# Self-Configuring IoT Service QoS Guarantee Using QBAIoT
## 1 Introduction  
Internet of Things (IoT) is nowadays evident in our everyday life. We estimate the economic impact of the IoT to be between $3.9 and $11 trillion dollars by 2025 [1]. Indeed, billions of connected objects exist with an average of two devices per human on earth resulting in creating the IoT environment [2]. The future growth of IoT will lead to an important usage of technology in our daily life. Thus, this usage of technology aims to improve the human's quality of life by facilitating everyday tasks. To ensure better user experience and improve the usage of IoT applications, a certain service level corresponding to specific IoT services is needed to motivate the users to use the IoT applications. The expected service level should consider not only QoS guarantee, measured through different performance parameters (i.e., delay, packet delivery ratio, etc.), but also security and users' privacy issues within different layers of the IoT architecture [3, 4]. We consider in this paper the QoS part of a service level and we specify a QoS mechanism enabling the guarantee of a service level prior to the IoT service subscription. In this context, the IEEE 802.15.4 standard is used as a base for different communication technologies in the IoT environment and specifically in the e-health application domain. Thus, we specify a novel QoS based wireless access method for IoT environments called QBAIoT. Our method is an enhancement of the slotted Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) technique, used by the beacon-enabled mode of the IEEE 802.15.4 standard. In this paper, we extend our previous work [5]. The objective of the proposed method is to guarantee QoS parameters corresponding to the requirements of a specific IoT service such as e-health. These requirements arespecified into a contract called IoT SLA (iSLA) negotiated between the IoT Service Provider (IoT-SP) and the IoT Client (IoT-C). In this research work, we aim to present the design details and performance evaluation of our proposed QBAIoT access method and its usage in an IoT architecture in order to satisfy the requirements of an e-health service according to a proposed iSLA. In addition, we present an enhancement of QBAIoT considering a self-configuring capability for minimizing human intervention and responding to the IoT environment changes. The reminder of the paper is organized as follows. We present in Section 2 the state of the art concerning the IoT environment, the self-management in IoT and the important characteristics of the IEEE 802.15.4 technology. Section 3 describes the QoS motivations in the IoT as well as our service level based IoT architecture along with the proposed iSLA and its establishment. Then, we specify in the same section our proposed method enabling QoS based access for IoT environments and the corresponding self-configuring capability. Section 4 presents a detailed performance evaluation of our novel self-configuring access method while we compare it to the standard IEEE 802.15.4 access method as well as another QoS based access method called SDA (Service Differentiated and Adaptive) CSMA/CA. Finally, we conclude the paper in Section 5 and present future works.