### Instruction:

Extract the cause and effect entities from the following sentence:
These challenges include the following d in the AP–17 Future Communications Study (FCS): “Estimated RMS delay spreads for this channel, on the order of 1.4 µs, can lead to frequency selective fading performance for some technologies

### Assistant:

NOT_RELEVANT: These challenges include the following d in the AP–17 Future Communications Study (FCS):
VARIABLE: frequency selective fading performance for some technologies
CONDITION: on the order of 1.4 µs
KEYWORD: can lead to
CAUSE_1: Estimated RMS delay spreads for this channel, on the order of 1.4 µs
EFFECT_1: frequency selective fading performance for some technologies

