6G ?                                                          Home : www.sharetechnote.com





Here goes the list of the items in this page, as the techology grows and my knowledge on this subject gets wide and deep enough I will spin out separate pages for more specific topics.




What is It ?


Simple answer is 'We don't know yet' -:). At least, as of Jul 2019 when I was writing the first note on this topic.

But from various presentations and documents that I've gone through, it seems that we may identify a few pillars as we did at the early stages of 5G as shown below. I tried to set the three pillars as in 5G. It seems that the first two pillars Terahertz and AI/ML seems to the ones that are most commonly mentioned in the early discussion but I am not sure whether the third pillar High Data Rate in eMTC/URLLC can be a clear target for 6G or not.




Teraherz/Tera bps : In many of the documents, this goal is described as Terahertz. The literal meaning of Teraherzh implify that the carrier frequency of the signal is in the range of TeraHz(1000 Ghz). But I would interpret this as a Tera bps rather than Tera Hertz since the carrier frequencies being proposed in various documents are not always in the range of Tera Hz. The frequency range being discussed in those documents are in the range of several hundreds of Ghz or in Tera Hz. However, it seems to be clear that the final target is to achieve Tera bps range of data transfer.

Now you may have some fundamental questions and stick to it for several years. What kind of electronics would be used to achieve this goal ?  Would we call this mmWave ? or Optical wave ?


AI(Artifical Intelegence)/ML(Machine Learning) : In 6G, it seems that AI/ML would be a feature that is integrated into the functionality of the radio and core network. It would implie that most of the network component should be virtualizied to apply the flexibility of AI/ML to the network functionality.




Isn't it too early to get into this ?


I asked the same question when I started looking into things about 5G around mid 2013. 5G activities in some pioneering organizations started even earlier. Now I heard some leading company in 5G has started their research back to 2007 or so.

I would say, "Yes it is too early if you are interested only in solid/determined 3GPP specification". I don't think you would see much formal activities in 3GPP until release 18 or later (probably sometime around 2026 or later ?).

However if you are interested in observing the whole process of how a new technology is being formed and evolved and finally turns into operational products, nothing is too learly. To me, it is always enjoyable to follow something from the very early conception through the full developmental process.




Following along Evolutionary Path - Physical Layer/MAC Layer


I will write down some technical progess and my learning process as I am writiing tech diary. This is not necessarily very technical .. just a little memo on my learning process.


[ Jul 2019 ]

  • For now (Jul 2019), I am writing comments on this based on the assumption that 6G physical layer will be based on THz(Tera Hertz) technology,
  • Roughly two major technology of Thz implementation is being discussed. One is based on Optics and the other is based on electronics, but it is highly likely that electonics based technology would be adopted (at least for communication between mobile station and base station).
  • There are many options to implement this, but preferred one would be transistor based on implementation. Then need to check if a source(osciallator), mixer, power amplifiers can be implemented for the selected technology. I am not the expert on this area, so not in the position to share the latest information on this. If you are interested, you may refer to Ref [11] as a start and follow through the references listed there. It is published in 2011, so I think the technology has been much more matured by now(Jul 2019).
  • Once the basic components (e.g, Source, Mixer, Amplifer etc) is developed and commercialized, some pioneering test equipment vendor would come up with signal generator and analyzer. Then the industry or academia would start researching on physical channel properties for the target frequency. This is what had done by 5G several years back (see this as an example).   
  • The result on this physical channel properties and propagation model would be a critical step to determine whether the selected technology can be adopted for the new communication technology or not. Once it is determined to be feasible to use the technology, you may start hearing on possible concepts of physical layer protocol issues like waveform, modulation scheme, frame structure etc.
  • Channel Modeling : As they did for 5G, NYU Wireless is doing pionioring work in this area as well. It seems that they starting  researching on this and sharing the research result for a while. Check on NYU Wireless / NYUSIM site.
  • MAC for Terahertz Communicaition System : Even if there has been some changes in detail in terms of MAC layer between LTE and 5G, the fundmantel mechanism is almost same in LTE and 5G/NR. But it is likely to be drastic change in Terahertz MAC comparing to conventional cellular technology (e.g, LTE, 5G/NR) since the physical layer properties in Terahertz communication would be drastically different. As of now, I don't see any concrete proposals or specification on this, but I would suggest you to start with this survey paper(Ref [15]) as a starter. If you are interested in protocol side (rather than physical layer hardware implementation), this can be a good starting reference.


[ Aug 2019 ]

  • This month my study has motly focused on reading papers on Machine learning application to this area. At first, I thought the machine learning would mostly for core network optimization, but I learned there has been a lot of research on the application to physical layer process of wireless communication (e.g, detection of modulation scheme, auto encoder etc). See Ref[19]~[26]. I personally recommend you to start with Ref [26] and pick one of specific direction that you want to follow through.



