Network Basic Attributes And Network Planning Research In Wireless Multi-hop Networks

With the advent of the era of "Internet of Everthing",the demand for wireless communication in various fields is becoming more and more urgent.Although the traditional cellular wireless communication technology has entered the age of 5G,wireless LAN technology has also experienced a lot of technical innovation,wireless multi-hop network still occupies an irreplaceable position in many application fields because of its network flexible,easy deployment,low cost and strong extensibility.Now the wireless multi-hop network has been widely used in post-disaster emergency communication,battlefield communications and environmental monitoring,etc.Meanwhile,according to different application scenarios,the wireless multi-hop network spawned a large number of application oriented networks,such as wireless sensor network,vehicle ad-hoc network and aviation ad-hoc network,etc.,which has greatly enriched the diversity of wireless multi-hop network.Since the birth of the wireless multi-hop network,to ensure its usability,researchers have proposed a lot of network strategies such as networking and accessing strategies.At the same time,a lot of research models for network basic attribute have been proposed.With the maturity of wireless multi-hop network technology,network performance analysis has become a research hotspot.Therefore,the research of wireless multi?hop network mainly focuses on the design of network strategy,the research of network properties and the analysis of network performance,and the emphasis is on the design of network strategy.In order to improve the performance of wireless multi-hop network,such as delay,throughput,energy consumption of nodes and convergence time and so on,a lot of research gradually tend to improve the existing network strategies by applying a number of optimization algorithms.Eventhough we get many technical support on all levels,such as data fusion and network coding on application level,routing strategy on network level,the development of wireless multi-hop network still faces a lot of problems.Bandwidth slump problem,hop spot problem and stability problem of large scale networking all limit the practical application of wireless multi-hop network.One of the primary causes is that we blindly pursue the promotion of network performance and do not do a deep research on the network basic attributes and ignore their theoretical guidance.The basic attributes of wireless multi-hop network determine the usability and stability of the network,which is the basis and design direction of network strategy and the premise of network performance analysis.Any form of communication network,cable and wireless nertwork,cellular and wireless multi-hop network,the network strategy designing and network planning should be done according to the research of network basic attributes.However,at present,the research on wireless multi-hop network attribute is fragmented and has no systematic research results.The above theoretical deficiency is the main factor limiting the development of wireless multi-hop network and it is also a key problem to be solved urgently.This article focuses on the research of network basic attributes,such as network connectivity,path reliability and node mobility.By modelling the inherent attributes of multi-hop network,we analyze the basic attributes comprehensively on three levels,network,link and node.According to the relationship of these basic attributes,we analyze their limitations on network planning,including network radius,node density and network architecture designing.After getting the inherent defects of wireless multi-hop network and the limitation on the network planning brought by the basic attributes,we design a new network architecture for wireless sensor network.Further more,we also design an energy-efficient algorithm for the new designed network architecture.According to the main line mentioned above,this article mainly contains the following parts.1.Network basic attributes modellingNetwork basic attributes modelling is the core of the paper.This part mainly completes the network connectivity,path reliability and node mobility modelling and put forward a wireless multi-hop network basic attributes research framework.For network connectivity,we apply a statistical parameter model to analyze the probability of the existence of a multi-hop path for a given node,which is the measurement of network connectivity.For path reliability,we model the routing process of a given multi-hop path with Markov chain model and finally get the rouoting success probability of a given node,which is the measurement of path reliability.For node mobility,we analyze the stability duration of a given path and make it the measurement of topology dynamic change degree.Then we compare the routing discovery time and the stability duration of the same given multi-hop path.The time difference between routing discovery time and stability duration is the measurement of node mobility.In this part,we focus on two essential characteristics of wireless multi-hop network,wireless and multi-hop.We first analyze the existence of a multi-hop path,then the probability of successfully finding such multi-hop path,and finally the stability duration of this multi-hop path.For the follow-up research,the way we analyze the basic network attributes offers a feasible research framework.2.The limitations of basic attributes on network planningIn this part,we mainly analyze the limitations of basic attributes on network radius designing,node density designing and network architecture designing.Based on the research results of network basic attributes modeling,we get the closed-form solutions of each indicators of network basic attributes.Through the comparison of simulation and theoretical results,the limitations on network radius,node density and network architecture designing are analyzed.Network planning is one step before the utility of multi-hop network and our research proboses the theoretical direction of network planning.3.New network architecture designingIn this part,we design a new network architecture for wireless sensor network.In consideration of the restriction of path reliability,we apply the software defined networking architecture in wireless sensor network and design a software defined wireless sensor networking architecture.The original intension of our design is to use the advantages software defined networking to overcome the limitation of path reliability on wireless sensor network.By applying the centralized control and data and control plane separation mechanism,the probability of routing success is improved.In this part,we first analyze the feasibilities of applying software defined networking in wireless sensor network.Then we design the new network architecture as well as the network protocol process.We finally test the performance difference between traditional wireless sensor network and the new proposed wireless sensor network architecture.4.Energy-efficient algorithm for the new network architectureBased on the new proposed wireless sensor network architecture,we design an energy-efficient algorithm,multi-energy-space based energy-efficient algorithm.We consider the residual energy of sensor nodes and assign an energy space for each sensor node.According to the principle that the nodes in higher energy space protect the nodes in lower energy space,we design data forwarding rules for all sensor nodes to reap the benefit of energy saving.Finaly,the simulation results show that the proposed energy-efficient algorithm performs better than the traditional energy-efficient algorithms.