Using Local Expiration Timers to Reduce Buffer Utilisation When Using Epidemic Diffusion
Enrique Hernández‐Orallo, Carlos Borrego, Carlos T. Calafate, Juan‐Carlos Cano · 2019
Opportunistic Networking (OppNet) is a consolidated networking paradigm based on intermittent connectivity between wireless mobile devices. In OppNet, mobile nodes store, carry and forward messages by taking advantage of wireless ad-hoc communication opportunities. A common approach for the diffusion of information in OppNet is the epidemic protocol, which carries out a fast information diffusion at the expense of increasing the usage of local buffers on mobile nodes. Nevertheless, due to this high local buffer usage and the usually reduced hardware capabilities of Internet of Things (IoT) devices, OppNet utilisation for IoT applications can be severely reduced. Therefore, a way to reduce the local buffer usage is to set a message expiration timer that forces the removal of old messages in the local buffers. Nevertheless, since dropping messages may reduce the speed of message diffusion, we propose to conveniently adjust this expiration timer, using a model to obtain the optimal expiration times that achieve performances similar to those ideal approaches where no expiration is considered, with a significant reduction of local buffer usage.