One of the emerging networking standards that gap between the physical world and the cyber one is the Internet of Things. In the Internet of Things, smart objects communicate with each other, data are gathered and certain requests of users are satisfied by different queried data. The development of energy efficient schemes for the IoT is a challenging issue as the IoT becomes more complex due to its large scale the current techniques of wireless sensor networks cannot be applied directly to the IoT. To achieve the green networked IoT, this paper addresses energy efficiency issues by proposing a novel deployment scheme. This scheme, introduces: (1) a hierarchical network design; (2) a model for the energy efficient IoT; (3) a minimum energy consumption transmission algorithm to implement the optimal model. The simulation results show that the new scheme is more energy efficient and flexible than traditional WSN schemes and consequently it can be implemented for efficient communication in the IoT.

Migration of virtual machines (VMs) from one data center to another is essential to deal with scenarios such as load balancing, maintenance, power management, VM failures, etc. Application of VM migration is not only limited to a single cloud service provider, but also to inter-cloud architectures such as cloud federation. Migration in a federation is a complex operation as it encompasses many autonomous service providers with different standards, rules, and protocols. Migration can be carried out in two ways, first, live and, second, non-live. In case of live migration, a VM continues to execute at the source in contrast to non-live where its execution is suspended. In this paper, a framework for secure live migration of VMs in a cloud federation is proposed. Costs associated with it is analyzed for serial, parallel, and improved serial strategies. The proposed framework is simulated using a CloudSim simulator. Metrics considered for evaluation are communication overhead, migration time, and downtime. Further, power consumption for all strategies is calculated and compared. It is observed that downtime is least for parallel, whereas migration time is least for improved serial. The power consumption is highest for parallel and least for improved serial.

The objective of this letter is to improve the bit error performance of backscattering sensors that implement Orthogonal Frequency Division Multiplexing (OFDM). Many recent works in the literature have demonstrated the implementation of OFDM transmission from backscattering tags. A persistent shortcoming in such systems is the Bit Error Rate (BER) floor due to increased levels of Inter-Carrier Interference resulting from spectral spreading. In this letter, the authors employ unused subcarriers of the OFDM modulator to design an interference cancellation signal. The time domain signal is matched to the resolution of the impedance switching states of the tag. Significant suppression of the inter-carrier interference is possible with roughly equal numbers of used and unused subcarriers. Lower interference values result in lower BER floors. Furthermore, this technique allows the use of a larger number of data subcarriers than other existing techniques in the literature. The tag power consumption per bit can therefore be reduced.

Although the needs for sustainable urban infrastructure systems are increasingly being recognized and addressed, the same is not true for Native American communities, where existence, condition, and access to a collection of infrastructure systems is often lagging behind urban and non-native communities. To date, there has been a quite limited number of studies exploring Native American perspectives on infrastructure challenges and how to build sustainable and resilient infrastructure systems in their communities. Thus, the purpose of this study is to identify the challenges and opportunities for building sustainable infrastructure systems for Native American communities in Southern California and investigate how those communities experience, understand, and apply engineering practice in the context of their community and culture. Drawing from six group interviews, our study highlights challenges and opportunities for building sustainable and resilient infrastructure systems on tribal reservations in San Diego County, California, from the perspectives offered by Native Americans themselves. We focus on infrastructure systems fundamental to well-being: built environment, water/wastewater, telecommunications, transportation, energy, human capital, and education. Our research participants emphasized the importance of their cultures, sovereignty, and care for the welfare of their communities in innovating sustainable and resilient infrastructure. To accomplish this, a key priority should be to train native engineers, who are best positioned to understand the infrastructure needs and opportunities in their own communities.

Several energy saving techniques in cellular wireless networks such as active base station (BS) selection, transmit power budget adaptation and user association have been studied independently or only part of these aspects have been considered together in literature. In this paper, we jointly tackle these three problems and propose an integrated framework, called dynamic cell reconfiguration (DCR). It manages three techniques operating on different time scales for ultimate energy conservation while guaranteeing the quality of service (QoS) level of users. Extensive simulations under various configurations, including the real dataset of BS topology and utilization, demonstrate that the proposed DCR can achieve the performance close to an optimal exhaustive search. Compared to the conventional static scheme where all BSs are always turned on with their maximum transmit powers, DCR can significantly reduce energy consumption, e.g., more than 30% and 50% savings in uniform and non-uniform traffic distribution, respectively.