  6G wireless networks will integrate communication, computing, localization,
and sensing capabilities while meeting the needs of high reliability and
trustworthiness. In this paper, we develop similar techniques as those used by
communication modules of previous generations for the sensing functionality of
6G networks. Specifically, this paper introduces the concept of extended
automatic repeat request (e-ARQ) for integrated sensing and communications
(ISAC) networks. We focus on multi-static sensing schemes, in which the nodes
receiving the reflected sensing signals provide the transmitting nodes with
configurable levels of feedback about the sensing result. This technique
improves the sensing quality via retransmissions using adaptive parameters. We
show that our proposed e-ARQ boosts the sensing quality in terms of detection
accuracy and provides a sense of adaptability for applications supported by
ISAC networks.
