WO2003069798A1 - Communication system and method - Google Patents

Abstract

A method is disclosed of receiving and/or transmitting remote commands and/or data from and/or to master transceivers and monitors and/or controllers within a discrete environment, which includes transferring modulated data between the master transceivers and the slave transceivers, wherein the modulated data is transferred in time slots.

Description

"COMMUNICATION SYSTEM AND METHOD"

Technical field

This invention relates to a communication system and method. 5 The invention has particular but not exclusive application to communication systems and methods, and components therefor, for use in a discrete environment such as a high-rise building.

In one aspect the invention has particular application to an interface device programmable to receive and/or transmit remote commands from and/or to diverse equipment within the discrete environment. In this aspect the invention also relates to a method of receiving and/or transmitting 10 remote commands from and/or to diverse equipment within the discrete environment.

In another aspect the invention has particular application to a radio network for communication within the discrete environment. In this aspect the invention also relates to a method of radio communication within the discrete environment.

In a further aspect the invention has particular application to a bio-recognition system for 15 controlling access within the discrete environment, and to a method of controlling access within the discrete environment.

Background of Invention

In discrete environments such as high rise buildings for example, it is known to provide

20 communications from a number of sensors and to a number of controlled devices. The communications preferably provide rapid response times and need to be highly reliable. High rise building provide an environment particularly unkind to electronic and wireless communications because of interference from sources such as high electrical noise, high attenuation, and reflections. Communication systems preferably provide for reuse in the same or adjacent buildings.

25 High-rise buildings are major investments and typically undergo several cycles of internal refurbishment. Regulation relating to fire alarms systems and evacuation systems are continually being upgraded and need to be complied during refurbishment. Access and security systems require continual upgrade to be more effective and cost effective.

Known building control systems typically consist of distributed sensors and controlled

30 devices. The location of these devices is critical to effective designs. In addition to power supply these devices need to be interconnected and/or wired to a central or a number of centralised intelligent controllers or computers. In many cases these system concentrate the data (eg. fire sensors) and the combined data is fed to systems external to the building (eg. fire control rooms or brigade headquarters).

35 The electromagnetic spectrum available for wireless systems is limited and under growing pressure from increasing numbers of applications and users. Authorities are moving more to policies where the user pays for the spectrum used and is more responsible for the use of the spectrum. To this end more Industrial Scientific and Medical (ISM) "class" license blocks of frequencies are being allocated to short range radio systems. The onus falls on the design of the

<to system and the users to provide efficient and interference free use of the available spectrum. The ISM bands and the regulations controlling their use is progressively being aligned throughout the world.

Bio - Recognition systems are based on identifying unique aspects of a person's anatomy and using this "key" to provide recognition with high integrity. The best of these systems require matching of hundreds or thousands of elements. To provide high security, the "key" is typically stored on a central computer and the "image" at the recognition unit passed to the central computer for comparison with the key. Some systems utilise a hierarchy of comparisons based on critical points. Matching of the higher level points provides a tree search to construct a match and recognition. These approaches require a high bandwidth communications channel between the recognition unit and the computer. Typically these channels are required to be two way to allow the tree search to occur.

A number of passive tag systems have been developed. In these systems a sensor station excites the tag. The excited tag broadcasts its identification, which is received and the tag identified by the sensor station.

Summary of Invention

The present invention aims to provide an alternative to known communication systems and methods, and components therefor.

This invention in one aspect resides broadly in an interface device constituting a slave transceiver programmable to receive and/or transmit remote commands and/or data from and/or to master transceivers and monitors and/or controllers within a discrete environment, the interface device including:- means for transferring modulated data between the slave transceivers and the master transceiver, wherein the modulated data is transferred in time slots. As used herein the expression "discrete environment" is to be given a broad meaning. The expression includes buildings (and particularly high rise buildings), mines (whether pit or open-cut), off-shore platforms, industrial complexes, workshops etc.

As used herein the expression "monitors and/or controllers" is to be given a broad meaning. The expression includes (by way of non-limiting example), temperature sensors, smoke detectors, presence detectors, motion detectors, personal identifiers, lift controllers, warning controllers, equipment controllers, access controllers and all other sensors, controllers, monitors and equivalent which have an effect or input into any operational aspect of an environment or equipment in the environment.

It is preferred that the means for transferring modulated data includes a radio transceiver. It is preferred that the modulated data is frequency modulated.

It is also preferred that the interface device is adapted:- to monitor and discern connected multi-facet signals from a master transceiver; to formulate a pre-programmed signal response for transmission to a master transceiver; to convert the response to a compressed digital prioritised package; to monitor the availability of in-coming time synchronised packages, and to transmit an interference-free response to a master transceiver so positioned in the discrete environment to provide interference-free transmission between the interface device and the master transceiver.

In a preferred embodiment the interface device includes a printed circuit board on which is mounted an application specific integrated circuit including:- microprocessor means programmable by application specific software; memory means for storing the application specific software; timing means; means for generating, allocating and synchronising the time slots, and input/output means including at least some of data radio interface means, analog interface means, digital interface means, voltage interface means, current interface means, voltage free contact means, signal sensor means and serial interface means.

