So, given any one cluster head, if there are N other nodes in the same cluster (total N+1 nodes in the cluster), and there are C other clusters (total C+1 clusters), and there is 1 server of some kind, then:
- how much energy does the cluster head spend receiving sensor data from the other N nodes in the cluster? How many data packets have to be received from one non-head node per round?
- how much energy does the cluster head spend sending responses to the other N nodes transmitting data to the cluster head?
- Does the cluster head transmit its own sensor readings separately, or is it somehow bundling its own data and the data for the other cluster members when it transmits the data onwards?
- Does the cluster head exchange overhead packets with its cluster members apart from the data packets, such as "I am alive!" beacons from the members (which it might need in order to be able to transmit data needed by other clusters to form routing tables) ?
- Does the cluster head exchange routing packets with the other cluster heads and the host? If so is it sending to all of them, or is it a "store and forward" system where it transmits to the "next" cluster head in the chain which transmits onwards? Or is it a "store and aggregate" system where each node merges together all of the recent routing information from its "downstream" neighbours and sends it upstream?
- Is the energy needed to send a packet fixed, or does the transmitter adjust the sending power based on estimates of how far away the intended receiver is? Is there beamforming that can reduce the power towards the directions that the destination node is not expected to be present?
- Are you using "broadcast" packets intended to be heard by multiple cluster heads? Since there is a range of distances for which it is less expensive to broadcast a packet to two "nearby" destinations instead of sending two point-to-point packets?
- If you are aggegating information from multiple nodes to send on to other nodes, then what is the plan to deal with the fact that you might not have heard from some of the nodes this round?
- If you are using store-and-forward or aggregate-and-forward to send data "upstream" then what is the plan to deal with the possibility that the upstream node does not receive the data? What is the plan to deal with the possibility that the upstream node does receive the data but you do not hear the acknowledgement ?
