Quorum Systems towards an Asynchronous Communication in Cognitive Radio Networks

Abstract

This paper reviews quorum systems (QS) from the perspective of cognitive radio networks. Quorum systems were originally developed for and widely used in the scope of operating systems. Recently, quorum systems have been also started to be applied to wireless communications. The objective of this paper is threefold. First, the paper provides survey and guidance on the use of quorum systems. Second, it shows that QS properties provide an interesting alternative towards an asynchronous communication in cognitive radio ad hoc networks (CRANs). Due to properties of quorum systems it is possible to establish CRANs without employing a common control channel (CCC), perfect synchronization, or central controller architecture. QS properties can be efficiently utilized to handle the rendezvous (RDV) problem in CRANs. New RDV protocols must be designed in such a way that there is a guarantee that all nodes meet periodically within reasonable periods of time. Since pseudorandom solutions do not provide this guarantee, systematic approaches are needed such as QSs. Third, we also propose a novel distributed RDV protocol, MtQS-DSrdv, which is based on mirror torus QS and difference set concepts. The proposed protocol guarantees RDVs on all available channels while CR nodes have the same channel set.

An analysis of asynchronism of a neighborhood discovery protocol for cognitive radio networks

“…In [5] one can find a comprehensive guidance on the application of QSs in wireless communications, and RDV issues in decentralized CRNs. There are a number of different approaches of a neighborhood discovery such as,…”

“…• QS-based protocols for CRNs ( [5], [14], [16], [17]). There are only a few papers considering the asynchronism of the CR nodes during the rendezvous phase.…”

“…In [18], through the comparison of the MMC [8] with RCA [19] algorithms on a testbed using USRP, it is shown that added asynchronism can have a large beneficial effect reducing the time-to-rendezvous (TTR) 1 . To the best of our knowledge there are only a couple of papers focusing on quorum based asynchronous rendezvous [14], [16], [5], [17]. The references [14], [16], [5], and other above mentioned articles dealing with the asynchronism, do not consider the channel heterogeneity in the generation of channel hopping sequences and asynchronous operation for rendezvous between CRs.…”

Quorum system and random based asynchronous rendezvous protocol for cognitive radio ad hoc networks

“…In [6] one can find a comprehensive guidance on the application of quorum systems in wireless communications, and rendezvous issues in decentralized CRNs. In general, rendezvous approaches can be divided into three branches, first, non-quorum based solutions representing blind or pseudo-random RDV techniques ( [7][8][9] and more sophisticated [10,11]).…”

“…Up to the best of the authors' knowledge there is only a couple of papers focusing on quorum based asynchronous rendezvous [6,17,20,22]. However, these papers as well as the aforementioned work dealing with the asynchronism, do not handle the channel heterogeneity in the generation of channel hopping sequences and do not handle the details of asynchronous operation and rendezvous between the devices.…”