5G/NR - Challenges  




5G Challenges

In this note, I am going to try to keep track of somes challenges on 5G in terms of technology and business perspective. Not for deep-dive into the details, just tracking high level descriptions on various challenges. (NOTE : I am also tracking high level description on how 5G evolves in terms of deployment and applications with a little bit of positive aspects in another note here).

Things to think of

Followings are some of things that popped lately in my mind as 5G challenges. I am NOT trying to say "there are so many issues / challenges with 5G and it will eventually fail". I am a strong believer in the science and engineering, and great human minds. We will eventually see most of the challeges will be cleared. What I am trying to do in this note is to write down those challenges in my mind and in various forums/discussions, and more importantly to show how these challenges are getting resolved.

Is it over-hyped ?   

(Apr 2021) : In any new technologies, there has been a certain level of hypes and I don't think those hypes are intentional or any malignant intentions. But often too much hypes would result in dip trough. Personally, I got the impression that there was hypes in 5G comparing to previous generations.  Most people would recall those statements saying "You can download huge and high quality movie in a few seconds (or even in a fraction of a second)", "A laser pointer like beam would track your mobile devices in realtime whereever you move around", "You can remotely control drones, cars, industrial robots, medical surgery robots as if you manipulates by your own hands" etc. At least for now, I don't think these statement has been realized as many people expected. Technically it is understantable as 5G is still at early phase, but the current state may look a little bit disappointing for many of general public.

Is mmWave performance as good as expected ?

(Apr 2021) : You may have watched many of YouTubes showing near 2Gbps throughputs at many places. Most of those result came from mmWave 5G Cells. Definately it is an amazing technical achievement. But you might have watched other videos complaining about the robustness of the connectivity with mmWave cells, like call drop (or fall back to LTE) when they change the direction or position of the mobile phone just a little bit or walking down the street just a few hundred meters away from the cell site. It seems that implementation of beamforming and beam management with desired quality is not as easy as expected.  ==> this video captures pretty good status of mmWave deployment / challengest as of 2022

Are we getting enough indoor penetration with 5G ?

Even though there were some demonstrations showing pretty good performance from outdoor gNB and indoor reciever, a lot of end users are complaining about the poor indoor user experiences. There are many factors affecting the indoor user experience like the material and thickness of walls, glasses and how many walls the signal has to go through to reach the device etc. By RF common sense, we can easily figure out that outdoor to indoor penetration of 5G/NR would not be as good as legacy technology. Not to say of FR2 which is using extremely higher frequency than the legacy technologies, even common used FR1 frequencies (e.g, FR1 band higher than 3Ghz) is using the higher frequencies than the legacy frequencies. This kind of higher frequency would be the major factors for the poor indoor experience. I personally don't see any easy technical solutions for this. Probably the only solution would be to use indoor small cells... then we have to justify why we should take the indoor small cells when there is low cost/easy-to-setup solution called WiFi.

Is there any killer APP ?

(Apr 2021) : Up to 4G, I think there had been some killer apps which was well recognized and accepted from the early stage of deployment, but I don't see any appealing applications (or business models) for 5G yet. Why ? There had been a lot of use cases that claimed to be a 5G killer app (e.g, VR/AR, Remote Control, V2X, IoT etc), but I don't see any of those use cases are attracting people as yet. Is it because 5G technology is not mature enough to implement the use cases or those use cases themselves are not so attractive as expected ?

Does the number of sold devices and the deployed carrier indicate the acceptance of 5G ?

(Apr 2021) : Various types of report or press releases numbers showing how many carriers deployed 5G and how many 5G phone are rolling out, trying to hint that 5G is getting well accepted in the market and 5G business would blossom in no time. Would it be really the case ? I think the number itself would be true, but it wouldn't necessarily mean that those numbers are directly associated with the acceptance of 5G in the market.  Almost every network operators wants to show that they are not behind the trend. Large portions of 5G phone buyers are just passive buyers. They just wanted to buy the latest high end phone and all of the highend phone happened to support 5G.

Is 5G Core Network Deployment fast enough ?

(Apr 2021) : A lot of promises that 5G made would not be kept only with Radio Access Network(RAN), it would require the innovations all the data path along the end-to-end. From various reports and statistics, we see how fast the RAN is getting deployed, but we don't see similar reports/satistics showing the progress of 5G Core Network (5G CN) and other backend data path. I think the technical solution to deploy 5G RAN without 5G CN (i.e, NSA : Non-Stand Alone) was a good idea and it might be a very important factors to show such an amazing speed of provisioning 5G service, but it would be a factor that slow down 5G Core Network deployment. Many carriers managed to claim that their network is 5G capable with only RAN investment and then they would wait further until they will be more confident about 5G business model without much investment on 5G Core Deployment.

Good business opportunities for contents or application service provider, but not so lucrative for carriers ?

(Apr 2021) : For every new licensed spectrum, carriers has to invest a lot for the auction. For every new technology (e.g, 3G, 4G, 5G etc) they have to invest a lot for deployment and maintenance. It seems that some network operators start thinking "Will all these investment bring enough return for us ? or we are just paving the road with a lot of investment, but all the drivers are running on the road without paying tolls. See we set up all the infra structures of the mobile network, but now most of voice call, video call, short messages are being provided by somebody else almost for free. Woudn't this repeat in 5G as well ?". You may say "Carriers are still charge a lot for data service", but the carrier may have different opinion.

Why 3GPP is so complex  ?

(Apr 2021) : 5G promised about many applications which might not have been the area of cellular communication (like industrial automation, V2X etc). To expand 5G playground, the technology should accommodate those engineers to 3GPP worlds who was not so familiar with 3GPP. But to be honest, 3GPP would look overwhelming (or itimidating) for a lot of good engineers but not familiar with 3GPP. This can be a huge practical and psychological barrier for many application. Should it be designed in such a complicated way ? You sure that there no simpler way ?

Can 5G win over WiFi  ?

(Apr 2021) : I personally didn't think of this much before. I just thought Cellular and WiFi has its own advantage and doesn't compete much. In some part, it still holds true. But as cellular technology try to expand its application and WiFi tries the same thing as well, I think I see the competition between the two grows stronger especially when WiFi 6 came out with many of the features which used to be the strong points of celluar system and WiFi 7 will be ready in a few years claiming that I would be amount to (or even surpass in some as aspect) the features that seemed to be the unique capability of 5G. Then how 5G can justify on taking 5G instead of WiFi considering the cost, easy of use, easy of deployment etc ? According to this and this statistics, the smartphone sales is about 1.5 billion units per year and the sales of wifi connected devices are over 20 billions per year in the latest year.

NOTE 1 : You may refer to another list of 5G challenges summarized by ABI Research in 5 Beyond The Consumer Market.


3GPP Reference