Cellular signals often have difficulty penetrating massive steel high-rise buildings. But in Washington's downtown, matters are worse because of height restrictions that force builders to add multiple basement floors.

One law firm knew that a new headquarters facility near the White House might pose problems for 500 lawyers and staffers using wireless handhelds, so it commissioned a site survey before the headquarters was finished. The survey found that cellular signals would probably be poor, especially in a new law library three stories underground.

"Indoor cellular coverage is a real problem in D.C., and we're one of the few tenants to get to a solution," said Rodney Carson, director of administration for the Washington headquarters of Kirkpatrick & Lockhart Preston Gates Ellis LLP (K&L Gates). "The cellular phone companies have not been real forthcoming in solving these problems."

Indeed, two hotels operated by Marriott International at the Grand Lakes resort in Orlando had to install special indoor antennas to boost cellular signals for guests, several years after the hotels opened.

Carson's law firm started researching the indoor cellular problem in early 2006 and by April had finished installing a system to boost cellular signals for both T-Mobile USA Inc., provider of Research In Motion Ltd.'s BlackBerry service, and Verizon Wireless, the carrier that the majority of cellular voice users at the law firm rely upon, Carson said.

Carson asked Glasgow Group Inc., a Washington-based telecommunications consultancy, to recommend vendors of equipment to boost the cellular signals, and the law firm eventually chose LGC Wireless Inc. San Jose-based LGC installed a system of cables, three communications hubs and 24 remote antennas as the new 11-story high-rise building was completed.

The LGC InterReach Unison system cost K&L Gates about $80,000. The law firm also paid T-Mobile about $20,000 to install a mini base station, and it paid Verizon about $50,000 for a rooftop antenna.

At the Marriott hotels in Orlando, Mobile Access Networks Inc. in Vienna, Va., installed special distributed antennas to handle cellular and Wi-Fi, and the total of all the related costs topped $2 million. InnerWireless Inc. in Richardson, Texas, also competes in the market for in-building wireless systems, according to a spokesman for LGC.

Carson said today that the cellular signals now work well, even three stories underground in the law library, where about 60 people work. "We had all sorts of complaints about the signal at our older building, and with three floors underground, we knew we faced life safety issues, and needed some sort of solution," Carson said.

"Now we get rave reviews from users as well as clients and attorneys from other firms who can get a signal but say they can't get their phones to work at their own offices," he said.

K&L Gates also has Wi-Fi service throughout its new building, but a decision to add voice over the Wi-Fi has been delayed as IT staff consider security issues, Carson said.

Carson said he realizes that the costs for the project were much less because the work was done during construction and not afterward, as was the case at the Marriott hotels in Orlando.

Having reliable indoor cellular access is going to prove to be a sound decision, Carson added. "That's especially true because everybody has gotten more reliant on handhelds," he said.