Efficient Coding-Based Scheduling for Multi-Item Requests in Real-Time On-Demand Data Dissemination

Algorithm 1

NC-based PVC scheduling algorithm.

  At the beginning of each broadcast slot

() for Each arrived multi-item request   do

()   Insert into the requests’ queue

() end for

() while The requests’ queue is not empty do

()    for Each multi-item request   do

()      Calculate ’s scheduling weight according to Definitions 1–10, insert into the service queue in descending order of

         scheduling weight ;

(   end for

()   Select the request with the most scheduling weight as the schedulable request , further select the data item with the

      most absolute profit, , as the seed for network coding. That is

()   Construct the instantly decodable coding graph as described in Section 4.2.2

()   Find the maximal clique in graph which contains the seed item and XOR all items in this clique as the encoded packet,

       and broadcast the packet to all clients.

()   Update each client’s status of received and request data items. Renew the requests’ queue and the service queue by removing

       requests which get satisfied or miss their deadlines.

() end while