TDMA allocates slots in round-robin fashion to all the nodes (whether transmitting/receiving or not)

Dynamic TDMA allocates slots to those nodes that are currently part of the network. In DTDMA additional options for a node to Node Join or Node Leave is provided.

Node join(s) - It is the time at which the node joins the network and accesses the communication channel.
Node leave (s) – It is the time at which the node leaves the network.

For Eg,

Node join - 0, 10

Node leave - 5, 100

In this case, the node joins the network at 0s and leaves at 5s and the node re-joins the network again at 10s and leaves again at 100s. 

Whenever a node leaves the network, slot allocation is done without factoring in the node that has left. Therefore in Dynamic TDMA there is no wastage of slots like in TDMA.

DTDMA Slot Allocation is done based on either Round Robin or Demand-Based slot allocation techniques. The parameters that affect slot allocation are:

  • Slot Duration
  • Guard Interval
  • Slot Allocation Technique

The slot allocation pattern explains which time slot is allocated to which device. Slot allocation metrics are not available directly in the results window of NetSim and needs to be calculated from the Event Trace log file.

A document containing the steps to obtain the Slot allocation pattern for DTDMA protocol from the even trace is attached below.