# Device Centric Throughput and QoS Optimization for IoTsin a Smart Building Using CRN-Techniques
## 1 Introduction
Without loss of generality, we keep the same terms of PUs and CRs for our cognitive IoT-enabled smart building system, i.e., the mobile users, IoT devices and networking monitors (NMs) deployed inside the building are referred to as CRs or SUs and the few mobile terminals as PUs. The work in the domain of channel assignment of CRNs can be classified based on their architecture (centralized or distributed), allocation behavior (cooperative or non-cooperative), access technology (underlay or overlay) and scope (intra or inter) [33; 34; 35]. The research articles [27; 34; 35] are focused on the QoS provisioning in CRNs, but they are inclined towards cellular communication. In [36], an internetwork channel assignment scheme is presented to improve overall throughput at reduced interference. However, it ignores the QoS requirement desired by the PUs. Although the scheme presented in [37] considers the QoS parameters, it completely ignores the availability of the channel due to PU activity. In [38], the authors present a channel assignment scheme considering both the QoS parameters and PU activity. However, this scheme does not incorporate the traffic pattern for the applications running on different IoT devices. Similarly, the schemes presented in [39; 40; 41; 42] target the energy efficiency, but they all lack in considering the PU activity and QoS of SUs. Likewise, the authors in [43; 44] concentrated on congestion avoidance along with energy balancing, but do not consider individual QoS for optimal operation. Although the aforementioned schemes [33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44] are optimizing their objective functions, they are not suitable and applicable for the data dissemination of the IoT devices in a smart building environment. Hence, we propose a novel channel assignment scheme that considers the QoS requirements of different IoT devices, the availability of a channel due to the PU activity and the traffic patterns of different applications running on different IoT devices. The main contributions of our scheme can be summarized as follows:* An optimization problem is formulated for the channel assignment to different SUs (i.e., IoT devices, mobile user) in a smart building environment. The objective is to serve the maximum SUs while satisfying their desired QoS. * The optimization problem considers the number of QoS parameters (e.g., data rate, bit error rate and channel stability index) while taking into account the availability of channels by the PU activity and traffic patterns for different IoT applications. * A novel particle swarm optimization-based algorithm is proposed to solve the optimization problem. * To evaluate the performance of the proposed algorithm, exhaustive simulations are carried out by varying different parameters (e.g., the number of channels, the number of devices under scenarios where each IoT device uses different applications). The rest of the paper is organized as follows. Section 2 describes the system model. Section 3 defines the problem formulation steps. Section 4 illustrates the details about the PSO implementation. Simulation results are presented in Section 5. Finally, Section 6 concludes the findings and sets the future directions.