Homework 2 Similar to the experiments done in the paper “Online Game QoE Evaluation using Paired Comparisons “ “Online Game QoE Evaluation using Paired Comparisons Compare gaming performance using different wireless media –WiFi vs. 3G vs. WiMax The experiments will be done in LENS lab using the multihomed mobile router 2015/7/31

Multi-homed mobile router A mobile router with multiple interfaces Will be setup in LENS lab The mobile router will periodically change to a difference interface 2015/7/32 Game server game client

Multi-homed mobile router You job: –Play game –Make comparison about your perceived gaming performance –Create graph similar to what shown in the paper (you don’t need to write program for that purpose. Some programs will be offered to you to generate the plots) 2015/7/33

Use QoE for handoff decision Traditionally people use signal strength to decide when to do handoff when switch to a different AP Signal strength: network-level perception QoE: user-level perception Using QoE for handoff decision makes more sense

Scenario You are in a moving train playing game using a wide-area radio (like WiMax), now the train is approaching the station and there is free WiFi available at the station Should the game device handoff to WiFi from WiMax?

QoE measurements Divide the WiMax signal strength into 5 different levels (e.g. L1, L2, L3, L4, L5) by changing the transmission power Divide the Wifi signal strength into 5 different levels (e.g. l1, l2, l3, l4, l5) by changing the transmission power Totally C(10,2)=45 pair comparisons=one set

deliverables Each person needs to perform 3 sets Collect packet-level traces at the same time when you are doing the comparisons 3 type of graphs –Consistency check (table 3 on the paper) –QoE vs. signal stength One for WiMax One for WiFi –CDF of delay probability distributions for each signal strength levels 10 in Total

Due date The last week (same as the project presentation week)