Theses & Dissertations

Permanent URI for this collection

https://hdl.handle.net/20.500.14170/209

Browse

Browsing Theses & Dissertations by Subject "Ad hoc networks"
  • Publication
    An optimized congestion control mechanism of Vanets for non-safety messages transmission using Taguchi method
    ( 2017)
    Shamsul Jamel Elias
    Vehicular ad hoc networks (VANETs) are emerging technology concept in mobile ad hoc networks (MANETs). High speed and frequent network topology changes are the main characteristics of vehicular networks and Internet accessibility. This networking technology provides vehicles with endless possibilities of applications, including non-safety, comfort and entertainment. Due to high speed and mobility of nodes and their frequent disconnections, it is difficult to design a MAC scheme in VANETs that satisfies the Quality-of-Service (QoS) quality-of-service requirements in all networking scenarios. In this thesis, we provide a comprehensive evaluation of the mobility impact on the IEEE 802.11p MAC performances. The study evaluates basic performance metrics such as delay, packet delivery ratio (PDR), throughput, as well as the impact of mobility factors. The study also presents a relation between the mobility factors and the respective medium access impact according to the changes in tested network environment. Moreover, a new discriminatory problem according to node relative speed is identified for city (eCCOM), highway (paMAC) and hybrid (inHAN) scenarios. To achieve better performance, we propose smart optimization mechanism for congestion control and algorithm to alleviate network performance degradation due to high mobility. Extensive simulation results show the significant impact of mobility on the IEEE 802.11p MAC performance, an identification of a new unfairness problem in the vehicle-to-infrastructure (V2I) communications.
  • Publication
    New design of wireless ad-hoc network (WAHCN) for motorway monitoring system
    ( 2013)
    Layth Abdulkareem Hassnawi
    Motorway surveillance system is one of the most important technologies used today to collect information about traffic conditions. Traditional camera motorway surveillance systems are based on wired or infrastructure wireless network technology; whereby the system is designed to send the information (images) to a predetermined location (the “Base Station”). The traditional system does not provide effective access to the surveillance system network for motorway users. In this thesis a newly designed motorway surveillance system network called Wireless Ad Hoc Camera Network (WAHCN) is proposed, modeled and analyzed. WAHCN enables motorway users to access image data taken by a network of cameras placed along the motorway. It provides improved safety awareness by allowing motorway users to view traffic and road conditions. The topology design of WAHCN imposes several constraints on the amount of images can be transmitted through the network depending on the size and the rate of the packets generated by each camera. Moreover, the results showed that the WAHCN provides better performance for vehicle speeds of less than 120 Km/h. A new protocol based on transmission range of the nodes is developed to effectively manage the operation of selecting, finding and requesting the desired camera without using GPS. This protocol is called Selecting and Finding Position (SFP) protocol and provides an effective way to acquire images from any camera within the WAHCN. Routing in any network system is a critical task, especially for WAHCN due to the highly dynamic environments. Different types of routing protocols may give different network performance due to the different functional mechanisms of these protocols. The performance evaluations, comparisons, and analysis for three routing protocols (AODV, DSR, and OLSR) for WAHCN are presented in this thesis. The evaluation and analysis are performed for different performance metrics and under different network conditions. The results showed that under various vehicle speeds and different network loads AODV outperforms DSR and OLSR protocols, with respect to network throughput (by 35.11% and 10.24%, respectively) and protocol overhead (by 20.51% and 57.38%, respectively). From these results a new routing protocols is proposed and called Modified AODV (MAODV). MAODV protocol has all the characteristics of the original AODV protocol since it follows all the steps of the route discovery and route maintenance mechanism of the original AODV. In MAODV, one of the cameras which belongs to the old route is forced to start the process of rediscovering a new path to the unreachable destination instead of the source node when link breakage occurs. The modification of AODV reduces protocol overhead and packet transmission time delay, which leads to an improvement in WAHCN performance.