Speaker: Yu-Fu HuangAdvisor: Dr. Kai-Wei KeDate : 2013, Dec. 16

Outline• LTE and the DRX concept•An analytical model for power saving • Power saving factor (PS)• The mean of wake up delay•Numerical results•Reference

4G LTE architecture

4G LTE architecture

The procedure in the paper• System state define•Each state probability calculation •Expectation of each state holding time • Power saving factor• The probability of packet call delivery start in DRX cycle• The mean of wake up delay

An analytical model for power saving

An analytical model for power saving

State 1 to state 1 and state 1 to state 2

State 3 to state 1

Adjustable DRX time state for light sleep

State 2 to state 1 and state 2 to state 3

Transition probability matrix

E[H1] (holding time of S1) calculation

E[H1] (holding time of S1) calculation

E[H2] and E[H3] calculation

E[H2] and E[H3] calculation

Power saving factor (PS)

The probability a packet call delivery start for the ith fixed DRX cycle

The probability a packet call delivery start for the ith adjustable DRX cycle

The mean of wake up delay

TN=10Tds 　 　 　 　 　 　 　 　 　

TN=20 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　

TN=40 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　

Cds 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　 　

TN: light sleep(Adjustable area)

TD: deep sleep

TA: Active mode

Numerical results

* TA: Longer (Ti as X-axis) PS & E[D] in TN10, TN20, TN40, Cds are not much difference.* TN: Longer (Tds as X-axis) E[D] is shorter & PS is lower due to go into TD lately.* TD: Longer (Tdl as X-axis) Shorter in TN gets longer E[D] & higher PS.

Reference• IEEE ICC 2012 - COMMUNICATION SOFTWARE SERVICES

AND MULTIMEDIA APPLICATIONS SYMPOSIUM