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4G vs 5G


When I started writing the pages about 5G in around mid 2013, I thought we will have a completely new (at least in Radio Access Protocol perspectivie) and I said to myself "After spending a couple of years in LTE and with a lot of struggle, finally just started to get used to this technology. Do I need to go through this kind of struggling again ?".

At the early discussion, most of the discussions were around new physical waveform, implying that 5G is likely to be completely new technology from the bottom.


Fortunately to me (and probably to many people), with most of the initial implementation target determined in 3GPP as of TR 38.801, 38.802, 38.803, 38.804, it seems to me that most part (at least most part of Radio Access Procotol) overlaps with the current LTE and only small portions of new items are to be implemented anew as illustrated below (Of course this would sound over-simplified. You may say 'each of these new items are so fundamental, it should be regarded as pretty new technology'. I agree with this to some degree. It would be a huge changes in terms of low PHY. However, if you move forware only a half step upward and getting into high PHY(e.g,physical layer processing) and higher layer protocol, a lot of things would sound very similar (or almost same) to current LTE.


As of Jun 2017, 3GPP started releasing the formal technical specification. You would be able to get some more details of the big picture from 38.300 and for more detailed specification for each layers of protocol stack you may refer to 38.211(low PHY), 38.321(MAC), 38.322 (RLC), 38.323 (PDCP), 38.331(RRC) etc.