Sushanta Karmakar

Indian Institute of Technology Guwahati, Gauhāti, Assam, India

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Publications (27)9.53 Total impact

  • Sandip Chakraborty · Sukumar Nandi · Sushanta Karmakar
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    ABSTRACT: Sensor network deployed for the critical infrastructure monitoring requires high degree of reliability in sensory data gathering, in spite of arbitrary node or sink failures. This paper proposes a robust data gathering scheme specially designed to provide guaranteed delivery of the sensory data for applications on the critical infrastructure monitoring. Redundancy in a sensor network, in terms of both the number of deployed sensors and the amount of duplicate data delivery, is explored to design an effective protocol that ensures the reliable data delivery while assuring the timeliness, connectivity and the sensing coverage. A set of active sensors is selected from all the sensors deployed, based on the network connectivity and the sensing coverage criteria that participates in the data forwarding process. Rest of the sensors go to the sleep state, and act as a replacement on the failure of an active sensor. The proposed protocol aims to find out multiple node-disjoint paths to multiple sinks, so that the loss of connectivity in one path due to node failure does not disrupt application services. The effectiveness of the proposed scheme has been analyzed using simulation results, and compared with other protocols proposed in the literature for reliable data delivery.
    No preview · Article · Nov 2015 · Journal of Network and Computer Applications
  • S Chakraborty · S Nandi · S Karmakar
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    ABSTRACT: The lifetime of a sensor network is influenced by the efficient utilization of the resource constrained sensor nodes. The tree-based data gathering offers good quality of service (QoS) for the running applications. However, data gathering at the sink reduces the network lifetime due to a fast failure of highly loaded nodes. Loss of connectivity and sensing coverage affect the performance of the applications that demand critical QoS. In this paper, a data gathering tree management scheme has been proposed to deal with arbitrary node failures in delay-sensitive sensor networks. A load-balanced distributed BFS tree construction procedure has been introduced for an efficient data gathering. Based on the initial tree construction, a tree maintenance scheme and an application message handler have been designed to ensure the reliable delivery of the application messages. The correctness of the proposed scheme has been verified both theoretically and with the help of simulation. The proposed scheme offers low overhead, enhanced network lifetime and good QoS in terms of delay and reliability of the application messages.
    No preview · Article · Dec 2014 · International Journal of Wireless Information Networks
  • Sandip Chakraborty · Ramesh Singh · Sushanta Karmakar
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    ABSTRACT: Distributed systems such as the peer-to-peer and the content management systems have to deal with large volume of data stored in several participating nodes. In a distributed environment, concurrent node joins and node leaves impose new design challenges to effectively manage the structure of the system. Deterministic 1–2 skip list is an efficient structure to manage the topology of an overlay network. However, the existing works on distributed deterministic 1–2 skip list [(S. Mandal, S. Chakraborty, and S. Karmakar, Deterministic 1–2 skip list in distributed system. in Proceedings of the 2nd IEEE International Conference on Parallel Distributed and Grid Computing, IEEE, 2012, pp. 296–301.)] in a decentralised environment do not support concurrency, where multiple parallel join and leave operations may be executed simultaneously. This paper presents a set of algorithms for achieving concurrency in a distributed deterministic 1–2 skip list. The properties and the correctness of the proposed algorithms are analysed theoretically. The proposed set of distributed algorithms for search, join and leave operations has message complexity similar to the centralised versions of the algorithms.
    No preview · Article · Oct 2014 · International Journal of Parallel Emergent and Distributed Systems
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    ABSTRACT: Sink based spanning tree topologies are effectively used in convergecast applications for efficient packet delivery with minimum forwarding delay, eliminating packet loss or duplicate packet delivery. For tree based convergecast, this paper theoretically shows that there is a trade-off between the topology architecture and the network traffic load. Depending on this trade-off, a hierarchical topology adaptation scheme is proposed for the tree based convergecast to improve overall application performances. The effectiveness of the proposed scheme is analyzed using simulation results.
    No preview · Conference Paper · Mar 2014
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    ABSTRACT: Wireless sensor networks have grown significant attentions among researchers for providing a flexible and low-cost framework to design an architecture for Intelligent Transport Systems. The inherent challenges in distribution and management of sensor networks along the road require an application-specific protocol support for the network connectivity, the sensing coverage, the reliable data forwarding, and the network lifetime improvement. This paper introduces the concept of $k$-strip length coverage along the road, which ensures a better sensing coverage for the detection of moving vehicles compared with the conventional barrier coverage and full area coverage, in terms of the availability of sufficient information for statistical processing and the number of sensors required to be active. To extend the network lifetime, every sensor follows a sleep–wakeup schedule maintaining the network connectivity and the $k$-strip length coverage. This scheduling problem is modeled as a graph optimization, the NP-hardness of which motivates to design a centralized heuristic, providing an approximate solution. As a sensor network is inherently distributed in nature, properties of the centralized heuristic are explored to design a per-node solution based on local information. Performance of the proposed scheme is analyzed through simulation results.
