Title: Wireless Mobile Telephony Public Address System
This invention relates to public address systems, and in particular, but without limitation, to wireless public address (PA) systems utilising wireless mobile telephony (WMT) networks.
PA systems generally comprise an audio input device, such as a microphone or a recorded sound playback device, which is operatively connected to one or more speakers at a remote location. A PA system thus enables an operator to broadcast a message to people located in the vicinity of the speaker or speakers. In most PA systems, there are a number of speakers that can be addressed individually, globally or in groups via a patch panel or selector device, which routes the output of the input device to the selected one or more speakers. Analogue PA systems generally comprise an amplifier that boosts the signal from the input device such that it can be used directly by the speaker or speakers via multi-conductor cabling, such as speaker wire. More modern digital PA systems are configured to transmit a data signal to each of the selected speakers, which allows the cable lengths to be considerably longer, with the digital to analogue conversion and amplification being carried out at the speaker.
One of the main drawbacks of PA systems is the cabling that is required, which can be expensive, difficult and time-consuming to install. A wired PA system suffers from a number of drawbacks, that is to say: being "fixed" -it being difficult to relocate the speakers subsequent to installation; loss of operation and/or functionality in the event of one of more of the cables failing; and loss of operation and/or functionality in the event of a power outage.
Due to their very nature, PA systems are often needed in emergency situations, for example to alert the public of hazards such as fires and flooding. However, hard-wired PA systems are often rendered inoperative in such situations, making them a potentially unreliable means for broadcasting announcements.
One particular situation in which PA systems are being more widely used is in conjunction with town centre closed circuit television systems, which can be enhanced by means of a public address speaker to facilitate one way communication from the CCTV operator to members of the public being observed by the cameras. This is usually facilitated by means of an interface unit which converts audio signals from a microphone to light waves which are modulated down a fibre optic link and then converted via another interface unit back to an audio signal which is then fed into a PA system and the a speaker or PA horn.
This is an expensive system to install and is quite difficult as a retrofit to an existing CCTV system.
A need therefore arises for an alternative and/or improved PA system that addresses one or more of the above problems.
According to the invention, there is provided a PA system as set forth in the appendent claims.
According to a second aspect of the invention, there is provided a PA system comprising an input means and an output means interconnected via a wireless mobile telephony (WMT) network, wherein the input means comprising an audio input device, means for converting an audio signal received by the audio input device into a signal transmittable over the WMT network, an exchange adapted to route the said signal transmittable over the WMT network to one or more uniquely identifiable output means, and wherein the output means comprises a uniquely identifiable WMT network receiver, a converter, amplifier and speaker adapted to convert the said received signal transmittable over the WMT network into an amplified audible sound corresponding to the said audio signal received by the audio input device.
A third aspect of the invention provides a WMT Public Address System comprising a WMT Receiver/Transceiver which receives audio communications from either the mobile phone, terrestrial landline telephone system, computer system via ADSL or any other equipment capable of sending WMT audio messages, which is then announced via a speaker or public address horn.
Preferably the WMT network is a public WMT network, which suitably enables the PA speaker units to be located anywhere in the world with an operational WMT network and/or for the PA system to be implemented globally.
The WMT network may comprise any one or more of the group comprising: a Time Division Multiple Access (TDMA), Global System for Mobile communications (GSM); a third generation (3G), fourth generation (4G) or indeed any suitable WMT network that enables telephone, data or telephone-like communications via a telephone exchange.
The invention aims to overcome one or more of the aforementioned problems by using a WMT Public Address system which is suitably easy retro-fit to many existing CCTV systems and which suitably requires minimal installation.
Suitably, the system utilises current WMT technology on either 2G, 3G, or 4G networks to receive an audio signal from either a mobile phone, landline telephone, computer via the Voice Over Internet Protocol, or any other device capable of transmitting an audio message to a WMT transceiver. The system will facilitate the use of either TDMA (Time Division Multiple Access), GSM (Global System for Mobile communications), CDMA (Code-Division Multiple Access), High-Speed Circuit-Switched Data (HSCSD), General Packet Radio System (GPRS), Enhanced Data GSM Environment (EDGE), or Universal Mobile Telecommunications Service (UMTS) to receive the audio signal. This audio signal can then be fed into a Power Amplifier to amplify the audio to the correct level to be heard in its area of operation and then announced via some form of speaker or PA horn so that the intended recipients can hear it.
