Addressable speaker system

[0002] This invention is related in general to message broadcast systems. More specifically, it is related to a system for the selective activation of individual speakers in a broadcast audio communications system.

[0003] Noise in the workplace is not a new problem, but one that is getting increased attention as work configurations and business operating models evolve. A number of recent studies indicate that noise in the form of conversational distractions is the single largest negative influence on workers' productivity. Additionally, announcement broadcasts from overhead sound systems are primary distractions, as attention is naturally drawn to these messages. This disruption in the normal workflow creates inefficiencies in people's productivity, and it degrades the overall quality of the workplace environment.

[0004] The negative effects of noise are influencing larger groups of people. As the service sector of the economy continues to grow, an increasing number of workers find themselves in office settings rather than manufacturing facilities. The need for flexible reconfigurable space has resulted in open-plan workspaces, larger rooms with reduced heights, and movable partitions over which sound can pass. The density of the office workplace is also increasing with more workers occupying a given physical space. More workers are using speakerphones along with conferencing technologies and multimedia computers with large, sound reflecting screens and voice input. All these factors have contributed to the dramatic increase in the noise level of the work place. As a result, the loudness of the paging systems and overhead sound systems has increased in order for the broadcast to be heard above the increasing ambient noise.

[0005] A major drawback of the current paging system used in most schools and businesses is the inability to confine the audio messages only to the space occupied by the intended recipient. As a simple example, consider a small business office environment having three rooms separated by partitions or walls. Each wall blocks the sound from reaching into an adjacent room. Each room is equipped with an individual speaker, which is connected to a broadcast audio power unit. Audio messages are typically maintained in a central location and sent to a broadcast power unit, which in turn drives speakers in each room. Further, consider that room 1 is empty and rooms 2 and 3 have occupants. The occupants in rooms 2 and 3 are subject to the same announcement driven by the speaker system, which is integrated into the overhead ceiling tiles, even though the announcement may only be intended for the occupants in room 2. Power used to broadcast the message into room 1 is unnecessarily wasted, since this room is unoccupied.

[0006] This mode of messaging is disruptive, inefficient, and outdated. What is needed in today's workplace environment is a message broadcast system that does not broadcast messages to all speakers simultaneously, but does drive selectively only the speaker that is nearest to the intended recipient.

[0007] The present invention provides a system and method for sending an audible message to a specifically identified individual through a selected single broadcast speaker closest to the identified individual within an environment having multiple speakers scattered throughout. A feature of the present invention is the capability to predefine the location of all broadcast speakers in a predefined area and to broadcast a message through each speaker on an individual basis. The system has the capability of locating an intended message recipient from all other personnel working within the predefined area. By combining these capabilities, a unique individual can receive an audible message from a single speaker closest to the individual without all the speakers becoming active simultaneously.

[0008] In one embodiment of the present invention, a building, such as an office or school, is equipped with a public addressing system having multiple speakers scattered throughout the building. The speakers are connected to a speaker power unit, which is also known as an audio power unit, and the public addressing system is connected to a central controller. This building is also equipped with a network of cell controllers located above the ceiling space, and each cell controller is equipped with a radio frequency communication system of transmitters, receivers, and antennas. This network of cell controllers is connected to the central controller. The central controller can be accessed by an intelligent workstation. Each person working inside the office building is given a badge equipped with an active radio frequency identification (RFID) tag. When there is an audio message to be delivered to a particular person inside the building, all cell controllers, which are mounted above the ceiling plane, will broadcast a radio frequency (RF) signal through the transmitters into the area below which includes all the rooms. When an RFID badge receives the radio frequency signal from a cell controller, the badge responds by transmitting back another RF signal that contains a unique ID code that identifies itself. This radio signal transmitted by the RFID badge is received by the nearest antennas. Each antenna may receive more than one RF signal from more than one RFID badge. Each cell controller then scans and receives the information from all the antennas that are connected to it. Upon receiving the information, each cell controller calculates the distance between each badge and the receiving antenna, and from this distance calculation, the cell controller determines the location of each tag. The location information is sent by each cell controller to the central processor which maintains a log of the location of each individual carrying an RFID badge in the building. This location log which is stored in the central processor can be accessed by the intelligent workstation when it needs to send an audio message to a particular user wearing an RFID badge.

[0009] In operation, when there is a need to broadcast an audio message to a particular user wearing an RFID badge inside the building, the receptionist, for example, identifies the person and delivers the audio message to the intelligent workstation that is connected to the central processor. The central controller, after associating the person with an RFID badge, looks in the log to determine the location of this individual and delivers the audio message by enabling the closest speaker through the speaker power unit and sending the audio message to this speaker.

[0010] The invention is better understood by reading the following detailed description of the invention in conjunction with the accompanying drawings, wherein:

[0011] FIG. 1 illustrates prior art public addressing system with multiple room speakers connected to an audio power unit.

