What is the company's current investment plan in in-building systems? 
me with fiber and small cells. And it's why we made the investment many years ago, got ourselves into the space and started to learn how to build it, how to deploy it and get the right kind of assets for where the world was headed. We saw this densification coming and the need for it, realized that macro towers wouldn't be able to entirely meet that need. And so we began to invest in the complementary assets of small cells and fiber that are going to make this densification possible. So I think you'll see co-locations on towers. Towers is going to see a great amount of growth from the deployment of these spectrum bands, and then I think you're really going to see the reason why we originally made these investments and have continued to make the investments.
As densification happens, I think that will happen in great amounts on fiber and small cells. Are there other areas of infrastructure that are interesting to us? You spoke to in-building. There are some small number of in-building systems that we are doing. We find venues to be attractive when they meet our rigorous approach to allocating capital, if they exceed our returns and we think there's co-location there. Some of those make sense. But frankly, in terms of the scale of investment, it's really relatively small compared to what we see in the more public right-of-way opportunities to do infill and site densification with small cells and fiber, complementing the tower portfolios that are out there. So I don't see anything on the horizon currently that would cause us to deviate from our plan of the primary investment opportunities in front of us are small cell related.
Brett Feldman -- Goldman Sachs -- Analyst
If I can just ask a quick follow-up question. Your customers, your carrier customers have generally been able to use all of the spectrum bands that they hold licenses for off of their macro tower locations. Are you expecting that any site that they occupy today will eventually be upgraded to use the new mid-bands they're acquiring? Or do you think it's going to maybe be a subset of your towers that are in the right geographic locations to help with those frequencies?
Jay A. Brown -- President And Chief Executive Officer
I think If we took a long view and not kind of -- I don't think you're asking this question over the next two to three years because I would defer on that answer. But if I think about long term, 10 years, 15 years, 20 years out, in the top 100 markets, I think virtually all of the spectrum bands that the carriers have today will be operating all of those spectrum bands over time. The carriers will upgrade their equipment. They'll add additional lines and antennas and ultimately be broadcasting all of the spectrum bands that they have for the -- on the vast, vast majority of the macro tower sites that they're on. And then I think based on the amount of usage that ultimately happens, you'll see them be targeted in terms of the deployment and densification inside of those markets to supplement and extend the -- and expand the network capacity by utilizing fiber and small cells to make those macro sites as efficient as they possibly can.
That generally happens over a period of time. So if we go back in history and watch and look at how the carriers have deployed network, you can almost look at kind of the top urban markets, the most densely populated, and those will see the benefit of this kind of activity first. And then over time, you'd see that expand out to the more suburbia as well as to other markets that maybe are not quite as densely populated. So I think it's a long game and probably focused, at least initially, on the top markets.
Brett Feldman -- Goldman Sachs -- Analyst
Thank you.
Operator
Next, we'll go to Ric Prentiss with Raymond James.
Ric Prentiss -- Raymond James -- Analyst
Hey guys.
Jay A. Brown -- President And Chief Executive Officer
Good morning, Ric.
Ric Prentiss -- Raymond James -- Analyst
A couple of questions. On the small cell side, given the Verizon contract within the Sprint's cancellation, how should we think about pac
me with fiber and small cells. And it's why we made the investment many years ago, got ourselves into the space and started to learn how to build it, how to deploy it and get the right kind of assets for where the world was headed. We saw this densification coming and the need for it, realized that macro towers wouldn't be able to entirely meet that need. And so we began to invest in the complementary assets of small cells and fiber that are going to make this densification possible. So I think you'll see co-locations on towers. Towers is going to see a great amount of growth from the deployment of these spectrum bands, and then I think you're really going to see the reason why we originally made these investments and have continued to make the investments.
As densification happens, I think that will happen in great amounts on fiber and small cells. Are there other areas of infrastructure that are interesting to us? You spoke to in-building. There are some small number of in-building systems that we are doing. We find venues to be attractive when they meet our rigorous approach to allocating capital, if they exceed our returns and we think there's co-location there. Some of those make sense. But frankly, in terms of the scale of investment, it's really relatively small compared to what we see in the more public right-of-way opportunities to do infill and site densification with small cells and fiber, complementing the tower portfolios that are out there. So I don't see anything on the horizon currently that would cause us to deviate from our plan of the primary investment opportunities in front of us are small cell related.
Brett Feldman -- Goldman Sachs -- Analyst
If I can just ask a quick follow-up question. Your customers, your carrier customers have generally been able to use all of the spectrum bands that they hold licenses for off of their macro tower locations. Are you expecting that any site that they occupy today will eventually be upgraded to use the new mid-bands they're acquiring? Or do you think it's going to maybe be a subset of your towers that are in the right geographic locations to help with those frequencies?
Jay A. Brown -- President And Chief Executive Officer
 I think If we took a long view and not kind of -- I don't think you're asking this question over the next two to three years because I would defer on that answer. But if I think about long term, 10 years, 15 years, 20 years out, in the top 100 markets, I think virtually all of the spectrum bands that the carriers have today will be operating all of those spectrum bands over time. The carriers will upgrade their equipment. They'll add additional lines and antennas and ultimately be broadcasting all of the spectrum bands that they have for the -- on the vast, vast majority of the macro tower sites that they're on. And then I think based on the amount of usage that ultimately happens, you'll see them be targeted in terms of the deployment and densification inside of those markets to supplement and extend the -- and expand the network capacity by utilizing fiber and small cells to make those macro sites as efficient as they possibly can.
That generally happens over a period of time. So if we go back in history and watch and look at how the carriers have deployed network, you can almost look at kind of the top urban markets, the most densely populated, and those will see the benefit of this kind of activity first. And then over time, you'd see that expand out to the more suburbia as well as to other markets that maybe are not quite as densely populated. So I think it's a long game and probably focused, at least initially, on the top markets.
Brett Feldman -- Goldman Sachs -- Analyst
Thank you.
Operator
Next, we'll go to Ric Prentiss with Raymond James.
Ric Prentiss -- Raymond James -- Analyst
Hey guys.
Jay A. Brown -- President And Chief Executive Officer
Good morning, Ric.
Ric Prentiss -- Raymond James -- Analyst
A couple of questions. On the small cell side, given the Verizon contract within the Sprint's cancellation, how should we think about pac