What exactly is RedCap?

With the freezing of the 3GPP R17 version, a new term gradually begins to make popularity, which is RedCap.

What exactly is RedCap? Why introduce it? What is the difference between it and the current 5G?

Look at the in -depth analysis of Xiao Zaojun ...

█ What is redcap

Redcap, the full name is Reduced Capability, which means "reducing ability" in Chinese. It is the 3GPP in the 5G R17 stage, which specializes in project research

A new technical standard.

Everyone may feel strange for the name RedCap. In fact, it may have heard of the previous name, which is NR Light

(NR Lite).

To put it plainly, redcap is a light and low 5G.

It is worth mentioning that some domestic articles have described the full name of RedCap as Reduced Capacity. This is obviously wrong, Capacity’s meaning

Thinking is capacity, Capability is ability.

█ Why is there redap

5G is done well, why do you want to engage in a lightweight version? The reason is as follows:

As we all know, 5G is divided into three major application scenarios, namely EMBB (enhanced mobile broadband), URLLC (low time extension high reliable communication),

MMTC (Mass Communication).

EMBB is the upgrade of MBB (mobile broadband) in the 4G era, which mainly focuses on network rates, bandwidth capacity, spectrum efficiency and other indicators. The 5G mobile phone we currently use belongs to the EMBB scene.

URLLC and MMTC, the former focuses on reliability and delay, the latter focuses on the number of connections and energy consumption. Both of them are mainly serving the industry Internet, including industrial manufacturing, Internet of Vehicles, and remote metering and other vertical industries.

I have told you before that the application scenarios of the Internet of Things are extremely complicated and diverse. Different scenarios have different indicators of the network.

Taking the rate as an example, VR/AR and high -definition broadcasts require high -speed connections. However, remote meter (water meters, meters), and shared cycling synchronous data, only low speeds are required. Compared with the rate, many application scenarios are more concerned about power consumption and cost.

After so many years of development, the Internet of Things has formed three categories: high -speed, medium speed and low speed:

"631" structure

If you count on the passive Internet of Things (ultra -low rate) that is now getting more and more popular, it is four categories:

Only 5G alone cannot meet all the needs. Therefore, at this stage, 5G and 4G are carrying together. Even 2G and 3G are helping.

With the retreat of 2G and 3G, most of the 2G and 3G IoT business will be migrated to LTE Cat.1, LTE CAT.4 and NB-IoT. That is

4G, 5G hit the world.

So the question is, what should I do if 4G will be retired in the future? Or, the establishment of a new operator is established, in addition to 5G, it is necessary to build another 4G network

?

Therefore, 5G must consider the long -term and establish a lightweight version to cover the needs of current LTECAT.1 and CAT.4, which is

Speed ​​and high -speed demand.

So there is RedCap.

In other words, NB-IoT/EMTC is a castrated version of 4G. The RedCap is a castrated version of 5G.

In terms of technical characteristics, RedCap is between EMBB (ultra-broadband) and LPWA (low power consumption wide area network, NB-IoT, etc.).

Redcap is mainly targeted at the needs of bandwidth, power consumption, cost, etc. based on applications between EMBB and LPWA.

Its bandwidth rate is lower than EMBB, but much higher than LPWA. Its power consumption and cost are higher than LPWA, but they are far lower than EMBB.

Redcap's ability, very "balanced" (yellow line is redcap)

Another driving force for RedCap is the cost of 5G terminal chips and modules.

The full version of the 5G terminal chip and module, the design is extremely complicated, the research and development threshold is extremely high, and the investment cost is huge. Their price has always been high

Next (500-1000 yuan).

The high price affects the landing of 5G in the vertical industry, and users are unwilling to spend so much money.

Therefore, making a lightweight 5G is also to reduce 5G deployment and use in some scenarios with low requirements and delay requirements.

This, better serve users and accelerate 5G landing.

How does █REDCAP achieve low cost?

Come to the key part of this article, how the RedCap is castrated Reduced.

The following form shows the main differences between 5G RedCap devices and 5G traditional devices.

The original picture comes from Ericsson (translation of fresh jujube classroom)

First, the spectrum bandwidth of RedCap is smaller. In the SUB-6GHz band, the bandwidth of RedCap is 20MHz, less than the traditional 5G

100MHz.

Secondly, Redcap reduces the number of receiving antennas and reduces the number of MIMO layers. For the Sub-6GHz band, the receiving chain of the RedCap terminal

The road can be reduced to 1 or 2, and the corresponding downward MIMO is reduced to 1 layer or 2 layers. In this way, the capacity requirements for terminal radio frequency receivers and baseband processing modules are reduced.

Third, Redcap uses a more simple modulation method such as 64QAM, which also means that the requirements for radio frequency and baseband have been greatly reduced.

Fourth, Redcap uses half-dual-work FDD (HD-FDD), which can be transceled at different frequencies at different times without dual instruments. Do not

It only saves costs, and has obtained better integration capabilities (dual -instruments are generally large), which reduces the occupation of equipment space, which is conducive to setting

Preparation of miniaturization.