    No preview · Article · Mar 2014 · IEEE Transactions on Intelligent Transportation Systems
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    Sushanta Karmakar · Subhrendu Chattopadhyay
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    ABSTRACT: Consider a distributed system with n processors, which receive triggers from the outside world. The Distributed Trigger Counting (DTC) problem is to raise an alarm if the number of triggers over the sys- tem reaches w, which is an user specified input. DTC is used as a primitive operation in many applications, such as distributed monitoring, global snapshot etc. In this paper, we propose an algorithm for the DTC problem in a ring topology with a message complexity of O(n2 log(w/n)) and each node in the system receives O(n log(w/n)) number of messages. We also discuss about the possible tuning of the algorithm which results better complexities.
    Full-text · Conference Paper · Jan 2014
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    ABSTRACT: The efficiency and reliability of convergecast in sensor network depends on the correct and efficient accumulation of data to the sink. A tree, rooted at the sink, that utilizes sensor resources properly is an ideal topology for data gathering. Resource constrained sensor nodes are highly prone to sudden crash. So the application demands a quick and efficient repairing of the tree when a node dies. The proposed scheme builds a data gathering tree rooted at the sink. The tree eventually becomes a Breadth First Search (BFS) tree where each node maintains the shortest hop-count to the root to reduce the routing delay. Each node collects some extra neighborhood information during the tree construction. Thus a little pre-processing at each node helps in taking prompt actions to repair the tree through local adjustment if any arbitrary single or multiple nodes fail in future. On failure of a node, each affected node in its vicinity fixes the parent through a pair of control message transmissions. Simulation results show that the repairing delay is significantly less in average and the convergecast messages are delivered with minimum data loss and no redundancy even in presence of node crash.
    No preview · Article · Aug 2013 · Ad Hoc Networks
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    ABSTRACT: Sensor networks deployed for the border area monitoring requires a high degree of reliability for the data gathering in spite of any arbitrary node or sink failures. This paper proposes RelBAS, a robust data gathering scheme specially designed for the border area network to provide a guaranteed delivery of sensory data. The proposed protocol aims to find out multiple node-disjoint paths to multiple sinks so that the disconnectivity in one path due to a node failure does not disrupt the delivery of data to the sink. The forwarding path selection at every node in RelBAS is based on the combination of three parameters - the hop-count, the residual energy and the number of children for for parent of the corresponding tree. This helps in adapting the protocol to the application requirement depending on the delay, energy efficiency and data aggregation. Moreover, RelBAS is capable of detecting an affected zone due to multiple node failures. The effectiveness of the proposed scheme has been analyzed using the simulation results.
    No preview · Conference Paper · Jul 2013
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    ABSTRACT: The lifetime of sensor network depends on the efficient utilization of resource-constrained sensor nodes. Several MAC protocols like DMAC and its variants have been proposed to save critical sensor resources through sleep-wakeup scheduling over data gathering tree. For applications where data aggregation is not possible, the sleep duration decreases gradually from the leaves to the root of the data gathering tree. This results early failure of sensor nodes near the sink, and affects network connectivity and coverage. Deploying redundant sensors can solve this problem where a faulty node is replaced by a redundant node to maintain network connectivity and coverage. However, the amount of redundancy depends on the node failure pattern, and thus more number of redundant nodes required to be deployed near the sink. This paper proposes a gradient based sensor deployment scheme for energy-efficient data gathering exploring the trade-off among connectivity, coverage, fault-tolerance and redundancy. The density of deployment is estimated based on the distance of a node from the sink while dealing with connectivity, coverage and fault-tolerance. The effectiveness of the proposed scheme has been analyzed both theoretically and with the help of simulation.
    No preview · Conference Paper · Jul 2013
  • Sushanta Karmakar · A. Chandrakanth Reddy
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    ABSTRACT: Consider a distributed system with n processors, which receive triggers from the outside world. The distributed trigger counting (DTC) problem is to raise an alarm if the total number of triggers over the system reaches w, which is an user-specified input. DTC is used as a primitive operation in many applications, such as distributed monitoring, global snapshots, etc. Many of the earlier studies on DTC was done using non-deterministic algorithms. In this paper, we propose a deterministic algorithm for the DTC problem with a message complexity of O(n log w log n) and each node in the system receives O(n log w) number of messages, which is an improvement over earlier result for certain values of w. The distribution of triggers among the n nodes may be arbitrary. This paper gives insight into the deterministic algorithm for the DTC problem. Also to the best of our knowledge the overall message complexity and per node message complexity are better than earlier deterministic algorithms.
