# Performance Optimization of MANET Networks through Routing Protocol Analysis
## 1 Introduction  
A Mobile Ad Hoc Network (MANET) is an autonomous ad hoc wireless network that consists of many nodes, in which the nodes dynamically move so that the topology changes [1]. MANET can communicate without centralized administration and is supported by wireless communication technologies such as WiFi, ZigBee, and WiMAX [2]. MANET is generally used in places where a permanent infrastructure cannot be formed, such as disaster areas, battlefields, cars, military formations, ships, and aircraft intended to form temporary networks, so that the devices can be free both in and out of network coverage [3, 4, 5]. Nodes in MANET in the form of communication devices are laptops, smartphones, and sensors. Their performance characteristics include dynamic topology and limited bandwidth, battery life, processing power, and storage capacity [6]. The MANET simulation's mobility model is divided into four categories: random models, models with temporal dependency, models with spatial dependence, and models with geographic restrictions [7]. In this research, we used mobile modeling of moving nodes to avoid obstacles [8], randomly [9], in a limited simulation space on an ad hoc network. The challenges of routing and security should be identified properly before deploying a MANET [10]. The routing protocols play an important role in ensuring reliable communication among nodes in MANET [11]. Routing is the process of transmitting packets from one network to another [12]. Routing protocols in MANET must also be able to adjust the changes in the changing network topology. Therefore, a reliable routing protocol is needed with a low overhead in managing MANET, which can be seen from the Quality of Service (QoS) parameters such as Packet Delivery Ratio (PDR), throughput, packet loss, and delay [13, 14, 15]. Several kinds of research have been conducted on reactive and proactive routing protocols on MANET. Among the results, studies show that the Ad Hoc On-demand Distance Vector (AODV) protocol has good throughput and end-to-end delay [5], good energy consumption [16], is suitable for application to moving nodes [17], and has a good performance with increased speed for average end-to-end metrics [18]. In contrast, the Optimized Link State Routing (OLSR) protocol is a proactive routing protocol developed based on the link state routing algorithm and is an optimal technique to extract information relating to the network topology [19]. OLSR has the advantage of the delay being relatively low because it is a routing table. Compared with AODV, OLSR has better throughput, packet loss, and delay [6]. OLSR has the advantage of average end-to-end delays, where the delay is less than other protocols [20], better in terms of dense and highly dynamic topology [21], and suitable for delay-sensitive applications [22]. Previous research using the AODV protocol has not examined the effect of the performance's changing parameters. However, in an ad hoc network environment such as MANET, the route discovery and route maintenance process is the key concept that deals with topology changes [23]. Other than that, routing parameter values such as Active Route Timeout (ART) also play an important role in providing stable routing in a dynamic environment, where the network topology changes continuously and quickly [23; 24]. Research on the performance of the default parameters has been carried out by [23; 24; 25; 26; 27]. Studies [25; 27] examined the effects of route maintenance and HELLO messages parameters. The route maintenance parameters are Active Route Timeout (ART) and delete period constant (n), while HELLO messages include HELLO_INTERVAL and ALLOWED_HELLO_LOST. Both studies show that the default parameters of the AODV protocol do not always produce the best results. The best results from the two studies were generated by reducing the parameter values, such as changing the ART value to 2.5 (default value: 2.5) and the HELLO_INTERVAL value to 0.5 (default value: 1).