Link-quality based routing framework for wireless sensor networks

Intelligence is the power which makes the owner capable of making a decision defined by reasoning. When traditional solutions and approaches, such as First Principal Modelling or Statistical Modelling, are not feasible or able to effectively address complex real- world problems, then Computational Intelligence with some nature-inspired computational techniques and methodologies is employed. For transferring data between two non-directly connected devices when some other devices are in-between, a set of rules are used by routers which are devices between sender and receiver, to determine the most appropriate paths into which routers should forward data toward the intended destination. This set of rules is called routing protocol. Researchers use some computational itelligence techniques to design network routing protocols. Wireless Sensor Networks (WSNs) play an important role in today's data communication systems and researchers are expected to proliferate in the field of wireless communication in the near future. The deployment of wireless sensor networks offer several advantages in comparison to traditional infrastructure-based networks, such as fully distributed mobile operation, the easy discovery of joining wireless devices, and instant and low cost network setup. Designing an effective routing protocol is one of the main challenges in the ad-hoc networking paradigm and the utilisation of an adequate link-cost metric is essential. WSN researchers address issues such as low throughput and high latency in wireless sensor data communication. Routing Protocols in WSNs play a key role in data communication and the main parameter in all routing protocols is data communications link-cost. This research delivers two surveys on existing routing protocols and link-quality metrocs for wireless sensor networks. Most of the routing protocols in this area are considered in different groups. The majority of link-quality metrics in WSNs are studied in different categories. Link-quality and traffic-aware metrics account for most of the metrics, as well as metrics in multi-channel networks and cognitive radio systems, which are also considered in detail. Metrics are reviewed in detail in terms of their performance; summary and comparison tables of link-quality metrics are provided to enable better comparison and show a brief overview of their appearance to get a clearer picture. Routing-metrics are important is determining paths and maintaining quality of service in routing protocols. The most efficient metrics need to send packets to maintain link-quality measurement by using the Radi Frequency (RF) module. In this study, a set of statistical analyses is done on some link-quality metrics to select the best metric for energy-aware scenarios. Two prominent link-quality metrics; Received Signal Strength Indication (RSSI) and Link-Quality Indication (LQI), are described in detail. The symmetry of RSSI and LQI in two directions is studied, and relations with the Expected Transmission Count (ETX), RSSI, and LQI as link-quality metrics are analysed. The evaluation in this research is based on a series of WSN test-beds in real scenarios. Due to implementation of routing protocols in limited power supply devices in WSNs, one novel link-quality metric and also some routing protocols for wireless sensor networks are proposed in this research to obtain better performance in different scenarios. Rainbow Collection Tree Protocol (RCTP) is presented and evaluated as an enhanced version of Collection Tree Protocol (CTP). It uses the Trickle algorithm to optimise overhead cost and the algorithm also makes RCTP quickly adaptable to changes in topology. The Rainbow mechanism is used in RCTP to detect and route around connectivity nodes and avoid routes through dead-end paths. Energy-efficient Rainbow Collection Tree Routing Protocol (ERCRP) is presented and evaluated as a novel, real-time, position-based and energy-efficient routing protocol in this research. ERCRP is a lightweight protocol that reduced the number of nodes which receive the RF signal using a novel Parent Forwarding Region (PFR) algorithm. ERCRP as a Geographical Routing Protocol (GRP) reduced the number of forwarding nodes and thus decreases traffic and packet collision in the network. WSNs are used in three-dimension (3D) scenarios such as sea or land surfaces with different levels of height. Three-Dimension Position-Based Adaptive Real-Time Routing Protocol (3DPBARP) is presented and evaluated as a novel, real-time, position-based and energy-efficient routing protocol for WSNs in this research. 3DPBARP is a lightweight protocol that reduces the number of nodes which received the RF signal using a novel PFR algorithm. 3DPBARP as a GRP decreases the number of nodes which participate in packet forwarding and thus shrink the traffic and collision in the network.