Michael Prior
Analyst · Raymond James
Thank you, Justin. Good morning, everyone. As usual, I will start with some highlights for what's proved to be an excellent quarter for ATN. Starting with U.S. wireless, U.S. wireless had a very strong quarter, showing promising returns on the capital we have spent over the past year in order to expand our mobile broadband coverage and capacity. That being said, as we noted in the press release, we use the word exceptional deliberately. We don't expect to see year-on-year growth rates in this segment at anywhere near these levels in subsequent quarters this year. And there are other areas of strength as well, improving margins and revenue growth at a number of our smaller wireless properties and revenue growth in U.S. wireline.
So let me get into few more specifics after that, starting again with U.S. wireless. The U.S. wireless generated 34% revenue growth in the quarter. The driver of this increase, as we noted, was markedly higher data traffic volumes. And digging a little deeper into that, the growth in data volumes was due to a combination of 3 factors: first, upgrading our capacities and 3G capabilities; two, expanding our coverage in a number of sites and service; and third, the general industry trend of higher usage for customer -- data usage, that is.
I'll put some hard numbers to that. Megabytes billed expanded by about 115% year-on-year, and we increased our 3G base stations and service from approximately 20 last year to 220 this year. On the other end of the spectrum, sorry for that pun, voice minutes declined by 7% from a year ago. And as we said, we expect the data traffic increase to be largely offset in coming quarters due to expected declines in the rates we receive from carriers per megabyte. And therefore, we expect the next couple of quarters to be flat to slightly positive year-on-year.
So despite likely continued expansion of data traffic volumes, we would expect year-on-year wholesale revenue growth then to be reduced.
These rate reductions, going back to the pricing reductions, the thing I would note there is they're to be expected, and in fact, they're an important part of how we manage our relationship with our biggest customers and our value proposition. As they put more volume on our network, we can continue to lower rates so that our solution remains one that fits their strategic outlook and internal cost benefit analysis.
Our offering is essentially a lease versus own solution in areas where owning confers no strategic benefit to the carrier and certainly should rank well below in returns and positioning compared to other potential uses of their capital.
So moving on to international wireless, revenues there also grew nicely, up 8% over last year, and revenue growth was a function of both subscriber and ARPU across most of those markets. Operating margins in our Island Wireless business also improved as a result of growing economies of scale in each of these markets. On the other hand, there's still more work to be done in order to bring all of these operations to solid, sustainable profit and cash flows.
In wireline operations, total wireline revenues were up as well, following a number of flat quarters, so that was good to see. And I think it was largely the case of the shifting mix, with some of the areas of strength, such as U.S. wholesale wireline revenues and international broadband revenues, growing in comparison to the areas of weakness and decline, such as international voice and legacy CLEC revenue.
So last, as you may have noticed, we are still sitting here with substantial balance sheet capacity. We continue to be very active in the market but have run into a few disconnects between sellers' expectations and ours. That can be frustrating, but it's part of the deal world, and it doesn't concern me unduly. And I would also add that we remain confident that we will uncover the right opportunities if we stay patient and are creative in our approach.
In summary, for ATN overall, this is a very strong quarter and one that demonstrates the solid performance that we can achieve with our existing businesses. While it'd be hard to replicate first quarter growth level as the year goes on, we are investing in areas that build out our footprint and leverage our existing infrastructure as we look for other more strategic opportunities to expand.
So with that, I would like to turn the call over to Justin -- or back over to Justin for a more detailed financial review.