Research On Discrete-Time Priority Polling System With Multi-times Gated And Exhaustive Service

As a periodic dynamically dividing service resource,polling system is stable and periodic.Polling scheduling strategy has been widely used in communication,industrial control,production,traffic control and other fields.With the development of ubiquitous network,communication system services will meet transferability,scalability of overall service capability and flexible service demand of different individual besides meeting the changes of increasing in the number of terminals,transferring data increased dramatically,distinguishing between business diversity and real-time security.How to design an efficient polling control method is a valuable research direction.At the same time,the paper makes a deep research on the communication network by using the polling system model,which can be used to quantify the performance and quality of service.Therefore,it is a hot research topic for scholars to further optimize the structure and improve the polling system.On the basis of the theoretical model and simulation experiment of the gated,multi-gated,exhaustive and gated-exhaustive polling systems.Starting with the following three basic elements:optimizing and improving the query sequence,service strategy and service order,so as to meet the requirements of flexible controllable service and differentiated priority service,this paper proposed a new two-class priority polling system which on foundation of dividing the queues into the key queue and the common queues with different priorities,the key queue use exhaustive service while the common queue use multi-times gated service that could control the times of gated service.Iterative equations are set up by taking second-order partial derivatives of the generating function,and then the integral mathematical analytical expressions of the key indexes are derived via simultaneous solution,concerning the mean queue length,the mean waiting time of the key queue and common queues,and the mean polling period time of this system.Lastly,computer simulations is done,finding that theoretical and simulation results are identical.Showing that the system increases the flexibility by changing the service mode to control the ability of the station to obtain the service resources,on the basis of providing the periodic high and low priority services.This result is a perfect illustration of the evolution process from gate-exhaustive service to exhaustive-exhaustive service,complement and perfect the theory about the polling system.