TECHNICAL FIELD

This invention relates to a communication system.

Reference throughout the specification shall be made to the communication system as being used for alarm situations, although it may be possible for the present invention to apply to other situations.

Reference shall also be made to the present invention as being a communication system from a building such as a household to other parties. Again, this is not necessarily limiting.

BACKGROUND ART

Many people in today's society are concerned about the security of their households. Opportunistic or premeditated burglaries may rob a household of most of its valuables as well as destroying intangibly valued memorabilia of the occupant. After a burglary a householder may feel their rights have been violated and they are unsafe anywhere.

One recent move to combat such theft has been the instigation of neighbourhood watch support groups within a local region such as a street. Members of such a support group agree to watch over one another's properties and alert authorities if they detect evidence of a burglary or another emergency condition such as a household fire.

The disadvantages of this watch system are now becoming apparent to the people associated with them. If one member of the group leaves their property unoccupied for a period of time others are required to monitor the property in their absence. This is time consuming for the watcher

while for the property owner it is worrying to entrust their household to someone who may not actually care what happens to it. Members of this system have to be continually in contact with each other to co-ordinate day to day operations. A member of such a group is continually having to inform their neighbours of their movements and estimate the time in which they will be absent from their household.

This monitoring system is also ineffective in some instances when a burglary or other alarming condition is not obviously apparent to someone outside the household. A burglar may stealthily enter and rob a property, or a fire may start and consume most of a household before anyone is aware of what is happening.

To improve on this watch system which involves a strong degree of manpower several electrical security systems have been designed to alleviate these problems.

There are many security systems available for households which have alarms in various forms. One of the most common alarms used is an audible alarm such as a siren.

There are a number of disadvantages with an audible alarm. One disadvantage is that is difficult to pin-point the source of the alarm and thus it is difficult for neighbours and the like to give assistance where it is required. Quite commonly, audible alarms are ignored because of this difficulty in locating them.

Other alarms are known which send out a signal via a telephone line to a predetermined location such as a security firm. A problem with this system is that alerting just one location such as this is not always satisfactory. For example, the single location may not have anyone there

or be too busy to answer the call. The single location may also be too far away from the household from which the alarm emanates to provide the immediate assistance often required.

If an alarm system was programmed to make a number of calls, then this would take considerable time, as with telephone lines only one call can be made at a time. When time is of the essence, this is a problem.

Other attempts have been made to produce a security system which overcomes these disadvantages.

US Patent No. 4812820 Chatwin describes a network of electronic surveillance system transceiver nodes connected together with twisted pair wires. A set number of transceivers are connected to this network. During a cycle of operation, each transceiver in turn reports its position and status, triggering the next transceiver.

This system provides information to all members of the network. There is no selective communication from one node to another where a node may transmit only to other nodes it selects for reception. This means that if this system was used for a neighbourhood watch scheme all neighbours would be notified whether they wanted to be or not. This non- selectiveness can lead to casual responses to an alarm as each neighbour may assume another is reacting to the alarm.

To install this system, the operators also have to go to the expense of providing a dedicated twisted pair network. This is a substantial cost when considering the twisted pair network will only every have one use.

There is only serial transmission of the alarm signal, each element of this network having to wait in turn until the transmitted signal reaches

it after passing through other nodes. This means that if there is a discontinuity in the line the alarm cannot propagate any further which may lead to the alarm not being received by the appropriate locations.

Another communication system is US Patent No. 4429299 Kabat which describes a communication system operating over an AC power line. A central unit polls slave units with an addressed signal requesting status information. The slave unit then transmits the requested information on receipt of the correct addressed signal.

In the case of a system configured as a neighbourhood watch group, this device does not facilitate the types of communication required by the users. Data may be gathered by a central unit from other units but not distributed. The area of operation of this network is limited to one structure only. This is not suitable for communicating between structures/households, some of which can be separated by large distances.

US Patent No. 4400688 Johnson describes a means for communicating over an electric power line in the direction of a load on the power line to the source of power for the power line. Several loads may communicate back to the power source, placing signals on the power distribution line at the same time.

The specification does not describe a true broadcast system where a transmitted signal such as alarm may be sent to several receivers at the same time. A transmission may only be received by the power source as it is the only point in this system capable of receiving a signal.

The types of communication this system is capable of are limited, with the power source being the only element capable of receiving signals, this

source element also unable to transmit signals of its own.

For these reasons this system is particularly unsuited for a neighbourhood watch application.

US Patent No. 3818481 Dorfman describes a multi-address two way communication system which transmits along an AC power distribution network for a region. Coupling devices are inserted at transformer stations or any points where power distribution lines are not connected at a low impedance. The system is used as an apartment block intercom system, whereby from a master front door position a visitor may poll the address of the person they wish to visit. On receipt of a signal from the master position, an apartment's occupant may signal the master position to unlock the front door.

