Nowadays, the development of information technology can be described as extremely rapid, especially with the widespread use of the Internet; the security of communications in the network has become an important issue we are facing. The purpose of this article is to solve the problems in today’s network security data encryption algorithms. Starting from the computer network communication security data encryption algorithm, we discuss the effects of several different encryption methods on improving network security. The research results show that it is known that the application of link encryption algorithm in network communication security encryption algorithm can increase the security index by 25%, the node encryption algorithm can increase the security index by 35%, and the end‐to‐end encryption algorithm can make the cyber activity safety index to increase by 40%. Among them, RSA algorithm and DES algorithm are two very representative algorithms; they represent different encryption systems. From the perspective of network data link, there are three methods of encryption algorithm, namely, link encryption algorithm, node encryption algorithm, and end‐to‐end encryption algorithm.

As the popularity of smart phones and tablets, users have an increasing desire to enjoy ubiquitous game playing. The emerging cloud gaming turns this desire into reality, enabling users to play games at anywhere on any devices. However, due to the huge amount of data transmission, it is challenging to provide a high quality game experience under the limited bandwidth capacity. In this paper, we propose a novel cloud gaming framework, in which we introduce two synchronized graphics buffers at both the server and the client sides. The server not only streams the compressed frames captured from game scenes, but also progressively transmits graphics data. The received graphics data is used to generate reference frames. When compressing the next frame, the cloud server will choose the reference frame with a lower residual error, from the previous frame and the current frame rendered from the graphics buffer. With the accumulation of graphics data, the frame rendered from the graphics buffer is close to the captured frame, which greatly reduces the transmission bit rates. Based on the proposed framework, we study the rate allocation problem, in which we optimize the allocated bit rates between the compressed frame and the graphics data to minimize the total distortion under the bandwidth constraint. Experimental results demonstrate that the proposed framework can optimally allocate bit rates to achieve a minimal distortion for cloud gaming compared to the traditional video streaming and graphics streaming approaches.

An oscillator is a key component of a satellite communication measurement and control system, performing symmetry precisely as a time frequency reference. At the same time, the phase noise index has a close coupling relationship with the overall performance of the entire system, while persistently breaking the symmetry property of the oscillator during work. It is very important to study and reasonably allocate the phase noise index. According to the theoretical formula of phase noise, this paper analyzes the power law spectral model in the frequency domain and the noise jitter characteristics in the time domain. Using the carrier tracking loop in the measurement system, the frequency domain transfer model of phase noise is established, and typical analysis results are given. A discrete fractional integration algorithm is proposed, which can generate the phase noise time domain sequence under the given power law spectral model coefficients. The proposed algorithm is more realistic compared with the previous numerical calculation method, and has sufficient accuracy compared with the results of the instrument. After frequency domain conversion, the RMS deviation between the simulated noise sequence in the frequency domain and the measured single sideband power spectral density is less than 2.5 dB, indicating that the phase noise sequence can reflect the frequency domain characteristics more completely. A communication measurement simulation system is built, and a discrete sequence simulation analysis method combining frequency domain and time domain is provided, and the coupling relationship of key indicators such as phase noise, thermal noise, communication data rate, modulation method and bit error rate is synthesized. The results show that the BER of the QPSK/BPSK communication system will not be significantly reduced if the phase jitter RMS caused by the phase noise is less than 5 degrees, so 5 degrees can be used as a reference for the decomposition of the carrier SSB phase noise index. The simulation results have been successfully applied to a satellite inter-satellite link system, which has universal practical application value.

With the rapid development of network technology and computer technology, network applications can be seen everywhere. From life, finance to politics, the development of all walks of life has been inseparable from computer communication networks. Once there is a problem with the computer communication network, it will cause serious economic losses and may even cause national turmoil. Therefore, the reliability requirements of computer communication networks are getting higher and higher, and the reliability analysis and application of computer communication networks have become the focus of research. Based on genetic algorithm, this paper optimizes the reliability of computer communication networks. Firstly, the theory of reliability of computer communication network is briefly introduced, and the factors affecting reliability are simply analysed. Secondly, based on the influencing factors, the reliability optimization analysis model of computer communication network is established. Finally, the genetic algorithm is used to solve the established reliability optimization analysis model. The experimental results show that with the increase in the number of iterations of the genetic algorithm for data regression calculation, the algorithm reaches more than 0.99, and the optimal solution is obtained, which improves the reliability of the network, and the adaptability of the network link also increases. The genetic algorithm is applied to the reliability analysis of computer communication network, and the corresponding reliability optimization method is designed, which can improve the reliability of computer network while reducing the cost.

Many multimedia applications involve real-time video communication over distributed systems, in which there is no centralized controller. Examples of such distributed systems are peer-to-peer (P2P) networks, wireless ad hoc networks, and wireless sensor networks. In this paper, we provide a review of recent advances on optimal resource allocation for video communication over some major distributed systems including P2P streaming systems, wireless ad hoc networks, and wireless visual sensor networks. In P2P streaming systems, we review the scheduling optimization problem, streaming capacity problem, routing optimization problem, and the prefetching optimization problem. In wireless ad hoc networks, we present the routing optimization problem, joint optimization of the source rate and the routing scheme, joint optimization of sender selection and the routing scheme, and joint optimization of the source rate, the routing scheme and the power. In wireless visual sensor networks, we discuss the network lifetime maximization problem, optimal power allocation, maximization of accumulative visual information (AVI). Illustrative simulation results are provided to demonstrate the performance improvement brought by the optimal resource allocation in the distributed systems. Finally, we give our vision on the future work in the area of video communication over distributed systems.