Research On Spatial-Temporal Dimensions Of 5G Networks Based On User Mobility

The fourth-generation mobile communications system(4G)has been utilized for many years,and the data carried by it is gradually increasing.However,due to the new requirement of wireless applications,the transmission capabilities of 4G systems have been overstretched.Based on the above fact,the 3rd Generation Partnership Project(3GPP)affiliated has put the development and standardization of the 5th generation mobile communication technology(5G)on the agenda and planned to commercialize the 5G system by 2020.According to the plan of 3GPP,the maximum capacity of the 5G system will be 1000 times larger than that of the 4G system and take into account a variety of different types of application requirements.To this end,5G systems are decided to be divided into three major application scenarios named enhanced mobile broadband scenarios(EMBB)for high-speed data transmission,massive machine-based communication for large-scale device access(MMTC),and ultra-reliable low latency communication scenario(URLLC)for low latency and highly reliable data transmission.On the other hand,as a hotspot technology in the field of 5G communication,high-density heterogeneous cellular networks(UDHNs)have attracted worldwide attention.By widely deploying the low-power small cell base stations(SBS),the distances between network users and base stations can be greatly reduced as well as the large-scale fading experienced by wireless signals,and hence improving users' experience and network performance.On the other hand,due to the highdensity deployment of SBS,the spatial data transmission capacity in the network has been greatly improved,and the user experience can be greatly improved in the areas with high user density.However,since the data processing capability and the signal transmission power of SBS are very low compared to macrocell base stations(MBS),the coverage area of SBS is much smaller than that of MBS.Therefore,unlike the traditional MBS-based cellular network,the movement of UDHN users will affect the overall performance of the network,and from the traditional mobile users to the vehicular type users,this impact will increase with the user's increasing velocity.How to model the moving characteristics of the user,and how to further analyze the network performance and assess the impact of user dynamic characteristics on the network performance on this basis have not yet been systematically studied.Based on this,this article will study the performance of 5G UDHN under dynamic user scenarios,and further explore the methods of modeling user mobility and its impact on network performance.The main contributions of this article are as follows:Firstly,considering the fact that the density of SBS is very large in 5G UDHN,currently there is no effective technology for the full usage of such a large density of SBS.A 5G UDHN SBS group service strategy to overcome this challenge was proposed in this paper,and a stochastic geometry and group service strategy based 5G UDHN model was proposed to solve the implicit expressions of interferers and signal sources.Moreover,the expression of an expected number of SBS in a serving cluster is derived.The corresponding numerical results show that when considering the SBS group service strategy,a lower density of SBS can also achieve very objective network performance.Secondly,as the density of SBS is very high in a 5G UDHN,user mobility may have a larger impact on network performance.In order to study this problem,an individual mobility model(IMM)and stochastic geometry based 5G UDHN model was introduced to solve the problem caused by the aggregation characteristics and tendencies of network user's.Based on the proposed model,the coverage probability for network users and the expected number of SBS in a serving cluster are derived.Corresponding numerical simulation results show that SBS density outside of the hotspot area has a greater impact on network coverage performance.Thirdly,the performance of 5G UDHN is highly related to the distribution of users in the network and the actual distribution of users in the network is non-uniform.In order to deeply study the influence of non-uniform distributed user density on network performance,the queuing network theory is used to expand the radiation and absorption model in the time domain.Based on the proposed model,user density distribution,user coverage probability,call blocking probability,network throughput and other important performance indicators were derived in this paper.Corresponding numerical simulation results show that the blocking rate of the user first increases and then decreases with the increase of the threshold of signal to interference plus noise ratio(SINR)instead of increasing monotonically.Fourthly,as a main application of 5G UDHN in the URLLC communication scenario,5G vehicular networks have extremely high requirements for the delay and reliability of data transmission,while the transmission delay and transmission reliability in a 5G vehicular network are a pair of coupled performance indicators that the optimization for one of them individually may cause a performance drop for another.In order to study this issue in depth,a spatial-temporal two-dimensional analysis model of 5G vehicle networking was constructed in this paper,and the coupling expression of data transmission delay and reliability in 5G vehicle networks is derived.Corresponding numerical simulation results show that the delay and reliability of data transmission in 5G vehicle networks are not linear coupled,but nonlinear coupled with the multidimensional parameters of the network.To sum up,in the actual deployment environment,this paper considers the performance of UHDN where the user's spatial position changes dynamically,the UDHN performance under non-uniform user density,and the modeling and analysis of data transmission delay and reliability in 5G vehicular networks.Out of innovative research.The research results have a certain guiding significance for the actual deployment of UDHN and 5G vehicular networks,and it is helpful for the further design and optimization of network transmission protocols.It also provides a reference for the actual design and optimization of 5G vehicular networks.