Random access schemes for satellite networks, from VSAT to M2M: a survey

Summary In this survey paper, we review the random access (RA) techniques with particular emphasis on the issues and the possible solutions applicable to satellite networks. RA dates back to the 1970s when the ALOHA protocol was developed to solve the problem of interconnecting university computers located in different Hawaiian islands. Since then, several evolutions of the ALOHA protocol have been developed. In particular, solutions were devised to mitigate the problem of packet collisions severely degrading the RA protocols performance. The approach followed for many years has been to avoid the occurrence of collisions rather than solving them. More recently, techniques tackling the RA packet collision problem have appeared triggered by the need of improving RA performance in satellite and terrestrial wireless networks. In particular, satellite networks large propagation delay does not allow the adoption of enhanced terrestrial RA techniques based on channel sensing. Adopting conventional demand assignment multiple access protocols is not suitable for supporting a large number of sensors or devices transmitting small‐size low duty cycle packets as required for machine‐to‐machine communications. This provided the stimulus to exploit successive interference cancelation schemes to solve packet collision issues. The use of successive interference cancelation in RA is relatively new and has opened up a promising research area. We provide an extensive review of recent high‐performance RA techniques achieving more than three orders of magnitude throughput increase compared with the original ALOHA at low packet loss rate. In this survey, we cover both slotted and unslotted techniques. Finally, we review the use of RA in satellite systems and related standards including recent proposals for machine‐to‐machine applications. Copyright © 2016 John Wiley & Sons, Ltd. This survey aims to review recent advances in the field of random access (RA) for satellite networks. Until recently, the use of RA in satellite networks was limited to initial logon or to low‐efficiency messaging systems. The large satellite propagation delay and its noise‐limited nature have recently triggered the development of some unconventional solutions to make RA protocols able to efficiently cope with collisions, which may find also application in terrestrial networks for machine‐to‐machine communications.