Real-time geographic routing is one of the most popular examples relying on a greedy
algorithm to deliver real-time data in wireless networks. Each sender node decides a next-hop node
among one-hop neighbours in stateless manner. However, this sender-side decision paradigm suffers
from periodic and network-wide beaconing to discover neighbour nodes. To overcome the limitation,
this paper suggests a passive and greedy beaconless real-time routing, called PGBR. To forward
real-time data by receiver-side selection, PGBR focuses on two major challenging issues: a delay
estimation procedure and a contention function design. The delay estimation procedure estimates both
waiting delay and packet transmission delay used for the contention function. PGBR also redesigns
receiver-side contention function with deliberating the estimated delay and discuss combinations of
important metrics for the contention. The experimental results show that PGBR could improve the
energy-efficiency as well as keeps high delivery deadline success ratio.