  We consider a wireless network with a base station broadcasting and
collecting time-sensitive data to and from spatially distributed nodes in the
presence of wireless interference. The Age of Information (AoI) is the time
that has elapsed since the most-recently delivered packet was generated, and
captures the freshness of information. In the context of broadcast and
collection, we define the Age of Broadcast (AoB) to be the amount of time
elapsed until all nodes receive a fresh update, and the Age of Collection (AoC)
as the amount of time that elapses until the base station receives an update
from all nodes.
  We quantify the average broadcast and collection ages in two scenarios: 1)
instance-dependent, in which the locations of all nodes and interferers are
known, and 2) instance-independent, in which they are not known but are located
randomly, and expected age is characterized with respect to node locations. In
the instance-independent case, we show that AoB and AoC scale
super-exponentially with respect to the radius of the region surrounding the
base station. Simulation results highlight how expected AoB and AoC are
affected by network parameters such as network density, medium access
probability, and the size of the coverage region.
