Some cafes and retail stores in Seattle next week will begin individually marketing products and services to bypassers in Seattle using RFID (radio frequency identification) technology.

The first target group is visually and hearing-impaired individuals who can benefit from positioning and navigation applications added to the system.

Six wireless public areas, called activation fields, will go live next week throughout downtown Seattle and at the city's ferry terminal. Over a few months 15 more city areas will be added. Users carrying an active tag and entering the activation field are recognized as the tag is read, and then are presented with announcements.

"Speakers are mounted on the telephone booth or the facade of the store. So they will be above the individual's head when they pass underneath or nearby," said Harry H Hart. III, founder and chief executive officer of Seattle's Awarea, which owns and manages the system.

Users of the personalized marketing system carry an active RFID tag roughly the size of a stack of four credit cards. When the tag comes within 100 feet of a transmitter sending low frequency signals at 126 kilohertz, the tag transmits a unique identification signal to a receiver connected to a monitoring and execution server.

Depending on what information the system has filed on the individual carrying the tag, the server selects the correct file to output -- either an audio file in Wave-format for an announcement or a Quicktime file for sign language to be displayed on a video monitor. The first message could be the address and sale information from a nearby retailer.

Customers needing more information can push a tell-me-more-button, explained Ben Donohue, vice president of business development for Axcess, which is providing the hardware and designing the system.

Data about the customer can be mined and sold to the retailers, Donohue said. It can also be used to personalize marketing and map customer behavior.

One hundred thirty active RFID tags have been in use at a test site with only one transmitter at Pioneer Square in Seattle for a year. Beginning June 1, when more transmitters are activated in downtown Seattle constituting six tag activation zones, more tags will be sold and rented.

Awarea plans to market the system at the National Federation of the Blind of Washington's legislative luncheon this weekend.

Assistive technology could include safety and navigation information displayed on a personal digital assistant or a smart phone. The information could also be delivered in audio format the same way as it is today to speakers mounted in information zones or to a Braille reader.

Other possible applications might be for tourists who might want guidance in the downtown Seattle area.