Sleep modes: cell DTX/DRX, carrier shutdown, symbol blanking

Three Levels of Sleep Modes

Modern gNBs support three progressively aggressive sleep modes. Symbol-level DTX/DRX blanks unused OFDM symbols within a slot when no data is scheduled — the PA powers down for microseconds, saving 5-10% of power with sub-millisecond wake-up time. This is transparent to UEs and can be enabled permanently. Carrier shutdown turns off secondary NR carriers during low traffic periods while keeping the primary carrier active for coverage — this saves 15-25% and takes seconds to reactivate when traffic rises. Deep sleep powers down the entire RF chain on a cell, relying on neighboring cells for…