  Age of Information (AoI) is a newly appeared concept and metric to
characterize the freshness of data. In this work, we study the delay and AoI in
a multiple access channel (MAC) with two source nodes transmitting different
types of data to a common destination. The first node is grid-connected and its
data packets arrive in a bursty manner, and at each time slot it transmits one
packet with some probability. Another energy harvesting (EH) sensor node
generates a new status update with a certain probability whenever it is
charged. We derive the delay of the grid-connected node and the AoI of the EH
sensor as functions of different parameters in the system. The results show
that the mutual interference has a non-trivial impact on the delay and age
performance of the two nodes.
