Source: 5G NR Numerology

# Numerology

Numerology () is a 5G parameter which changes 5G parameter which changes Subcarrier Spacing (SCS) and other system parameters. It ranges from 0 to 5.

• num0 = low band
• num1 = mid band

For the numerology, we have several terms that we have to be familiar with:

• A radio frame in 5G consists of 10ms duration
• Each frame consists of 10 subframes, making each subframe 1ms duration
• Each subframe consists of slots

Since I am working on the low band, I only worry about Num0 and Num1, so lower frequencies, i.e. SCS.

### Slots

• Each slot can have either 14 (normal Control Plane (CP)) or 12 (extended CP) OFDM symbols.
• All the subcarrier spacing options have 14 OFDM symbols
• This enables slot based scheduling. One slot is the possible scheduling unit and slot aggregation is also allowed.
• Logically, Slot length = ms.
• Higher num () = higher frequency = lower period

Mini-slot ? Mini-slot occupies 2, 4 or 7 OFDM symbols. It enables non-slot based scheduling. It is minimum scheduling unit used in 5G. As mentioned mini-slots can occupy as little as 2 OFDM symbols and are variable in length. They can be positioned asynchronously with respect to the beginning of a standard slot.

Frequency Range • There are two frequency ranges supported in 5G NR viz. FR1 and FR2.
• FR1 supports frequencies below 6 GHz where as FR2 supports frequencies above 6 GHz (i.e. mmwave range).
• FR1: Frequency range is from 450 to 6000 MHz
• FR2: Frequency range is from 24250 to 52600 MHz
Refer complete 5G NR Frequency Bands >>.