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Internet of Things (IoT) refers to an infrastructure which enables the forms of communication and collaboration between people and things, and between things themselves. In order to improve its performance, we present a tradeoff between bandwidth and energy consumption in the IoT in this paper. A service providing model is built to find the relationship between bandwidth and energy consumption using a cooperative differential game model. The game solution is gotten in the condition of grand coalition, feedback Nash equilibrium and intermediate coalitions and an allocation policy is obtain by Shapley theory. The results are shown as follows. Firstly, the performance of IoT decreases with the increasing of bandwidth cost or with the decreasing of energy cost; secondly, all the nodes in the IoT composing a grand coalition can save bandwidth and energy consumption; thirdly, when the factors of bandwidth cost and energy cost are equal, the obtained number of provided services is an optimised value which is the trade-off between energy and bandwidth consumption.

In this article, a novel microwave photonic filter with negative coefficient using semiconductor optical amplifiers and Fiber Bragg Gratings is proposed. Three major factors, including input current, grating coefficients and the input signal power are analyzed and compared respectively with scrutinize their affects to the filter response. Through the simulation, a better performance of the flat-top microwave photonic filter can be achieved. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 9–13, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24824

To solve the problem that current intrusion detection model needs large-scale data in formulating the model in real-time use, an intrusion detection system model based on grey theory (GTIDS) is presented. Grey theory has merits of fewer requirements on original data scale, less limitation of the distribution pattern and simpler algorithm in modeling. With these merits GTIDS constructs model according to partial time sequence for rapid detect on intrusive act in secure system. In this detection model rate of false drop and false retrieval are effectively reduced through twice modeling and repeated detect on target data. Furthermore, GTIDS framework and specific process of modeling algorithm are presented. The affactivity of GTIDS is proved through emulated experiments comparing snort and next-generation intrusion detection expert system (NIDES) in SRI international.

Context-aware plays a key role in the wisdom network information processing. Due to limited resources, context conflict is inevitable in context-aware. User satisfaction is a good reflection for the wisdom degree of the network. In this paper, through considering the user satisfaction, we propose a novel context-aware conflict solution model based on SPA(set pair Analysis). The model obtain the best server mode by the maximum satisfaction connection degree to solve the conflict in context-aware. The simulation analysis show that the proposed method is simple, effective and can solve many users compete for the same scene of conflict.

Different from Internet networks, DTN has its own unique characteristics, like intermittent connectivity, low data transfer rate, high latency and limited storage and node resources. Routing technology is always the key to DTN research. In this paper, a routing protocol that is PNCMOP was proposed. It makes some improvement of Epidemic routing protocol, and also to decrease the end-to-end average delay and improve delivery ratio, especially with congestion control. Simulation results show that PNCMOP achieved a good performance. DOI: http://dx.doi.org/10.11591/telkomnika.v11i10.3348

The radio-over-fibre (ROF) uplink, which combines the merit of optical fibre with that of microwave technology, can supply the high capacity of communication. However, there are two major issues: nonlinear distortion of the optical link and the multipath dispersion of the wireless channel, affecting the performance of the system. We propose an equalizer based on hybrid neural networks. The compensation needs no estimation of the channel. The simulated result shows that the ROF uplink can be adequately compensated and the performance of the equalizer depends on the channel noise.

In optical fiber communication systems, reshaping is crucial for long-haul transmission and networks due to the accumulated noise and dispersion, which will gradually degrade the signals. In this article, a SOA (Semiconductor Optical Amplifier)-based interferometer is proposed to realize all-optical signal reshaping. Such scheme is known as advantageous for operation at high speed, which is analyst in theory. The distorted picosecond optical pulses train with repetition rate of 10 GHz is reshaped successfully in experiments employing this simple interferometer. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1606–1608, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22534

In cyberspace, there are decision nodes which include several processors. Proper mechanism of events decision is needed to maximum the processors utilization. This mechanism is also effect to pick up the event most important and can be handled quickly. In this paper, a weighted event decision mechanism was advanced. In this mechanism, a weighted factor is used to mark each event which enters the decision node buffer by its type of operation and decision time. This mechanism is fully taken into account to the limited loads and the real-time processing requirements of wisdom network decision nodes. The simulation results show that, this mechanism improved the processors utilizing efficiency better than FIFO.

With the development and application of communication, Cyberspace is becoming more and more popular with many organizations, but it has brought safety risk. Cyberspace security has become the key problem of restricting the development of it. The paper has a deep research of Cyberspace structure and Cyberspace security, proposes a authentication protocol for Cyberspace based on Signature of knowledge, including intra-domain authentication mechanism and inter-domains authentication mechanism. This method using the concept of Signature of knowledge can obtain an effective safe strategy. The multi-domain hash tree is built to Ensure inter-domain security. At the same time, symmetrical key algorithm and public key algorithm are just combined to reduce the authentication delay effectively and increase the network lifetime and enhances the security of the networks. Moreover, because of using signatures of knowledge, the number of hash is reduced, the power which notes consume is debased, and the network load is decreased. The performance of the system is discussed, and the encryption method has high efficiency and high security.

Clustering is an effective approach for managing nodes in wireless sensor networks(WSN). In this paper, we consider selfish avoidance clustering in WSN. A differential game model is proposed to stimulate forwarding. Based on the payoff value of the differential game, called Forwarding Contribution(FC) in this paper, a centralized clustering algorithm is proposed. Mathematical proof shows that our algorithm can ensure connection between cluster heads(CHs), and also shows that FC value can reasonably reflect energy consumption in terms of competition while considering forwarding efficiency. Simulation on the lifetime of network is performed, and the results illustrate that our algorithm is selfish avoidance while the clustering approaches according to residual energy are seriously influenced by selfishness.

It is only simply assumed that network links are bidirectional in most routing protocols. However unidirectional links may exist in a real network due to the variation of transmission power in different nodes, the affection of noise and other signal propagation. We find that the AODV protocol can not support unidirectional links and the Hello mechanism increases overmuch overhead on traffic. In this paper, we introduce an improved Hello mechanism named Hello2 mechanism which can reduce overhead and overcome the phenomenon of unidirectional links. We present a scalable and efficient way to provide this abstraction by finding and maintaining multi-hop reverse routes to each unidirectional link. We simulate the mechanism based on the modified AODV version that uses Hello2 to route packets in networks with unidirectional links. The simulation results show that the packet delivery is substantially increased and the overhead is distinctly reduced in unidirectional networks.