5G Spectrum Discussions

While most people are looking at 5G from the point of new technologies, innovative use cases and even lumping everything under sun as part of 5G, many are unaware of the importance of spectrum and the recently concluded ITU World Radio Conference 2015 (WRC-15).

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.

Further reading:

• WRC-2015 and the impossible task of achieving a delicate balance

ADS-B to enable global flight tracking

One of the things that the World Radio Conference 2015 (WRC-15) enabled was to provide a universal spectrum allocation for flight tracking. What this means in simple terms is that once completely implemented, flights will hopefully no longer be lost, like MH370. It will now be possible to accurately track flights with satellites across nearly 100% of the globe, up from 30% today, by 2018.

To make you better understand this, see this video below:


Automatic Dependent Surveillance (ADS) is a surveillance technique in which aircraft automatically provide, via a data link, data derived from on-board navigation and position-fixing systems, including aircraft identification, four-dimensional position and additional data as appropriate. ADS data is displayed to the controller on a screen that replicates a radar screen. ICAO Doc 4444 PANS-ATM notes that air traffic control service, may be predicated on the use of ADS provided that identification of the aircraft involved is unambiguously established. Two main versions of ADS are currently in use:

• Automatic Dependent Surveillance-Broadcast (ADS-B) is a function on an aircraft or surface vehicle that broadcasts position, altitude, vector and other information for use by other aircraft, vehicles and by ground facilities. It has become the main application of the ADS principle.
• Automatic Dependent Surveillance-Contract (ADS-C) functions similarly to ADS-B but the data is transmitted based on an explicit contract between an ANSP and an aircraft. This contract may be a demand contract, a periodic contract, an event contract and/or an emergency contract. ADS-C is most often employed in the provision of ATS over transcontinental or transoceanic areas which see relatively low traffic levels. 

The ITU press release on this topic:

The frequency band 1087.7-1092.3 MHz has been allocated to the aeronautical mobile-satellite service (Earth-to-space) for reception by space stations of Automatic Dependent Surveillance-Broadcast (ADS-B) emissions from aircraft transmitters.

The frequency band 1087.7-1092.3 MHz is currently being utilized for the transmission of ADS-B signals from aircraft to terrestrial stations within line-of-sight. The World Radiocommunication Conference (WRC-15) has now allocated this frequency band in the Earth-to-space direction to enable transmissions from aircraft to satellites. This extends ADS-B signals beyond line-of-sight to facilitate reporting the position of aircraft equipped with ADS-B anywhere in the world, including oceanic, polar and other remote areas.

WRC-15 recognized that as the standards and recommended practices (SARP) for systems enabling position determination and tracking of aircraft are developed by the International Civil Aviation Organization (ICAO), the performance criteria for satellite reception of ADS-B signals will also need to be addressed by ICAO.

This agreement follows the disappearance and tragic loss of Malaysian Airlines Flight MH370 in March 2014 with 239 people on board, which spurred worldwide discussions on global flight tracking and the need for coordinated action by ITU and other relevant organizations.

For more details see: globalflightsafety.org

ITU Workshop on VoLTE and ViLTE Interoperability

ITU recently held a workshop on "Voice and Video Services Interoperability Over Fixed-Mobile Hybrid Environments,Including IMT-Advanced (LTE)" in Geneva, Switzerland on 1st December 2015.

The following is the summary of that workshop:

I also like this presentation by R&S:

All the presentations from the workshop are available online from ITU website here.

5G Spectrum and challenges

I was looking at the proposed spectrum for 5G last week. Anyone who follows me on Twitter would have seen the tweets from last weekend already. I think there is more to discuss then just tweet them so here it is.

Metis has the most comprehensive list of all the bands identified from 6GHz, all the way to 86GHz. I am not exactly sure but the slide also identifies who/what is currently occupying these bands in different parts of the world.

The FCC in the USA has opened a Notice of Inquiry (NoI) for using the bands above 24GHz for mobile broadband. The frequency bands above have a potential as there is a big contiguous chunk of spectrum available in each band.

Finally, the slides from ETRI, South Korea show that they want to have 500MHz bandwidth in frequencies above 6GHz.

As I am sure we all know, the higher the frequency, the lower the cell size and penetration indoors. The advantage on the other hand is smaller cell sizes, leading to higher data rates. The antennas also become smaller at higher frequencies thereby making it easier to have higher order MIMO (and massive MIMO). The only way to reliably be able to do mobile broadband is to use beamforming. The tricky part with that is the beam has to track the mobile user which may be an issue at higher speeds.

The ITU working party 5D, recently released a draft report on 'The technical feasibility of IMT in the bands above 6 GHz'. The document is embedded below.

ITU Working Party 5D: The technical feasibility of IMT in the bands above 6 GHz from Zahid Ghadialy

xoxoxo Added Later (13/12/2014) xoxoxo
Here are some links on the related topic:

• IEEE ComSoc: 5G Wireless Demos Use High Frequencies
• HUAWEI, TELE2 disagree on role of spectrum for 5G

xoxoxo Added Later (18/12/2014) xoxoxo
Moray Rumney from Keysight (Agilent) gave a presentation on this topic in the Cambridge Wireless Mobile Broadband SIG event yesterday, his presentation is embedded below.