Topicality of the problem. GSM mobile networks are very widely used in the world and the number of GSM users exceeds 10^9. In the last decade, the GSM/GPRS network has been very rapidly expanded in Lithuania as well. Coverage of the network has reached 99 % of territory of the country. Load of the network in largest cities reaches up to several hundred Erlangs for square kilometre. Voice traffic still generates the largest part of the network load, however mobile data traffic also grows rapidly. Radio interface between the user of mobile services and the network is not stationary. The received QoS of every user in different places is different. Even in a single cell, radio link characteristics differ in different parts of the cell. The signal level may easily vary about 10–20 dB just within several or tens of meters. Moreover, a mobile user experiences different link conditions while moving in the natural environment within or between cells. However, historically characteristics of QoS of mobile services are measured and evaluated like the ones of the fixed network using statistical methods. Statistically calculated characteristics of QoS do not include information about the received quality of mobile telecommunication services of every individual user. Conception of the received quality of services of individual users (individual QoS – iQoS) in the GSM/GPRS network has not been analysed in the world before. QoS should be measured not only at the network level, as it is... [to full text]

Topicality of the problem. GSM mobile networks are very widely used in the world and the number of GSM users exceeds 10^9. In the last decade, the GSM/GPRS network has been very rapidly expanded in Lithuania as well. Coverage of the network has reached 99 % of territory of the country. Load of the network in largest cities reaches up to several hundred Erlangs for square kilometre. Voice traffic still generates the largest part of the network load, however mobile data traffic also grows rapidly. Radio interface between the user of mobile services and the network is not stationary. The received QoS of every user in different places is different. Even in a single cell, radio link characteristics differ in different parts of the cell. The signal level may easily vary about 10–20 dB just within several or tens of meters. Moreover, a mobile user experiences different link conditions while moving in the natural environment within or between cells. However, historically characteristics of QoS of mobile services are measured and evaluated like the ones of the fixed network using statistical methods. Statistically calculated characteristics of QoS do not include information about the received quality of mobile telecommunication services of every individual user. Conception of the received quality of services of individual users (individual QoS – iQoS) in the GSM/GPRS network has not been analysed in the world before. QoS should be measured not only at the network level, as it is... [to full text]