Biblio
In this paper we report preliminary results from the novel coupling of cyber-physical emulation and interdiction optimization to better understand the impact of a CrashOverride malware attack on a notional electric system. We conduct cyber experiments where CrashOverride issues commands to remote terminal units (RTUs) that are controlling substations within a power control area. We identify worst-case loss of load outcomes with cyber interdiction optimization; the proposed approach is a bilevel formulation that incorporates RTU mappings to controllable loads, transmission lines, and generators in the upper-level (attacker model), and a DC optimal power flow (DCOPF) in the lower-level (defender model). Overall, our preliminary results indicate that the interdiction optimization can guide the design of experiments instead of performing a “full factorial” approach. Likewise, for systems where there are important dependencies between SCADA/ICS controls and power grid operations, the cyber-physical emulations should drive improved parameterization and surrogate models that are applied in scalable optimization techniques.
Cross layer based approaches are increasingly becoming popular in Manet (Mobile Adhoc Network). As Manet are constrained with issues as low battery, limited bandwidth, link breakage and dynamic topology, cross layer based designs are trying to remove such barriers and trying to make Manet more scalable. Cross layer designs are also facing attacking problem and ensuring the security of network to defend the attack is must. In this paper we discuss about technique to optimize the performance by minimizing delay and overhead of secure cross layer routing protocol. We have designed SCLPC (Secure cross layer based Power control) protocol. But when security is imposed using AASR (Authenticated and anonymous secure routing), the network metrics as end to end delay and control overhead is disturbed. To optimize the network performance here we proposed OSCLPC (Optimized secure cross layer based power control protocol). The proposed OSCLPC has been evaluated using SHORT (Self healing and optimizing route technique). The OSCLPC is simulated in ns2 and it is giving the better performance compared with SCLPC.
Next generation cellular networks will provide users better experiences by densely deploying smaller cells, which results in more complicated interferences environment. In order to coordinate interference, power control for uplink is particularly challenging due to random locations of uplink transmitter and dense deployment. In this paper, we address the uplink fractional power control (FPC) optimization problem from network optimization perspective. The relations between FPC parameters and network KPIs (Key Performance Indicators) are investigated. Rather than considering any single KPI in conventional approaches, multi-KPI optimization problem is formulated and solved. By relaxing the discrete optimization problem to a continuous one, the gradients of multiple KPIs with respect to FPC parameters are derived. The gradient enables efficiently searching for optimized FPC parameters which is particularly desirable for dense deployment of large number of cells. Simulation results show that the proposed scheme greatly outperforms the traditional one, in terms of network mean load, call drop & block ratio, and convergence speed.
The main challenge of ultra-reliable machine-to-machine (M2M) control applications is to meet the stringent timing and reliability requirements of control systems, despite the adverse properties of wireless communication for delay and packet errors, and limited battery resources of the sensor nodes. Since the transmission delay and energy consumption of a sensor node are determined by the transmission power and rate of that sensor node and the concurrently transmitting nodes, the transmission schedule should be optimized jointly with the transmission power and rate of the sensor nodes. Previously, it has been shown that the optimization of power control and rate adaptation for each node subset can be separately formulated, solved and then used in the scheduling algorithm in the optimal solution of the joint optimization of power control, rate adaptation and scheduling problem. However, the power control and rate adaptation problem has been only formulated and solved for continuous rate transmission model, in which Shannon's capacity formulation for an Additive White Gaussian Noise (AWGN) wireless channel is used in the calculation of the maximum achievable rate as a function of Signal-to-Interference-plus-Noise Ratio (SINR). In this paper, we formulate the power control and rate adaptation problem with the objective of minimizing the time required for the concurrent transmission of a set of sensor nodes while satisfying their transmission delay, reliability and energy consumption requirements based on the more realistic discrete rate transmission model, in which only a finite set of transmit rates are supported. We propose a polynomial time algorithm to solve this problem and prove the optimality of the proposed algorithm. We then combine it with the previously proposed scheduling algorithms and demonstrate its close to optimal performance via extensive simulations.
In this paper, we study the problem of privacy information leakage in a smart grid. The privacy risk is assumed to be caused by an unauthorized binary hypothesis testing of the consumer's behaviour based on the smart meter readings of energy supplies from the energy provider. Another energy supplies are produced by an alternative energy source. A controller equipped with an energy storage device manages the energy inflows to satisfy the energy demand of the consumer. We study the optimal energy control strategy which minimizes the asymptotic exponential decay rate of the minimum Type II error probability in the unauthorized hypothesis testing to suppress the privacy risk. Our study shows that the cardinality of the energy supplies from the energy provider for the optimal control strategy is no more than two. This result implies a simple objective of the optimal energy control strategy. When additional side information is available for the adversary, the optimal control strategy and privacy risk are compared with the case of leaking smart meter readings to the adversary only.
With the rapid development of Wireless Sensor Networks (WSNs), besides the energy efficient, Quality of Service (QoS) supported and the validity of packet transmission should be considered under some circumstances. In this paper, according to summing up LEACH protocol's advantages and defects, combining with trust evaluation mechanism, energy and QoS control, a trust-based QoS routing algorithm is put forward. Firstly, energy control and coverage scale are adopted to keep load balance in the phase of cluster head selection. Secondly, trust evaluation mechanism is designed to increase the credibility of the network in the stage of node clusting. Finally, in the period of information transmission, verification and ACK mechanism also put to guarantee validity of data transmission. In this paper, it proposes the improved protocol. The improved protocol can not only prolong nodes' life expectancy, but also increase the credibility of information transmission and reduce the packet loss. Compared to typical routing algorithms in sensor networks, this new algorithm has better performance.