In this research we have investigated the effect of QoS performance for video conferencing in the LTE network with E2E delay, packet loss and packet delay variation metrics. Three networks scenarios have been created namely Sce-nario 1(Low Load) network, Scenario 2 (Medium Load) network and Scenario 3 (High Load) network. Comparison were carried out between them and pre-sented in Chapter 4. OPNET Modeler 16.0 has been used to simulate the net-work scenarios to evaluate the answers for the research questions by graphical representation. The simulation result shows that GBR and Non GBR bearers have great impact on video conferencing under congested network.
E2E delay for low load scenario is almost zero for both GBR and NGBR bearers. For medium load network, the delay ranges 0.0281~0.041 seconds and 3.150~39 seconds for GBR and NGBR bearers respectively. This indicates that packet partially rejected for NGBR. Whereas in scenario 3 (High Load) network, only highest priority GBR has tolerable E2E delay of 0.0371 seconds.
The average PDV for GBR bearer in scenario 3 (High Load) network is 48 % higher than medium load network and 97% higher than low load network. For lower priority GBR bearer with high load network, average PDV is 612ms higher than low load network which is relatively high. The average PDV for silver (NGBR) bearer under scenario 3 (High Load) network is 821ms. The average PDV for Bronze (NGBR) bearer under high load network is 322581ms, which is impractically high.
The packet loss rate for low load network corresponding to GBR and NGBR bearer are almost 0%. Whereas, in case of congested (medium and low load) network, the average packet loss of video traffic for highest priority GBR bearer was found to varies within 0.001 %~0.005% while for lower priority NGBR bearer varies between 89%~99%.
In all cases we can conclude that, highest priority GBR bearer is getting more opportunity to use available resources in ESP of eNodeB while the net-work is congested. Compared to GBR bearer traffic, NGBR is almost rejected.
In future, there are scopes for focusing on other QoS metrics with larger network model. GBR and NGBR bearersí behavior can studied for network with mobility.
I feel that the past simple is more appropriate than the present perfect for the verbs I have underlined - the research is finished.