The type of communication described by this patent specification is limited to master/remote communication. It is not a true broadcast system, as a signal must initially be sent by the master position and addressed to one single remote position, the signal not being receivable by several different remote positions at the same time due to its coded addressed nature.

The communication system described is not a true network communication system as remote locations may not communicate with each other, one remote station (say a house) being incapable of broadcasting a signal to be received by many other remote stations (such as a neighbour's house). Signals must be initiated by the master position to be acknowledged and acted upon by the remote positions.

For these reasons this device would be unsuited for a neighbourhood watch surveillance application.

US Patent No. 4815106 Propp describes a power line communication system specifically designed for local area computer networks. Two or more computers linked together on the same phase power distribution line may communicate freely with each other.

The area of operation for this network is limited to the one common phase of the power distribution network for local area.

No provision is made for communication with devices on different phase power lines than the transducer indicating an alarm condition. In this way this device would be unsuited to a neighbourhood watch surveillance system as the number of receivers the system may communicate with would be limited only to those connecting to the same phase power distribution line.

An invention which could overcome all the problems described above would be a great improvement on any of the prior art in this case.

If a system which could achieve these objectives was to be implemented in an existing household fixture, many setting up and component costs may be saved. By implementing an electronic neighbourhood security system in a pre-existing device with an existing function costs may be restricted where normally dedicated devices would need to be put in place.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the following description which is given by way of example only.

DISCLOSURE OF INVENTION

According to one aspect of the present invention there is provided a method of operating an alarm network, the alarm network including the components of, one or more sensors situated at- a first location, a first transceiver situated at the first location, a router connected to the first transceiver, multiple transceivers situated at locations distant to the first location, the multiple transceivers being connected to the router, the method of operating an alarm network characterised by the steps of:

(a) at least one sensor at the first location transmitting an alarm signal indicative of an alarm condition to the first transceiver at the first location, and

(b) the first transceiver processing the alarm signal into a form actionable by the router, and

(c) the first transceiver transmitting the processed signal to the router, and

(d) the router broadcasting a signal indicative of an alarm condition at the first location in a format receivable by the multiple transceivers at locations distant to the first location, and

(e) the multiple transceivers using selection criteria to determine what action is required in relation to the signal received.

The sensor may be any device capable of detecting an alarm condition. For example, the sensor may detect motion of an intruder, the interruption of a security perimeter, emergency conditions such as fire or floods, or the sensor may be a user operated device such as a panic button, or any other suitable device.

In preferred embodiments of the present invention the connection between the network components is made along a pre-existing network having a primary function other than transmitting alarm signals. This makes for an efficient use of resources as there is no requirement to set up a dedicated line or to separately maintain same. Obviously, considerable cost and time savings would be involved.

In further preferred embodiments of the present invention the pre¬ existing network is a power distribution network. Reference shall now be made throughout the specification to the alarm network as operating on a power distribution network.

It should be appreciated however that the network may be cable, fibre- octic links, or any other network which allows operation of an alarm network as previously described.

However, there are a number of specific advantages of using a power distribution network.

One advantage is that a power distribution network enables a single alarm signal to be placed on the network that can be received by a number of predetermined locations.

Power distribution networks are not serial systems and are never "engaged" - unlike telephone lines.

While the present invention can be used with respect to any locations, it is envisaged that preferred embodiments of the present invention have the locations as being households which form part of neighbourhood watch group. For example, the first location may be a household but some of the multiple distant locations may be other households or even security

firms, emergency services and the like.

In some embodiments of the present invention the transceiver may be a unit separate from the sensors having processing means capable of receiving signals from the sensors and processing these signals into a form actionable by a router. The componentry within the transceiver may include an appropriate micro processor. The transceiver may also include peripheral devices such as displays, key pads, visual and audible alarm units and so forth.

In preferred embodiments however the transceiver is included into an existing device at the location.

In especially preferred embodiments, the transceiver is incorporated into a power meter.

A power meter is a device that is situated on a power distribution network and usually contained with a household. The primary function of a power meter is to monitor energy consumption.

However, it would also be beneficial to the electricity supplier if the power meter could incorporate a number of additional functions such as pre¬ processing of information relating to energy consumption, making the power meter user friendly by providing information to the householder, have payment options incorporated, and the transmission of information back to the electricity supplier.

Unfortunately, these features would contribute greatly to the cost of the power meter and often it is not justified to have such an expensive item as a stand alone unit within a household.

