Applied Mechanics and Materials Vols. 303-306

Abstract: The 3G wireless network video acquisition system based on the DM6446 is designed, which ARM side of DM6446 complete the main control functions of the system, then it calls H.264 video compression algorithm in DSP side of DM6446 through the Codec Engine, which greatly improves the efficiency of the system, and the RTP protocol control data transmission in the CDMA2000 network. The monitoring display terminal gets video resource by accessing the corresponding IP address. The experimental results show that the system designed completes wireless network video acquisition task safety and reliably, and the image is clear, also the video is coherent.

Abstract: The multivariate public key cryptosystem is a new and fast public key cryptosystem. This paper presents a multivariate public key cryptographic scheme over a finite field with odd prime characteristic. The idea of embedding and layering is manifested in its construction. The security of the scheme is analyzed in detail. The result indicates that the proposed scheme can resist all known attacks effectively.

Abstract: In order to solve the complicated network system modeling and optimization problem, in this paper, at first the simple genetic algorithm is analyzed and discussed in detail, and then the improvement of the genetic algorithm is studied, and finally summarizes the characteristics of the algorithm. Through the experiment, it is demonstrated that this method can effectively solve the complicated network of the two problems.

Abstract: A QoS aware routing protocol for Wireless Mesh Networks is studied in this paper, the QoS metrics taken into account are bandwidth in our studies, end to end delay and stability of the routes. The routing metric reflects the maximal available bandwidth of a routing path, which is calculated based on the available bandwidth of mesh nodes with the consideration of the interference caused by the hidden terminals in WMNs. With the help of admission control decision, QRBC uses the routing metric in the route discovery process to find a QoS guarantee route for the real-time applications. The simulation results demonstrate that the QRBC protocol can find a less interfering and bandwidth guaranteed routing path for real-time flows.

Abstract: Higher education institutions have a moral as well as legal responsibility to protect the sensitive data maintained on campus computers. Higher education institutions are beginning to look at areas to improve the protection of their information technology structure due to the increase of viruses, spam, hackers, and identity theft. The main goal of this paper is to study network security in university. The result shows the genuine exposure, the risk of being effectively compromised is real. Consequently, this network trap should be closely monitored and data control mechanisms, such as a reverse firewall, should be configured to prevent an attacker from using the network trap to damage other production resources.

Abstract: In accordance with the existing problems in the process of fast re-authentication, tabled a fast re-authentication scheme based on the mobility model and dynamic network access identification (DNAI), also simulated and analyzed of the performance of both existing programs and new programs. Research shows that the scheme can greatly increase the switching re-authentication performance of the outer area, and resolve the privacy problem of the mobile terminal position.

Abstract: This document analyzes the wireless ad hoc networks used in vehicle communication. Using the NS2 software, the typical ad hoc on-demand distance vector routing (AODV) and destination-sequenced distance-vector (DSDV) routing protocol are simulated respectively with 25 mobile nodes and 11 mobile nodes. By reasoning on the simulation data, many performance indicators including the routing protocol throughput, jitter, packet loss rate and end-to-end delay performance are compared and analyzed. Final we have come to an important conclusion that AODV is better than DSDV protocol on a number of performance indicators.

Abstract: A cooperative partial message relaying (CPMR) scheme based on distributed polar codes (DPC) is proposed to achieve the maximal decode-and-forward (DF) rate of the stochastically degraded symmetric binary-input two-relay network with orthogonal receiver components (TRN-ORCs). In the proposed scheme, the code design problem of the degraded TRN-ORCs is transformed into a problem of polar codes with CPMR protocol. According to the nested structure of polar codes, the messages transmitted by the source and the first relay are recovered successfully at the two relays, respectively, and then the two relays yield correct partial messages for transmission to solve the uncertainty of the source message at the destination. With the help of the CPMR protocol, the destination should be able to reconstruct the source message correctly. In addition to the practical consideration of the construction of the CPMR protocol based on DPC, we also derived that the block error probability of the proposed scheme can be upper bounded by O(2^-Nβ) for any constant β (0 < β < ½), and sufficiently large block length N.

Abstract: Using multipath routing technology in MANET can improve network stability and reduce end-to-end latency. This paper proposes a Gateway-Centric, Node-Disjoint Multipath Routing Protocol called GC_NDMR to provide efficient data transmission scheme in the connectivity of MANET and Internet. The main idea of GC_NDMR is setting up multipath routing from source nodes to the gateway in MANET, and assigning data flows on multipath based on hops and latency algorithm. Simulation shows that, compared with single path routing protocol AODV interconnect scheme, GC_NDMR has more stable and low end-to-end latency performance. GC_NDMR meets the need of data transmission in the connectivity of MANET and Internet.

Abstract: Wireless Mesh network is widely adopted in both wideband mobile communication network and short distance RF industrial network. As for the latter field, network robustness and real-time are two important issues. Network dimensioning is therefore required for this kind of networks. We models wireless mesh network as four tuples and present a topology transform methodology to change the mesh topology to a cluster tree. Research results from network calculus theory are then applied to obtain key merits such as buffer requirement, bandwidth requirement and end to end delay bound.