[ Nov 2019 ]

  • I realized that there are TeraHz physical layer deliverables are defined in Teranova. This seems to be similar activities that we saw from METIS specification at early 5G research. As we saw in the difference between METIS specification and final 3GPP specification, it is not sure how much of this early specification will be adopted by the final industry specification (3GPP), but at least it will be good to shape the overal pictures of Terahertz PHY/MAC.
  • I see more and more papers coming out in 2019 about applying Machine Learning to Wirless PHY layer especially signal detection, modulation detection ([31],[32],[33])



[ May 2020 ]

  • A few month ago(Mar 17, 2020), 2nd 6G Summit was held and videos for presentations are posted here. Comparing to those from the 1st summit, most presentations shows more on technical aspect of 6G. I think it is worth watching.



[ Jul 2020 ]

  • SamSung released a good white paper on 6G : 6G The Next Hyper Connected Experience for All. At least to me, this is one of the best white papers on 6G giving huge insights on 6G on technical aspects. For me, the section 4 (Candidate Technologies) is the most interesting and informative. Esepcially those topics on Terahertz Technologies, Novel Antenna Technologies,Comprehensive AI were the most intersting ones to me.



[ Oct 2020 ]



[ Nov 2020 ]

  • A good Webinar video is shared in public about PHY and low layer aspect/idea on 6G. Status of Radio Module development for Teraherz and a lot of talks on massive MIMO for 6G etc. See this video on YouTube.








Event / Workshop / Symposium






Followings are the list of articles mostly for general public. If you think it is too early to talk about 6G when 5G  just start being deployed (as of Jan 2020). See my list of articles on 5G and check how early they started talk about 5G.  Not very technical, but I found it intresting to observe how public opinion is formed and new technology is planned and evolve.




Papers/White Papers




Videos - 6G Summit




Video - 6G Research Visions Webinar Series (2020)




Videos - Terahertz Technology




Videos - General




Further Readings


[1] How TeraHertz Technology Will Change The World Of Wireless Communication ?

[2] An overview of integrated THz electronics for communication applications

[3] Terahertz Waves for Communications and Sensing

[4] A Perspective on Terahertz Next-Generation Wireless Communications (2019)

[5] Tuning to Terahertz Electronics (2015)

[6] THz Electronics

[7] Terahertz electronics: The last frontier (2014)

[8] A New Technology for Terahertz Electronics (2003)

[9] Joint Lab THz Components & Systems   

[10] Terahertz breakthrough allows for ultrafast wireless communications  (2015)

[11] Last Meter Indoor Terahertz Wireless Access:Performance Insights and Implementation Roadmap (2018)

[12] Compact Terahertz Reciever for Short-range Wireless Communications of Tens of Gbps  (2017)

[13] Micro- and nano-scale Terahertz Band Communications  

[14] Terahertz (THz) Wireless Systems for Space Applications (2019)

[15] MAC Protocols for Terahertz Communication: A Comprehensive Survey (2019)

[16] Advances in THz Wireless Communications (2017)

[17] How AI is Starting to Influence Wireless Communications

[18] The 5G Future Will Be Powered By AI (2019)

[19] DeepSig: Deep Learning for Wireless Communications

[20] Deep Architectures for Modulation Recognition (2017)

[21] Physical Layer Communications System Design Over-the-Air Using Adversarial Networks (2018)

[22] Deep Learning-Based Communication Over the Air (2017)

[23] Deep Learning-Based Channel Estimation (2019)

[24] "Machine LLRning": Learning to Softly Demodulate (2019)

[25] ORACLE: Optimized Radio clAssification through Convolutional neuraL Networks (2019)

[26] Deep Learning in Mobile and Wireless Networking:A Survey (2019)

[27] Terahertz Band: The Last Piece of RF Spectrum Puzzle for Communication Systems (2019)

[28] A Speculative Study on 6G (2019)

[29] 6G Wireless Communications: Vision and Potential Techniques (2019)

[30] The Roadmap to 6G – AI Empowered Wireless Networks (2019)

[31] A Deep Learning Framework for Signal Detection and Modulation Classification (2019)  

[32] Fast Deep Learning for Automatic Modulation Classification (2019)  

[33] Automatic Modulation Recognition Using Deep Learning Architectures

[34] Deep Learning for Physical-Layer 5G Wireless Techniques: Opportunities, Challenges and Solutions (2019) 

[35] 6G Wireless Communication Systems: Applications,Requirements, Technologies, Challenges, and Research Directions (2019)

[36] Towards 6G Networks: Use Cases and Technologies (2020) 

[37] Sixth Generation (6G) Wireless Networks:Vision, Research Activities, Challenges and Potential Solutions (MDPI)