An arms race is escalating between the cable and telecommunications industries, and television might end up being the secret weapon. Tensions have run high this summer in the "battle of the bundle," with companies competing to offer discounted combinations of phone, broadband and video services. The Bells are getting into the TV distribution business intent on chipping away at cable's market share, much as cable operators have done to the phone business during recent years.

In June, AT&T followed fellow phone giant Verizon into the video market, the third leg of the so-called triple-play bundle. Penetration has been slow, but legislation wending its way through Congress could accelerate the telcos' TV invasion by granting them a nationwide franchise. Not to be outdone, Comcast and Time Warner this month will begin testing the quadruple play, folding mobile-phone service into their bustling bundles in select markets alongside their new partner, Sprint Nextel.

But the real action is still to come. What is known as a bundle today will seem primitive in a few years, when companies will combine not only the billing for multiple services but also the services themselves.

The Bells and Big Cable are intent on integrating the computer, phone and television in ways that will blur the boundary between entertainment and communications. That means customers won't simply watch their favorite TV channels on their mobile phones; soon enough, they'll be answering their phones through their TV sets.

"For a long time, the triple play of voice, video and data was going to be enough," says Matthew Davis, program director of consumer multiplay services at research firm IDC. "The problem is that the world is changing so fast that there's new complexities coming into it."

The implications of the quadruple play are not only being felt in the U.S. but also taking various shapes in Europe at such companies as France Telecom, which is marketing all four services under the Orange brand, and British cable provider NTL, which is expected to follow suit once its acquisition of Virgin Mobile is complete.

The telcos' domestic TV invasion began in September in Keller, Texas, the first U.S. market to access FiosTV, a Verizon video service complete with hundreds of channels, video-on-demand, HDTV and other innovations offered by cable providers. Planning to invest about $20 billion to deploy fiber-optic lines, Verizon subsequently has launched FiosTV in at least 50 other communities across seven states.

Verizon declines to state how many subscribers have signed up for FiosTV but reveals that about 80% of them buy both land-line and broadband services. "Currently, the bundle is the hot thing -- that's where you have to compete," FiosTV vp programming and marketing Terry Denson says.

In June, AT&T launched its own TV service, U-verse, in its home market of San Antonio, with plans to expand to as many as 20 more markets by year's end. Also getting active in video are other big telcos including Qwest and BellSouth, the latter of which AT&T is in the process of acquiring. In addition to the Bells, nearly 200 smaller companies are launching similar services in various U.S. markets.

But as the telcos close in on completing their first year in the TV business, their efforts have underwhelmed some. Bernstein Research analyst Jeff Halpern estimates that telcos will enroll fewer than 60,000 video subscribers this year, and his projection for 2007 is a modest 340,000. "The deployments have gone a lot slower than people have expected," Kagan Research analyst Mariam Rondelli says.

The cable industry has supplemented its core video product with broadband -- cable connections account for 57% of the high-speed market -- and voice. Convergence Consulting estimates that cable companies will have 8% of residential phone subs by year's end and 22% by 2009.

Compare that with telcos projected to have far fewer than 1% of TV subs by year's end and 6% by 2009. "We have a lot more voice customers than they do video customers," Comcast senior vp marketing Marvin Davis says. "They're trying to catch up to where we are."

Cable companies account for 55% of the 7.7 million triple-play subs amassed to date, according to IDC, and that percentage increases as one subtracts bundled subs that come through the telcos' partnerships with satellite services. Verizon and DirecTV share 415,000 subscribers, and AT&T is set to make a big push this month with EchoStar's Dish Network for a new joint offering dubbed Homezone.

The bundle business is booming, but some wonder for how long. The cumulative price of three services can trigger sticker shock, especially when subscribers lured by $99 price tags wake up six months later to bills in the $130-$140 range. Denson wonders whether triple play will stay sticky much longer.

"The greater the penetration, the more it becomes a commodity," he says. "Instead of a customer churning out of cable, telephony or broadband, they could churn out of all three services."

Adds Rondelli: "Going into the price wars is not helping telcos or cable. Ultimately, they have to differentiate their product if they are going to win the market share."

Differentiation is only beginning to creep into bundles through their expansion to mobile-phone service. The two largest telcos enjoy a built-in advantage in offering quadruple play through their respective wireless divisions, Cingular and Verizon, but they have barely begun to tap the potential, enrolling only 147,000 such subscribers to date, according to IDC.

Putting four services on one bill is harder than it sounds, according to Denson. "Integration is the biggest hurdle," he says.

To counter the telcos in wireless, cable operators Comcast, Time Warner, Cox Communications and Advance/Newhouse in November announced a $200 million joint venture with Sprint, the nation's third-largest mobile service behind Cingular and Verizon. Still more operators are expected to join, and Cablevision has hinted that it is pursuing its own wireless strategy.