With the present invention incorporating a power meter that can be used

as a transceiver in relation to an alarm network, the power meter can have multiple uses and therefore provide more value for money.

Further, by incorporating an alarm system into the power meter there are extra savings in that a separate alarm control system (which is a standard device) is not required. This also represents a cost saving.

The alarm signal may be processed into a form by the transceiver having a number of components to make the processed signal actionable by the router.

For example, the transceiver may receive notification from a sensor that an alarm condition has been met. This information may be transmitted to the router along with the location of the transceiver so that the router recognises that alarm condition has been met at a certain household.

In some embodiments of the present invention, the sensors may transmit to the transceiver a particular type of alarm condition. This information may also be passed from the transceiver to the router.

It is envisaged that in most embodiments of the present invention, the alarm signal from the sensor to the transceiver cannot be readily transmitted along the lines forming part of alarm network system from the transceiver to the router. Therefore, in preferred embodiments the function of the transceiver is to process the actual format of the alarm signal received from sensors into a form that can be readily transmitted to and recognised by the router across the alarm network.

This change in form may constitute applying a communication protocol into which can be incorporated in error checking, noise elimination and any other features required in a communication system.

The router may come in a variety of forms.

In one embodiment of the present invention the router is a stand alone unit connected to the network. Preferably, the router is connected to the network in such a position that it can receive signals from the transceivers and redirect those signals to multiple transceivers over the network.

A preferred embodiment of the present invention has the router associated with or forming part of a power distribution transformer.

Typically households operate on different phase power lines to each other. Therefore, it may not be possible for one household to directly contact another household via a power distribution network.

Therefore, the function of the router can be to process the signal received from the transceiver into a format (for example, a format that takes into account phase separation) which is receivable by the multiple transceivers in other households on the power distribution network.

This is a significant feature of the present invention as it enables an alarm signal to be effectively broadcast over the whole of an existing power distribution network through the action of a router converting the alarm signal into one that can travel over the three different phase power lines.

In some embodiments of the present invention the router may also communicate to other routers, either using substantially a similar system to that described in relation to transceivers, or through using another broadcast facility, such as radio transmission.

The router may also communicate to a central control centre. This

central control centre may be used to send an alarm signal to a security monitoring company or via a telephone link to contact some one outside the local power distribution network.

In one embodiment of the present invention the transceiver may contain a list of all parties to be notified for a particular alarm signal and send the relevant information to the router, or possibly direct to a household if a household is on the same phase line.

However in preferred embodiments of the present invention the router has a distribution list either in addition to or preferably instead of the list held at the original household.

The distribution list may contain identification codes which are effectively addresses of the multiple transceivers to which a signal is intended to be received by.

The identification code to be included with the formatted signal is determined by matching the address of the original alarm signal from the first transceiver. For example, any alarm signal emanating from a certain household may be matched on a distribution list with multiple transceivers/households which will receive notification of that alarm signal.

In other embodiments of the present invention, only certain households may be notified according to the type of alarm signal received from a certain address. For example, all relevant households may be notified if a panic button is pressed, but only some may be notified if there is an intruder alert.

In other embodiments of the present invention there may be a

distribution list held by the multiple transceivers. The multiple transceivers may receive all addresses from where alarm signals originate and use selection criteria (within the form of distribution list or otherwise) to determine whether to action the receipt of the signal or how to action same.

In preferred embodiments of the present invention the selection criteria has a primary function of recognising if an identification code sent by the router corresponds to that transceiver.

Once the transceiver recognises that the received signal is relevant, then additional selection criteria can be used to determine what action can be taken in relation to the signal received.

The action taken may merely be alerting the householders that a member of the neighbourhood watch has an alarm condition.

In some embodiments of the present invention there may be further refinement. The action taken may be to identify the address at which there is an alarm condition or even the type of alarm condition.

In preferred embodiments of the present invention multiple transceivers may be connected to one or more sensors and operate over the alarm network in the same manner as the first transceiver.

Thus, it can seen that the present invention in preferred embodiments may consist of standard alarm system within the house having sensors connected to transceivers incorporated into power meters which then connect to a router (or routers) which broadcast the alarm signal to like power meters and other households.

It can be seen that the present invention has a number of advantages over

the prior art.

For example, a neighbourhood watch system can be readily set up which is linked to the predetermined locations. A person may wish to notify certain neighbours or relatives when an alarm occurs.

In preferred embodiments, the neighbours and relatives chosen can only receive an alarm signal if they agree to same.

The ability to notify other households encourages households to provide mutual support for security situations which may otherwise be lacking.

