As can be seen in the picture above, quite a few bands above 24GHz were identified for 5G. Some of these bands have an already existing allocation for mobile service on primary basis. What this means is that mobile services can be deployed in these bands. For 3G and 4G, the spectrum used was in bands below 4GHz, with 1800MHz being the most popular band. Hence there was never a worry for those high frequency bands being used for mobile communication.
As these bands have now been selected for study by ITU, 5G in these bands cannot be deployed until after WRC-19, where the results of these studies will be presented. There is a small problem though. Some of the bands that were initially proposed for 5G, are not included in this list of bands to be studied. This means that there is a possibility that some of the proponent countries can go ahead and deploy 5G in those bands.
For three bands that do not already have mobile services as primary allocation, additional effort will be required to have mobile as primary allocation for them. This is assuming that no problems are identified as a result of studies going to be conducted for feasibility of these bands for 5G.
To see real benefits of 5G, an operator would need to use a combination of low and high frequency bands as can be seen in the picture above. Low frequencies for coverage and high frequencies for capacity and higher data rates.
As I mentioned in an earlier blog post, 5G will be coming in two phases. Phase 1 will be Rel-15 in H2, 2018 and Phase 2, Rel-16, in Dec. 2019. Phase 1 of 5G will generally consist of deployment in lower frequency bands as the higher frequency bands will probably get an approval after WRC-19. Once these new bands have been cleared for 5G deployment, Phase 2 of 5G would be ready for deployment of these high frequency bands.
This also brings us to the point that 5G phase 1 wont be significantly different from LTE-A Pro (or 4.5G). It may be slightly faster and maybe a little bit more efficient.
One thing I suspect that will happen is start of switching off of 3G networks. The most commonly used 3G (UMTS) frequency is 2100MHz (or 2.1GHz). If a network has to keep some 3G network running, it will generally be this frequency. This will also allow other international users to roam onto that network. All other 3G frequencies would soon start migrating to 4G or maybe even 5G phase 1.
Anyway, 2 interesting presentations on 5G access and Future of mmWave spectrum are embedded below. They are both available to download from the UK Spectrum Policy Forum (SPF) notes page here.