Hemminger T L, Pomalaza-Raez C A
School of Engineering and Engineering Technology, Penn State University, Behrend College, Erie 16563-1701, USA.
Int J Neural Syst. 1996 Nov;7(5):617-26. doi: 10.1142/s0129065796000609.
The primary function of a packet radio network is the efficient transfer of information between source and destination nodes using minimal bandwidth and end-to-end delay. Many researchers have investigated the problem of minimizing the end-to-end delay from a single source to a single destination for a variety of networks; however, very little work is reported about routing mechanisms for the common case where a particular information packet is intended to be sent to more than one destination in the network. This is known as multicasting. A simplified version of the problem is to ignore the packet delay at each node, then the problem becomes one of finding solutions which require the least number of transmissions. Determination of an optimal solution is NP-complete meaning that suboptimal solutions are frequently tolerated. The problem becomes more rigorous if packet delays are included in the network topology. This paper describes a practical technique for the computation of optimum or near optimum solutions to the multicasting problem with and without packet delay. The method is based on the Hopfield neural network and experiment has shown this method to yield near optimal solutions while requiring a minimum of CPU time.
分组无线网的主要功能是使用最小带宽和端到端延迟在源节点和目的节点之间高效传输信息。许多研究人员针对各种网络研究了将从单个源到单个目的的端到端延迟最小化的问题;然而,对于特定信息包要发送到网络中多个目的的常见情况的路由机制,所报道的工作很少。这就是所谓的多播。该问题的一个简化版本是忽略每个节点处的分组延迟,那么问题就变成了寻找所需传输次数最少的解决方案之一。确定最优解是NP完全问题,这意味着经常容忍次优解。如果在网络拓扑中考虑分组延迟,问题就会变得更加严格。本文描述了一种计算有和没有分组延迟的多播问题的最优或接近最优解的实用技术。该方法基于霍普菲尔德神经网络,实验表明该方法能产生接近最优的解,同时所需的CPU时间最少。