Anupam Kumar Bairagi

LTE-U sum-rate maximization considering QoS and co-existence issue

Wireless communication industry is facing storm of exponential mobile traffic increase due to richer contents sharing over the network through smart devices. A innocent resolution for envisaging this contravention is to employ more licensed spectrum. But this is a scare resource and sufficient additional spectrum will be unavailable in the upcoming days. So, both academia and industry are engaging different new technologies to deal with this traffic cyclone in cellular networks. Long Term Evaluation-Advanced (LTE-A) is such a recent technology that serves heavy mobile traffic. But with insufficient licensed spectrum, LTE-A also cannot meet the quality of service (QoS) requirements of all its users. So, by augmenting the benefits of LTE-A into unlicensed spectrum known as LTE-U with the help of carrier aggregation (CA) technique, we can boost the performance of 4G/5G cellular network. The process will degrade the performance of other technologies which are already using same unlicensed band. Moreover, if multiple cellular network operators (CNOs) use the same unlicensed band then they will diminish the benefits of each others. In this paper, we explore the CA of licensed and unlicensed spectrum when QoS of user cannot be met with licensed spectrum by deploying dual mode small cell base station (SBS) and considering minimum requirement of unlicensed WiFi access points (WAP). Here, we formulate the resource allocation as an optimization problem which wants to maximize the sum-rate of LTE-U system. Then we solve this problem with the help of Nash bargaining game (NBG) between LTE-U and WAP by cooperative approach. Simulation results show the effectiveness and efficiency of the proposed approach considering QoS requirement of LTE-U users and coexistence issue with WAPs.

QoS aware collaborative communications with incentives in the downlink of cellular network: A matching approach

The demand for data rate is increasing exponentially in the cellular networks due to the emergence of more and more data-driven applications and smart-devices. Currently, these demands cannot be met by cellular networks with any single technology. As a consequence, Quality-of-service (QoS) needs to be sacrificed by some users. To provide guaranteed QoS to the users, researchers are considering massive MIMO, LTE-A, cooperative communications etc as the suitable candidate for the next generation cellular network. In this paper, we propose a collaborative communication mechanism with incentive for downlink in the cellular network for providing guaranteed QoS by utilizing multiple connectivity of the users smart equipments. We formulate the problem as an optimization problem first and afterwards, we solve this problem with the help of matching theory. Simulation results are shown to represent performance of the technique.

An efficient steganographic approach for protecting communication in the Internet of Things IoT critical infrastructures

ABSTRACT With the manifestation of the Internet of Things (IoT) and fog computing, the quantity of edge devices is escalating exponentially all over the world, providing better services to the end user with the help of existing and upcoming communication infrastructures. All of these devices are producing and communicating a huge amount of data and control information around this open IoT environment. A large amount of this information contains personal and important information for the user as well as for the organization. The number of attack vectors for malicious users is high due to the openness, distributed nature, and lack of control over the whole IoT environment. For building the IoT as an effective service platform, end users need to trust the system. For this reason, security and privacy of information in the IoT is a great concern in critical infrastructures such as the smart home, smart city, smart healthcare, smart industry, etc. In this article, we propose three information hiding techniques for protecting communication in critical IoT infrastructure with the help of steganography, where RGB images are used as carriers for the information. We hide the information in the deeper layer of the image channels with minimum distortion in the least significant bit (lsb) to be used as indication of data. We analyze our technique both mathematically and experimentally. Mathematically, we show that the adversary cannot predict the actual information by analysis. The proposed approach achieved better imperceptibility and capacity than the various existing techniques along with better resistance to steganalysis attacks such as histogram analysis and RS analysis, as proven experimentally.

An approach of cost optimized influence maximization in social networks

Social networks have gained huge research interest, especially in viral marketing due to their rapid boom in the past years. It is very crucial to identify the influential users in the social networks for viral and target marketing. Influence maximization (IM) problem estimates such influential users in the social networks. With an initial seed set, the IM finds a maximum number of nodes that can be activated in the network under some diffusion models e.g. Linear Threshold model or Independent Cascade model. But previous works in this field have not studied about the minimum cost, termed as opportunity cost (OC), to motivate those seed nodes. In this work, we define a novel Reverse Influence Maximization (RIM) problem to determine the opportunity cost of influence maximization. Employing the influence propagation in opposite order, the RIM determines the minimum number of nodes that must be activated in order to motivate a set of target nodes. We propose Random RIM (R-RIM) and Randomized Linear Threshold RIM (RLT-RIM) models to tackle the RIM problem. We also perform a simulation to evaluate the performance of the algorithms using two real world datasets. The result shows that the proposed models determine the optimized opportunity cost with faster running time margin.

D2D communications under LTE-U system: QoS and co-existence issues are incorporated

Daily-life oriented applications and multimedia entertainments through smart devices are creating immense stress to the current cellular foundation. To overwhelm from this loopholes, both academia and industry are trying their best by incorporating different technologies with existing ones using licensed spectrum. On the other side, Device-to-Device (D2D) communications are also being used to improve the spectrum efficiency and user experience by reutilizing licensed cellular spectrum. But with insufficient licensed spectrum, it is impossible to meet the demand of users in the current scenario. So, peoples are thinking to utilize unlicensed spectrum with licensed one to alleviate this scarcity issue and provide guaranteed Quality of Service (QoS) to the users. In this paper, we want to extend D2D communication and LTE-A network into the unlicensed spectrum. But this initiative will harm the performance of other technologies which are already working in the same unlicensed band. Moreover, if multiple mobile network operators (MNOs) use the same unlicensed band then they will diminish the benefits of each other. So this paper wants to maximize the sum-rate of LTE users and D2D pairs by allocating licensed and unlicensed subchannels considering their QoS requirements while protecting minimum requirements of WiFi Access Points (WAPs). Then we solve this problem with the help of Nash bargaining game (NBG) between Small Cell Base Stations (SBSs) and WAPs by the cooperative approach. Simulation results show the effectiveness and efficiency of the proposed approach.

An overlapping coalition formation approach to maximize payoffs in cloud computing environment

Data-intensive applications are anticipated to increase day by day. The amount of computing and storage resources required by these are also increasing simultaneously, creating high demands for cloud resources. Cloud providers limited resources are not adequate to meet the elastic demand of consumers. Cloud coalition is the key approach to deal with such elastic demand of resources in the environment. But traditional coalition formation mechanism allows a cloud provider to participate into a single coalition which leads to under-utilize of coalition resources with increasing security risk like botnet attacks. In this paper, a mathematical framework from cooperative game namely overlapping coalition formation (OCF) game to overcome the under-utilization problem and to reduce security risk for cloud providers (CPs) is introduced by permitting a CP to participate into multiple small coalitions. First, the concepts of OCF game in cloud is presented and then, an algorithm for the stability in OCF game is introduced. We analyze the performance of the proposed approach with traditional coalition formation and no-coalition scenarios in perspective of payoffs, yielding higher payoffs for the participating CPs.