随着移动设备和无线应用爆炸式增长,蜂窝网络流量迅速增加,许可频段蜂窝网络容量难以满足用户日益增长的数据速率需求.WLAN(Wireless Local Area Network,无线局域网)与LTE(Long Term Evolution,长期演进)蜂窝异构网络中的数据卸载技术...随着移动设备和无线应用爆炸式增长,蜂窝网络流量迅速增加,许可频段蜂窝网络容量难以满足用户日益增长的数据速率需求.WLAN(Wireless Local Area Network,无线局域网)与LTE(Long Term Evolution,长期演进)蜂窝异构网络中的数据卸载技术能有效缓解蜂窝无线访问的频谱资源紧缺问题.然而,现有LTE-WLAN数据卸载方案并未考虑密集部署问题,也未考虑基于IEEE 802.11ax协议的下一代高效WLAN针对密集部署提出的提速新技术所带来优势.本文利用下一代WLAN的多用户传输特性来缓解蜂窝的资源竞争,通过将部分蜂窝用户卸载到IEEE 802.11ax WLAN网络来保障蜂窝网络的单用户吞吐率.提出的卸载方案建立WLAN和LTE异构密集网络的吞吐率形式化表达式,根据网络系统容量查找蜂窝网络中的最优卸载数,以解决有限的蜂窝网络资源与海量高速业务需求的矛盾.仿真结果表明:在密集部署的异构网络中,所提的方案在保证WLAN用户服务质量的同时,最大限度地提高了LTE网络单用户吞吐率,提升了LTE网络的用户体验.展开更多
IEEE802.11,known as WiFi has proliferated in the last decade.It can be found in smartphones,laptops,smart TVs and surveillance cameras.This popularity has revealed many issues in health,data privacy and security.In th...IEEE802.11,known as WiFi has proliferated in the last decade.It can be found in smartphones,laptops,smart TVs and surveillance cameras.This popularity has revealed many issues in health,data privacy and security.In this work,a WiFi measurement study has been conducted in Amman,the capital city of Jordan.An Android App has been written to harvest WiFi information of the transmitted frames of any surrounding Access points(APs).More than 240,000 APs information has been harvested in this work.The harvested data have been analyzed to find statistics ofWiFi devices in this city.Moreover,three power distribution models have been derived from the data for three different areas,closed,open and hybrid areas.In addition,the collected data revealed that the SSID can be leveraged as a landmark for the access points(APs).To this end,SSIDtrack algorithm is proposed to track shoppers/walkers in closed areas,such as malls to find their walking route utilizing only the SSID information collected from the surrounding area.The algorithm has been tested in two different malls that consist of four different floors.The accuracy recorded for the algorithm acceded 95%.展开更多
This paper explores and compares FER (Frame Error Rate) of a MAC (Medium Access Control) layer in the IEEE 802.11 a/g/n wireless LAN. It is evaluated under the fading wireless channel, using theoretical analysis metho...This paper explores and compares FER (Frame Error Rate) of a MAC (Medium Access Control) layer in the IEEE 802.11 a/g/n wireless LAN. It is evaluated under the fading wireless channel, using theoretical analysis method. It is analyzed by using the number of stations with both variable payload size and mobile speed on the condition that fading margin and transmission probability are fixed. Especially, in the IEEE 802.11n, A-MSDU (MAC Service Data Unit Aggregation) scheme is considered and the number of subframe is used as the variable parameter. In the IEEE802.11a/g wireless LAN, fixed wireless channel is assumed to be Rayleigh fading channel. Mobile wireless channel is assumed to be flat fading Rayleigh channel with Jake spectrum. The channel is in fading states or inter-fading states by evaluating a certain threshold value of received signal power level. If and only if the whole frame is in inter-fading state, there is the successful frame transmission. If any part of frame is in fading duration, the frame is received in error.展开更多
IEEE 802.11ah is a new Wi-Fi standard for sub-1Ghz communications,aiming to address the challenges of the Internet of Things(IoT).Significant changes in the legacy 802.11 standards have been proposed to improve the ne...IEEE 802.11ah is a new Wi-Fi standard for sub-1Ghz communications,aiming to address the challenges of the Internet of Things(IoT).Significant changes in the legacy 802.11 standards have been proposed to improve the network performance in high contention scenarios,the most important of which is the Restricted Access Window(RAW)mechanism.This mechanism promises to increase the throughput and energy efficiency by dividing stations into different groups.Under this scheme,only the stations belonging to the same group may access the channel,which reduces the collision probability in dense scenarios.However,the standard does not define the RAW grouping strategy.In this paper,we develop a new mathematical model based on the renewal theory,which allows for tracking the number of transmissions within the limited RAW slot contention period defined by the standard.We then analyze and evaluate the performance of RAW mechanism.We also introduce a grouping scheme to organize the stations and channel access time into different groups within the RAW.Furthermore,we propose an algorithm to derive the RAW configuration parameters of a throughput maximizing grouping scheme.We additionally explore the impact of channel errors on the contention within the time-limited RAW slot and the overall RAW optimal configuration.The presented analytical framework can be applied to many other Wi-Fi standards that integrate periodic channel reservations.Extensive simulations using the MATLAB software validate the analytical model and prove the effectiveness of the proposed RAW configuration scheme.展开更多
