  The transmission capacity of an ad-hoc network is the maximum density of
active transmitters per unit area, given an outage constraint at each receiver
for a fixed rate of transmission. Most prior work on finding the transmission
capacity of ad-hoc networks has focused only on one-way communication where a
source communicates with a destination and no data is sent from the destination
to the source. In practice, however, two-way or bidirectional data transmission
is required to support control functions like packet acknowledgements and
channel feedback. This paper extends the concept of transmission capacity to
two-way wireless ad-hoc networks by incorporating the concept of a two-way
outage with different rate requirements in both directions. Tight upper and
lower bounds on the two-way transmission capacity are derived for frequency
division duplexing. The derived bounds are used to derive the optimal solution
for bidirectional bandwidth allocation that maximizes the two-way transmission
capacity, which is shown to perform better than allocating bandwidth
proportional to the desired rate in both directions. Using the proposed two-way
transmission capacity framework, a lower bound on the two-way transmission
capacity with transmit beamforming using limited feedback is derived as a
function of bandwidth, and bits allocated for feedback.
