PhoneLabs

The Uniden ELBT595 model, which will be replaced next year with a model that has a full-size phone. More Photos »

But now a handful of companies are marketing household devices that they believe meld the best of both worlds: the convenience, calling features and free minutes of a cellphone with the reliability and ease of use of a landline.

Connect a cellphone to the device — with a docking station or in some cases wirelessly — and all of its incoming calls now ring through to a cordless landline phone often included as part of the package. That same cordless instrument can be used to dial out over the cellular network, saving money by using the cell plan's available minutes.

Calls are also clearer because the actual cellphone remains docked and stationary, located in the part of the house that gets the strongest signal, while the caller roams around using a standard cordless phone.

When the user is leaving the house, the cellphone can be removed and the cordless phone reconnected to the landline network.

"A cell dock is just the first step in the concept of seamless mobility," said Kevin Keefe, a vice president for marketing at Motorola, the maker of a phone system that combines a cell dock with other features.

Because cellphone manufacturers use a wide variety of proprietary plugs, only a few of the most popular cellphones could be connected to the earliest docking stations, introduced last year. One of the first, RCA's Cell Docking System, supplied four separate connection cables o connect the dock to just a handful of Motorola, Nokia and Sony Ericsson cell models. RCA recently withdrew the product from the market but plans to introduce an updated model in the fall.

Its next model will incorporate Bluetooth technology, soon to be found in all cell dock systems, which lets cellphones communicate with a base station wirelessly. This eliminates adapter plugs and opens the technology to a much wider range of phones.

"Bluetooth is the key" to cell dock technology, said Carlos Hernandez, a product manager for Panasonic's telephone division. Mr. Hernandez puts his Bluetooth-compatible Motorola Razr phone in the corner of the house closest to a cellphone tower, and uses a Panasonic cell docking product to connect his home cordless phone to the cell network.

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A Motorola SD4500 series cellphone dock, remote handset and base unit. More Photos >

Equipment Choices

For those intrigued by the idea of harnessing a cellphone's features through standard cordless handsets, there are a handful of devices from which to choose.

Both Motorola and Panasonic combine cellphone docking into "home communications systems," sophisticated devices that offer much more than just voice calls.

MOTOROLA Motorola's current offering, the SD4500 series ($80 to $100 depending on features), includes a cordless phone and a base with an answering machine; accessories, at additional cost, offer video monitoring and voice extensions. A cellular connection is enabled when the phone is paired with a $100 docking station.

Slide Show: Making Cellphone Calls From a Landline

The current system works with only a few Motorola cellular models; inexplicably, the company's best-selling Razr is not one of them. And because of incorrect instructions in the manual, setting up the cellphone dock and synching it to the base station took several tries. Customer support workers could not solve the problem as they were not familiar with the unit.

To use the cordless handset for an incoming or outgoing cellular call, the user first selects the cellphone from a menu of available devices linked to the base. Once the call is complete, the handset reverts back to landline use, unless the cell dock is set as the default connection device.

This spring, Motorola will introduce the Bluetooth-enabled C51 model. In addition to a $99 base station and answering machine, a Bluetooth adapter ($129) is to go on sale in the summer, allowing the unit to work with any Bluetooth phone.

PANASONIC The KH-TH102-M system ($349) from Panasonic includes a two-line base unit with answering machine plus a cordless phone. The phone includes a video camera and screen that can be used for video phone calls with compatible units. The other side is used for standard voice calls.

The system also includes a cordless video camera that functions as a motion-activated baby monitor, with the image displayed on a PC or on the cordless phone's screen. System setup is straightforward, with a well-written manual. Windows-only software allows users to download phone books, ring tones, music and photos from a PC into the base or satellite units, or to monitor the video unit from the PC.

The Panasonic also offers the best audio quality of all units tested. Static and hiss were absent when the cordless unit was used in conjunction with the docked Bluetooth cellphone.

UNIDEN When Uniden introduced its ELBT595 model ($200) last year, the company designed the unit's cordless phone to resemble a cellphone. But consumers were not pleased.

"The good news is that customers very much want to use their cellular minutes on a landline," said Rich Tosi, Uniden America's president. "But the unit's handset is too small; they wanted full-sized models."

Next year, the company will introduce a revamped model with a bigger handset, priced from $79 to $129. In addition to its Bluetooth cellular docking feature, "it will be a basic phone," Mr. Tosi said, "with caller ID and downloadable ring tones."

PHONE LABS For those who want only the cellular docking feature, there is no more elegant solution than Phone Labs' Dock-N-Talk ($150). It's a small box that plugs directly into an existing home phone. A compatible cord or Bluetooth module ($80) links the cellphone and the standard phone. When connected to the Dock-N-Talk, the home phone no longer works as a landline phone.

The Dock-N-Talk offers one feature its competitors do not: dialing through the cellphone network is done just as one would dial a normal landline phone: pick up a standard handset, listen for the dial tone and dial. When using the cell docking feature with competing handsets, one must dial the number first, and then push "send," increasing the time it takes to connect a call.

The company's newest model, the Enterprise ($200), combines a full-featured desk phone with cell docking technology. The unit's screen displays most cellphones' phone books, as well as caller ID and other information.

Cutting the Cord

For those who can make use of cell docking systems, the technology raises a fundamental question: why not just cut the cord for good?

For some, there are technical reasons. Because of incompatible standards, home burglar alarms, for example, require a landline rather than a cellular network to transmit alerts to a monitoring station, but that may change in the future.

And those who value the short time it takes to connect landline calls will be disappointed with a cell dock system. Because calls go through the cellular network, connection times are slower. And while voice quality is improved because the cellphone remains stationary, it still does not rival the quality on a traditional network.

But for the undeterred, new federal rules on number portability make it easy to switch, letting customers transfer any of their phone numbers to any other carrier.

Many cell carriers offer inexpensive second wireless lines, so the landline number familiar to friends and relatives can be transferred to a second cellphone account for permanent use in a cell docking system, cutting costs.