What is RedCap in 3GPP R17?

RedCap (Reduced Capability), that is, "reduced capability". It is a new technical standard protocol specially launched by 3GPP in the 5G R17 stage for 5G application scenarios with low requirements for rate and latency, aiming to comprehensively improve the quality and coverage of 5G networks. It can also be understood as "lightweight 5G".

Application scenarios
5G is divided into three major application scenarios: eMBB (Enhanced Mobile Broadband), uRLLC (Low Latency and High Reliability Communication), and mMTC (Massive Internet of Things Communication). eMBB is an upgrade of 4G MBB (Mobile Broadband), mainly focusing on indicators such as network speed, bandwidth capacity, and spectral efficiency. uRLLC focuses on reliability and latency, while mMTC emphasizes the number of connections and energy consumption. Both serve the industry Internet, including vertical industry fields such as industrial manufacturing, Internet of Vehicles, and remote meter reading.

However, different application scenarios in the Internet of Things have different requirements for network capabilities. For instance, in terms of speed, VR/AR and high-definition broadcasting require high-speed connections. Remote meter reading and shared devices only require data synchronization, and low speed can meet the requirements. Apart from speed, there are many application scenarios that are more concerned about power consumption and cost. The complete version of 5G terminal chips and modules is extremely complex in design, has a very high research and development threshold, and incurs huge investment costs. The high price has also affected the implementation of 5G in vertical industries.

Therefore, 5G needs to establish a lightweight version to meet the application scenarios with medium and medium-high speed requirements, reduce the deployment and usage costs of 5G, and accelerate the commercial application of 5G.

Thus, RedCap came into being. 5G RedCap can support 5G devices with lower complexity. It lies between eMBB and LPWAN in terms of bandwidth, power consumption, antenna design and cost, effectively balancing the capabilities of 5G's large bandwidth, high speed, wide connection and low latency, and meeting the networking needs of different industries.

The features of RedCap

• Low cost: The maximum bandwidth requirement for RedCap devices in the band below 6 GHz is reduced to 20 MHz. RedCap reduces the number of required receiving antennas and device layers, supports 1R or 2R, and significantly lowers the cost of 5G device chipsets and modules. It is estimated that the cost of RedCap components is five times lower than that of eMBB components, and the price of large-scale commercial components can be comparable to that of Cat 4 components.

• High-capacity and efficient coexistence: RedCap devices can operate on 5G networks through separate initial BWP (Bandwidth Part) and cell-defined synchronous independent signals, and can coexist efficiently with eMBB devices, fully leveraging the advantages of 5G's high bandwidth and large capacity (compared to 4G).

• High integration: RedCap data can be transmitted and received at different frequencies, making the connection simple and integrated, and the device tends to be miniaturized.

• Multi-functional: low latency, slicing, positioning, low power consumption, etc.