Channel Access Using Opportunistic Reservations and Virtual MIMO

We propose ORCHESTRA, a channel access protocol that uses reservations and virtual MIMO to provide high throughput and bounded channel access delays. Channel access process is divided into a contention-based access period and a scheduled access period. To attain high throughput, nodes build the channel schedule using the contention-based access period, and utilize the spatial multiplexing gain of virtual MIMO links in the scheduled access period. To attain bounded channel access delays, nodes reserve time slots through opportunistic reservations. We evaluate the performance of ORCHESTRA through numerical analysis and simulations, and show that it results in much better throughput, delay, and jitter characteristics than simply using MIMO nodes together with scheduled access (i.e., NAMA) or contention-based access (i.e., IEEE 802.11 DCF).