On Performance Modeling of 3 D Mobile Ad Hoc Networks

Three-dimensional mobile ad hoc networks (3D MANETs) are a class of peer-to-peer networks, where nodes moving in three-dimensional space communicate with each other via wireless link without any pre-existing infrastructure and central management. As 3D MANETs can be easily deployed and flexibly reconfigured, they are used in many fields, such as (1) modern warfare, aircrafts in the sky, troops on the land, fleets on the sea, communicate with each other for cooperative combat, (2) ocean surveillance, underwater vehicles communicate with each other for data collection and transmission, (3) disaster monitoring, unmanned aerial vehicles communicate with each other for data collection and transmission. However, there is still a long way to go before 3D MANETs could be widely commercialized and implemented. The very roadblock that has been stunting the application of 3D MANETs is the lack of a general network information theory, which is expected to establish a thorough understanding on the fundamental performances in such networks, like the delivery probability, delivery delay, throughput capacity, etc. The available works on this line mainly focus on two-dimensional network scenario, which cannot tell us about the fundamental performances in 3D MANETs. Towards such a target in 3D MANETs, we develop theoretical frameworks to analytically study the MANET delivery probability, delay and the throughput capacity performances in this thesis. Specifically, we focus on an important class of 3D MANETs—the twohop relay 3D MANETs, i.e., the MANETs adopting the popular and efficient two-hop relay algorithms for packet routing. Firstly, we study packet delivery probability in 3D MANETs. We develop a Markov chain theoretical framework to depict packet delivery process under two-hop relay algorithm with packet redundancy. With the help of the theoretical framework, the analytical expression was derived for packet delivery probability. We further present extensive simulation and numerical results to validate our theoretical framework and to show our findings. We also attempt to simulate the packet delivery probability over the broadcast channel mode. When a node gets a transmission opportunity, it broadcasts the copies of the packet to the nodes which locate in the same cell or its 26 adjacent cells. The number of the broadcast is set to f for each packet. The simulation results show that the delivery probability of using broadcast is higher than using unicast. Although the simulation results show that the delivery probability performance under broadcast is better than that under unicast. This thesis does not adopt the broadcast traffic pattern. This is because under such a traffic pattern, the number of relay nodes carrying the packet is unknown, which makes it more difficult to develop a Markov chain to analytically study the packet delivery performance. Secondly, we study the packet delivery delay performance in 3D MANETs. A Markov chain theoretical frame is developed to depict packet delivery process under two-hop relay algorithm with packet redundancy. Under the Markov chain theoretical framework, the analytical expression was derived for mean packet delivery delay. Besides that, the corresponding relative standard deviation was further derived. We provide simulation results to validate the theoretical models on the packet delivery i delay and corresponding relative standard deviation not only under independent and identically distributed (i.i.d.) mobility model, but also under the random walk and random waypoint mobility models. Extensive simulation and numerical results with different parameters are further provided to do performance analysis and show the packet delivery performance in 3D MANET is different from that in 2D MANET. Thirdly, we study the throughput capacity in 3D MANETs. We first construct two absorbing Markov chain theoretical frameworks to depict the packet distributing process at source and the packet receiving process at destination. Based on these two Markov chain theoretical frameworks, an analytical expression for the throughput capacity is further derived. We provide extensive simulation and numerical results to validate our theoretical models and to show our findings. Finally, we introduce our future works. In this thesis, we adopt unicast for packet dispatching, one interesting future direction is to further explore the performance of 3D MANETs under a more efficient packet dispatching way, e.g. broadcast. We developed Markov chain-based theoretical frameworks to explore packet delivery performance in cell-partitioned 3D MANETs, it will be an interesting direction to study how to evaluate the performance under our theoretical frameworks in other network scenarios, such as delay tolerant networks (DTNs) and ALOHA networks. We focus on two-hop relay 3D MANETs, another interesting direction is to further extend the developed theoretical models to analyze packet delivery performance in multi-hop relay 3D MANETs. It is also interesting to explore the network performance with the consideration of constraints of nodes buffer size and packet loss in our future research.