What is 5G ?

“I don’t know -:).” was the answer to this question when I first wrote this page in mid 2013 and the answer hasn’t changed until the mid 2016. From late 2016 many things started happening in 3GPP and now (Mar 2017) we got several TRs (38.801, 38.802, 38.803, 38.804) that describes the details of technical requirement to be specified in formal NR(5G) specification, meaning that now we know what 5G (NR) will look like in pretty much detail.

If you want to get the formal 3GPP definition right away, just jump to Formal (3GPP) Definition but I will keep all of the other definitions as well in case when you are interested in tracking down what kind of vision multiple major players had and how those visions has been consolidated into the formal definition (requirement).

Nothing about 5G is defined officially in any standard organization as of now. However there are several organization that describes key technical component or key performance indicator (KPI) that may envision on what 5G will be like. I would put the list of features from several different organization.

Initial Definition

When the first talk about 5G started and some of prototyping test result came out, the focus was mainly around throughput. (This kind of focus hasn’t been changed much until mid 2013)

At least, one thing for sure will be that the data rate will be at least several G bps. (The final goal of 4G data rate is 1 Ghz and we still have a long way to go to achieve this 1Gb rate).

By now (as of Nov 2015), you may see a couple of dozen whitepapers about the 5G. If you read through all of these whitepapers, you would notice that the key concepts they claim in the documents are almost same. Personally, I would recommend you to read through the documents from METIS. I think METIS documents are by far the most extensive and most in-depth. The only problem is that those documents are too thick :)

Followings are some of my personsl keywords about the 5G reading through most of these papers.

Keywords Description
Extremly High Data Rate By far, we don’t know yet (as of Nov 2015) what would be the maximum throughput. But I think it will be targeted to be at least around 10 Gbps.
Extremly Low Data Rate Just achieving the extermly low throughput has no technical problem. But critical technological issue is that achieving the extremely low data rate with extremly low cost and extremely low energy (battery) consumption. Refer to MTC criteria for the details.
Extremly Low Latency We don’t know yet (as of Nov 2015) what would be the target latency. But by far, around 1 ms latency are the most commonly mentioned number. (In terms of subframe length, it would be around 100 us or 200 us)
Super High Frequency The words ‘High Frequency’ or ‘Low Frequency’ can be misleading because it would be a relative concept, but I say ‘Super High Frequency’ comparing to current cellular communication frequency (mostly under 3 GHz). By far (as of Nov 2015), the most frequently commented frequenty blocks are 6 GHz, 15 GHz, 20~30 GHz and the highest frequency being tried is a little bit over 70 GHz.
Super Wide Bandwidth The words ‘Wide Bandwidth’ or ‘Narrow Bandwidth’ can be misleading because it would be a relative concept, but I say ‘Super Wide Bandwidth’ comparing to current cellular communication bandwidth (100 MHz, ideal max in 4G). The most commonly mentioned bandwidths are 160 MHz, 400 MHz, 800 MHz. Currently the widest bandwidth being mentioned are 2 GHz bandwidth.
Softwares as much as possible Many components in core network would be software based and with this it would become very flexible and accomdate news features in short time frame

Formal (3GPP) Definition

Recently (as of Jun 2016) there has been a couple of RAN meeting with major focus on 5G and several official technical terms has been defined.



The first thing to be defined would be ‘what is the name that refers to the whole 5G technology ?’. As we call 4G as LTE, there must be similar name for 5G. What is it ? At least for now, the official name for 5G is NR that stands for New Radio. (I already see many people saying NR is not a proper name because 5G does not refers only to Radio Technology.. but anyway for now, NR is the official term.

Then what is official definition of NR. Since there is no single line official definition for LTE, there is no single line official definition for NR. But in my personal definition, I would say ‘NR is a collection of technology from Physical layer to Core Network that need to achieve the followiing three major feature (requirement) as illustrated below. The term shown in this diagrams are also formal 3GPP terms and you will see these terms in most of the 3GPP documents on NR. So it would be good for you to get familiar with these terminologies.
5G Definition - 图1

Build Up Intuition on 5G

Definition by METIS

Definition by 5GNOW

Definition by SKT

Definition by 4G America

Definition by NTT DOCOMO