In preferred embodiments of the present invention each household can elect whether it will receive or react to codes sent by the alarm household. For example, a neighbourhood may have an irresponsible householder with a continually triggering system. Only households willing to take on the responsibility for monitoring that householder's alarm may do so, while the rest of the neighbourhood may lock that householder's code out. This selective monitoring is an important aspect of the present invention as it encourages co-operation between households to set up a security network or "neighbourhood watch".

One advantage of having the distribution list only at a router is that the distribution information only needs to be entered and updated at the one station. This is in preference to updating information at each household on the alarm network.

The major advantage in the present invention is that it provides added value to existing systems at minimal cost. For example, the present invention uses an existing network obviating the need to install a dedicated network.

The present invention also can be used with existing household components such as a power meter, to make it easier for an electricity supply authority to justify the installation of an expensive power meter into a household, as it can contain added features such as a security system.

This could be achieved by having a power meter in each predetermined location, with a distribution list in the power meter, determining whether the signal is reported depending on its origins.

The present invention also can provide an alternative to the existing alarm control stations presently required in normal household alarm networks.

A further advantage of the present invention is that it provides a rapid broadcast system that allows pre-determined destinations to the notified of an alarm, the location and possibly even the type of alarm condition.

In an alternate embodiment of the present invention messages may be sent sequentially to each transceiver which effectively provides a result equivalent to broadcasting to all transceivers.

According to another aspect of the present invention there is provided method of operating an alarm network, the alarm network including the components of, one or more sensors situated a first location, a first transceiver situated at the first location, multiple transceivers situated at locations distant to the first location, the multiple transceivers being connected to the first transceiver, the method of operating an alarm network characterised by the steps of:

(a) at least one sensor at the first location transmitting an alarm signal

indicative of an alarm condition to the first transceiver at the first location, and

(b) the first transceiver processing the alarm signal into form actionable by the multiple transceivers, and

(c) the first transceiver transmitting the process signal to the multiple receivers, and

(d) the multiple transceivers using selection criteria to determine what action is required in relation to the signal received.

It is envisaged that this embodiment of the present invention would only work in relation to transceivers connected to each other on the same phase power line.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 illustrates a block diagram of the communication system according to one aspect of the present invention, and

Figure 2 illustrates one means by which a household can be connected to a power supply line.

BEST MODES FOR CARRYING OUT THE INVENTION

With reference to Figure 1, there is illustrated nine different transceivers at households (represented by blocks 1 - 9). The transceivers 1 - 9 are connected to a router 10 via three phase power lines A, B and C.

Typically, power companies try to even the load on each phase power line and therefore the distribution of transceivers on the phase power lines as illustrated is common.

The router 10 is located at distribution transformer. As the router 10 is connected to each of the phase power lines A, B and C, the router 10 can receive signals to and from each of the transceivers 1 - 9. Therefore, it is also possible for the router 10 to receive a signal from transceiver 1 on a phase power line A and relay the appropriate signal to say transceiver 4 on the phase power line B. The signal relayed may be the same signal as transmitted from transceiver 1, or may be a different signal which is either calculated or looked up by the router 10 in response to the signal from the transceiver 1.

It should be apparent that transceivers 1 to 3 may communicate with each other without requiring the router 10 as these transceivers share the same phase power lines. The situation is the same for transceivers 4 to 6 which share power supply line B and transceivers 7 to 9 which share the power supply line C.

In this embodiment the router 10 has a radio transmitter 11 which enables the router 10 to communicate with similar routers 12 and 13 or a central control station 14.

Upon receiving a RF signal from the router 10, routers 12 and 13 may also communicate to transceivers (not shown) connected to them using similar methods as described previously.

The central control station 14 may be the control room electrical utility or an alarm company.

It should be seen that this networking enables the emission of a single alarm signal from a household to be transmitted to a number of predetermined locations whether nearby or at a considerable distance.

With reference to Figure 2 there is illustrated an alternatively configured embodiment of this invention. This figure illustrates a method of configuring three separate sensors associated with a transceiver included in a power meter.

When movement is detected by a sensor, a message is sent from the sensor to the backup unit via the twisted pair network.

The backup unit then determines if an alarm should be generated according to the systems configuration and current state. When an alarm is generated, a message is sent from the backup unit to both the control unit and the meter (again via the twisted pair network) detailing the nature of the alarm.

The meter upon receiving this alarm message over the twisted pair communications network, generates a new message which describes the location and nature of the alarm and then broadcasts this onto the power line.

Upon receiving an emergency message via the power line network, the power meter determines if the message is for its location. If so, then the power meter sends the location and nature of the alarm to the control unit which then turns on its buzzer for a time to indicate that an alarm has occurred. The meter also informs the sensors which then flash a LED to indicate that the alarm is not located on the premises.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope of the appended claims.