    No preview · Article · Jun 2013 · The Computer Journal
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    ABSTRACT: Data gathering or converge cast is one of the most popular applications of road side sensor network where the data sensed from the road are accumulated in the road side gateways or sinks for traffic monitoring purpose. The required delay sensitivity and reliability of the application as well as the scarcity of sensor resources make the task challenging. In this paper, a novel tree based data gathering scheme has been proposed exploiting the strip like structure of the road network. Sensor nodes are distributed in several virtual blocks along the road and a converge cast tree is constructed selecting one active node from each block. Implementation of efficient scheduling assures both the coverage and critical power savings of sensor nodes. The network connectivity is guaranteed throughout by the proposed tree maintenance module that handles the sensor node joining and leaving events. Simulation results show that the tree maintenance overhead in terms of both delay and control message communication is nominal.
    No preview · Conference Paper · Mar 2013
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    ABSTRACT: The changes in environmental parameters may demand switching between underlying topologies for better performance of distributed message passing applications. Arbitrary topology switching using distributed tree construction may lead to loss or redundancy in delivery of application messages. In this work, a set of algorithms has been proposed for dynamic switching between two spanning trees to offer better adaptivity towards the environment for different applications. Here, two extreme cases of spanning trees, a Breadth First Search (BFS) tree and a Depth First Search (DFS) tree, rooted at the core node, have been considered for switching. The core node initiates the switching and all other nodes cooperatively change their parents on the fly maintaining the DFS or BFS properties as required. However, the application remains transparent to the switching that assures the availability of the system at any instance of time. Simulation results show that each application message is delivered correctly to the destination without any loss or redundancy. The proposed scheme is scalable and the control message overhead for switching is linear with respect to the number of edges in the communication graph. Furthermore, there is no control message overhead to assure the delivery of application messages at the time of switching.
    No preview · Article · Jan 2013 · Journal of Network and Systems Management
  • Subhrangsu Mondal · Sandip Chakraborty · Sushanta Karmakar
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    ABSTRACT: Data management in the peer-to-peer system is a challenging task due to the random distribution of data among several participating peers. Efficient data structures like distributed hash tables (DHT) and its variants are designed and implemented to reduce the complexity of data management in such environment. However, DHT has its limitations in supporting range queries and its variants like distributed segment trees often perform poorly when the number of peers is high. Further, distributed lists and distributed balanced trees require significant amount of time for stabilizing after a new peer joins or a peer leaves. In this paper, a new distributed data structure called deterministic 1–2 skip list is introduced as an alternate solution for data management in the peer-to-peer systems. A deterministic skip list can be viewed as an alternate of a balanced tree, where the semantic locality of each key is preserved. Thus it can support the range queries as well as the single shot queries. This paper proposes three main operations on this data structure - searching data based on keys, insertion when a new peer joins, and deletion when a peer leaves. The correctness of the proposed operations are analyzed using theoretical arguments and mathematical proofs. The proposed scheme is simulated using NS-2.34 network simulator, and the efficiency of the scheme has been compared with DHT, DST, distributed list and distributed tree based data management.
    No preview · Article · Jan 2013 · Peer-to-Peer Networking and Applications
  • Subhrangsu Mandal · Sandip Chakraborty · Sushanta Karmakar
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    ABSTRACT: Searching data efficiently in distributed applications like peer-to-peer system is a challenging task due to the random distribution of data among several participating nodes. Efficient data structures are designed and implemented to reduce the complexity of data searching in such an environment. In this paper a data structure called deterministic 1-2 skip list has been proposed as a solution for search problems in distributed environment. The data structure has three main operations viz. search, insert, and delete. The detailed description of the insertion, deletion and search operations are given in this paper. It is found that the message complexity of the insertion, deletion and search algorithm is O(log n) where n is the total number of nodes in the skip-list.
    No preview · Conference Paper · Dec 2012
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    ABSTRACT: Event driven data gathering or convergecast through sensor nodes requires efficient and correct delivery of data at the sink. A tree rooted at the sink is an ideal topology for data gathering which utilizes sensor resources properly. Resource constrained sensor nodes are highly prone to sudden crash. A set of algorithms, proposed in this paper, builds a data gathering tree rooted at the sink. The tree eventually becomes a Breadth First Search(BFS) tree where each node maintains the shortest distance in hop-count to the root to reduce the routing delay and power consumption. The data gathering tree is repaired locally within a constant round of message transmissions after any random node fails. Simulation result shows that the repairing delay is very less in average, and the proposed scheme can repair from arbitrary node failure using constant number of message passing.