Power for the unit can be provided directly from a mains power supply or from a battery. A battery, where provided, may form part of an uninterruptible power supply (UPS) that is trickled from the mains, a vehicle power supply, such as a 6V DC, 12V DC or 24V DC battery, or which is charged via a solar panel, wind turbine, or the like, mounted on or adjacent to the unit housing.
The invention is not limited for use in a town centre CCIV system but can be utilised for any CCTV system, or other application where there is a need for a wireless Public Address system, including emergency evacuation procedures. In addition, the invention may suitably be applied to vehicles, such as emergency response and/or military vehicles.
Preferred embodiments of the invention shall now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a schematic diagram showing the showing the various modules of a system according to the invention; Figure 2 is a schematic system diagram for a first PA speaker system of Figure 1; Figure 3 is a schematic view of a Graphical User Interface for a control centre computer of Figure 1; Figure 4 is a schematic system diagram for a second PA speaker system of Figure 1; and Figures 5 and 6 are schematic receiverjtransceiver diagrams for PA speaker systems in accordance with the invention.
In Figure 1, a system lOin accordance with the invention comprises a number of PA speaker systems 12, 14, 16 operatively connected to a public wireless mobile telephony network (PWMIN) 18 via wireless radio signals 20. Each PA speaker system 12, 14, 16 can be addressed individually, collectively or in groups by users 22, 24, 26 dialling into the PWMIN 18 using a telephone. Once connected, each user 22, 24, 26 is able to broadcast a message by speaking into their respective telephone, or by playing a pre-recorded sound into the PWMIN 18.
The operator of the system will call the telephone number of the WMT transceiver which is in essence a mobile phone, albeit not necessarily having the physical appearance of a mobile phone but would have a SIM (Subscriber Identity Module) card giving it a designated mobile phone number with a mobile network provider. This call can be made in a variety of ways such as by mobile phone) by landline phone, by Voice Over Internet Protocol (VOIP) phone, or any other means which can communicate either directly or indirectly with the WMT network.
Once the communication is connected the operator is able to speak, with the audio being received by the WMT transceiver (mobile phone). The WMT transceiver is connected to a Power Amplifier so that the audio from the transceiver goes into the input of the Power Amplifier. This audio input is then amplified the required level. The output of the amplifier is connected to a speaker or PA horn which will then enable the amplified audio to be broadcast in the area that it is sited enabling people to hear what is being said by the operator or system user.
In one example, a first user 22 uses a landline telephone 28 to dial the designated telephone number of a specific PA speaker system 12, and his or her call is connected directly 30 to that PA speaker system via a telephone exchange 32 and the PWMTN 18. When the connection is made, whatever the user says 22 is broadcast over the remotely-located PA system 12 that has been dialled.
In a second example, the same user 22 wishes to broadcast a message over a number of selected PA speaker systems 12, 14, in which case he or she can make use of a conference call facility provided by the telephone service provider operating the telephone exchange 32 or the PWMTN 18 to connect to the plurality of PA speaker systems 12, 14 simultaneously. In this example, whatever the user says 22 is broadcast 34 over the selected plurality of remotely-located PA systems 12 that have been included in the conference call.
In a third example, where the user 22 wishes to broadcast a message over one or more PA speaker systems 12, 14, the user 22 dials the number of a call centre 36 and asks to be connected to the required PA speaker systems 12, 14. The call centre operative 26 then makes a connection 40, suitably via a VOIP system 42, to the selected PA speaker systems 12, 14 and then patches the user's incoming call to the VOIP "one-to-many" connection so that whatever the user 22 says is broadcast over the selected PA speaker systems 12, 14.
