The inherent mobility of nodes leads to frequent changes in network structure and resource location delay larger in MP2P network. Existing search algorithms for MP2P is not efficient enough, and is only for single application model. In this paper an epidemic diffusion strategy about index of resource is proposed to implement diffusion resources to solve low efficiency and long latency positioning defects in a large search. Results demonstrate the principle of the proposed algorithm can improve the resource search efficiency.

Online classification of network flows is a process that captures packets generated by network applications and identifies types of network applications (or flows) in real time. There are three key issues about online classification: observation window size, feature selection, and classification algorithms.
In this paper, by collecting five types of typical network flow data as the experiment sample data, the authors found observation window size 7 is the best for the sample data and most classifiers. The authors proposed a full feature set based on the standard feature set which reflects statistical features of network flows. Using five commonly used feature selection methods, the authors identified the most effective features could be reduced from 56 original features to 11 effective features. Lastly, according to special need for online classification, the authors studied 11 different classifiers on their classification accuracy, model construction time, and classification speed. The results show that C4.5 and JRip are the two best algorithms for online classification.

Federated filter was an important method to estimate high-precision navigation parameters based on “SINS/GPS/CNS”. A no-feedback federated filter with UD_UKF algorithm was designed in the paper, a three-time amendment scheme to correct navigation parameters was designed at the same time and the mathematical model of SINS/GPS/CNS was established in launch inertial coordinate system too. The paper discussed the simulation conditions and a lot of simulations were carried out to compare 2 aspects: (1)the performance between four navigation mode, which respectively is SINS, SINS/GPS, SINS/CNS, SINS/GPS/CNS;(2)the estimate precision of federated filter and that of centralized Kalman filter. The results of simulation showed that the designed federated filter and amendment scheme based on SINS/GPS/CNS had high estimate precision and led to gain high hitting precision of ballistic missile, that is to say position errors were less than 20 meter and velocity errors were less than 0.1m/s in simulation.

Massive security alerts produced by safety equipments make it necessary to recognize and predict multi-step attacks. In this paper, a novel method of recognizing and predicting multi-step attacks is proposed. It calculates attack conversion frequencies, and then mines the multi-step attack sequences. On this basis, it matches the new alert sequences dynamically, recognizes the multi-step attacks and predicts the next attack step. The result of experiment shows that the proposed method is effective and accurate.

Opportunistic routing (OR) for multi-hop wireless networks was first proposed by Biswas and Morris in 2004, but again as a modified version in 2005 as Extremely Opportunistic Routing (ExOR). A few other variants of the same were also proposed in the meanwhile time. In this paper we propose a Dynamic Opportunistic Routing (DOR) protocol which depends on network density and also provides spatial diversity. Our routing protocol is distributed in nature and provides partial 802.11 MAC layer abstraction. To verify the results of our protocol we took a network with light-density of nodes and bigger in size (as OR performs better in higher node density). A wireless mesh network in “QualNet network simulator” was created, where the average end-to-end delay and throughput at every node are compared with that of other standard routing protocol OLSR-INRIA.

Sensor networks are becoming closer towards wide-spread deployment so security issues become a vital concern. Selective forwarding attack is one of the harmful attacks against sensor networks and can affect the whole sensor network communication. The variety of defense approaches against selective forwarding attack is overwhelming. In this paper we have described all the existing defensive schemes according to our best knowledge against this attack along with their drawbacks, thus providing researchers a better understanding of the attack and current solution space. This paper also classifies proposed schemes according to their nature and defense. Nature of scheme classifies into Distributed and Centralized. Defense of scheme classifies into detection and prevention.

The increase of the demand for gasoline in transportation and traffic vehicles results in excessive fuel consumption problem. However, by the extension strategy generating methods, the way of urban transportation changing from bus into metro may be analyzed and evaluated through extension reasoning, extension transformation and optimal calculation in order to solve the problem of excessive fuel consumption of the urban roads.

Based on the union bound, formulas to estimate the BER distribution of channel codes are derived. By using these formulas, the BER for every position in the information sequence can be estimated. Appling the formulas to Turbo codes, several examples were given, and the results are also compared with simulation results. The results show that the derived formulas can give out good estimations of the BER distributions for Turbo codes. Therefore this would be helpful for the BER analysis, especially the unequal error protection analysis of Turbo codes.

We make research on the virtual channels scheduling algorithm based on priority in packet telemetry system. Probability of occupying physical channel and packets losing rate of the virtual channel with the highest priority are considered, on condition that the packet arrival rate contribution is Poisson contribution. Theoretical analysis and simulation results show that when the running time of the scheduling module is long enough, probability of occupying physical channel by the virtual channel with the highest priority converge on a fixed value. Formulas of calculating packets losing rate are also given, which can offer reference to engineering design.

The directed routing protocol ends in failure when it faces a situation of the destination node with a very low velocity in a sparse ad hoc network so that none of nodes exist in its forwarding zone. Illuminated by BFDREAM and ZONER, the paper firstly proposes a novelty routing protocol that is fairly immune to forwarding failure through projecting the present source node on the boundaries of convex baffle holes of underwater acoustic networks in deep sea. Compared with DREAM and BFDREAM, the experimental results show our protocol achieves a great improvement in decreasing the propagation delay and reducing quantities of the non-effect information. So the new protocol may have a bright application prospect in deep sea acoustic networks.