    No preview · Conference Paper · Apr 2012
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    ABSTRACT: A reliable broadcast demands that each data packet forwarded from the source node is received by all other nodes in the network without any loss. A flooding based Broadcast scheme incurs significant overhead due to explosion of packets in the network. So an efficient way of routing packets in order to broadcast saves the energy of resource constrained sensor nodes. The delivery of broadcast packets at each node in correct sequence is also crucial for certain applications. In this paper a tree based broadcast mechanism is proposed that constructs a spanning tree out of all nodes in the network rooted at the source of the broadcast. The broadcast tree eventually becomes a Breadth-First Search(BFS) tree where each node maintains the shortest path to the root. So packets routed through the shortest paths reduce transmission delay and packet loss. BFS tree based broadcast saves the battery power at each node by reducing the number of packet transmissions. The proposed scheme for broadcast is also crash tolerant. Each node computes a maintenance plan during the broadcast tree construction for future requirement. If a node dies, all the nodes in neighborhood repairs the tree locally within constant round of message transmissions. Each broadcast packet is assured to be delivered at each node without redundancy and maintaining the correct order.
    No preview · Conference Paper · Sep 2011
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    ABSTRACT: Query driven Broadcast through wireless sensor nodes also leads to the domain of event driven converge cast. A query-response based application in Wireless Sensor Networks(WSN) demands the correct delivery of data message at each sensor node. A Breadth-First Search(BFS) tree rooted at the base station offers shortest path traversal for each data message which utilizes the sensor resources efficiently. Resource constrained sensor nodes are highly prone to sudden crash. So the application demands a quick and smart approach to repair the tree when a node dies. In this paper a novel scheme has been proposed to locally repair the tree with constant round of message transmissions. Each node piggybacks a few bytes of extra information along with each query and response messages. Based on these piggybacked values each node calculates its alternate parent. When a parent node fails, its children can contact their respective alternate parents immediately to establish an alternate path to the root. Reduced communication cost in terms of extra message transmissions saves battery power at each node. Efficient query-response message handler ensures the correct delivery of messages. Fast repairing offers good Quality of Service(QoS). Simulation result shows that no message is lost except the one holding by the crashed node.
    No preview · Conference Paper · Aug 2011
  • Suchetana Chakraborty · Sushanta Karmakar
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    ABSTRACT: A convergecast is a process in which all the sensor nodes sense data and fuse them to forward to a base station. A correct data gathering requires that there is no data loss or delivery of redundant data. Nodes can form a spanning tree rooted at the sink to perform the convergecast. Leaves of the tree can sense and forward data independently. But for any internal node data can be forwarded to its parent only after receiving data from all its children. It has been observed that a Breadth-First-Search (BFS) tree is a better choice for convergecast under low system load because the depth of any node from the root is always minimum; whereas under higher system load condition a Depth-First-Search (DFS) tree may be a better option as the degree of any node in a DFS tree is lower than that in a BFS tree. Hence per node load is lower in case of a DFS tree than that of a BFS tree. So to meet the requirement of load based adaptation, a dynamic tree switching algorithm has been proposed in this paper. The convergecast application remains transparent of the switching assuring the availability of the system at any instance of time. Also each convergecast message is assured to be delivered correctly to the base station without any loss or redundancy.
    No preview · Conference Paper · Jul 2011
  • Shivendra Katiyar · Sushanta Karmakar
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    ABSTRACT: Termination detection in distributed systems has been a popular problem of study. It involves d e t e r m i n i n g whether a computation running on multiple nodes has ceased all i t s a c t i v i t i e s . A l a r g e number of ter m ination detection algorithms have been proposed with different computational models and methodologies. Here, termination detection is being investigated i n t h e c o n t e x t o f l i n k -failure m o d e l which i s common in Delay Tolerant Networks. A spanning tree based termination detection algorithm is used to suit such a model. Termination detection is freezed locally until the spanning tree is restored, rather than restarting it from the scratch again.
    No preview · Article · Jan 2011
  • Shivendra Katiyar · Sushanta Karmakar
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    ABSTRACT: Termination detection in distributed systems has been a popular problem of study. It involves determining whether a computation running on multiple nodes has ceased all its activities. A large number of termination detection algorithms have been proposed with different computational models and methodologies. Here, termination detection is being investigated in the context of link-failure model which is common in Delay Tolerant Networks. A spanning tree based termination detection algorithm is used to suit such a model. Termination detection is freezed locally until the spanning tree is restored, rather than restarting it from the scratch again. Keywords-Termina tion detection, spanning tree, delay toler­ ant networks, link failure.
    No preview · Article · Jan 2011