Ad Hoc Network Routing Scheme And Resource Scheduling Scheme In Hybrid Network With Cellular Network

Nowadays with the significant popularity of notebook computers and wireless infrared equipment, wireless technologies have gained amazing development. Under this background, Ad Hoc Network's applications and researches in non-military field have developed considerably, due to its advantage in mobility, flexibility and autonomy. The researches on Ad Hoc network routing scheme and hybrid network with cellular network are becoming research focuses.At first, the paper researches the schemes of routing discovering and selecting in classification and analyzes their advantages and disadvantages. The importance of broadcast in routing discovering, the cause of broadcast storm, the method of preventing broadcast storm and the MAC-layer's random access mechanism in IEEE 802.11 are also investigated. This paper proposes a novel balanced energy-efficient routing scheme(BEERS)for Ad Hoc Networks with high speed nodes and frequent changing network topology. Compared with the existing routing scheme for Ad Hoc Network, the scheme proposed in this paper pays more attention to the balance of energy consumption between nodes while considering the energy consumption of the whole network from the perspective of distance between nodes and the node's residual energy. Thus, Ad Hoc Networks can have a longer lifetime. At the same time, the scheme reduces the collisions and improves the forwarding efficiency further through the random assess delay(RAD)and unified back-off.Then a simulation platform for Ad Hoc Networks is designed. The platform provides an independent network layer module and the interfaces so that it can be used in different routing scheme for Ad Hoc Networks. At the same time, the platform provides the simulation module of network layer and lower layers for the Ad Hoc network simulation. The proposed scheme and the counter-based scheme are simulated in this paper. By comparing in different simulation scenes, we can see that the performances of energy saving, power consumption balancing and network lifetime of the proposed scheme are better than that of the counter-based scheme. When the nodes are denser and their speeds are higher, the advantage of the proposed scheme is more obvious.At last, a resource scheduling scheme in two-hop OFDMA (Orthogonal Frequency Division Multiple Access) systems for the hybrid network of Ad Hoc network and cellular network is proposed. In the future mobile communication systems, hybrid organization of Ad Hoc network and cellular network can bring many advantages such as coverage increase, lower power consumption, and balanced flow of business. The proposed scheme, which is considered both in the first time sub-slot between direct link users and relay stations, and the second time sub-slot among relay link users, takes QoS (Quality of Service) support into consideration, as well as the system throughput and the fairness for users. The paper simulates the Two-Hop Proportional Fairness (THPF) scheme as well as the proposed scheme for comparison. Through the simulation results, we can see that the proposed scheme has better performances in system throughput, average service delay and average packet loss rate compared with the THPF scheme. The performances advantages of the proposed scheme become more pronounced especially when the number of users increases.