Frequent-Pattern-Based Broadcast Scheduling for Conflict Avoidance in Multichannel Data Dissemination Systems

Algorithm 2

Functions used for the FP-tree’s backbone construction.

1: Function

   Input: a sorted set of queries (clients) ;

   Output: a basic FP-tree ;

2:  create a empty FP-tree and the root of ;

3:  set into a query table ;

4:  let .first()

5:  let a temporary pointer ;

6:   for each requested data in do;

7:    ;

8:  end;

9:  update ;

10:  while contains any unhandled required data do

11:    the query with the maximum number of unhandled data items in ;

12:   for each unhandled requested data in do;

13:     find the other queries which also needs data and then choose one of the handled data nodes whose slot is maximum in

14:    ;

15:   end;

16:   update ;

17:  end;

18:  return;

19: end;

20: Function

   Input: an FP-tree , the parent node , and a new data item ;

   Output: an added node ;

21:  create a new node with data item

22:  if has children then

23:   create an empty node ;

24:   .addChild();

25:   let a temporary pointer ;

26:   while.isOverload(.slot+1) do

27:    create an empty node ;

28:    .addChild();

29:    ;

30:   end;

31:   .addChild();

32:  else

33:   .addChild();

34  end;

35:  return;

36: end;