To forward or not to forward: optimal message scheduling in mobile opportunistic networks

Official URL: https://dx.doi.org/10.1109/LCN52139.2021.9524986

Mobile opportunistic networks (MONs) are characterized by frequently changing network topology that rely on multi-copy transmission schemes to ensure the delivery of messages. However, the limited buffer capacity of mobile nodes leads to buffer overflow and head-of-line blocking. Head-of-line-blocking is caused due to short contact duration, which causes the older messages to be replicated at a faster rate than the newer messages waiting behind them. This unfair replication decreases the message delivery ratio and increases the average delivery delay. For implementation, we categorize a message as new or old and calculate the necessary maximum number of replicas required to deliver a message to the destination. If the instantaneous number of replicas in the network is less than this number, we schedule a message for replication and vice-versa. We demonstrate that our proposed scheme achieves a delivery ratio comparable to a utility-based optimal message drop algorithm with significantly lower overhead.