基于情景感知的Ad Hoc网络带宽管理机制

Context awareness based bandwidth management scheme for Ad Hoc network

为了在资源受限的Ad Hoc网络中优先保障关键业务,提出一种基于情景感知的Ad Hoc带宽管理机制(context-aware bandwidth management scheme,简称CABMS)。网络节点收集本地情景信息,以贝叶斯网络作为情景推理工具判断业务重要性,确定带宽分配的效用函数。通过建立原问题的对偶问题和引入带宽"影子价格",实现节点自主根据带宽价格调整带宽请求,并使带宽分配算法快速收敛。CABMS将业务分为不同等级。当带宽资源紧缺时,高等级业务优先得到带宽;在带宽严重不足时,拒绝部分常规业务请求,以保证关键业务的带宽需求。仿真结果表明,在给定网络条件下,与比例公平机制相比,紧急业务分配的带宽增加了约42%,重要业务分配带宽基本未变,而常规业务分配的带宽下降了约37%,CABMS可在保证一定公平性前提下给相对重要的业务流分配更多带宽份额。

In order to guarantee key businesses when bandwidth resource is in shortage,an adaptive and flexible context-aware bandwidth management scheme（CABMS）is proposed to improve Ad Hoc network survivability.Nodes firstly query the local context information,and use Bayesian network（BN）to determine the importance of current business and the utility function of bandwidth allocation.Through establishing the dual problem of original one,the ＂shadow price＂ of bandwidth is introduced,so that the nodes are able to adjust bandwidth requests on their own according to the price with the convergence of allocation result.CABMS business is classified into different levels.When bandwidth resource is in shortage,the highclass business will be biased in bandwidth allocation;when in severe shortage,some regular business bandwidth requests will be rejected in order to guarantee the bandwidth requests of key business.Simulation results indicate that CABMS can assign more bandwidth to relatively important business under given conditions,compared with proportional fairness,urgent business bandwidth allocation increases by about 42%,important business bandwidth allocation remains essentially unchanged,and the regular allocate bandwidth falls by about 37%.