To facilitate one-to-many communications between the call centre 36 and a number of PA speaker systems 12, 14, a gateway (not shown) is suitably used. A gateway suitably comprises a computer equipped with a plurality of GSM interface cards that can each establish GSM (or other types of WMT calls) to individual PA speaker systems 12, 14. The gateway is thus configured such that the inputs of the GSM interface cards are connected to a common source such that the control centre or a user only needs to connect to the gateway to enable his or her message to be simultaneously broadcast to a number of PA speaker systems. The gateway suitably comprises an interface allowing a user to select which PA speaker system to connect to so that each of the GSM interface cards can establish a connection to its respective PA speaker system. Once all of the required connections have been made between the gateway and the PA speaker systems concerned, the user can connect to the gateway to broadcast a message to all of the connected PA speaker systems simultaneously. Such a system avoids the need to employ complex PBX and/or VOIP routing protocols to establish a one-to-many connection, since the patching is done by the gateway, and the broadcast is sent, via a single connection, to the gateway, for re-transmission via the GSM interface cards.
The number of simultaneous calls that can be made from a single gateway will) of course, depend on the number of GSM interface cards that the gateway has. If the number of PA speaker systems to be addressed exceeds the number of available GSM interface cards) then the gateway is suitably configured to broadcast to groups of PA speaker systems sequentially, e.g. ten at a time, if GSM interface cards are provided in the gateway.
The originating caller 22 may be any person with a landline telephone, which may be a VOIP telephone. However, in the case of roaming users 24, a connection to individual, or groups of, PA speaker systems 12, 14, 16 could be made using a mobile telephone 46, either directly 30 to the or each PA speaker system via the PWMTN 18 or via the call centre 36.
The ability for anybody with a telephone, or telephone-like device to be able to address one or more of the PA speaker systems 12, 14, 16 is an important feature of the invention because it avoids the need for hard-wiring and for users 22, 24, 26 of the system to have direct access to a public address interface connected to each of the PA speaker systems 12, 14, 16.
Notably, each of the PA speaker systems 12, 14, 16 connects to the PWMTN 18 via a wireless link, which can be of any suitable type. As such, it is potentially possible for any user, located anywhere in the world, to address any one or more of the PA speaker systems 12, 14, 16, which could be located anywhere else in the world. Such a system 10 provides enormous versatility, and potentially enables public address systems and CCTV to be effectively, and cheaply outsourced to different service providers, who can be located anywhere in the world, in particular where an associated cciv system comprises an IP, or web-based, system.
The construction of each PA speaker system 12, 14, 16 shall be described in greater detail below, but it will be appreciated that various sets of features could be incorporated into the PA speaker systems. Moreover, because each PA speaker system 12, 14, 16 interfaces with the users 22, 24, 26 via a PWMTN 18, provided each speaker system 12, 14, 16 is able to receive calls from the PWMTN 18, then speaker systems 12, 14, 16 having different configurations and feature sets can be seamlessly integrated into the overall system 10 with minimal effort.
In Figure 1, a first type of PA speaker system 12 comprises a PA horn 50 powered by a mains power supply 52, which trickle-charged an on-board battery (not visible) so that during a mains outage, the PA speaker system 12 is still able to function for a period of time. In addition, a solar photovoltaic panel 54 is provided to trickle-charging the on-board battery instead of, or as well as, the mains power supply 52. The use of a solar PV panel extends the operational life of the PA speaker system 12 during extended power outages.
The PA speaker system 12 shown in Figure 1 also comprises a repeater unit 56 that enables the audio output to be routed to a smaller speaker 58, rather than to the PA horn 50, such that a more private message can be relayed to a single recipient or to a small group of addressees (not shown). The repeater unit 56 additionally comprises a push-to-talk button 60 enabling an addressee to speak with a user 22, 24, 26 via a microphone (not visible) built into the repeater unit 56 via the PWMTN 18.
Alternative versions of a PA speaker system 14, 16 are also shown in Figure 1, specifically, a PA speaker system 14 having no mains power connection, but which runs off an on-board battery (not visible) only that is trickle charged by a solar PV panel 54. Also, indoor versions of the PA speaker system 16 are also envisaged, that are not necessarily water/weatherproof, and which run off, and/or are trickle-charged by, a mains power supply 52.
