RedCap Will 5G spark an IoT gold rush?

A scaled-down version of 5G could spark a surge in wearables, industrial IoT, surveillance and security.

The arrival of 5G cellular technology was supposed to ignite the world of IoT, but that hasn’t been the case. It’s not that the flame has been doused, but rather that IoT growth has smoldered rather than blazed.

5G itself has been widely deployed in a variety of use cases, but adoption has been slow for IoT-centric enterprise applications such as healthcare-related wearables, industrial IoT networks, monitoring and security, asset tracking and fleet management.

“In terms of latency and bandwidth, the vast majority of IoT devices don’t need 5G,” said Jason Leigh, research manager for IDC’s 5G and Mobility research group. “5G is like a Ferrari engine, but most cars don’t need a Ferrari engine.” 5G’s advanced capabilities also come at a high price, and many IoT use cases cannot support the additional cost.

However, this may change with the upcoming 5G specification, called RedCap, which is designed specifically for IoT devices. RedCap may be the spark that ignites the world of IoT.

What is RedCap?

The next generation of cellular technology is 5G Advanced, or 5.5G. The specification is expected to be ratified within a year. A key feature that will be included in 5G Advanced is a class of devices called "New Radio Reduced Capability (RedCap) devices."

RedCap includes a variety of features that balance factors such as coverage and throughput with limitations such as limited battery life and lack of antennas. This combination supports use cases that do not always require the high performance of current 5G technology but can be expanded more quickly with advanced cellular networks.

“One of the main reasons for the slow adoption of 5G in the IoT space is that legacy technologies work well for many use cases,” Leigh said. If connectivity options like WiFi and legacy 3G LTE work, there’s no real incentive to change, and while 3G has been phased out in the U.S., it still dominates in much of the world.

RedCap expects IoT networks to benefit from the increasing scale of 5G deployments, which will make IoT viable in more locations and on more devices. Since many constrained IoT devices have fewer device features, RedCap will make it easier for device manufacturers to prioritize issues such as low power consumption and ruggedness.

What obstacles does RedCap face?

As operators and telecom companies rush to build the first wave of 5G networks, they divide 5G deployments into two categories: standalone (SA) and non-standalone (NSA). Today, most 5G networks are NSA 5G, which is usually a combination of 5G radio access equipment and 4G infrastructure.

However, judging from the current specifications, RedCap appears to require operators to deploy 5G SA, which is still a small part of 5G deployment. According to the Global Mobile Suppliers Association (GSA), 259 operators in 102 countries have launched commercial 5G services, but only 41 operators have launched or deployed public 5G SA networks, while 115 operators fall into a broader category that includes evaluating, testing, piloting and planning SA networks.

As 5G SA expansion steadily increases, RedCap is expected to become an important bridge from traditional connectivity to the standardized full 5G ecosystem.

RedCap testing has begun

Although 5.5G is still at least a few months away from becoming an official specification, mobile vendors and operators are not waiting. They are already testing pre-5.5G devices, infrastructure and networks.

AT&T, Ericsson, Nokia and MediaTek are all testing advanced 5G. In July, AT&T tested a 5G RedCap data call in the lab and in the field using a newly deployed 5G SA network. The test used MediaTek's RedCap platform connected to Nokia's AirScale radio access equipment and then connected to AT&T's 5G SA network core.

“5G RedCap is designed for devices currently served by LTE CAT-4, but with equivalent or better performance, with a theoretical maximum downlink throughput of up to 150Mbps. It helps reduce the complexity, cost, and size of 5G devices, and also introduces options that allow devices to operate at lower power levels,” AT&T’s Jason Sikes wrote in a corporate blog post about the RedCap testing. “These upgrades will bring 5G to products and applications that cannot be served by full-featured 5G technology, like wearables such as smartwatches and AR glasses, and IoT devices for healthcare, asset tracking, smart home systems, fleet management, and more.”

Another advantage of 5G RedCap is the ability to provide connectivity for cost-sensitive and space-constrained consumer wearable devices. Sikes pointed out: "The 5G RedCap core design has a single carrier maximum bandwidth of 20MHz, eliminating the need to aggregate multiple carriers together. Unlike the more complex MIMO antenna design required for full-featured 5G NR devices such as smartphones, this allows for simpler and smaller antenna designs using one transmitter (1TX) and one or two receivers (1RX or 2RX)."

MediaTek is also working with Ericsson to test data and Voice over New Radio (VoNR) calls on TDD and FDD bands at Ericsson’s lab in Sweden. TDD uses one frequency band for uplink and downlink, switching between the two. FDD uses different frequency bands for uplink and downlink. The test is designed to demonstrate the capabilities of Ericsson RedCap as a viable radio access network (RAN) software that will support 5.5G use cases such as wearables, sensors and industrial surveillance cameras that require consistent connectivity without quickly draining the device’s battery.

Sibel Tombaz, Head of 5G RAN Product Line at Ericsson, said: “Ericsson Reduced Functionality Software will open up a whole new world of possibilities for new types of devices that do not require the full range of 5G performance, and these FDD and TDD calls are a crucial first milestone in this journey. By enabling data and Voice over New Radio (VoNR) on both FDD and TDD bands, Ericsson RedCap is opening up a whole new range of use cases for consumers and industry in a cost-effective way.”

The test used pre-commercial Ericsson RedCap software and MediaTek RedCap test platform to conduct FDD data calls and achieve throughput speeds of 220Mbps downlink and 74Mbps uplink. Mobile partners also conducted TDD data calls, reaching 153 Mbps downlink and 13.5 Mbps uplink. These speeds are sufficient to support a range of IoT use cases, including consumer wearables and industrial sensors. Ericsson plans to make the pre-specified RedCap ecosystem commercially available by November and will provide it as a software supplement to existing 5G SA networks.

Is RedCap a necessary step towards 6G?

One big advantage of 5.5G is that it can be deployed as a software upgrade. "One thing the industry really got right in early 5G deployments was to design it to be upgradeable via software patches," Leigh said. In theory, that means 5.5G can fit into legacy LTE infrastructure and can include some backward compatibility measures to accommodate legacy devices.

The wearables most people think of tend to be devices that are already in use, such as smart watches. However, with better connectivity in low-cost devices, RedCap will support use cases such as sensors embedded in ID tags and even hard hats for geo-fencing. The advantage of RedCap over RFID and WiFi is that the device will not lose connectivity when it leaves the facility. But in most cases today, the cost of adding cellular networks is too high. In addition, adding cellular networks means adding additional antennas and upgraded batteries.

Experts believe that introducing capabilities for constrained devices is a necessary step toward a full 5G ecosystem, but a more realistic scenario is that this level of adoption will come with 6G.

Spectrum is the lifeblood of the industry, and if we start talking about 6G, where will the spectrum come from? 6G spectrum will likely come from shutting down traditional cellular connections. Today, LTE is declining globally, but in the United States, shutting down 3G is a painful thing. RedCap is a necessary component of the long-term migration to a universal mobile ecosystem.

Today, IoT devices are connected in a variety of ways: WiFi, LPWAN, Bluetooth, LTE, and 5G. This may seem rich and provide manufacturers and customers with abundant choices, but the reality is a fragmented market with poor interoperability, resulting in slower than expected growth.

RedCap could start to change that, prompting operators to accelerate upgrades to 5G SA, and then 5.5G, so they can serve customers who want more affordable versions of 5G, making their IoT use cases viable at scale.