The article discusses the data transmission quality in wireless telecommunication networks developed according to IEEE 802.11 standard, which are important for design, installation and further operation of the networks. In particular, attention is paid to determining the range of guaranteed radio communication and the probability of packet loss. It is proposed to use the ping program as a method of determining the range of guaranteed radio communication and the probability of packet loss for IEEE 802.11 standard routers. The program allows to approximate the conditions of data transmission to real conditions, and, working for a long period of time, allows to determine the probability of packet loss. One of the advantages of the method proposed in the article is its availability in use, as no special equipment is required. In addition, the article presents the results of comparison of the quality of data transmission evaluation obtained by the proposed method with the data of technical documentation for equipment. This fact confirms the adequacy and accuracy of the proposed method. During the testing of the equipment, information about the number of sent, received and lost packets in the radio channel under study will be obtained, in addition, the average value of the delay in the transmission of data over the channel will be determined. The scope of application of the considered method for determining the range of guaranteed radio communication in wireless telecommunication networks of IEEE 802.11 standard is also proposed. An example of using the method is building a network coverage map or creating a database with the technical characteristics necessary for the design of local telecommunication networks with wireless access. © 2018 CEUR-WS. All Rights Reserved.