Current quality of service(QoS) routing schemes for low earth orbit(LEO) satellites IP networks either neglect the varying population density or fail to guarantee end-to-end delay.As a remedy,QoS routing protocol based on mobile agent(QoSRP-MA) is proposed.QoSRP-MA is a source-based routing protocol.Once connection requests arrive,QoS mobile agents are dispatched from ingress satellite to explore routes,which migrate using satellite routing tables.Upon arriving in egress satellite,QoS mobile agents migrate back towards ingress satellite to reserve bandwidth.To construct satellite routing tables,load balancing routing algorithm based on mobile agent(LBRA-MA) is presented.In LBRP-MA,at regular intervals mobile agents launched on all satellites migrate autonomously to evaluate path cost and update routing tables.Moreover,path cost between source and destination is evaluated considering satellite geographical position as well as inter-satellite link(ISL) cost.Furthermore,ISL congestion index is considered to update routing table.Through simulations on a Courier-like constellation,it shows that QoSRP-MA can achieve guaranteed end-to-end delay bound with higher throughput,lower connection failing ratio and signaling overhead compared to high performance satellite routing(HPSR) scheme.
RAO Yuan,WANG Ru-chuan College of Computer,Nanjing University of Posts and Telecommunications,Nanjing 230001,China
In order to reduce makespan and storage consumption in data grids,a node selection model for replica creation is proposed. The model is based on the degree distribution of complex networks. We define two candidate replica nodes:a degree-based candidate pool and a frequency-based candidate pool,through which a degree-based candidate pool is defined in consideration of onsidering the access frequency; a candidate pool-based frequency is also defined. The data replica is copied to the node with the minimum local cost in the two pools. Further,this paper presents and proves a replica creation theorem. A dynamic multi-replicas creation algorithm (DMRC) is also provided. Simulation results show that the proposed method may simultaneously reduce makespan and data used in space storage consumption.
CHEN Dan-wei ,ZHOU Shu-tao,REN Xun-yi,KONG Qiang College of Computer,Nanjing University of Posts and Telecommunications,Nanjing 210003,China
As a novel application technology,wireless video sensor networks become the current research focus,especially on target tracking and surveillance scenario.Based on multiple agents' technique,this article introduces a series of intelligent algorithms such as simulated annealing algorithm(SA),genetic algorithm(GA),and ant colony optimization algorithm(ACO) or their mixed algorithms,to resolve the optimization of tasks schedule and data transmission.This article analyzes the performance of abovementioned algorithms and verifies their feasibility associated with agents.The simulations demonstrates that the mixed algorithms based on SA and GA obtain the optimal solution to tasks schedule,and those combined with SA-ACO show advantages on multimedia sensor networks routing optimization.
HUANG Hai-pingWANG Ru-chuanSUN Li-juanWANG Hai-yuanXIAO Fu
