How do i do packet size aggregation Hold time method or FIFO Method.

I have design for IEEE802.11b standard network running on different speeds 1,2,5.5,11mbs ,the code works fine but right now moving to the next stage for aggregation of packets size. i find it little difficult to design Packet size aggregation code using Hold time method aggregation or FIFO aggregation method or any other method to aggregates(sum) the packet to send it in one transmission process and compare the results. how to create the relay for the process . find attached image.