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arXiv 2020年

作者： Das, Nayana Majumdar, Ritajit Applied Statistics Unit Indian Statistical Institute India Advanced Computing & Microelectronics Unit Indian Statistical Institute India

The first two party Quantum Key Agreement (QKA) protocol, based on quantum teleportation, was proposed by Zhou et al. (Electronics Letters 40.18 (2004): 1149-1150). In this protocol, to obtain the key bit string, one of the parties use a device to obtain inner product of two quantum states, one being unknown, and the other one performs Bell measurement. However, in this article, we show that it is not possible to obtain a device that would output the inner product of two qubits even when only one of the qubit is unknown. This is so because existence of such device would imply perfectly distinguishing among four different states in a two-dimensional vector space. This is not permissible in quantum mechanics. Furthermore, we argue that existence of such a device would also imply violation of the "No Signalling Theorem" as well. Finally, we also comment that this protocol is not a valid key agreement protocol at all. Copyright © 2020, The Authors. All rights reserved.

关键词： Vector spaces

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Analyzing the Effect of Soft Handover on WLAN Usage Efficiency under Load Condition

Analyzing the Effect of Soft Handover on WLAN Usage Efficien...

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IEEE International Symposium on Network computing and Applications

作者： Nitish K. Panigrahy Sasthi C. Ghosh Advanced Computing & Microelectronics Unit Indian Statistical Institute Kolkata India

ISBN: (纸本)9781509018505

With increasing popularity of wireless local area network (WLAN) and emerging real time applications, seamless mobility has become one of the primary concerns. Hence the choice of a proper handoff algorithm is of utmost importance. Previous work suggests that WLAN usage efficiency can act as a good metric to measure the performance of a handoff algorithm. We argue that in a multiple AP scenario, the load on each of the APs, the requested data rate of the mobile terminal (MT) and the soft handover have a significant impact on the usage efficiency. In this paper we present an analytical framework to measure the usage efficiency under both load condition and soft handover for a specific data rate request. Our approach is based on finding the circular region centered around an AP within which the requested data rate can be satisfied. The usage efficiency is then computed based on finding the union of all such circular regions.

关键词： Wireless LAN Handover Throughput Load modeling Mathematical model Measurement

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Energy Efficient Resource Allocation for D2D Communications using Reinforcement Learning

Energy Efficient Resource Allocation for D2D Communications ...

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Conference on Local Computer Networks (LCN)

作者： Rathindra Nath Dutta Sasthi C. Ghosh Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata India

The millimeter-wave (mmWave) device-to-device (D2D) communication is already being employed to satisfy the high datarate demand of the internet-of-things nodes. Using mmWave signals has its own challenges as it suffers from high penetration losses. Therefore, presence of dynamic obstacles further complicates the already hard problem of allocation of channel resources to the demanding nodes. In this work, we have proposed a reinforcement learning (RL) based framework to jointly allocate the frequency channels as well as assign the transmit-powers to the demanding D2D pairs in order to maximize the energy-efficiency in presence of dynamic obstacles. We justify our choice of reward function through a formal proof and also ensure the convergence of the algorithm. Through extensive simulations, we show that our proposed RL framework not only converges, but also outperforms an existing approach.

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A predictive handoff mechanism for 5G ultra dense networks

A predictive handoff mechanism for 5G ultra dense networks

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IEEE International Symposium on Network computing and Applications

作者： Shankar K. Ghosh Sasthi C. Ghosh Advanced Computing & Microelectronics Unit Indian Statistical Institute Kolkata India

The fifth generation (5G) ultra dense network (UDN) is envisioned as a very dense deployment of low power base stations where heterogeneous radio access technologies are used to satisfy the data rate demand of users employing both licensed and unlicensed spectrum. In UDN scenario, conditions of the channels operating in licensed band may exhibit intermittent characteristics due to the varying level of interference received from large number of nearby access networks. On the other hand, channel conditions in unlicensed band may fluctuate drastically due to the interference caused by the co-existence of long term evolution (LTE-U) and wireless local area network (WLAN) in unlicensed band. The traditional handover mechanisms rely on the instantaneous assessments of link qualities such as RSS and SINR. The target network selected based on such instantaneous values may not be the appropriate one when the actual handover is executed. In this work, we have proposed a predictive handover mechanism which can estimate achievable throughput values from different candidate access networks after handoff execution. Simulation results confirm that our proposed predictive handover mechanism significantly outperforms an existing reference base station efficiency based approach.

