It is a misconception that the 700 band is a panacea for everything, explains Gopal Vittal

Gopal Vittal, Chief Executive Officer of Bharti Airtel and South Asia, in the Earnings Call for Q1FY23 explained,

“There are two modes in which 5G operates: Standalone or SA and non-standalone or NSA.

In the SA mode, 5G comes as a top-up to an existing 4G radio layer. The 4G layer then operates independently.

There are two issues here. The first is a lack of a well-developed ecosystem for SA devices. The second issue is propagation. The workhorse layer, 3.5 GHz has lesser propagation than even 2.3 GHz (which is the TDD band) and this impacts coverage in urban areas. As a result, SA can be effective, only if there is a sub-GHz layer that is also offering SA and the two work in conjunction. The role of the sub-GHz layer is only for coverage, it is not for capacity or speed. So, the sub-GHz basically goes and is needed, where 3.5 does not reach. In fact, we have seen in our trials, that the sub-GHz layer on 5G SA gives only 8 to 10 Mbps speeds. And therefore, it’s no different from 4G. This is a very important point to understand, given the misconceptions about the 700 band and why it is a panacea for everything. It is not. The band is absolutely no different from 850 or 900 in terms of propagation. All it does is to provide coverage at the edge, deep indoor or in far flung areas. And it gives you 4G-like speeds nothing more.

The second mode that 5G operates is NSA. Now a quick word on the physics involved. The limitations of radios and spectrum propagation is always the uplink. It is the uplink that allows a user device to upload a photo or any other content or even have a two-way voice conversation. The downlink, however, can travel much further, which is of no help for user experience. Because without uplink capabilities, there will be no coverage. In the NSA mode, the great advantage is that the 3.5 GHz layer actually travels much further, because it performs the downlink. It does not need to do the uplink, because that is done by the 4G layer. This is invariably the 1800 or 2100 band, also called the mid-band.

As a result, there are several advantages of the NSA mode. First, the 3.5 GHz band extends at least 30% more of the downlink, which implies a 100 meters extra coverage. This gives you substantially more coverage in urban areas, when mid-band is providing the upper. At the edge, when you need further extension of coverage and the mid-band doesn’t reach, the fallback in terms of coverage is provided by the sub-GHz layer 850 or 900, where we have a branch of spectrum all across the country.

The second advantage of NSA is that all devices work on this model. It is the most widely available ecosystem in the world. And as you know, telecom is a game of ecosystems. In the US and South Korea, where both SA and NSA have been launched, the traffic on SA is less than 10% of total 5G traffic.

The third advantage is it allows us to use existing 4G technology at no extra cost for the uplink, or what’s called the anchor band, since we already have the radios and the spectrum that is live on our network.

Finally, the last advantage of NSA is around experience. It will allow for faster call-connect time on voice. In addition, it allows us to provide a faster uplink than anyone else, given our massive spectrum holdings in the mid-band.

And this is what leads me to the crux of the issue. To offer NSA you need solid mid-band spectrum 1800 or 2100, because that’s what provides a great uplink experience. Over the last few years, we have strategically accumulated the largest pool of mid-band spectrum. Today we have 30 megahertz of mid-band spectrum. This does not include the 2300 band TDD, 30 megahertz of mid-band spectrum 4 circles and 20 or above in all of the rest. As competition does not have such a large mid-band spectrum.

Do remember that if we did not have this large chunk of precious mid-band spectrum, we would have had no choice but to buy the expensive 700 band spectrum. And once we had bought it, we would have to deploy large power guzzling radios on this band, not only would the costs have been higher, it will lead to more carbon emissions. And very, very importantly, given us no additional coverage than our existing 900 spectrum bank.

So in sum what would we have got: more cost, more ESG, unfriendly and no improvement in coverage. Therefore, this well thought out strategy for spectrum acquisition through a combination of auctions, M&A, and trading over the last few years, has allowed us to avoid the need for adding an expensive sub GHz band and yet deliver a world class 5G experience.

In sum, our consistent long term spectrum strategy will help us meet all our objectives. The best 5G experience, 100x capacity enhancement, the most power efficient solution and the lowest total cost of ownership.

We believe this will give us an enduring competitive advantage for years to come. With this option, we are fully confident that we will not be required to spend any material amount of spectrum for many years to come.”

CT Bureau