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 twoway transmission capacity are derived for frequency division duplexing. The obtained 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 the number of bits allocated for feedback. Most of the prior work on finding the transmission capacity has been limited to one-way communication (no data communication from the destination to the source) [1]-[4], [6]- [9] , and precludes the possibility of two-way communication. In two-way (bidirectional) communication the destination also has data to send to its source, e.g., downlink/uplink transmission, channel state feedback [10], packet acknowledgement [11] , or route initiation and update requests [12] . In this paper we consider an ad-hoc network with twoway communication, where each source destination pair has data to exchange in both directions. We consider a general system where the data rate requirement in both directions can be different, and a frequency division duplex (FDD) communication model, where two separate frequency carriers are used for two directions, thereby forming a full-duplex link. We define the metric of two-way transmission capacity when the transmitter and receiver locations are assumed to be distributed as a Poisson point process (PPP).
In REF , Vaze et al. derived the lower and upper bounds of two-way transmission capacity.
Two-Way Transmission Capacity of Wireless Ad-hoc Networks
IEEE Transactions on Wireless Communications
IEEE Transactions on Wireless Communications
Mathematics Computer Science