Hello Experts,
What’s the meaning of RedCap UE?
Admin note: this post was updated with image below.
Reduce UE capability.
In case ue report overheating, gnb can reduce mimo layers of data or deactive some SCC cells in CA mode.
Hi @Silf , @Hainm, it stands for Rel-17 Redcap (or Reduced capability)
We have today have clearly defined devices for IoT (NB-IoT, LTE-M) (for example applications that require less than 2 Mbps and Small Bandwidth). And we also have devices that are clearly suitable for 5G (NR) applications - High Data Rates and Large Bandwidth.
But what about those applications that do not apply to any of these cases?
That’s where RedCap enters. Formerly known as NR-Lite / NR-Light, RedCap UE fit those needs (range).
Motivation (Use cases)
- Wearables
- Industrial wireless sensors
- Video surveillance
- Target data rate 2~150Mbps to accommodate above use cases
Reduced device capabilities
- Bandwidth reduction
- Reducing the max number of MIMO layers
- Relaxation of the max downlink modulation order
- Half-duplex (HD) operations in FDD(only FR1)
Total cost reduction
- FR1 FDD ~67%, TDD ~61%@2Rx, ~72%@1Rx
- FR2 ~53%
Source: SG RAN Presentation - 3GPP Summit at CEATEC Japan 2021 - https://www.3gpp.org/news-events/partners-news/2238-ceatec21
By reducing devices Bandwidth, reducing the maximum number of MIMO layers, and also relaxing the maximum downlink modulation order the overall costs are reduced. As we can also see here: What is reduced capability (RedCap) NR? - Ericsson
Rel-17 RedCap targets the requirement space between eMBB, mMTC and URLLC:
Source: Toward 5G Advanced: overview of 3GPP releases 17 & 18 - Ericsson
In a Nutshell:
- RedCap is 3GPP’s track into low cost (still high-performance) non-smartphone NR devices.
- Even lower costs and even lower energy consuption.
- Long-term: infinite battery lifetime.
Hi Folks,
Sometimes lights about redcap UE. Redcap UE is R17 supported UE it should have RedCap capabilities like:
Some high later capabilities for REDCAP UE:
-Redcap NR Light UEs can support 16DRBs (as normal NR UE) but mandatory support for REDCAP UE is 8DRBs only as per 3GPP Specs R17.
-REDCAP UEs can optionally support 18-Bit PDCP/RLC sequence numbers but mandatory support is 16 Bit PDCP/RLC sequence numbers as per 3GPP Specs R17.
REDCAP UEs can support Automatic Neighbor Relation (ANR) but it’s not mandatory as per 3GPP specs R17.
REDCAP UE does not support CA and DC.
REDCAP UEs mandate to support DCI format 0_0/0_1 and support for DCi 2_0/2_1 is optional.
The number of RX branches for REDCAP are implicitly indicated by the corresponding capability parameter maxNumberMIMO-LayersPDSCH in the exiting UE capability framework.
For more info related to the REDCAP R17 feature read this article very informative.
5G NR Light / RedCap(Reduced Capability)
In 5G NR Release 17, 3GPP introduced a new tier of reduced capability (RedCap) devices, also known as NR-Light. It is a new device platform that bridges the capability and complexity gap between the extremes in 5G today with an optimized design for mid-tier use cases. 5G RedCap brings the mix of capabilities in throughput, battery life, complexity, and device density needed to cost-effectively power diverse use cases that do not always need the high-performance capability of regular 5G technology. When compared to 5G enhanced mobile broadband (eMBB) devices that can support gigabits per second of throughput in the downlink and uplink, NR-Light devices can efficiently support 150 Mbps and 50 Mbps in the downlink and uplink, respectively, due to the designed optimizations:
narrower bandwidths, i.e., 20 MHz in sub-7 GHz or 100 MHz in millimeter wave (mmWave) frequency bands
a single transmit antenna
a single receive antenna, with 2 antennas being optional
optional support for half-duplex FDD
lower-order modulation, with 256-QAM being optional
support for lower transmit power
Low power is not within the scope of RedCap, It may reduce some power due to narrow bandwidth, but there is no RedCap-specific power-saving technique.
Use cases targeted via these solutions are wearables, Industrial surveillance, and sensors
For the implementation of RedCap:
SIB elements declaring the support of RedCap on gNB (e.g, SIB1, SIB4)
RRC-UE Capability Information: UE is supposed to inform its capability of RedCap support
RRC Reconfiguration: gNB may configure RedCap (e.g, RLC, PDCP configuration)
MAC CE: A few additional MAC CE elements for RedCap operation
5G RedCap has the following advantages over LTE:
No need to support 3 different networks - NR,eMTC/NB-IoT, and LTE: Operators can migrate their spectrum to NR which can support both URLLC & NR-Lite on the same carrier as well as deploy eMTC/NB-IoT either in-band or in guard-band.
Better system efficiency with NR compared to LTE: NR features like beam-formed operation, higher subcarrier spacing for latency reduction, massive MIMO for coverage, mixed numerology, higher positioning accuracy, low-overhead carriers, etc. can be utilized using 5G RedCap
URLLC & NR-Lite can also be deployed in FR2 and new spectrum: FR2 can be very attractive for private networks due to its limited range and high spatial reuse e.g. each building or floor can have its own network and they will not interfere with each other
Better integration and benefits from 5G core and architecture - network slicing, service-based architecture, flow-based QoS, etc.
Credits: ASHISH SHUKLA on LinkedIn: 5G NR Light / RedCap(Reduced Capability) In 5G NR Release 17, 3GPP…