When there are bigger obstacles in the indoor environment such as elevator, the radio waves basically can not penetrate it. The contribution of received signal strength by transmission and reflection will be greatly r...When there are bigger obstacles in the indoor environment such as elevator, the radio waves basically can not penetrate it. The contribution of received signal strength by transmission and reflection will be greatly reduced, and most of the time, the radio waves will reach the user by bypass diffraction. Therefore, the traditional path loss model is no longer applicable, and the improved model should be proposed. In this paper, we firstly proposed an indoor radio propagation model based on dominant path in which the received signal strength has nothing to do with the direct distance between user and access point, but is related to the length of dominant path. Then on the basis of dominant path model, the NLOS influence is considered in order to further improve the accuracy of dominant path model. Experimental results demonstrated that the proposed dominant path model can improve the accuracy of traditional path loss model remarkably.展开更多
The Distributed Queue Dual Bus(DQDB) Metropolitan Area Network(MAN) is a promising solution for the evolution from current networks to B-ISDN. The performance of the DQDB MAN for Local Area Networks(LANs) interconnect...The Distributed Queue Dual Bus(DQDB) Metropolitan Area Network(MAN) is a promising solution for the evolution from current networks to B-ISDN. The performance of the DQDB MAN for Local Area Networks(LANs) interconnection is analyzed. The effects of message length, traffic load of upstream and downstream nodes and the parameters of bandwidth balancing mechanism and network counters on the sojourn time of message in the buffer are investigated, which present a valuable reference for the implementation of the DQDB MAN.展开更多
In this paper, an improved analytical model for IEEE 802.11 distributed coordination function (DCF) under finite load is proposed by closely following the specifications given in IEEE 802.11 standard. The model is inv...In this paper, an improved analytical model for IEEE 802.11 distributed coordination function (DCF) under finite load is proposed by closely following the specifications given in IEEE 802.11 standard. The model is investigated in terms of channel throughput under perfect and slow Rayleigh fading channels. It is shown that the proposed model gives better insight into the operation of DCF.展开更多
文摘When there are bigger obstacles in the indoor environment such as elevator, the radio waves basically can not penetrate it. The contribution of received signal strength by transmission and reflection will be greatly reduced, and most of the time, the radio waves will reach the user by bypass diffraction. Therefore, the traditional path loss model is no longer applicable, and the improved model should be proposed. In this paper, we firstly proposed an indoor radio propagation model based on dominant path in which the received signal strength has nothing to do with the direct distance between user and access point, but is related to the length of dominant path. Then on the basis of dominant path model, the NLOS influence is considered in order to further improve the accuracy of dominant path model. Experimental results demonstrated that the proposed dominant path model can improve the accuracy of traditional path loss model remarkably.
基金Supported by the National Natural Science Foundation of Chinathe Foundation of the Institute of Electronic Science of China
文摘The Distributed Queue Dual Bus(DQDB) Metropolitan Area Network(MAN) is a promising solution for the evolution from current networks to B-ISDN. The performance of the DQDB MAN for Local Area Networks(LANs) interconnection is analyzed. The effects of message length, traffic load of upstream and downstream nodes and the parameters of bandwidth balancing mechanism and network counters on the sojourn time of message in the buffer are investigated, which present a valuable reference for the implementation of the DQDB MAN.
文摘In this paper, an improved analytical model for IEEE 802.11 distributed coordination function (DCF) under finite load is proposed by closely following the specifications given in IEEE 802.11 standard. The model is investigated in terms of channel throughput under perfect and slow Rayleigh fading channels. It is shown that the proposed model gives better insight into the operation of DCF.
