Research On Capacity Of Heterogeneous Wireless Networks Based On Directional Antennas

Wireless ad hoc networks(WANETs)is a collection of connected nodes that can be self-organized dynamically.These nodes communicate with each other over a wireless medium.The network is infrastructureless,convenient and smart,hence it attracted more attention in the past years.Mobile ad hoc networks(MANETs)and wireless sensor networks(WSNs)are two typical examples of WANETs.In these network scenarios,efficient information transport is the primary objective as well as the biggest challenge of the network design.Meanwhile,how to evaluate the improvement of new technology to the network transmission performance is desiderate to solve.Network capacity theory is a key to solve these problems.By analyzing the capacity of large-scale networks,we can accurately evaluate the transmission performance of networks and the improvement of new technology to the network communication performance,which can be further of guide significance to the network design and optimization.As the types of networks become more and more,wireless heterogeneous networks are widely applied,because of the better transmission performance.Hence,the research on capacity of heterogeneous networks becomes a hot spot.In this paper,we investigate the throughput capacity of wireless networks with directional antennas.Firstly,for the hot area build-up effect,we investigate the capacity of inhomogeneous hybrid networks.By setting different distribution probabilities for each cell,an inhomogeneous hybrid network model is presented.On the basis,we derive the asymptotic expressions of network capacity.Moreover,we analyze the influence of some factors to the network capacity,such as different channel allocation schemes,the number of base stations and directional antennas.Our fruit is of great guide significance to the design and optimization of inhomogeneous hybrid networks.Then,for the heterogeneous mobile networks whose backbone networks consist of wireless communication nodes,we investigate the capacity problem based on D-delay transmission scheme.We adopt virtual channel model to give an intuitive analysis on the throughput capacity under fast mobility model and slow mobility model.Through strict mathematical proof,we obtain the asymptotic expressions of the two types of networks.We also analyze the impact of some network factors to the network capacity,such as mobility,delay constraint and the number of helping nodes.Our fruit fills a gap in the capacity research.Finally,for the trend of development which wireless networks are extending from two-dimensional space to three-dimensional space,we investigate the capacity of three-dimensional regular networks,three-dimensional stable heterogeneous networks and three-dimensional mobile heterogeneous networks.The asymptotic expressions on the throughput capacity of these three types of networks are obtained respectively.For three-dimensional regular networks,we analyze the impact of regular topology and directional antennas to the network capacity;for stable heterogeneous networks,we maximize the capacity under different channel allocation schemes;for mobile heterogeneous networks,we compare the difference between two-dimensional networks and three-dimensional networks,we also analyze the influence of mobility,delay constraint and the number of helping nodes to the network capacity.Our fruit is of great guide significance to the design and development of next generation networks.