An analytical model to study the impact of time-varying cell capacity in LTE networks

• Main Authors: Sas, B., Bernal-Mor, E., Spaey, K., Pla, V., Blondia, C., Martinez-Bauset, J.
• Format: Conference Proceeding
• Language: English
• Subjects: Admission control; Analytical models; Bit rate; Electronic mail; LTE; Mathematical model; Phase shift keying; Quality of service; Time-varying cell capacity
• DOI: 10.1109/WMNC.2011.6097234

Contemporary wireless networks like Long Term Evolution (LTE) employ a technique called adaptive modulation and coding (AMC) to enhance the throughput of the users in the system. Applying AMC however causes the total cell capacity to vary over time as sessions are started and stopped and users move around. The varying cell capacity has an impact on the quality of service (QoS) experienced by the users and also on the admission control (AC) algorithms used for such system as the variation of the cell capacity can cause the cell capacity to drop below the required amount that is needed to service all users in a cell. In this paper we present an analytical model that models this time-varying cell capacity and compare the results obtained with it to results obtained from more realistic simulations in order to verify the modelling assumptions made in the analytical model. We then use both the analytical model and the simulations to study the impact of the time-varying cell capacity on a simple AC scheme. Scenarios in which various parameters are varied are simulated and the results of both models are compared to each other. The results obtained from the analytical model and the simulations show that the analytical model is very accurate. The differences between the results only differ up to a couple of tenths of a percent. Only in extreme conditions both models differ. We also identify the cases and the reason why both models differ.