Speaker : Yuan-Hsun Lo (National Pingtung University)
Title : Random and Deterministic Schemes for a Collision Channel without Feedback
Time : 2019-08-09 (Fri) 15:00 - 16:00
Place : Seminar Room 722, Institute of Mathematics (NTU Campus)
Abstract: There are two main medium access control (MAC) approaches to a slot-synchronous collision channel without feedback: random (slotted ALOHA) and deterministic (protocol sequence-based) schemes. Unlike the traditional slotted ALOHA, protocol sequence-based scheme is a deterministic way to guarantee a positive individual throughput within an expectable period of time, even the time synchronous is hard to be achieved. In the first part of this talk, I will survey some results on protocol sequence-based schemes, including user-irrepressible (UI) sequences and conflict-avoiding codes (CACs). Then, for a fair comparison, deadline-constrained slotted ALOHA schemes will be introduced to maximize the probability that a packet can be successfully received within an pre-assigned deadline. Some recent progress including the derivative of the optimal transmission probability that maximizes the successful delivery probability is addressed as well.