one of the earliest AQM methods. However, RED suffers from several drawbacks like requirement of considerable effort in tuning its parameters to achieve good performance. The development...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jun 2010

    Residual White Space Distribution Based Opportunistic Channel Access Scheme for Cognitive Radio Systems

    The authors propose an opportunistic channel access scheme for cognitive radio-enabled secondary networks. In their paper, they model the channel occupancy due to Primary User (PU) activity as a 2-state Alternating Renewal Process, with alternating busy and idle periods. Once a Secondary Node (SN) senses the channel idle, the proposed...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2010

    Study Element Based Adaptation of Lecture Videos to Mobile Devices

    With devices like mobile phones and PDAs becoming pervasive especially among students, there is a demand for viewing lecture videos on such devices, to get quick access to educational content. But, being traditionally designed for desktop computers, lecture videos have high video bit-rates, due to which viewing them on low...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Architecting Protocol Stack Optimizations on Mobile Devices

    Applications using traditional protocol stacks (e.g. TCP/IP) from wired networks do not function efficiently in mobile wireless scenarios. This is primarily due to the layered architecture and implementation of protocol stacks. Cross layer feedback is one of the mechanisms to improve the performance of a layered stack, in mobile wireless...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    M2MC: Middleware for Many to Many Communication Over Broadcast Networks

    M2MC is a new distributed computing middleware designed to support collaborative applications running on devices connected by broadcast networks. Examples of such networks are wireless ad hoc networks of mobile computing devices, or wired devices connected by a local area network. M2MC is useful for building a broad range of...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2009

    Link Scheduling Algorithms for Wireless Mesh Networks

    The authors provide an overview of link scheduling algorithms in Spatial Time Division Access (STDMA) wireless mesh networks. These algorithms can be classified into three categories: those based only on a communication graph model of the network, those based on communication graph and verifying Signal to Interference and Noise Ratio...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Nov 2009

    Loss of Continuity in Cellular Networks Under Stabilizing Transmit Power Control

    Recently, passivity-based techniques to control the transmit power of mobile nodes have been proposed to ensure the finite gain stability of a class of cellular CDMA networks. These techniques implement the Zames-Falb multipliers at the mobile node and at the base stations. The finite gain stability of such a cellular...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Entropy-Optimal Generalized Token Bucket Regulator

    The authors derive the maximum entropy of a flow (information utility) which conforms to traffic constraints imposed by a generalized token bucket regulator, by taking into account the side information present in the randomness of packet lengths. Under constraints of maximum aggregate tokens and maximum aggregate bucket depth, information utility...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2011

    Discrete Rate Scheduling for Power Efficient Transmission Over Wireless Link

    While scheduling transmissions in a wireless communications system can result in significant power savings, a realistic scheduling scheme must take into acvount practical constraints that apply to wireless transmitters. Here, the authors examine scheduling actions for power efficiency under the constraints that physical transmission may be carried out at a...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Mar 2010

    Reachability of Safe State for Online Update of Concurrent Programs

    Online update helps in reducing the maintenance downtime by applying a patch to a running process. To avoid the errors that can arise due to an online update, existing online update solutions interleave the update with process execution at specific states called safe states. This approach works well for sequential...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Apr 2011

    Quantitative Synthesis for Concurrent Programs

    The authors present an algorithmic method for the quantitative, performance-aware synthesis of concurrent programs. The input consists of a non-deterministic partial program and of a parametric performance model. The non-determinism allows the programmer to omit which (if any) synchronization construct is used at a particular program location. The performance model,...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2011

    On the Usage of FDLs in Optical Parallel Transmission to Support High Speed Ethernet

    Parallel transmission in the optical layer can enable a scalable network migration from low speed interfaces to high speed serial interfaces, such as 100Gbps Ethernet, as they become available. It is based on the principle of inverse-multiplexing which distributes high speed data stream into multiple low rate optical paths. The...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Sep 2010

    Delay Contained: Scheduling Voice Over Multi-Hop Multi-Channel Wireless Mesh Networks

    In this paper, the authors consider the goal of scheduling the maximum number of voice calls in a TDMA-based multi-radio, multi-channel mesh network. One of main challenges to achieve this goal is the difficulty in providing strict (packet-level) delay guarantees for voice traffic in capacity limited multi-hop wireless networks. In...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jul 2009

    Feedback Based Distributed Admission Control in 802.11 WLANs

    A distributed Connection Admission Control (CAC) scheme where stations independently admit or reject flows based on channel utilization threshold is easy to implement for WLANs. However, owing to variable protocol capacity, the advisable threshold also is variable, limiting the efficacy of fixed threshold based CAC. If the admission threshold is...

    Provided By Indian Institute of Technology Bombay

  • White Papers // May 2009

    Adaptive Admission Control for Web Applications With Variable Capacity

    The system capacity available to a multi-tier Web based application is often a dynamic quantity. Most static threshold-based overload control mechanisms are best suited to situations where the system's capacity is constant or the bottleneck resource is known. However, with varying capacity, the admission control mechanism needs to adapt dynamically....

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jun 2011

    Automated Tagging to Enable Fine-Grained Browsing of Lecture Videos

    Many universities offer distance learning by recording classroom lectures and making them accessible to remote students over the Internet. A university's repository usually contains hundreds of such lecture videos. Each lecture video is typically an hour's duration and is often monolithic. It is cumbersome for students to search through an...

    Provided By Indian Institute of Technology Bombay

  • White Papers // May 2012

    On Throughput Performance of Decode and Forward Cooperative Relaying With Packet Combining and ARQ

    Cooperative Diversity can be used by wireless nodes to take the benefit of broadcast nature and inherent spatial diversity of wireless channel to relay messages for each others. This helps to propagate redundant signals over multiple paths, which can be used to combat the channel noise and fading effects. The...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Oct 2012

    Analysis of Blocking Probability in a Relay-Based Cellular OFDMA Network

    Relay deployment in Orthogonal Frequency Division Multiple Access (OFDMA) based cellular networks helps in coverage extension and/or capacity improvement. In OFDMA system, each user requires different number of subcarriers to meet its rate requirement. This resource requirement depends on the Signal to Interference Ratio (SIR) experienced by a user. Traditional...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2012

    Real Slepian-Wolf Codes

    The authors provide a novel achievability proof of the Slepian-Wolf theorem for i.i.d. sources over finite alphabets. They demonstrate that random codes that are linear over the real field achieve the classical Slepian-Wolf rate region. For finite alphabets they show that decoding is equivalent to solving an integer program. The...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Mar 2012

    Buffer-Based Channel Dependent Uplink Scheduling in Relay-Assisted LTE Networks

    The authors consider the problem of UpLink (UL) scheduling in relay-assisted Long Term Evolution (LTE) networks and propose a Buffer-based Channel dependent Scheduler (BCS) for the same. Their objectives are to minimize packet loss due to buffer overflow and increase resource utilization efficiency while ensuring fairness among users. This is...

    Provided By Indian Institute of Technology Bombay