RAC²E: Novel rendezvous protocol for Asynchronous Cognitive radios in Cooperative Environments

Abstract

This paper introduces a novel rendezvous protocol (RAC 2 E) for dynamic control channel provisioning among cognitive radios in a decentralized and cooperative ad-hoc environments. Unlike previous work in the field, RAC 2 E does not require synchronization in the radio environment. Its main characteristics are lightweight design and scalability. The paper elaborates RAC 2 E operation, gives a numerical analysis of its performance behavior under different circumstances and demonstrates its functionalities on a testbed platform realized with four Universal Software Radio Peripheral 2 (USRP2) nodes.

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

“…The former allows to benefit from the asynchronous and randomness properties, originally proposed in [3] as part of the RAC 2 E protocol. The latter uses a grid Quorum System (gQS) properties, originally proposed in [4,5], in order to deal with a rendezvous guarantee in a single cycle.…”

“…However, the reader should note that spectrum maps can be still utilized to determine the priorities of the channels and as a consequence the order of the channel in the channel ranking list. From now on, while talking about the RAC 2 E, we refer to the aforementioned part of the RAC 2 E-gQS protocol, and not original one designed in [3].…”

“…This goal is accomplished by an enhancement of the channel mapping algorithm by utilizing a torus QS properties in a grid array. Moreover, note that the RAC 2 E, proposed in [3], has already been implemented on a testbed platform (the results are presented in [3]), and the proposed protocol in this work, optimized RAC 2 E-gQS, is under implementation and evaluation phase. Figure 2 shows the steps of the RAC 2 E-gQS protocol.…”

“…In our optimized approach, opt GD RC , (for the sake of the RCP property we optimize the gQS mapping with the row-column selection and diagonal slot distribution) we use a torus concept allocating quorum slots for the best channels, but in a r × r grid, i.e., our torus-in-grid quorum is composed of r + ⌊ r 2 ⌋ elements, where a tail is selected in a forward-wrap manner (according the standard torus definition) 3 . The remaining elements of the column, which normally are also attributed to the best channels with the gQS mapping, are now equally distributed to the last worst channels.…”

“…Therefore, rendezvous (RDV), the ability of two or more nodes to meet each other and establish a link, is a challenging task in CRANs. This paper proposes a rendezvous protocol for CRANs that, firstly, utilizes the asynchronous and randomness properties of the RAC 2 E protocol [3]. Secondly, it investigates the suitability of different channel search orders that are based on:…”