Fifth, Redcap introduces some power -saving means, such as enhanced non -continuous receiving characteristics (EDRX), and adopts longer dormant models

Formation allows terminals to reduce power consumption and get higher endurance.

Based on the above changes, according to the forecast, the complexity of RedCap has decreased by 60%compared to the 5G public network terminal, and about 70%on the baseband and RF side

The cost of left and right is reduced. It is also said that the overall cost of RedCap can be reduced by 2-5 times, or even 7-8 times.

Although redcap is severely castrated, the basic performance is still retained. It can be introduced based on the smooth upgrade of 5G current network.

Big transformation.

To say well, it's not good. What did Redcap lose?

The first is the rate. With the decline in terminal bandwidth, the simplification of MIMO receiving and the decline in the highest modulation order, the peak rate of redcap also

It will drop sharply.

The specific rate value is different according to the number of antennas and frame structures. See the following form:

Redcap peak peak value reference

(From 5G Redcap Technology White Paper)

In terms of coverage capacity, due to the shrinkage of antenna design and the size limit of the wearable terminal, the coverage capacity has shrunk slightly.

In terms of transmission delay, HD-FDD cannot be sent and accepted at the same time, and the transmission delay will increase. However, for the application scenario of redcap

It is said that these issues have not been much influenced.

It is worth mentioning that considering the application scenario and cost, 3GPP proposes that RedCap can only work in a frequency band at a time without supporting the carrier

Jugglic or dual connection. (Of course, the early RedCap terminal must be dual -molded, after all, the coverage of 5G is not perfect.)

I almost forgot to say the price. According to predictions, Redcap's module price will be controlled between 100-200 yuan (RMB), which is far lower than that of the current one.

The 5G module of 100 yuan, but it will be higher than the NB-IoT modules of tens of yuan.

█REDCAP's typical business scenario

At present, according to the standard definition of 3GPP R17, Redcap supports three major business scenarios, namely: wearable devices, industrial sensors and videos

monitor.

The specific needs of these three scenarios on the network are as shown in the table below:

The original picture comes from Ericsson (translation of fresh jujube classroom)

Wearable devices take smart watches as an example.

At present, the mainstream smart watches on the market only support 4G and do not support 5G. Because the cost of 5G chips is too high, the heat is large, and the high of EMBB

The rate is a bit redundant for the screen size of the watch.

Using RedCap can fully meet the video call requirements of smart watches.

Cat.1.

In addition, RedCap can also meet the needs of smart watches in terms of size and power consumption.

Look at the industrial sensor.

Everyone may be unfamiliar with industrial wireless sensors. There are many categories of this thing, including pressure sensors, humidity sensors, motion sensors,

Temperature meter, acceleration meter, drive, and so on.

These sensors are widely used in the industrial field and huge. It has a slightly higher requirements for reliability, about 99.99%. However, not required to be extended

Calculate high, within 100ms. In terms of speed, it generally does not exceed 2Mbps.

There is no doubt that redcap can be satisfied.

Finally, video surveillance.

Video monitoring is currently a wide range of Internet of Things demand, and we are everywhere.

Many people think that video surveillance should be 5G. In fact, video surveillance is also divided into multiple categories. Some are 4K/8K ultra -high -definition, high -end monitoring

(7.5-25 Mbps). There are also high-definition or standard clearing, which belongs to Economic Monitoring (2-4 Mbps).

In practical applications, the proportion of economic video surveillance is greater. These do not need 5G. Use LTE CAT.1/Cat.4, and our

Redcap is enough.

In addition to the above three scenarios, there are many places that can be applied by RedCap, such as smart logistics, intelligent power, intelligent inspection, and intelligent system

Create.

According to the forecast data of major market consulting agencies, by 2025, domestic wearables, video surveillance and power industry terminals can reach 10 million.

class. For RedCap, the market prospects are broad.

When can █REDCAP be commercially used?

In June 2019, at the 3GPP RAN #84 conference, RedCap appeared for the first time as a R17 Study Item (research project) to appear in front of everyone.

In March 2021, 3GPP officially passed the establishment of the NR RedCap UE standardization (that is, the work item) project.

Today, on June 9, 2022, 3GPP R17 freezes, which means that the Redcap R17 is standardized.

According to experience, after standardization, it takes at least 1-2 years to achieve preliminary industrialization.Therefore, it is expected to be in the middle of 2023

(Or early 2024), we will see the early commercial products of RedCap.

Note that the standardization of Redcap has not completely ended.In December 2021, the standardization of 3GPP R18 Redcap has started.

3GPP Redcap Standardized Work process

(From 5G Redcap Technology White Paper)

The goal of R18RDCAP is the benchmarking Cat.1/1BIS, which further reduces the complexity of the terminal and achieves the ultimate simplification of the complex complexity of the RedCap terminal.

In other words, the technology of RedCap has a long way to go in the future.

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