[0012] FIG. 2 illustrates an exemplary embodiment of the operation of the present invention.

[0013] FIG. 3A illustrates a scenario in which all room antennas transmit a radio frequency (RF) signal to locate a user carrying an RFID badge.

[0014] FIG. 3B illustrates a scenario in which the RFID badges transmit RF signals containing personal identification codes in response to the RF signal to locate.

[0015] FIG. 4 illustrates the selection of one particular speaker to broadcast an audio message to a particular user.

[0016] FIG. 5 illustrates an alternate embodiment employing wireless transmissions between the speaker and the speaker-powered unit.

[0017] FIG. 6 illustrates another alternate embodiment in which speakers are embedded into the partition wall of a cubicle.

[0018] Referring now in more detail to the drawings in which like numerals refer to like parts throughout the several figures, FIG. 1 depicts a prior art configuration of a public addressing system 10, with the speakers 12 distributed one per each room 14, 16 and 18. The speakers are interconnected to an audio power unit 20. Audio power unit 20 provides the power to drive each speaker 12. Speakers 12 are attached to, or embedded in, the ceiling tiles 24. In the example environment illustrated in FIG. 1, there are three adjacent rooms 14, 16, 18 separated by a wall 22. Each wall 22 blocks sound from reaching into an adjacent room. The figure shows that no one is present in the first room 14; two people are present in the second room 16; and two other people are present in the third room 18. When there is a need to broadcast an audio message addressed to a person in the second room 16, the audio message is broadcast through the audio power unit 20 to all the speakers 12 in the system, including the speaker 12 in the unoccupied room and the speaker 12 in the room in which unintended recipients are present.

[0019] FIG. 2 illustrates one embodiment of the addressable speaker system 30 of the present invention including speakers 12 interconnected to an audio power unit (speaker power unit) 20 that is connected to a central processor 32. The speakers 12 are distributed one per room and are attached to the ceiling tiles 24. The central processor 32 is further connected by means not shown to an intelligent workstation 34 that can be operated by the system administrator. The audio power unit 20 is equipped with addressable switches that are enabled and disabled by the central processor unit 32. In this description the terms “audio power unit” and “speaker power unit” are used interchangeably. The central processor 32 activates and deactivates the audio power unit 20 by sending control messages to the audio power unit 20 indicating the individual speaker 12 that is to be powered, followed by the audio message. In this way, the central processor 32 controls each speaker 12 individually. The central processor 32 receives the audio message and the identity of the audio message recipient from the intelligent workstations 34. In FIG. 2 only speaker 2 in the second room broadcasts an audible message.

[0020] FIG. 3A illustrates an embodiment of the addressable speaker system 30 of the present invention, that is used to locate a particular user wearing an RFID badge 38 with a unique personal identification code. The addressable speaker system 30 includes at least one cell controller 36 and a plurality of RF antennas 40 in order to determine the precise location of a user wearing an RFID badge 38. Depending on the area to be covered, the addressable speaker system 30 can have multiple cell controllers 36 covering the entire area with each cell controller 36 having several antennas 40 connected to it. Cell controllers send and receive high frequency radio signals to and from long range RF electronic tags. A typical cell controller can read tags at distances up to 250 feet without requiring line of sight. A 2.4 GHz signal is sent to any tag in the coverage area. The cell controller receives a 5.8 GHz signal back from the tag's ID. The distance of the tag from a specific antenna is calculated by the cell controller using the signal's time of flight information. By calculating the distance of the tag from several different antennas, the cell controller can instantaneously identify the location of the tag.

[0021] As illustrated in FIG. 3A, the cell controllers 36 transmit signals that are received by the RFID tags 38. The RFID tags 38 simply translate a received signal's frequency and re-transmit it back to the receiving antennas 40 with tag ID information phase-modulated onto it. The return signal is received by the cell controller 36, and the tag ID information is extracted from this signal. Each cell controller 36 determines each tag's distance from its associated antenna by measuring the round trip time of the transmitted signal.

[0022] The cell controller 36 used in the present invention is available commercially. One example of the cell controller 36 is the 3D-iD cell controller manufactured by PinPont Corporation. The cell controller 36 tracks the tag IDs from the return signals and determines for each returned signal the tag distance from the receiving antenna 40 by measuring the round trip time of the RF signal.

[0023] RFID tags 38 and their corresponding tag readers are well known to those skilled in the art. RFID tags 38 may be broadly categorized as active or passive. The basic distinction is that passive tags require no battery, so that they tend to cost less but have shorter range. As a passive RFID tag passes within range of an interrogator (i.e., a tag reader), its circuitry is charged inductively or electromagnetically. Once powered, a passive RFID tag 38 identifies itself to the interrogator using techniques such as frequency shifting, half-duplex operation, or delayed transmission. An active RFID tag 38 tends to support longer read ranges and a broader set of features. It usually operates at a higher frequency and is more expensive than a passive RFID tag. As depicted in FIG. 3A the cell controllers 36 broadcast RF signals in order to log the location of every user wearing an RFID badges 38.