文摘随着移动设备和无线应用爆炸式增长,蜂窝网络流量迅速增加,许可频段蜂窝网络容量难以满足用户日益增长的数据速率需求.WLAN(Wireless Local Area Network,无线局域网)与LTE(Long Term Evolution,长期演进)蜂窝异构网络中的数据卸载技术能有效缓解蜂窝无线访问的频谱资源紧缺问题.然而,现有LTE-WLAN数据卸载方案并未考虑密集部署问题,也未考虑基于IEEE 802.11ax协议的下一代高效WLAN针对密集部署提出的提速新技术所带来优势.本文利用下一代WLAN的多用户传输特性来缓解蜂窝的资源竞争,通过将部分蜂窝用户卸载到IEEE 802.11ax WLAN网络来保障蜂窝网络的单用户吞吐率.提出的卸载方案建立WLAN和LTE异构密集网络的吞吐率形式化表达式,根据网络系统容量查找蜂窝网络中的最优卸载数,以解决有限的蜂窝网络资源与海量高速业务需求的矛盾.仿真结果表明:在密集部署的异构网络中,所提的方案在保证WLAN用户服务质量的同时,最大限度地提高了LTE网络单用户吞吐率,提升了LTE网络的用户体验.
基金This work is funded by Al-Zaytoonah University of Jordan under project name“miniature distributed architecture for massive data processing”with the grant number 15/12/2019-2020。
文摘IEEE802.11,known as WiFi has proliferated in the last decade.It can be found in smartphones,laptops,smart TVs and surveillance cameras.This popularity has revealed many issues in health,data privacy and security.In this work,a WiFi measurement study has been conducted in Amman,the capital city of Jordan.An Android App has been written to harvest WiFi information of the transmitted frames of any surrounding Access points(APs).More than 240,000 APs information has been harvested in this work.The harvested data have been analyzed to find statistics ofWiFi devices in this city.Moreover,three power distribution models have been derived from the data for three different areas,closed,open and hybrid areas.In addition,the collected data revealed that the SSID can be leveraged as a landmark for the access points(APs).To this end,SSIDtrack algorithm is proposed to track shoppers/walkers in closed areas,such as malls to find their walking route utilizing only the SSID information collected from the surrounding area.The algorithm has been tested in two different malls that consist of four different floors.The accuracy recorded for the algorithm acceded 95%.
文摘This paper explores and compares FER (Frame Error Rate) of a MAC (Medium Access Control) layer in the IEEE 802.11 a/g/n wireless LAN. It is evaluated under the fading wireless channel, using theoretical analysis method. It is analyzed by using the number of stations with both variable payload size and mobile speed on the condition that fading margin and transmission probability are fixed. Especially, in the IEEE 802.11n, A-MSDU (MAC Service Data Unit Aggregation) scheme is considered and the number of subframe is used as the variable parameter. In the IEEE802.11a/g wireless LAN, fixed wireless channel is assumed to be Rayleigh fading channel. Mobile wireless channel is assumed to be flat fading Rayleigh channel with Jake spectrum. The channel is in fading states or inter-fading states by evaluating a certain threshold value of received signal power level. If and only if the whole frame is in inter-fading state, there is the successful frame transmission. If any part of frame is in fading duration, the frame is received in error.
基金supported by the Spanish Ministry of Science,Education and Universities,the European Regional Development Fund and the State Research Agency,Grant No.RTI2018-098156-B-C52.
文摘IEEE 802.11ah is a new Wi-Fi standard for sub-1Ghz communications,aiming to address the challenges of the Internet of Things(IoT).Significant changes in the legacy 802.11 standards have been proposed to improve the network performance in high contention scenarios,the most important of which is the Restricted Access Window(RAW)mechanism.This mechanism promises to increase the throughput and energy efficiency by dividing stations into different groups.Under this scheme,only the stations belonging to the same group may access the channel,which reduces the collision probability in dense scenarios.However,the standard does not define the RAW grouping strategy.In this paper,we develop a new mathematical model based on the renewal theory,which allows for tracking the number of transmissions within the limited RAW slot contention period defined by the standard.We then analyze and evaluate the performance of RAW mechanism.We also introduce a grouping scheme to organize the stations and channel access time into different groups within the RAW.Furthermore,we propose an algorithm to derive the RAW configuration parameters of a throughput maximizing grouping scheme.We additionally explore the impact of channel errors on the contention within the time-limited RAW slot and the overall RAW optimal configuration.The presented analytical framework can be applied to many other Wi-Fi standards that integrate periodic channel reservations.Extensive simulations using the MATLAB software validate the analytical model and prove the effectiveness of the proposed RAW configuration scheme.
