Widely used
smart devices with networking capability form
novel networks, such as pocket switched network
(PSN). Due to the mobility of devices, PSNs are
intermittently connected, and effective routing
protocols are essential in such networks. Previous
methods relied on building and updating
routing tables to deal with dynamic conditions.
Actually, the social structure and the interaction
of users of smart devices have a great influence
on the performance of routing protocols. BUBBLE
Rap [13] is a social-based forwarding
method for PSNs. Two social and structural metrics,
centrality and community, are used to effectively
enhance delivery performance. As shown
in Fig. 2, BUBBLE Rap first uses a centrality
metric to spread out the messages (i.e., sending
messages to more popular nodes), and then uses
a community metric to identify the destination
community and focus the messages to the destination.
The evaluation shows that BUBBLE Rap
has a similar delivery ratio, but much lower
resource utilization than flooding, control flooding,
and other social-based forwarding schemes.