Scheduling and Dropping Policies in Delay Tolerant Network

Sometimes end to end connectivity may not exist between the nodes, sometimes it is too expensive to connect all the networks and sometimes due to some catastrophic effect, exchanging of messaging are difficult, so it can cause delays from hours to days, hence networking of this type of situation is called as Delay Tolerant Network. As no end to end connectivity between the nodes so it require buffer at each node to store incoming messages. The network uses a store-carry-forward mechanism, while sending a message from one node to another node. Messages which are stored at each node carry along with him until it reaches to the next node and then forward. Here two scheduling policies are named as PRIORITY+ algorithm and FACTOR algorithm. PRIORITY+ algorithm considers a priority of message with different routing algorithm. FACTOR algorithm considers the TTL value with priority of that particular message. Algorithms can achieve better delivery ratios with less overhead and latency ratio.