In Figure 2, the various components of the PA speaker system 12 are shown schematically, in which a mobile telephone receiver module 70 is powered by a battery 72, and which connects to the PWMTN 18 via an antenna 74. The mobile telephone receiver module 7Ois uniquely identifiable and addressable over the PWMTN 18 using a Subscriber Identity Module (SIM) card 76 in a known manner. The audio output 78 of the mobile telephone receiver module 70 can be selectively output to one of a number of amplifiers 80, 82, although just one amplifier may be provided, each providing a different level of output volume. In one example) one of the amplifiers is a 25W amplifier connected to a PA horn 50 for broadcasting a received message, although the second amplifier 82 is a 5W amplifier, enabling a lower volume level) for example, to be output to a speaker 58 of a repeater unit 56. The gain or volume of the amplifier or amplifiers may be remotely adjustable, for example) by sending a volume adjustment command over the wireless telephony network to the speaker system. The repeater unit 56, where provided) additionally comprises a microphone 84 allowing an addressee to communicate with users 22, 24, 26 of the system 10 via the PWMTN 18 as previously described. A push-to-talk button may be provided, although the mobile telephone receiver module 70 preferably has full-duplex capabilities, enabling this to be omitted. However, a push-button may be provided, for example, to enable an addressee to initiate a call to a call centre 36 or to a call centre operator 26.
As can be seen in Figure 2, the battery 72 is trickle-charged by any one or more of a mains power supply 52, a solar PV panel 54 and a renewable energy source, such as a wind turbine 84.
Such a system provides an on-board UPS that allows the PA speaker system 12 to operate effectively, for a period of time, or indefinitely, in the absence of mains power.
Turning now to Figure 3, it will be noted that the call centre 36 comprise number of workstations connected to VOIP server 42 -each workstation having a Graphical User Interface (GUI) to enable operatives 26 to intuitively interact with the system. The GUI 90 comprises a central map portion 92, which conveniently identifies the locations of various PA speaker systems 12 14, 16 using "map pin" icons on a map 12, 14, 16. The map 92 could be a user-defined and inputted map, for example) the floor plans of a building, with the locations of the individual PA speaker systems defined during installation and set-up. However, the map may be an interactive, web-based map, with the locations of the PA speaker systems 12 identified by grid references. A user 26 can thus scroll and zoom the map 92 to identify and select individual or groups of PA speaker systems 12, 14, 16 to address.
In a more sophisticated version of the invention, the locations of the PA speaker systems 12, 14, 16 can be identified and placed on the map 92 automatically, for example, using a GPS receiver in a PA speaker system 12 which relays its location to the call centre 26. As such, installation can be greatly facilitated since upon an initial boot-up of each PA system 12, its position can be re-mapped on the map 92 allowing the PA units to be moved or re-located. Also, if a PA speaker system 12 is vandalised or removed, or even just lost during a maintenance operation, it can be easily re-located without user intervention.
Each "map pin" 12, 14, 16 is associated with various functions, which can be accessed using a pointer device, such as a computer mouse or a touch screen. The map pins enable operators 12, 14, 16 to quickly access information relating to the corresponding PA speaker system 12, 14, 16, such as its individual phone number, its operational status, its power/charge status etc. such information is also displayable in a side panel 94 of the GUI 90.
To initiate a call to an individual PA speaker system 12 using the GUI 90, a user 26 selects individual or groups of PA speaker systems either by clicking on the pap pins in the map area 92 of the GUI, or be selecting check boxes in a list area 96 of the GUI, followed by pressing a "call" icon 98 in the GUI. The system then dials each of the selected PA speaker systems using a VOIP server 42 and the connection or connections are made, as previously described. Each of the mobile telephone receiver modules 70 of the PA speaker systems 12, 14, 16 are programmed to auto-answer and to put the mobile telephone receiver module 70 into a muted mode so that nothing that the user 26 says is broadcast until they are un-muted. To un-mute the or each mobile telephone receiver module 70, the user 26 presses a "speak" icon 100 in the GUI, which allows what he or she says into a microphone to be broadcast to addressees located in the vicinity of the PA speaker systems 12, 14, 16 concerned. When the "speak" icon 100 is un-checked, the mobile telephone receiver modules 70 mute, but the telephone connection remains connected. A user 26 can then broadcast another speech message by re-pressing the "speak" icon 100 whilst speaking, or he or she can broadcast a pre-recorded message by pressing a "recorded message" icon 104 in the GUI 90. In the latter case, the recorded message is patched directly into VOIP server 42, although it may also be monitored as well in the user's headset or a speaker so that the user 26 knows what has been broadcast and when he or she may subsequently be able to speak.
