Abstract: The success of Smart Grid will be based on grid-integrated real-time communication between various grid elements in generation, transmission, distribution and loads. Merit to the ZigBee/IEEE802.15.4std low cost, low power, low data rate, short range, simplicity and free licensed spectrum that makes wireless sensor networks (WSNs) the most suitable wireless technology for smart grid applications. This paper focuses at the distribution layer from advanced metering infrastructure (AMI) gateways at the consumer premises to the distribution point where a multi-hop mesh network is built for large coverage data exchange. While beacon-enabled mode is adopted for energy efficient operations, IEEE802.15.4std does not define any mechanisms to enable beacon mode in mesh network. Therefore, in this paper, a modified Zigbee WSN MAC protocol for real-time multi-hop mesh network topology is developed. The protocol performance is evaluated using NS-2 simulation and the preliminary results are encouraging.

Abstract: We investigate the first passage time and the multifractal for two kinds of absorbing ions, K+ and Na+, on a charged lipid membrane. We introduce the first passage time arriving for the first time at the absorbing barrier after starting from an arbitrary barrier. The first passage time for the random walk is the statistical quantity that defines the average time arriving at the absorbing barrier for the first time. For two ions of Na+ and K+, the first passage time distributions are approximately proportional to power laws with scaling exponent -1.5, and our result is shown to be in consistent with theoretical one. We also simulate and analyze the multifractal behavior from the charged ions arrived for the first time at an absorbing barrier. In future, we will extend the various investigation of multifractals to complicated stochastic models of other charged ions.