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Heterogeneity in wireless network architectures (i.e., the coexistence of 3G, LTE, 5G, WiFi, etc.) has become a key component of current and future generation cellular networks. Simultaneous aggregation of each client's traffic across multiple such radio access technologies (RATs) / base stations (BSs) can significantly increase the system throughput, and has become an important feature of cellular standards on multi-RAT integration. Distributed algorithms that can realize the full potential of this aggregation are thus of great importance to operators. In this paper, we study the problem of resource allocation for multi-RAT traffic aggregation in HetNets (heterogeneous networks). Our goal is to ensure that the resources at each BS are allocated so that the aggregate throughput achieved by each client across its RATs satisfies a proportional fairness (PF) criterion. In particular, we provide a simple distributed algorithm for resource allocation at each BS that extends the PF allocation algorithm for a single BS. Despite its simplicity and lack of coordination across the BSs, we show that our algorithm converges to the desired PF solution and provide (tight) bounds on its convergence speed. We also study the characteristics of the optimal solution and use its properties to prove the optimality of our algorithm's outcomes., Comment: Extended version of the 31st International Teletraffic Congress (ITC 2019) conference paper

As smart grids are getting popular and being widely implemented, preserving the privacy of consumers is becoming more substantial. Power generation and pricing in smart grids depends on the continuously gathered information from the consumers. However, having access to the data relevant to the electricity consumption of each individual consumer is in conflict with its privacy. One common approach for preserving privacy is to aggregate data of different consumers and to use their smart-meters for calculating the bills. But in this approach, malicious consumers who send erroneous data to take advantage or disrupt smart grid cannot be identified. In this paper, we propose a new statistical-based scheme for data gathering and billing in which the privacy of consumers is preserved, and at the same time, if any consumer with erroneous data can be detected. Our simulation results verify these matters.

Molecular Communications via Diffusion (MCvD) is a promising paradigm which enables nano-machines to communicate with each other. However, the reliability of existing systems degrade rapidly as the distance between the transmitters and the receivers grows. To solve this issue, relaying schemes must be implemented in practice. In this paper, we study two relaying schemes: In the first case, the relay node decodes the incoming signal symbol and forwards it to the receiver using a different type of molecule. Then, the receiver detects the information bits by only considering the molecules from the relay node. In the second case, the receiver considers both the types of molecules sent from the transmitter and the relay node. For these two scenarios, the optimal location of the relay node is obtained. We assume Quadruple Concentration Shift Keying (QCSK) modulation in which the signal is encoded into the four level concentrations of molecules emitted by the nano-machines. Our simulation results indicate that adding a relay improves the performance by 10dB and 15dB in the first and the second schemes, respectively., Comment: arXiv admin note: text overlap with arXiv:1401.3410, arXiv:1410.5585, arXiv:1504.03738, arXiv:1410.4258 by other authors

Wireless sensor network comprises of small sensor nodes with limited resources. Clustered networks have been proposed in many researches to reduce the power consumption in sensor networks. LEACH is one of the most interested techniques that offer an efficient way to minimize the power consumption in sensor networks. However, due to the characteristics of restricted resources and operation in a hostile environment, WSNs are subjected to numerous threats and are vulnerable to attacks. This research proposes a solution that can be applied on LEACH to increase the level of security. In Watchdog-LEACH, some nodes are considered as watchdogs and some changes are applied on LEACH protocol for intrusion detection. Watchdog-LEACH is able to protect against a wide range of attacks and it provides security, energy efficiency and memory efficiency. The result of simulation shows that in comparison to LEACH, the energy overhead is about 2% so this method is practical and can be applied to WSNs.