[0024] FIG. 3B illustrates radio frequency signals transmitted by RFID badge 38. When each RFID badge 38 receives an RF signal from a cell controller 36, each RFID badge 38 responds by transmitting an RF signal that contains the unique ID code. The distance is calculated as a result of time synchronization with the cell controller 36. The cell controllers perform a triangulation algorithm to uniquely identify the position of each individual wearing an RFID badge 38. This location information is transmitted by the cell controller to the central processor 32 through a hard-wired connection.

[0025] With this information, the central processor 32 maintains a log of the location of each individual in the predefined area. An exemplary location log is illustrated in Table 1.

[0026] The operator at intelligent workstation 34 (FIG. 2) is now able to send an audible message directly to any person in the specified area using the speaker 12 that is closest to that specific individual. In the configuration shown in FIG. 3B, each cell controller 36 is equipped with RF antennas 40 that captures the RF signals from each RFID badge 38.

[0027] FIG. 4 illustrates an operator at intelligent workstation 34 identifying person 1 in room 2 as the intended recipient of an audio message and sending the audio message to the intended recipient person 1. The recipient identification information and the audio message are sent to the central processor 32 where the location of the recipient is identified in the log. The central processor 32 sends a control signal to the speaker power unit 20 to power the speaker 12 closest to the intended recipient person 1. The central processor 32 routes the audio message to the selected speaker 12.

[0028] FIG. 4 also illustrates an alternative embodiment for the location of the antennas 40. In the embodiment shown, antennas 40 are located adjacent to the ceiling in each room 14, 16, 18 (the cell controllers 36 are not shown in this illustration). The antennas 40 are connected to the cell controllers 36 by means of coaxial cables. In this configuration, a less powerful receiving antenna can be used due to the proximity of each antenna 40 to the RF signal signal-emitting badges 38.

[0029] FIG. 5 illustrates a lower cost embodiment of the present invention. In this embodiment, the speaker control system and the RF communications system are integrated. It has the added advantage of having the speakers controlled through RF commands from the central processor 32. This embodiment eliminates the need for installing separate wiring for speaker control. In this embodiment, the intelligent workstation 34 identifies the message recipient and sends an audio message and the recipient's identification to the central processor 32. The central processor 32 then selects a speaker 12 and forwards the audio message through an RF signal to the selected speaker.

[0030] FIG. 6 illustrates yet another embodiment of this invention operating in an office environment having cubicle walls. Each antenna 40 and speaker 12 is embedded into a partition wall 50, and the system functions wirelessly as illustrated. By using the known position of speakers and the location of individuals within a predefined area, audible messages can be directed to the speaker closest to the individual to the exclusion of all other speakers in the broadcast system.

[0031] In another embodiment, the central processor 32 does not maintain a log of the location of every person wearing a RFID badge 38. Instead, the recipient of the audio message is located when there is an audible message to be delivered. In this embodiment, the intelligent workstation 34 sends the identity of the recipient along with the audio message to the central processor 32. The central processor 32 transmits RF signals through all the antennas 40 and reads the responses from all the RFID badges 38. Upon determining the location of the desired recipient, the central processor 32 selects the speaker 12 through the speaker power unit 20 and forwards the audio message to the selected speaker 12.

[0032] In another embodiment of the present invention, passive RFID tags are used for identification badges 38. Each room is equipped with a RFID reader that energizes the RFID tags 38 as they enter the room and reads the RFID tag's unique identification code transmitted by each RFID tag. The RFID readers are connected to the central processor 32 where a log of the locations of the RFID tags 38 are kept. In this embodiment the RFID readers in each room are active continuously, but only capture the RF signal with its unique identification code when a person wearing an RFID badge 38 enters the room.

[0033] In another embodiment, the invention enables individual remote paging to any person with access to the central processor 32, including access through an Internet connection. In this embodiment, the central controller's location broadcasting function is accessible through the Internet. A user can access the central controller's functions through a web page. The audio message and the identity of its recipient are sent to the central processor 32 through the Internet.

[0034] In summary using the known position of the speakers 12 and the location of the individual in a predefined area, audible messages can be directed selectively, according to the embodiments discussed herein, to that speaker 12 that is physically closest to the individual, to the exclusion of all other speakers 12 in the broadcast system.

[0035] Furthermore, the corresponding structures, materials, acts and equivalents of any means plus function elements in the claims below are intended to include any structure, material, or acts for performing the functions in combination with other claimed elements as specifically claimed.

[0036] While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various other changes in form and detail may be made without departing from the spirit and scope of the invention.