  In the next generation cellular networks, device-to-device (D2D)
communication is already considered a fundamental feature. A problem of
multi-hop D2D networks is on how to define forwarding algorithms that achieve,
at the same time, high delivery ratio and low network overhead. In this paper
we aim to understand group meetings' properties by looking at their structure
and regularity with the final goal of applying such knowledge in the design of
a forwarding algorithm for D2D multi-hop networks. We introduce a forwarding
protocol, namely GROUPS-NET, which is aware of social group meetings and their
evolution over time. Our algorithm is parameter-calibration free and does not
require any knowledge about the social network structure of the system. In
particular, different from the state of the art algorithms, GROUPS-NET does not
need communities detection, which is a complex and expensive task. We validate
our algorithm using different publicly available data-sources. In real large
scale scenarios, our algorithm achieves approximately the same delivery ratio
of the state-of-art solution with up to 40% less network overhead.
