What is 5G NR Light ?
The basic massive MTC use cases, characterized by requirements on very low device cost and very low device energy consumption in combination with wide-area coverage, are assumed to be provided by means of LTE-based LTE-MTC and NB-IoT also in the 5G era.
However, there are several use cases that require lower device complexity and reduced energy consumption compared what can be provided by NR Release 15/16 and which, at the same time, has higher requirements in terms of latency and data rates compared to what can be provided with Nb-IoT and LTE-M.
To address such use cases, 3GPP has initiated Release-17 activities on reduced-capability NR devices referred to also as NR Light, those type of devices have UE capability/complexity trade-off in-between the conventional eMBB services and the low-complexity services enabled NB-IoT and LTE-M.
Reduced Device complexity and energy consumption
In terms of reduced device complexity, the following modifications have been considered:
- Support for reduced number of Transmission/Reception antennas at the device side
- Reduction of the minimum required device bandwidth
- Support for devices only capable of half-duplex operation (no simultaneous Transmission/Reception) in paired spectrum
In terms of reduced device energy consumption, the following modifications have been considered:
- Reduced complexity in PDCCH monitoring by reducing the number of required blind decoding
- Extended DRX functionality
- The aim is to achieve the reduced device complexity and energy consumption without compromising the achievable coverage.
Expected capabilities of NR-Light devices
The characteristics required for these categories of devices, compared with full 5G NR devices and low-power wide-area (LPWA) IoT devices, are illustrated schematically in this figure:
Adressing new types of use cases:
As we said this Release-17 technology capability is not intended to replace NB-IoT and LTE-M devices, but to address new type of use cases in Industrial IoT and other verticals:
- Industrial wireless sensors with low latency (5-10ms) and medium data rate (<2 Mbps)
- Medium to high data rate (2-25 Mbps) video transmission
- High data-rate wearables (5-50 Mbps) with long battery life (1-2 weeks)
