Latency investigation -including Speedtest

1. Latency investigation-including Speedtest.net

2. Agenda • Objective • Test Cases • Performance Results & Analysis • Prescheduling • Initial UL Buffer Size • SR Periodicity • Moving Forward

3. Objective • Ericsson has been asked by customer to investigate the latency time by parameter changes due to observing poor latency via Speedtest.net • Areas of testing are: • Prescheduling • Initial UL buffer size • SR periodicity

4. Test cases The below test cases were executed while recording TEMs, using a Samsung Galaxy S3 LTE I9305 UE Test are performed on good LTE radio condition where: • RSRP > -80dBm • RSRQ > -7dB • SINR < 20dB

5. Comparison • Prescheduling ON and Disabled • Baseline vs TC1 • Initial UL buffer size Default vs 300B • Baseline vs TC3, TC1 & TC2 • SR periodicity 10 ms vs 5 ms • Baseline vs TC4

6. Performance ResultsSummary • prescheduler = Disabled • prescheduler = Enabled • prescheduler = Enabled, initial buffer size = 300 • prescheduer = Disabled, initial buffer size = 300 • prescheduler = Disabled, SR periodicity = 5 • Below is the Average Results of performance

7. Performance ResultsSummary • Delta comparison is based on the individual Test Cases (TC) vs Baseline (TCB). • Highest latency improvements observed with preschedulingON (TC1 & TC2). • Higher initial UL buffer sizeimproves latency for bigger ping sizes, where whole data can be sent without data fragmentation. • Average of 3ms latency improvement is observed with a lower SR periodicity setting.

8. PRescheduling

9. What is causing delays? Current behaviour for small ping