Multiple-Relay Slotted ALOHA: Performance Analysis and Bounds

Wireless random access protocols are attracting a revived research interest as a simple yet effective solution for machine-type communications. In the quest to improve reliability and spectral efficiency of such schemes, the use of multiple receivers has recently emerged as a promising option. We st...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on communications Vol. 69; no. 3; pp. 1578 - 1594
Main Authors: Munari, Andrea, Clazzer, Federico, Liva, Gianluigi, Heindlmaier, Michael
Format: Journal Article
Language:English
Published: New York IEEE 01.03.2021
The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subjects:
Coding
Encoding
Fading channels
grant-free access
Lower bounds
Machine type communications
multiple receivers
Packet transmission
Policies
Random access
random linear coding
Receivers
Relays
Spatial diversity
Statistics
Throughput
ISSN:0090-6778, 1558-0857
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Wireless random access protocols are attracting a revived research interest as a simple yet effective solution for machine-type communications. In the quest to improve reliability and spectral efficiency of such schemes, the use of multiple receivers has recently emerged as a promising option. We study the potential of this approach considering a population of users that transmit data packets following a simple slotted ALOHA policy to a set of uncoordinated relays ( phase-1 ). These, in turn, independently forward - part of - what decoded towards a collecting sink ( phase-2 ). For an on-off fading channel model, we provide exact expressions for phase-1 throughput and packet loss rate for an arbitrary number of relays, characterising the benefits of multi-receiver schemes. Moreover, a lower bound on the minimum amount of phase-2 resources needed to deliver all information collected at the relays is provided. The bound is proven to be achievable via random linear coding when no constraints in terms of latency are set, with an overhead that approaches zero with the inverse of the packet length. We complement our study discussing a family of simple forwarding policies that require no packet-level coding, and optimising their performance based on the amount of available phase-2 resources. The behaviour of both random linear coding and simplified policies is also characterised when receivers are equipped with finite buffers, revealing non-trivial tradeoffs.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 14
ISSN:0090-6778
1558-0857
DOI:10.1109/TCOMM.2020.3042552