Mignon Clyburn said healthy competition is key to continued innovation.

“We have taken a light regulatory approach, but have touched when necessary,” Mignon said, speaking at the opening of the CTIA 2013 show in Las Vegas.

The most notable of those touches, of course, was the agency’s opposition to AT&T’s purchase of T-Mobile USA. The agency has since approved other combinations, including Verizon’s partnership with the cable companies, and T-Mobile USA’s acquisition of MetroPCS.

Clyburn had some specific words of praise for smaller, regional carriers that she said provide excellent customer service and help connect rural America.

Speaking in her first week as acting chair, Clyburn said that an incentive spectrum auction remains on track, with rules to be issued this year and the bidding itself to take place next year.

“The agency is doing a lot of creative things to make more spectrum available,” said Clyburn, who will hold the post until confirmation of her successor, Tom Wheeler.

The aluminum-clad phone is similar to the Lumia 920 that has been sold for months at AT&T, as well as the just-introduced Lumia 928 for Verizon. The new phone, being introduced globally and headed here to T-Mobile, features a few new twists.

In addition to its different outer shell, the 925 features an improved camera with a sixth lens (other recent high-end Lumia models have five). The added lens helps better capture natural light.

On the software side, the company is offering what it calls Nokia Smart Camera — a feature that captures 10 images at once, offering the ability to choose the best shot or blend the results into an action shot or one with motion focus. Nokia said the software-based camera features would also be made available for all of Nokia’s other Windows Phone 8 products sometime in the third quarter.

The Lumia 925 is due to go on sale in Europe in June, with T-Mobile’s U.S. launch likely to be the following week. It is priced at 469 euros ($608), though Nokia U.S. head Matt Rothschild said he expected T-Mobile’s upfront price to be under $100.

“We expect really aggressive pricing,” Rothschild said.

With the launch of this phone, the recent announcement of the Lumia 928 at Verizon, as well as the entry-level Lumia 521, also headed for T-Mobile, Rothschild said that Nokia’s U.S. operation has plenty to keep it busy in the months ahead.

Nokia has struggled to make the same kind of inroads in the U.S. market that it has seen in some other places, but Rothschild said he is pleased with where the company finds itself.

“From where we were … basically starting from scratch with Lumia and Windows Phone, I couldn’t be happier with our progress,” Rothschild said.

The phone will go on sale May 16 for $99 (after a $50 rebate).

It’s a new take on the Lumia 920 that debuted last year. Though generally similar, it features a different screen technology, improved flash and audio recording, and is a bit thinner than the model that has long been on sale at AT&T.

The timing is a bit odd, coming on a Friday and ahead of an event Nokia has next week to talk about what’s next for the Lumia line.

Nokia and Windows Phone as a whole have been slower to bring models to CDMA carriers, focusing much of their time and energy on the more globally used GSM technology at the core of T-Mobile and AT&T’s networks.

Verizon has been selling the Lumia 822, a more midrange model, as well as Windows Phones from Samsung and HTC.

Sprint has said it will offer its first Windows Phone 8 devices this summer.

Meanwhile, two other Nokia models — on sale elsewhere — are just making their way to the U.S. T-Mobile is selling the entry-level Lumia 521 for $150 without subsidies, while AT&T’s new Aio prepaid brand is carrying the Lumia 620.

Aio Wireless (pronounced Ay-Oh) is launching Thursday in three cities — Houston, Orlando and Tampa.

Plans range from $35 to $70 a month, and devices offered include smartphones from ZTE and Samsung, as well as the Nokia Lumia 620 (a Windows Phone model that previously hadn’t found its way stateside). Customers can also bring their own devices to the network.

It also has the iPhone at standard unsubsidized prices, meaning that a 16 gigabyte iPhone 5 sells for $649. At the other end of the spectrum, the ZTE Prelude, an entry-level Android device, is priced at $49.

Aio’s website has a decidedly non-corporate feel, with a woodgrain background and promises of being “simple” and “delightful” — two words not always associated with wireless carriers.

AT&T is taking another page from T-Mobile’s playbook, offering unlimited data with all its plans, but pricing the different options based on how much of that data customers want at full speed.

