1 Department of Electronic Systems, The Technical Faculty of IT and Design, Aalborg University, VBN2 Antennas, propagation and radio networking, The Technical Faculty of IT and Design, Aalborg University, VBN3 The Faculty of Engineering and Science (TECH), Aalborg University, VBN4 MassM2M, The Technical Faculty of IT and Design, Aalborg University, VBN
Various applications of wireless Machine-to-Machine (M2M) communications have rekindled the research interest in random access protocols, suitable to support a large number of connected devices. Slotted ALOHA and its derivatives represent a simple solution for distributed random access in wireless networks. Recently, a framed version of slotted ALOHA gained renewed interest due to the incorporation of successive interference cancellation (SIC) in the scheme, which resulted in substantially higher throughputs. Based on similar principles and inspired by the rateless coding paradigm, a frameless approach for distributed random access in the slotted ALOHA framework is described in this paper. The proposed approach shares an operational analogy with rateless coding, expressed both through the user access strategy and the adaptive length of the contention period, with the objective to end the contention when the instantaneous throughput is maximized. The paper presents the related analysis, providing heuristic criteria for terminating the contention period and showing that very high throughputs can be achieved, even for a low number for contending users. The demonstrated results potentially have more direct practical implications compared to the approaches for coded random access that lead to high throughputs only asymptotically.
I E E E Transactions on Communications, 2013, Vol 61, Issue 11, p. 4653-4662