In multi-controller Software Defined Network (SDN), since the existed switch migration strategies always have low efficiency and need to migrate many times which only consider single migration factor, a mechanism of switches migration based on progressive auction named PASMM (Progressive Auction based Switches Migration Mechanism) was proposed. To improve network benefit, the switch migration problem was optimized by auctioning controllers' remaining resources in the mechanism. By increasing the trading price of the over-demanded controllers' resources, PASMM completed the auction and redeployed the controllers and switches. The simulation results show that, compared with some typical switch migration policies, PASMM achieves good load balancing of controllers, reduces the response time of the PACKET_IN messages by an average of 13.5%, and spends the least migration time with the increasing of switches flow requests.

The key issue of network virtualization is Virtual Network Embedding (VNE), and the rapid growth of energy cost makes infrastructure providers concern energy conservation. An energy conservation VNE algorithm that centrally used network topology for saving energy on VNE problem was presented. The importance of the nodes was characterized by the conception of closeness centrality and the capabilities of the nodes, and the working nodes were preferentially used for resources integration to reduce energy consumption and calculation cost, that ensured the distance of the substrate links won't be too long. The simulation results show that the proposed algorithm improves revenue-energy ratio more than 20% when accept ratio reaches 70% and revenue cost ratio reaches 75%, and has advantages compared with the previous algorithms.

Network virtualization is recognized as a significant technology to solve the ossification of current Internet. Virtual Network Embedding (VNE) is a major challenge in network virtualization. The main object of VNE is to increase the acceptance ratio of Virtual Network (VN) and the revenue of infrastructure providers. Regarding VNE as an Integer Linear Programming (ILP) model with an assumption that substrate network needs to support path splitting, a new VNE algorithm based on hybrid swarm intelligence optimization was proposed. The proposed algorithm took advantage of the Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) to optimize the mapping scheme in view of the balance of the mapping overhead and the mapping proportionality. Compared with the existing mainstream approaches, the simulation results demonstrate that the proposed algorithm can increase the long-term average revenue and acceptance ratio.

A communication system with several serial ports was developed to realize the communication between On-Board Computer (OBC) and cameras in micro-satellite simulation system. The system was designed in Host-Target model. The Host sever managed the multiplex communications between the host and its clients. It also sent out trigger signal to control five cameras through a Field Programmable Gate Array (FPGA) chipset. In addition, a multiplex serial communication protocol based on RS-232 protocol was proposed to complete the communication. The logic analytical tool SignalTapⅡ was used to capture the real-time signal of FPGA to verify the performance of the system. The results indicate that the system can control and manage a single camera or multiple cameras flexibly.