关键词： Interference Handover Wireless LAN Throughput Long Term Evolution Logic gates

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An Energy Efficient Component Carrier Selection Mechanism for LTE-NR Dual Connectivity

An Energy Efficient Component Carrier Selection Mechanism fo...

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IEEE International Symposium on Network computing and Applications

作者： Shankar K. Ghosh Sasthi C. Ghosh Advanced Computing & Microelectronics Unit Indian Statistical Institute Kolkata India

ISBN: (纸本)9781665495516

In recent past, a new dual connectivity (DC) mechanism has been standardized to deal with two different radio access technologies, namely long term evolution advanced (LTE-A) and new radio (NR). The DC mechanism calls for a higher number of component carrier (CC) allocation which in turn causes increased power consumption. Moreover, to maximize the gain in DC mode, throughput received from the serving base stations need to be nearly equal. The existing CC allocation mechanisms do not take care of these facts. In this work, we first formulate the CC selection problem for LTE-NR DC as an integer linear program (ILP) which accounts load balancing across the serving BSs while minimizing CC allocation. The considered CC selection problem has also been shown to be NP hard. Due to such characteristics, we propose a suboptimal greedy algorithm to solve the CC selection problem. Simulation results confirm that our proposed algorithm outperforms the existing CC selection algorithms.

关键词： Greedy algorithms Power demand Simulation Performance gain Throughput Load management Energy efficiency

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Performance analysis of dynamic location updation strategies for mobile users

Performance analysis of dynamic location updation strategies...

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International Conference on Distributed computing Systems

作者： A. Bera N. Das Advanced Computing and Microelectronics Unit Indian Statistical Institute Calcutta India

This paper focuses on the important issue of strategies for tracking users in a mobile communication network. Since the users are mobile, the network must keep track of where the users are, a prerequisite for routing calls to the users. We assume that the mobile users periodically inform the network of their present location. Now, it is very important to decide an efficient location updation strategy that will optimize the overhead in terms of usage of radio spectrum and power, as well as the search cost for a mobile when a call is to be set up. Static location updation strategies often result in poor performance. Three dynamic location updation strategies have been considered, namely, the time-based strategy, the movement-based strategy and the distance-based strategy. A memoryless movement pattern on a two-dimensional mesh topology of cells has been studied. Analytical models have been developed to compare the performance of the strategies. Simulation studies also have been made for performance evaluation.

关键词： Performance analysis Personal communication networks Cellular networks Databases Mobile computing Computer networks microelectronics Mobile communication Routing Cost function

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Relay Selection in Millimeter Wave D2D Communications Through Obstacle Learning

Relay Selection in Millimeter Wave D2D Communications Throug...

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International Communication Systems and Networks and Workshops, COMSNETS

作者： Subhojit Sarkar Sasthi C. Ghosh Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata India

ISBN: (数字)9781728131870

ISBN: (纸本)9781728131887

There has been growing interest in device to device (D2D) millimeterwave (mmwave) communication, due to the promising high speeds and immense amounts of unused bandwidth available. However, mmwaves suffer from unusually high attenuation, through free space, and especially through obstacles. The accepted way to avoid such attenuation is to break up the transmission path into multiple short hops, such that there are no obstacles between nodes. We extend the possibility of using a global positioning system (GPS) based, location aware, centralized approach to the problem of relay selection. Satellite imagery can be used to avoid static obstacles in the transmission path. However, satellite imagery cannot acquire smaller obstacles ones like bushes, trees and signboards. Moreover, depending on the size of the obstacle with respect to the heights of the mmwave base station (BS) and an user equipment (UE), presence of an obstacle does not guarantee obstruction. We propose a simple learning based approach to detect the presence of static as well as dynamic obstacles, without resorting to satellite imagery. We then use this knowledge to efficiently select an appropriate relay for a UE, lowering the chance of allocating an obstacle prone link. Finally we compare our relay selection algorithm with an existing algorithm and show that there is a significant improvement in the quality of link allocation.

