| 摘要: |
| 作为下一代互联网的核心问题之一,多约束的服务质量路由(QoSR)用来寻找一条同时满足多个约束条件的可行路径.然而,该问题具有NP完全的复杂度.将模拟退火引入多约束QoSR计算中,首先使用非线性能量函数将多个QoS度量转化成单一能量,然后基于模拟退火的方式求解最小能量路径.首先概述了模拟退火的方法,分析了在QoSR中应用模拟退火所面临的关键问题以及解决方案,然后给出了SA_MCP算法及其复杂性分析.实验结果表明,该算法具有很高的性能,同时对网络规模和约束个数都具有很好的扩展性,对QoS约束的分布状况也不敏感.此外,只要大部分QoS约束存在可行路径,算法的实际运行时间约为O(k(m+nlogn)),即传统Dijkstra算法的k倍(k为约束个数). |
| 关键词: 模拟退火 能量函数 QoS路由 多约束 可扩展性 |
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| 基金项目:Supported by the National Natural Science Foundation of China under Grant Nos.90104002, 60203025 (国家自然科学基金); the National High-Tech Research and Development Plan of China under Grant Nos.2002AA103067, 2001AA121013 (国家高技术研究发展计划(863)) |
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| A QoS Routing Algorithm by Applying Simulated Annealing |
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CUI Yong,WU Jian-Ping,XU Ke
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| Abstract: |
| As a challenging problem of the upcoming next-generation networks, multi-constrained quality-of- service routing (QoSR) is to find a feasible path that satisfies the multiple constraints simultaneously. For the NP complete problem, the heuristic SA_MCP by applying the simulated annealing to Dijkstra’s algorithm is proposed. SA_MCP first uses a non-linear energy function to convert multiple QoS weights to a single metric and then seeks to find a feasible path by simulated annealing. This paper overviews the simulated annealing method and analyzes the issues when it is applied to QoSR. Extensive simulations show the following conclusions: (1) SA_MCP has a high performance w.r.t. routing success ratio. (2) It has a good scalability in both network scale and weight number k. (3) It is insensitive to the distribution of QoS constraints. Furthermore, when most QoS requests are feasible, the running time of SA_MCP is about O(k(m+nlogn)), which is k times that of the traditional Dijkstra’s algorithm. |
| Key words: simulated annealing energy function QoS routing multiple constraints scalability |
