  Due to the increasing demand on user data rates, future wireless
communication networks require higher spectral efficiency. To reach higher
spectral efficiencies, wireless network technologies collaborate and construct
a seamless interconnection between multiple tiers of architectures at the cost
of increased co-channel interference. To evaluate the performance of the
co-channel transmission based communication, we propose a new metric for area
spectral efficiency (ASE) of interference limited Ad-hoc network by assuming
that the nodes are randomly distributed according to a Poisson point processes
(PPP). We introduce a utility function, U = ASE/delay and derive the optimal
ALOHA transmission probability p and the SIR threshold \tau that jointly
maximize the ASE and minimize the local delay. Finally numerical results has
been conducted to confirm that the joint optimization based on the U metric
achieves a significant performance gain compared to conventional systems.
