Energy-aware spectrum coordination with intelligent frequency-hopping for software defined networks

Abstract

Software-defined Cognitive radio (CR) networking is considered a promising communication paradigm that can deliver huge spectrum opportunities for enabling massive deployment for wireless Internet-of-Things (IoT) applications and services. An important challenge in this domain is how to provide effective energy-efficient distributed spectrum coordination mechanisms (known as Spectrum Rendezvous), through which the CR IoT users can opportunistically coordinate their transmissions over the idle licensed frequency channels without relying on the existence of a dedicated common control channel (CCC). This paper proposes a novel frequency hopping (FH) distributed rendezvous mechanism for CR-capable IoT (CR-IoT) networks using grid-based quorum systems, referred to as adaptive grid-based quorum channel-hopping scheme. The proposed quorum-based scheme divides the time into equidistant cycle segments, referred to as quorum-based FH intervals. Each quorum interval consists of equal-duration beaconing intervals, each associated with a licensed channel. According to the proposed algorithm, each CR-IoT device randomly selects awake-sleep schedules based on the adopted quorum system structure. Any two devices can exchange their control information over the assigned channels of their common awake beaconing intervals. The proposed algorithm provides probabilistic guarantees on the successful rendezvous (RDV) between any two CR-IoT users within a single quorum-based FH interval (cycle) and dynamically adjusts the adopted QS structure based on the time-varying traffic load in the CR-IoT network such that the RDV probability and the expected average time to rendezvous improve with the least possible energy consumption. Compared to reference design schemes, the simulation results demonstrate that the proposed algorithm significantly increases the RDV probability, reduces the average rendezvous time, and reduces the energy consumption per successful RDV.