Cat. NB1 and Cat. NB2 Devices Comparison

IoT, LTE, Narrow Band IoT, Tech Fundas

Narrow Band IoT specifications was first introduced in 3GPP release 13 and then further enhanced in 3GPP release 14 with some essential features. Release 13 NB-IoT device category is referred as Cat NB1 or Cat N1 and Release 14 devices are referred as Cat NB2 or Cat N2.

Parameter Cat. NB1 Cat. NB2
3GPP Release Specification Release 13 Release 14
Operation Mode FDD FDD
No. of Rx Antenna 1 1
Tx Power Class 20, 23 dBm 14, 20, 23 dBm
Maximum Channel Bandwidth 180 KHz 180 KHz
Highest Modulation for UL and DL QPSK QPSK
Downlink Spatial Layers 1 1
Maximum DL Transport Block (TBS) 680 bits 2536 bits
No. of HARQ Processes 1 up to 2
Peak DL Physical Layer Data Rate 226.7 Kbps 282 Kbps
DL channel coding type Tai Bit Convolutional Coding (TBCC) Tai Bit Convolutional Coding (TBCC)
Physical Layer Memory Requirement 2112 soft channel bits 7680 soft channel bits

Additionally Cat NB2 devices has following features which are not available in Cat NB1

  • Support of Positioning of Device using OTDOA
  • Mobility enhancement from seamless cell re-selection
  • Push to talk voice messaging
  • New Device Power Class (14 dBm)
  • Multicast transmission