"They have a strong-enough understanding that their competitive Achilles' heel is wireless," Matthew Davis says of cable operators. "They've moved a lot more quickly and a lot more easily than a lot of the insiders thought was possible."

In August, select subscribers will get a glimpse of that collaboration through Comcast and Cox services in test markets including Boston, Austin, Texas, and Portland, Ore.

At first, integration will come in small strokes, including unlimited calling from Sprint wireless to one's cable voice IP account, combined voicemail and e-mail and remote recording of one's home DVR. In a few years, though, the quadruple play will grow more sophisticated, untethering cable's video feed from the home for mobile viewing.

"The quad bundle allows us to integrate our products and services," Marvin Davis says. "There's more mobility and service for customers on how to receive it."

But migrating TV channels from the home to the phone is really only the beginning. To create differentiated services, the cable and telecommunications industries are racing each other through a thicket of technical logistics to deliver unprecedented interoperability among the television, computer and phone. In time, consumers might not even think of those devices as having distinct functions.

The stakes of bringing it all together are huge. Research firm Parks Associates estimates that add-ons to triple-play service will boost monthly per-subscriber revenue to $206 by 2010 -- nearly double that current tally.

AT&T's bundle already is beginning to exhibit indications of what's to come. Cingular users with Nokia 6682 phones can access AT&T Yahoo! GoMobile, a broadband offering that allows e-mail, photos and instant messages to travel fairly easily between the phone and PC. Another product, Mobile2Home, allows Cingular users to call from their cell phone to their land line and not be charged for cell minutes.

AT&T assistant vp consumer marketing Michael Grasso cites such services as the first signs of how his company is trying to surpass the cable bundle. "We're well beyond me-too content," he says. "We're on to me-too-plus."

But the television also will play a role in AT&T's three-screen attack. U-verse allows one set-top box to control feeds in multiple rooms, a dynamic that will enable the service to offer what it calls the "whole-home DVR," which lets the consumer record programming on one set and play it back on another. Even live TV can jump sets.

"We're going to be able to do a lot of whiz-bang things with the television," Grasso says.

AT&T could end up reinventing some of the most basic notions of TV viewing. Technology company Alcatel is working with AT&T on transforming the linear channel to allow customers to mix and match programming from various channels and set their own lineups. They would even be able to insert homemade video programs into those lineups.

But the true innovation lies in freeing television from its silo as strictly a font of video. "I feel like TV gets ignored as a communications device," says Hunt Norment, vp business development at Integra5, a company working on convergent bundle applications. "TV is the ultimate communications device."

During the next few years, telcos and cable will conduct trial runs for any number of ways to render TV channels, the Internet, e-mail, IMs and games platform-agnostic. In addition, text-based content such as e-mail and IMs will become more videocentric.

Quadruple-play integration will make the television a more versatile device, adopting phonecentric abilities including playing voicemail and reviewing call logs. A TV channel might, in effect, have the ability to "call" with an alert, like a Weather Channel storm update that leads to a relevant VOD offering.

Then there is video telephony, that "Jetsons"-like ability to see who with whom one is speaking on the phone, and vice versa. It's a long way off, but in time that feature will make its move from the corporate market to the consumer mainstream.

At its simplest level, the integrated bundle eliminates unnecessary duplication. Even the tech-savviest of current consumers must maintain multiple accounts, passwords, address books, parental controls, etc., to navigate overlapping services.

No wonder the innovation widely acknowledged to be the first to be mainstreamed is known as fixed-mobile convergence, which could eventually eliminate the distinction between a land line and a cell phone. One device with one number would seamlessly transfer between calling networks inside and outside the home. Strategy Analytics projects that 7% of U.S. telephony users will utilize such technology by 2010.

These myriad innovations are powered by a group of interconnecting technological standards. The first is Internet protocol television, an infrastructure that delivers video through the same pipeline as data and voice.

Bridging the IPTV and cellular realms is a combination of standards called IP multimedia subsystem (IMS) and session initiation protocol, which allow subscribers to be identified and billed for remote access. ABI Research estimates that at least $10 billion will be invested in IMS development during the next five years.

While most of these innovations are being developed in companies' respective labs, they don't inhabit a vacuum. The evolution of the bundle will affect -- and be affected by -- forces shaping the media arenas.

To an extent, cable and the Bells are playing defense against not each other but other players. Microsoft, Google and Yahoo! are capable of developing or partnering their way into the quadruple play, with broadband and voice products at their disposal.

In addition, satellite can't be counted out. DirecTV and EchoStar are teaming to make a joint bid in the FCC's wireless-license auction, a partnership that some have speculated might lead to a merger. Regardless of whether that happens, both companies are positioned to acquire licenses that will allow them to make wireless broadband networks part of their consumer offerings.

For now, though, the battle of the bundle has put cable and the telcos ahead of the pack. "For a long time, the term 'convergence' meant services on a single bill," Norment says. "The next step is a single, integrated user experience over integrated devices."