The pre-recorded message may be a speech segment, for example, in the form of a digital sound file) or it could be an alert tone) such as a siren, beep or other sound file. Various pre-recorded sound files may be accessible from a drop-down menu in the GUI 90 enabling the user 26 to select which one of many pre-recorded messages to broadcast.
The GUI 90 additionally comprises icons 102 and 104 to enable rapid selection of pre-defined groups of PA speaker systems 12) 14, 16, which facility may be useful in fixed installations, such as on a school campus, where, say, a message needs to be broadcast to all PA speaker units in a particular building.
A side bar 94 of the GUI 90 may also provide links to recordings of broadcast messages to facilitate playback and monitoring of usage of the system, which may be important, say) when gathering information for a criminal prosecution. As such, each broadcast is preferably recorded and logged in the system) and is accessible at a later time for playback and analysis. The logging facility may also be integrated with a CCTV system such that individual broadcasts can be associated with different segments of CCTV footage.
In Figures Sand 6, schematics of typical WMTJGSM type units are shown, but these are for the purpose of showing typical component modules of a WMT/GSM mobile phone and not the actual circuit diagram of all the connections. The system may use any type of WMT transceiver as deemed suitable and it is the use of a WMT Transceiver which makes it unique as a WMT public address system.
With regards to the power amplifier used) any suitable power amplifier may be used with the most appropriate wattage of power output.
The type of speaker to be used will be determined by its area of use. For indoor use a standard internal speaker may be used) for an outdoor environment either a waterproof speaker or public address horn may be used. No specific make or model of speaker is to be specified only one which is suitable for the intended application.
The unit may be housed within a protective casing or enclosure, or even fitted integrally within the actual speaker housing or case. The enclosure may also be IP rated if to be used in an outdoor environment, or any environment where there is a requirement to provide specific protection to the equipment.
The power supplies to be used to power the electronics in the system will be either via standard transformers connected to the mains llOv/240v supplies, or via a suitable battery which can be trickle charged using a solar panel or any other device capable of charging the battery.
In essence, the unique combination of a WMT transceiver connected to a public address system is what gives the system a global means of broadcasting audio to the public. The system may also incorporate peripheral features such as notification of tampering with the protective housing and low battery warning.
Because the PA speaker system is based on mobile telephony technology, it is possible to incorporate bi-direction data communications into the PA speaker system, which affords an opportunity for the PA speaker systems to provide interaction with a remote location. Previously described is the option to permit two-way communication, but it will be appreciated that a mobile telephone module may additionally comprise date inputs and outputs, which can be used to provide additional functionality albeit with minimal additional complexity or cost. For example, a typical mobile telephony unit may be provided with 12 or so inputs and 8 or so output ports, that can be addressed individually over a PWMTN 18. The I/O ports may conveniently be used for sensing functions, that is to say, to provide real-time status updates regarding the battery charge state, the ambient lighting conditions, the ambient temperature etc., which information can be relayed via the mobile telephony network to a remote user, for example, using SMS text messaging. This information may be useful in emergency situations and/or for general maintenance and monitoring of the system.
The outputs may be used to switch on local flood lighting, to operate doors and gates etc., or to perform a variety of remote-control operations.
The input and output functionalities of the I/O ports may be remotely configurable and/or re-programmable, for example, by transmitting AT commands to the or each speaker unit. Since it is not possible to remotely re-program a conventional mobile telephone using AT commands via conventional SMS messaging, the mobile telephony module of the speaker system differs from that of a convention mobile telephone.
In order to conserve power, the power amplifiers 80, 82 of the PA speaker systems 12, 14, 16 are normally switched off, but upon receipt of an incoming "call", they can be automatically powered up by a battery management circuit or program of the mobile telephony unit 70.
A watchdog circuit may also be provided for monitoring the status of the system and to trigger a re-boot in the event of a system failure or crash.
Uses for the system include, but are not limited to: town centre CCTV; emergency evacuation notification; school's public address system; car park public address systems; hospital public address systems; and any other areas where there is a public address requirement.