LTE: Connected Mode DRX Calculations

Long and Short DRX occasions for both FDD and TDD can be calculated using this tool. The tool basically uses the below two equations given in 36.321

Full details about Connected Mode DRX are presented here

For Long DRX, DRX onDuration starting time can calculated from,

[(SFN * 10) + subframe number] modulo (longDRX-Cycle ) =  drxStartOffset

The below equation needs to be used for calculating Short DRX occasions,

[(SFN * 10) + subframe number] modulo (shortDRX-Cycle) = (drxStartOffset) modulo (shortDRX-Cycle)

When DRX is configured, long DRX is mandatory whereas short DRX can be optional.

Long DRX-cycle           Offset          onDurationTimer           Short DRX-cycle
10 20 32 40 64 80 128 160 256 320 512 640 1024 1280 2048 2560                                 1 2 3 4 5 6 8 10 20 30 40 50 60 80 100 200                      2 5 8 16 20 32 40 64 80 128 160 256 320 512 640

                                                                                              UL-DL Config
        Is Short DRX?         Is TDD?          0 1 2 3 4 5 6

Long DRX Occasions

Long DRX Occasions will be displayed here

Short DRX Occasions

Short DRX Occasions will be displayed here