Zigzag-Division Multiple Access for Wireless Networks with Long and Heterogeneous Delays

A new random channel access framework, named as zigzag-division multiple access (ZDMA), is proposed for wireless networks with long and heterogeneous propagation delays to achieve system throughput significantly larger than 1. The key idea is to allow simultaneous transmissions at the transmitters and employ zigzag decoding at the receiver. After studying the zigzag decoding, we present three new random access protocols. Extensive numerical studies show that incorporating ZDMA in existing slotted Aloha and tree splitting protocols can significantly increase system throughput. The third protocol of greedy scheduling with ZDMA achieves the highest throughput performance.