## 1 Introduction  
### Motivation  
Smart Grid (SG) is the 21 st century electric power grid infrastructure that has been proposed to improve the efficiency, reliability, and safety of the 20 th century hierarchical, centrally controlled power generation, transmission, and distribution methods [1, 2]. These improvements can be established by introducing two-way electrical and information flows for traditional power grids. Smooth integration of renewable energy sources and modern information and communication technologies are the key milestones in the process of transition from a traditional power grid to SG [3, 4]. Smart Grid Architecture basically consists of three layers: the Application layer, power layer, and communication layer. Application layer consists of interoperable advanced applications, whereas the power layer integrates renewable energy sources into power generation system and two way communication into all power generation, transmission and distribution system, and customer premises [3]. This paper directly addresses aspects on Application layer and communication layer. When considering about the communication layer, information and communication technologies provide a platform to collect this information from different entities in SGs. The most attractive platform is the Internet of Things (IoT) which is a network of connected devices [5; 6; 7]. In SG environments, the end device of the IoT platform is a smart object that has the sensing, processing and networking capabilities [8]. Typical examples are sensor nodes and Radio Frequency Identification Devices (RFIDs) [9; 10]. The accuracy of the information produced by these devices is a key factor for reliable power delivery from generation to end user in SGs. The information generated by these devices is contaminated by measurement noise and quantization noise [11; 12]. Thus, it is more reliable to gather information from multiple end devices corresponding to a single physical phenomenon. As these devices are not expensive and small in size, it is feasible to deploy these devices in larger quantities. Usually, these devices are not directly interfaced to the internet backbone. There exists a fewer number of units that are capable to collect all information of these devices and route them to the internet backbone. There are back-bone points, back-haul aggregation points, and access points at the end of Wide Area Networks (WANs), Field Area networks (FANs) and Home Area Networks (HANs), respectively. These aggregating nodes are called as sink nodes. Effective information gathering methods are essential to propagate the information from end devices to sink node. Sensor nodes need to be energy efficient since the sensor nodes have a limited energy. Information gathering using wired cable is not feasible in SG environments due to electromagnetic interference from power lines, incompatibility to wide area network architecture, and availability only to licensed users despite the available resources of power lines and low latency communication. When the wireless sensors network is equipped with cognitive radio, which dynamically access the spectrum, the spectrum efficiency increases and interferences and congestion decreases, and communication errors can be further reduced in SGs [13]. In particularly, installation of expensive cables and regular maintenance of them are an additional burden for SGs. The most cost effective and easiest approach is to use wireless medium. It can be realized through modern IoT end devices that have wireless capabilities [14]. However, drastic environmental conditions such as highly caustic or corrosive environments, high humidity levels, vibrations, dirt and dust, which exist in SG environments can cause high bit error rates during transmissions. In addition, wireless communication is prone to multipath fading and channel characteristic can be dynamic. Therefore, bit errors which occur during the wireless communication added with quantization and sensor noise will degrade the overall accuracy of the sensed parameter.