关键词： Relays Long Term Evolution Global Positioning System Satellites Interference Attenuation Millimeter wave communication

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Network-Assisted D2D Relay Selection Under the Presence of Dynamic Obstacles

Network-Assisted D2D Relay Selection Under the Presence of D...

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Conference on Local Computer Networks (LCN)

作者： Durgesh Singh Sasthi C. Ghosh Advanced Computing & Microelectronics Unit Indian Statistical Institute Kolkata India

Millimeter wave (mmWave) channels in device to device (D2D) communication are susceptible to blockages in spite of using directional beams from multi-input multi-output (MIMO) antennas to compensate for high propagation loss. This motivates one to look for the presence of obstacles while forming D2D links among user equipments (UEs) which are in motion. In D2D communication, moving UEs also act as relays to forward data from one UE to another which introduces the problem of relay selection. The problem becomes more challenging when the obstacles are also in motion (dynamic obstacles) along with the moving UEs. First we have developed a probabilistic model for relay selection which considers both moving UEs and dynamic obstacles. Then we have analyzed the probability of dynamic obstacles blocking a link in 3D Euclidean space by exploiting the information from MIMO radar connected to the base station. Finally, using this information, we have developed unique strategies based on simple geometry to find the best relay which maximizes the expected data rate. Through simulations we have shown that our proposed strategy gives a significant improvement in packet loss due to mobility of nodes and dynamic obstacles in a mmWave channel over the traditional approaches which do not consider dynamic obstacle's presence.

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Circle formation by asynchronous fat robots with limited visibility

Circle formation by asynchronous fat robots with limited vis...

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8th International Conference on Distributed computing and Internet Technologies, ICDCIT 2012

作者： Dutta, Ayan Gan Chaudhuri, Sruti Datta, Suparno Mukhopadhyaya, Krishnendu Computer Science and Engineering Department Heritage Institute of Technology Kolkata 700107 India Advanced Computing and Microelectronics Unit Indian Statistical Institute 203 B.T. Road Kolkata 700108 India

ISBN: (纸本)9783642280726

This paper proposes a distributed algorithm for circle formation by multiple autonomous mobile robots. The vision of each robot is limited to a maximum distance. The robots do not store past actions or records of past data. They are anonymous and cannot be distinguished by their appearances. All robots agree on a common origin and axes. Earlier works report algorithms for gathering of multiple autonomous mobile robots in limited visibility considering the robots to be dimensionless or points. This paper models a robot as a unit disc (fat robot). The algorithm presented in this paper also assures that there is no collision among the robots. The robots do not share a common clock. They execute the algorithm asynchronously. © 2012 Springer-Verlag.

关键词： Mobile robots

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On finding shortest isothetic path inside a digital object

On finding shortest isothetic path inside a digital object

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15th International Workshop on Combinatorial Image Analysis, IWCIA 2012

作者： Dutt, Mousumi Biswas, Arindam Bhowmick, Partha Bhattacharya, Bhargab B. Department of Information Technology Bengal Engineering and Science University Shibpur Howrah India Department of Computer Science and Engineering Indian Institute of Technology Kharagpur India Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata India

ISBN: (纸本)9783642347313

Shortest path algorithms are finding interesting applications in recent times in various emerging areas of image analysis and computer vision. Such algorithms are designed to solve shortest path problems with variegated need-based constraints. We present here an efficient combinatorial algorithm to find a/the shortest isothetic path (SIP) between two grid points in a digital object such that the SIP lies entirely inside the object. The algorithm first obtains the inner isothetic cover (simple and without holes) of the object and then applies certain combinatorial rules to construct the SIP and its constituent monotone sub-paths. For a given grid size, the entire algorithm runs in O(n logn) time, n being the number of grid points on the border of the cover. Experimental results show the effectiveness of the algorithm and its further prospects in shape analysis. © 2012 Springer-Verlag.

关键词： Graph theory

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