The heftiest plan offers a whopping 7GB of high-speed data for $70, while a 100MB plan costs $35 a month.

AT&T is not alone in establishing separate brands aimed at different segments of the market. Sprint, for example, sells prepaid service under both the Boost Mobile and Virgin Mobile brands. Sprint has used both to try out different pricing and marketing tactics than it uses with its main brand.

The phone, which went on sale for $99 on April 12, is currently priced at 99 cents.

“We do promotions like this all the time,” said AT&T spokesman Mark Siegel, declining to comment on how sales have been for the midrange Android device.

Facebook didn’t comment on sales, either, though a spokesman said, “We think this is a good move by AT&T, and have highlighted the new price on our Facebook Mobile page.”

An HTC representative was not immediately available for comment.

The HTC First is the first device to come with Facebook Home software built in, though it is a free download for other phones, and Facebook has updated its messenger software to include the multitasking Chat Heads feature.

The phone, which debuted on AT&T, is also headed to France Telecom-Orange, which plans to sell it in France and in the United Kingdom through its EE joint venture.

Facebook said at the launch of Home that it planned to work with a number of hardware makers to create phones with Home built in. Listed among partners were ZTE, Lenovo, Sony and Huawei.

Update: HTC chimed in with this comment.

“Promotional pricing is common in the mobile industry.”

As for what kind of sales it has seen for the First, the company said, “HTC doesn’t comment on sales outside of our official financial announcements.”

The carrier just announced that it will offer the LG Optimus G Pro starting May 10 for $200 with a two-year contract, with preorders starting May 3. Customers of other carriers wondering when they might be able to get their hands on the smartphone will be disappointed, because this will be an AT&T exclusive.

First introduced at Mobile World Congress, the Optimus G Pro features a 5.5-inch, full-HD touchscreen, and a 13-megapixel rear camera and front-facing 2.1-megapixel camera. Running Android Jelly Bean 4.1.2, the smartphone also comes preloaded with eye-recognition software that allows you to control the handset’s video player with eye movements.

Using the front-facing camera, the Optimus G Pro can track the position of your eye, so if you’re watching a movie and it detects that you’re no longer looking at the screen, it will pause the video and then resume when it senses you’re looking at the display again.

Sound familiar? That’s because the Samsung Galaxy S4 has a similar feature. LG will have a bit of a challenge taking on Samsung’s latest Galaxy phone, which has built up quite a following, and also faces stiff competition from the HTC One.

LG has struggled to compete in the U.S. market, partly because many of its high-end models aren’t widely available from carriers with subsidized pricing in the way Samsung’s devices are. Both the Galaxy S4 and HTC One are being sold at all four major carriers. I’ve asked LG whether it will bring the Optimus G Pro to other providers after AT&T has had the exclusive for a while, and will update the story once I hear back.

You recently mentioned the HTC One as being priced at $200. I’ve just been on the phone with my carrier T-Mobile, which offers me the HTC One for $100 down and $20 a month for 24 months. They explain they “no longer offer discounted phones” under their new world order or whatever. Can you explain?

A:

In the U.S., carriers traditionally subsidize the price of mobile phones and then make back the money by requiring buyers to sign a two-year contract, so they don’t defect before the carrier has made back the subsidy from them. Under this formula, the HTC One is indeed $200 at AT&T.

But T-Mobile recently announced a new approach under which it won’t subsidize the phones, but will charge something close to what the phone maker charges it, spread out in monthly payments. In return, it won’t require a two-year service contract. In the case of the HTC One and some other high-end smartphones, like the iPhone 5, that amounts to $100 down at purchase, plus $480 over two years — $20 a month. The actual voice and data service is in addition to the cost of the phone.

Q:

I have always been a Windows user, and always used security software. I just purchased a new iMac and the folks at the Apple store have told me that security software is not needed on Apple computers. What is your opinion?

