INVESTIGATION OF INFLUENCE OF THE SUBSCRIBERS MOVEMENT ON EFFECTIVE DATA TRANSFER SPEED IN WI-FI NETWORKS
In this paper, a study of the influence of Doppler frequency shift effect on the main criterion of channel quality of the wireless network standard 802.11n was carried out. However, as the 802.11x family of standards is a wireless technology, it is necessary to pay attention to the losses associated with the mobility of subscribers. In this case, at the input of subscriber's receiver it will be observed the slowly changing signal strength, which depends on the position in space, and the rapid change, which depends on the time and velocity. Exactly the rapid change in signal strength is called the Doppler shift frequency effect. The results of studies proved that using MIMO, the total radiation power of transmitting antennas is less than 100 mW. Any displacement of the transceiver equipment of standard 802.11 makes a significant impact on the effective information transmission rate in the channel. At speeds of 1 m/s it is observed a significant decrease of the efficiency criterion, and at speeds two or more meters per second - the falling reaches value of 1,5... 2 times.