Mobility metrics of wireless networks such as link availability, number of neighboring nodes, link duration, link state, and link stability make it difficult to provide a node with quality of services guarantee. In pr...Mobility metrics of wireless networks such as link availability, number of neighboring nodes, link duration, link state, and link stability make it difficult to provide a node with quality of services guarantee. In previous research on Quality of Service (QoS) for cellular networks especially for handling handoff connections, the design was based on a flat 2D hexagon cells. However, in reality Base Station antenna coverage is in a 3D space and there exists a blind spot;the area which is just above and bellow the radiated antenna. In this paper we introduce the concept of Blind Spot (BS) in which there is no signals to initiate a call or accepting a handoff one. In BS, the signal power equal zero. Even if there is enough bandwidth to initiate or accept a handoff call, it will be blocked or dropped respectively. We present an implementation of Static Borrowing Scheme (SBS) and we extend the dynamic-rate based borrowing scheme [1] into 3-Dimentional structure and call it 3-Dimensional Dynamic Based Borrowing Scheme (3D DBBS). The proposed new technique for resource sharing is to ensure the continuity for both originating and handoff connections in 3-D cellular networks based on Dynamic-Based Borrowing Scheme (3D BBS). This technique aims to minimize the blocking probability of the originating calls by minimizing the dropping probability of the handoff requests and maximizing the channel utilization. The results revealed that 3D DBBS outperformed the static based schemes by 5% on average even when the blind spot of the base station antenna is taken into consideration. When moving to a 3D space, the results of the simulation showed the 3D DBBS outperformed the static scheme by 2% on average. As a result, considering nodes in a 3D space will have better QoS guarantee as the blocking and dropping probabilities are decreased. Thus, the bandwidth utilization is increased.展开更多
在基于长期演进(Long-Term Evolution,LTE)技术的高速铁路(High-Speed Rail,HSR)通信中,信号的不稳定及频繁的切换给无线通信服务质量(Quality of Services,QoS)造成严重影响,时常发生掉话现象,从而导致通信中断。前、后天线的多次切换...在基于长期演进(Long-Term Evolution,LTE)技术的高速铁路(High-Speed Rail,HSR)通信中,信号的不稳定及频繁的切换给无线通信服务质量(Quality of Services,QoS)造成严重影响,时常发生掉话现象,从而导致通信中断。前、后天线的多次切换可有效解决通信服务质量问题,但是并没有考虑到前、后天线的综合利用率,以及何时将后天线加入切换,并与前天线并行完成多次切换问题。因此,论文提出一种改进型基站切换优化算法,即将检测到的最佳QoS的后天线即刻加入切换,与前天线并行完成多次切换,否则仅利用前天线独自完成多次切换,来提高天线的综合利用率问题,并对改进算法进行性能分析。实验仿真结果显示通信中断概率和切换失败概率均明显降低,得出论文算法可有效改善天线的综合利用率和提升基站切换性能。展开更多
文摘Mobility metrics of wireless networks such as link availability, number of neighboring nodes, link duration, link state, and link stability make it difficult to provide a node with quality of services guarantee. In previous research on Quality of Service (QoS) for cellular networks especially for handling handoff connections, the design was based on a flat 2D hexagon cells. However, in reality Base Station antenna coverage is in a 3D space and there exists a blind spot;the area which is just above and bellow the radiated antenna. In this paper we introduce the concept of Blind Spot (BS) in which there is no signals to initiate a call or accepting a handoff one. In BS, the signal power equal zero. Even if there is enough bandwidth to initiate or accept a handoff call, it will be blocked or dropped respectively. We present an implementation of Static Borrowing Scheme (SBS) and we extend the dynamic-rate based borrowing scheme [1] into 3-Dimentional structure and call it 3-Dimensional Dynamic Based Borrowing Scheme (3D DBBS). The proposed new technique for resource sharing is to ensure the continuity for both originating and handoff connections in 3-D cellular networks based on Dynamic-Based Borrowing Scheme (3D BBS). This technique aims to minimize the blocking probability of the originating calls by minimizing the dropping probability of the handoff requests and maximizing the channel utilization. The results revealed that 3D DBBS outperformed the static based schemes by 5% on average even when the blind spot of the base station antenna is taken into consideration. When moving to a 3D space, the results of the simulation showed the 3D DBBS outperformed the static scheme by 2% on average. As a result, considering nodes in a 3D space will have better QoS guarantee as the blocking and dropping probabilities are decreased. Thus, the bandwidth utilization is increased.
文摘在基于长期演进(Long-Term Evolution,LTE)技术的高速铁路(High-Speed Rail,HSR)通信中,信号的不稳定及频繁的切换给无线通信服务质量(Quality of Services,QoS)造成严重影响,时常发生掉话现象,从而导致通信中断。前、后天线的多次切换可有效解决通信服务质量问题,但是并没有考虑到前、后天线的综合利用率,以及何时将后天线加入切换,并与前天线并行完成多次切换问题。因此,论文提出一种改进型基站切换优化算法,即将检测到的最佳QoS的后天线即刻加入切换,与前天线并行完成多次切换,否则仅利用前天线独自完成多次切换,来提高天线的综合利用率问题,并对改进算法进行性能分析。实验仿真结果显示通信中断概率和切换失败概率均明显降低,得出论文算法可有效改善天线的综合利用率和提升基站切换性能。
