Wireless Public Address

Present day Public Address and Announcement systems (PA's) are used in many places to broadcast location related information including warnings and alarms. As such PA's are used widely in public transport systems such as train, underground, bus stations, and airports.  Furthermore PA's are used at theatres, concerts, sport-events, conferences, schools etc.
With the availability of wireless communications and using its broadcast and group address features a new method is open to distribute public and semi-public announcement information. By including personal profiling and intelligent processing, announcements can be directed or adapted to the personal needs and in particular may open a range of assistive applications for disabled persons.
In HearCom a first schematic model for a wireless PA systems (WPA's) is presented in the next figure. In the left column the candidate wireless technologies are shown. The right shows the various output options for audio, vision and vibration (or tactile). By means of the Personal Communication System (PCS) these different technologies can be connected and integrated to each other. By the processing and communication power of the PCS new (assisteive) applications can be developed.   

 WPA scheme

Information streams for Wireless General Public announcement/address system.



The first step of the HearCom Wreless Public Announcement demonstrator focuses on a system that handles the data communications from a Transport Public Announcement System:

  • This scenario covers Transport Systems and in particular the Gate Information system in an Airport.

  • The user is able to receive at his PCS: data announcements including Warnings, Gate related and other airport announcements, and voice information coded in data messages. These announcements can be filtered by specific User Profiling that may include: travel plan, language, interest areas etc.,
  • The information itself will be simulated in the first step of this demonstrator.
  • The information streams consist of textual messages, voice mesaages and warnings.

  • The demonstrator is composed by a server, in order to send public announce messages, and a client at the PCS, in order to receive the Public Announce messages.

Three types of messages are taken into account:

  • Audio, corresponding to a bit stream sent via wireless support, and resulting by a low bit rate audio coding in the server on a recording microphone message;
  • Text, corresponding to a text format message sent via wireless support, and resulting by a writing message at the server side;
  • Audio/text, combining both previous message types. This option is defined as a next step after the first release of the demonstrator.
Before sending of the message, it is possible to choice different level of priority between. For the moment, three levels have been defined:
  • WARNING priority
  • Standard priority
  • Low priority
Other levels of priority can be added, such as “Advertising”. The “WARNING” priority messages are more important and are highlight with a specific icon and a specific sound when it is receipt by the client.
The first demonstrator is planned for mid 2007. That demonstrator will be tested technically and evaluated by an expert focus group. Based on that a second versions will be made that also will include the simultaneous presentation of text and audio messages (bimodal presentation). 
See also the resarch on the benefit of bimodal presentation for persons that are hearing impaired.