The RE mask is a 12-bit pattern applied per PRB. Element 0 of GetREMaskBitmap corresponds to RE index 0 (lowest frequency in the PRB); element 11 corresponds to RE index 11 (highest frequency in the PRB). A bit value of true (1) means the PxSCH section data is sent in that RE; a bit value of false (0) means the RE is treated as "missing" — zero in U-Plane, and the RE is excluded from demodulation, EVM, and decoding. See O-RAN.WG4.TS.CUS.0 §7.5.3.5.

The RE mask is applied where four selection bitmaps overlap: GetResourceBlockBitmap chooses which frequency PRBs are subject to the mask, GetSymbolBitmap chooses which OFDM symbols within a slot, GetSlotPatternBitmap chooses which slots within a repeating SlotPatternPeriodicity window.

Composability: a resource element at (PRB p, OFDM symbol s, slot σ, RE re) is masked (set to "missing") if and only if all of the following are simultaneously true:

• Enabled is true,
• bit p of GetResourceBlockBitmap is 1,
• bit s of GetSymbolBitmap is 1,
• bit σ mod (int)SlotPatternPeriodicity of GetSlotPatternBitmap is 1, and
• element re of GetREMaskBitmap is false (0).

Worked example matching the O-RAN Fronthaul WG4 LTE conformance test (downlink E-TM1.1 at 20 MHz, 100 PRBs, normal cyclic prefix): to mask every even-indexed RE on PRBs 1-5 of symbol #6 of every slot, set Enabled = true; RE mask = 010101010101b (PxSCH data on REs {1,3,5,7,9,11}, "missing" on REs {0,2,4,6,8,10}, MSB = RE0); the resource block bitmap with bits 1-5 set (within a 100-bit bitmap for 20 MHz); the symbol bitmap = 0000001b (MSB = symbol 0, LSB = symbol 6); SlotPatternPeriodicity = RateMatchPatternSlotPatternPeriodicity.One; and the slot-pattern bitmap = 1b (every slot active).

Target Platforms: Windows 11 Professional or Enterprise; Windows 10 Professional, Enterprise, or Education (64-bit)

Reference