Global Harmonisation of 5G Spectrum.

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I write this as a follow up from Huawei’s position paper released earlier this month.  I first saw this from a good article from Zenobia Hegde.    The presented classification of spectrum and approach is natural and logical since it follows laws of physics and technology capabilities.   Here are some comments supporting the position and how some vendors are positioned for industrial LTE.

Let’s look at the various layers, has proposed, with a manufacturer’s perspective.

  • Coverage layer: lower frequency spectrum <1Ghz (opinion).
    1. High Power RF is economical to build on this spectrum.
    2. High order MIMO due to wavelengths, antenna size, and separation requirements are It does not make sense to build higher order SU-MIMO systems. 2×2 or max 4×4 makes sense.
    3. With better propagation, better penetration in this spectrum, and with the above-stated attributes; it makes perfect sense to build LTE based solution for range and not density in this spectrum.
    4. Such very compact platform is perfectly fit-for-purpose in this spectrum to deliver Range for Private iLTE ™.
  • Coverage & Capacity layer: Between 1.7 and 6Ghz.  Interestingly, not that many bands in 3GPP exist between 1.7 and 6Ghz.
    1. The antenna sizes becomes significantly smaller
    2. Naturally, higher order MIMO’s, become more feasible.
    3. AT 3.5Ghz, Massive MIMO is very much feasible. A 64 antennas Massive MIMO system is going to be a flat panel around 1.2m X1.2m which is manageable.
    4. Massive MIMO will be using much lower power per antenna, so this helps with RF component cost to offset other inherent costs.
    5. Handset antennas are also smaller, so it is easier to place them properly in the handset and achieve better TRP and TIS, true radiated power and sensitivity numbers.
    6. It is a natural fit to use this spectrum for capacity.
    7. Again a compact form factor with the addition of MulteFire’s here will deliver range and capacity!
  • Ultra-High capacity layer: Above 6Ghz is what truly 5G was about in the first place; these are uW and mmW bands 28Ghz and above
    1. Propagation loss is much higher
    2. Water absorption loss and other phenomena’s are significant
    3. High power RF is not economical
    4. Antennas built on silicon and phasing has is used
    5. All this leads to about maximum 500m distances for fixed applications which is still amazingly good. For mobility, we are talking less than Bottom line this is not spectrum for long range, but several Gb/s is feasible to deliver considering the sheer size of spectrum available there.
    6. There are lots of the big TEM playing in this arena, and they will likely own it.

Does this make sense to you?  Do you see it differently?

Thanks:

  • Bojan Subasic, for the assistance in this Post

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