Indian Institute of Technology Bombay

Displaying 1-40 of 104 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

    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

    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

    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

    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 // 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 // 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 // Jan 2010

    On the Bounds of Separability in Sensor Networks

    A pair of target locations is separable if sensor observations can distinguish between the following choices: no targets are present, one target is present at either of the locations or a target is present at each location. The sensors of interest in this paper are binary proximity sensors, whose binary...

    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 // 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 // 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

    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 // 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

    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 2009

    Performance Analysis of Active Handoff in CDMA2000 Femtocells

    Cellular operators are developing femtocells to improve network coverage for indoor users. But in current CDMA systems, heavy reuse of PN codes among femtocells causes ambiguity in choosing the target for handoff. To resolve the ambiguity, a method which uses Reverse Link (RL) sensing at femtocells has been proposed. This...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2009

    A Class of Time-Frequency Product Optimized Biorthogonal Wavelet Filter Banks

    The analysis of non-stationary signals involves a trade-off in the sense that one has to sacrifice time localization in order to achieve better frequency localization and vice versa. If the authors assume that the function is normalized, the uncertainty principle states that the product of the time-spread (defined in the...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2009

    Coding Gain Optimized Finite Impulse Response(FIR) Paraunitary(PU) Filter Banks

    Filter bank optimization for coding gain maximization for given input statistics has been well studied before. Principal Component Filter Banks (PCFB) have proven to be optimal whenever the minimization objective is a concave function of the subband variances produced by the filter bank. However PCFBs are known to exist for...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2009

    Trajectory and surface modeling of LSF for low rate speech coding

    In low rate speech coders, frame-based speech spectral parameters, represented by Line Spectral Frequencies (LSF), are typically encoded by vector quantization without exploiting explicitly the temporal correlation between frames. Recently, however, methods have been proposed that model the temporal trajectory of each LSF over a speech segment by a low-order...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Dec 2009

    Broadband Reactively Coupled E-Shaped Microstrip Antennas

    The broadband microstrip antennas are realized by cutting the resonant slots of quarter wave in length on the edges of the patch or half wave in length inside the patch. The broadband E-shaped microstrip antenna is realized by cutting the pair of nearly quarter wavelength slots on one of the...

    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 // Sep 2009

    Robust Active Queue Management for Wireless Networks

    Active Queue Management (AQM) algorithms have been extensively studied in the literature in the context of wired networks. In this paper, the authors study AQM for wireless networks. Unlike wired link which is assumed to have a fixed capacity, a wireless link has a capacity that is time varying due...

    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 // 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 // Nov 2010

    Downlink Erlang Capacity of Cellular OFDMA

    In this paper, the authors present a novel approach to evaluate the downlink Erlang capacity of a cellular Orthogonal Frequency Division Multiple Access (OFDMA) system with 1:1 frequency reuse. Erlang capacity analysis of traditional cellular systems like Global System for Mobile communications (GSM) cannot be applied to cellular OFDMA because...

    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 // Oct 2009

    Social Network Analysis of the Short Message Service

    In this paper, the authors analyze patterns in the Short Message Service (SMS) behavior of customers in a large telecom service provider network. Toward this, they construct SMS Graphs, which are graphs induced by people exchanging SMSs, from the SMS Call Detail Records of the concerned service provider. These patterns...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jul 2009

    Diversity Combining and Packet Size Adaptation for Maximizing Throughput of ARQ Protocols in AWGN and Fading Channel

    Multi-hop wireless network based on IEEE 802.11 Wi-Fi technology has emerged as a cost effective solution for accessing cellular networks or the Internet from the remote rural areas of the developing countries. Such access networks, typically, have long distance links that span tens of kilometers. Because of the long distance...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Nov 2008

    Scheduling With Limited Information in Wireless Systems

    Opportunistic scheduling is a key mechanism for improving the performance of wireless systems. However, this mechanism requires that transmitters are aware of channel conditions (or CSI, Channel State Information) to the various possible receivers. CSI is not automatically available at the transmitters, rather it has to be acquired. Acquiring CSI...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Feb 2009

    Power Optimal Signaling for Fading Multi-Access Channel in Presence of Coding Gap

    The authors consider a Gaussian multi-access fading channel with perfect Channel Side Information (CSI) at the transmitters and the receiver. This models many important practical systems including the uplink of wireless LANs and the cellular systems. In a multi-access fading channel, dynamic allocation of bandwidth, transmission power and rates is...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Sep 2008

    SQ-AODV: A Novel Energy-Aware Stability-Based Routing Protocol for Enhanced QoS in Wireless Ad-Hoc Networks

    The authors propose a novel, energy-aware, routing protocol for Quality-of-Service (QoS) support in an infrastructure-less ad-hoc network. Their Stability-based, QoS-capable Ad-hoc On-demand Distance Vector (SQ-AODV) protocol is an enhancement of the well-known Ad-hoc On-demand Distance Vector (AODV) protocol. Their protocol utilizes a cross-layer approach, in which information about residual node...

    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 // Jul 2008

    Censor Networks: A Critique of "Sensor Networks" From a Systems Perspective

    This paper presents a critique of the field of "Wireless Sensor Networks (WSNs)". Literature in this domain falls into two main, distinct categories: algorithms or protocols, and application-centric system design. A striking observation is that references across these two categories are minimal and superficial at best. The authors argue that...

    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 // 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 // May 2009

    A Novel Remote User Authentication Scheme Using Bilinear Pairings

    Password authentication is an important technique to verify the legitimacy of a user. The technique is regarded as one of the most convenient methods for remote user authentication. The paper presents a remote user authentication scheme using the properties of bilinear pairings. In the scheme, the remote system receives user...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2009

    End-to-End QoS Over Internet

    The problem of end-to-end Quality of Service (QoS) over internet can be split into two parts: The first part is to develop framework for information exchange, signaling, path selection and setup spanning across multiple Autonomous Systems (ASes). The second part is to find an optimal inter-domain path based on specific...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2009

    RFIDPlanner - A Coverage Planning Tool for RFID Networks

    Radio Frequency Identification or RFID systems are emerging as economical solutions for fast identification of objects. One of the important aspects of setting up a RFID network is deploying RFID readers to ensure complete coverage of RFID tags in a given area. This task is usually accomplished by conducting site...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Jan 2009

    On TCP Aware Uplink Scheduling in WiMAX Networks

    This paper proposes polling based scheduling algorithms for TCP based applications in multipoint-to-point WiMAX networks. The first proposed scheduling algorithm uses TCP Congestion Window (cwnd) size, whereas the second one uses cwnd size and TCP timeouts to allocate time slots among the contending TCP flows. The authors ensure fairness among...

    Provided By Indian Institute of Technology Bombay

  • White Papers // Aug 2008

    TDMA Scheduling in Long-Distance WiFi Networks

    In the last few years, long-distance WiFi networks have been used to provide Internet connectivity in rural areas. The strong requirement to support real-time applications in these settings leads one to consider TDMA link scheduling. Such scheduling takes on a different flavour in long-distance mesh networks due to the unique...

    Provided By Indian Institute of Technology Bombay