A:

The Mac isn’t invulnerable to security problems. It’s just not targeted nearly as often as Windows PCs are. Relatively few Mac owners use security software because almost none of the vast array of malware programs around is designed for the Mac. Nearly every one is designed to run on Windows, and they can’t run on the Mac operating system, unless you install Windows on the Mac.

My advice: If security software makes you more comfortable, use it. Otherwise, unless you install Windows, the odds that your Mac could be successfully attacked are low enough that security software isn’t needed. However, you are still vulnerable to scams which rely on greed, carelessness or fear to get you to open suspicious links in email. Never do this, especially if the email purports to be from a financial institution or credit-rating service.

Email Walt at mossberg@wsj.com.

Starting tomorrow, the carrier is running a limited-time promotion during which customers can trade in their old smartphone for $100 off the purchase of a new device, including the Samsung Galaxy S4, BlackBerry Z10 and HTC One.

To be eligible for the discount, the smartphone must be no more than three years old and still in good working condition. The carrier said some handsets might even have a higher trade-in value than $100, and if so, the customer will receive a further discount.

Trade-ins will be accepted at AT&T stores and authorized dealers, and all credits are offered on the spot.

This is just the latest move by a carrier to retain and woo new customers. In April, Sprint and Virgin Mobile offered a $100 credit to people who switched their phone number over to their service.

AT&T did not reveal how long the promotion would last, but if I were you, I’d jump on the deal while you can.

After months of talking in broad strokes about its intent to get into the home security business, AT&T is ready with the full details.

The company says its “Digital Life” service is now available in 15 cities — Atlanta; Austin, Texas; Boulder, Colo.; Chicago; Dallas; Denver; Houston; Los Angeles; Miami; Philadelphia, Riverside, Calif.; San Francisco; Seattle; St. Louis and parts of the New York and New Jersey metropolitan area.

The company plans to expand to more than 50 cities by the end of this year.

As for pricing, the basic service will start at $30 a month (plus $150 upfront for equipment). For $10 more per month (and an additional $100 in equipment fees), users can add three additional services, including sensors for motion, glass breakage, smoke or carbon monoxide.

For even more, customers can add cameras, water-leak sensors, remote-controlled door locks and other features.

The service is designed to work regardless of which provider a customer has for their home phone or wireless service. Mobile apps for Android, iOS and Windows Phone allow customers to keep tabs on the service.

“We know how important security is to our customers, and this was our top priority when we set out to build Digital Life,” AT&T’s Kevin Petersen said in a statement. “People rely on their mobile devices more than ever, so Digital Life offers an easy and convenient way to secure their homes, protect their families and simplify their lives from virtually anywhere.”

AT&T’s pricing and options are designed to compete with similar services offered by security specialists like ADT as well as regional players and other new entrants, such as cable provider Comcast.

That’s the good news in a report from RootMetrics, which measures real-world cellphone performance nationwide.

Sprint, AT&T and T-Mobile all reduced their call failure rates from the first half of the year to the second, according to RootMetrics. Verizon’s rate increased fractionally, but was still an industry-best 0.7 percent for the second half of the year.

“In 2012, we found strong call performances from all carriers: the gap between each carrier’s average rate of call failures (dropped and blocked calls) was relatively minor,” RootMetrics said in its report.

Data speeds, meanwhile, are also showing across-the-board improvement as the major carriers spend billions to expand LTE service nationwide. Verizon was the first, and has the largest LTE network, but all its rivals are working hard to catch up.

A separate report from RootMetrics released earlier this year showed AT&T with the fastest LTE network and Verizon with the broadest LTE coverage.

“Due to overwhelming global demand of Galaxy S 4, the initial supply may be limited,” a Samsung representative told AllThingsD. “We expect to fulfill inventory to meet demands in the coming weeks.”

Earlier on Wednesday, T-Mobile and Sprint both said that full retail availability of the Samsung flagship device would come later than expected.

“We had planned to launch this next generation of the award-winning Samsung Galaxy line-up on Saturday, April 27,” Sprint said in a statement. “Unfortunately, due to unexpected inventory challenges from Samsung, we will be slightly delayed with our full product launch.”

AT&T, meanwhile, said it plans to start selling the S 4 on Saturday, as expected.