  The notion of age-of-information (AoI) is investigated in the context of
large-scale wireless networks, in which transmitters need to send a sequence of
information packets, which are generated as independent Bernoulli processes, to
their intended receivers over a shared spectrum. Due to interference, the rate
of packet depletion at any given node is entangled with both the spatial
configurations, which determine the path loss, and temporal dynamics, which
influence the active states, of the other transmitters, resulting in the queues
to interact with each other in both space and time over the entire network. To
that end, variants in the packet update frequency affect not just the
inter-arrival time but also the departure process, and the impact of such
phenomena on the AoI is not well understood. In this paper, we establish a
theoretical framework to characterize the AoI performance in the aforementioned
setting. Particularly, tractable expressions are derived for both the peak and
average AoI under two different transmission protocols, namely the FCFS and the
LCFS-PR. Based on the theoretical outcomes, we find that: i) networks operating
under LCFS-PR are able to attain smaller values of peak and average AoI than
that under FCFS, whereas the gain is more pronounced when the infrastructure is
densely deployed, ii) in sparsely deployed networks, ALOHA with a universally
designed channel access probability is not instrumental in reducing the AoI,
thus calling for more advanced channel access approaches, and iii) when the
infrastructure is densely rolled out, there exists a non-trivial ALOHA channel
access probability that minimizes the peak and average AoI under both FCFS and
LCFS-PR.