In another aspect this invention resides broadly in a method of receiving and/or transmitting remote commands and/or data from and/or to master transceivers and monitors and/or controllers within a discrete environment, the method including:- transferring modulated data between the master transceivers and the slave transceivers, wherein the modulated data is transferred in time slots.

In another aspect this invention resides broadly in a method of receiving and/or transmitting remote commands and/or data from and/or to master transceivers and monitors and/or controllers within a discrete environment, the method including:- providing an interface device constituting a programmable slave transceiver including means for transferring modulated data between the slave transceivers and the master transceiver, wherein the modulated data is transferred in time slots; monitoring and discerning connected multi-facet signals from a master transceiver; formulating a pre-programmed signal response for transmission to a master transceiver; converting the response to a compressed digital prioritised package; monitoring the availability of in-coming time synchronised packages, and transmitting an interference-free response to a master transceiver so positioned in the discrete environment to provide interference-free transmission between the interface device and the master transceiver.

In a further aspect this invention resides broadly in a radio network for communication within a discrete environment, the radio network including:- a base control facility, a plurality of zone transceivers and a plurality of site transceivers associated with monitors and/or controllers in the discrete environment; the base control facility communicating to and from the zone transceivers, and the zone transceivers communicating to and from the base facility and to and from the site transceivers; the base control facility and the zone transceivers when transmitting constituting master transceivers, and the zone transceivers when receiving and the site transceivers constituting slave transceivers; and means for transferring modulated data between the master transceivers and the slave transceivers, wherein the modulated data is transferred in time slots. In another aspect this invention resides broadly in a method of radio communication within a discrete environment, the method including:- establishing a communication network having a base control facility, a plurality of zone transceivers and a plurality of site transceivers associated with monitors and/or controllers in the discrete environment; the base control facility communicating to and from the zone transceivers, and the zone transceivers communicating to and from the base facility and to and from the site transceivers; the base control facility and the zone transceivers when transmitting constituting master transceivers, and the zone transceivers when receiving and the site transceivers constituting slave transceivers; and transferring modulated data between the master transceivers and the slave transceivers, wherein the modulated data is transferred in time slots.

In a preferred embodiment the modulated data is transferred by minimum shift keying (MSK).

It is preferred that the time slots include a lead-in time frame providing reference timing to a slave transceiver and facilitating data recovery at a master transceiver.

Preferably a time slot includes a data frame whereby a slave transceiver indicates to a master transceiver its status, the amount of data to be transferred and the estimated requirement for the next time slot.

It is preferred that the master transceivers constantly poll the slave transceivers. In a preferred embodiment interference monitoring means monitor interference or noise on the radio transmission spectrum within the discrete environment, and the master transceivers do not allocate a time frame for a transmission from a slave transceiver upon detection of the interference or noise.

The slave transceivers are preferably enabled to transmit data to a master transceiver if they receive a broadcast from a master transceiver allocating a time slot to the slave transceiver, if the message received in the broadcast is error free and if the slave transceiver is synchronised with the time slots and data frame of the master transceiver.

In a further aspect this invention resides broadly in a bio-recognition system for controlling access at locations within a discrete environment, the system including:- sensing means at the locations for sensing a bio-recognisable feature of a person or object requiring access to or within the discrete environment; conversion means for converting the sensed bio-recognisable feature into sensed bio- recognisable data; an interface device at the locations constituting a slave transceiver programmable to receive and/or transmit remote commands and/or data from and/or to master transceivers within the discrete environment, the interface device including means for transferring modulated data between the slave transceivers and the master transceivers, wherein the modulated data is transferred in time slots, and passive identification means for each person, the identification means being excitable proximate a location within the discrete environment for transmission of an identification of the person or object to the interface device; whereby authorised bio-recognisable data of a person or object which is stored in a cental control facility is transmitted therefrom to an interface device at a location upon excitation at the location of the passive identification means of the person or object for comparison at the location with the sensed bio-recognisable data.

In another aspect this invention resides broadly in a method of controlling access at locations within a discrete environment, the method including:- sensing at the locations a bio-recognisable feature of a person or object requiring access to or within the discrete environment; converting the sensed bio-recognisable feature into sensed bio-recognisable data; providing an interface device at the locations constituting a slave transceiver programmable to receive and/or transmit remote commands and/or data from and/or to master transceivers within the discrete environment, the interface device including means for transferring modulated data between the slave transceivers and the master transceivers, wherein the modulated data is transferred in time slots, and exciting passive identification means for the person or objectproximate a location within the discrete environment for transmission of an identification of the person or object to the interface device; transmitting authorised bio-recognisable data of a person or object which is stored in a cental control facility therefrom to the interface device at the location upon excitation of the passive identification means of the person or object, and comparing the authorised bio-recognisable data with the sensed bio-recognisable data at the location.

In the various embodiments and aspects of the invention described above it is preferred that the transferred data is prioritised time packaged metadata. It is also preferred that the means for transferring the modulated data includes a first radio transceiver for communicating with the monitors and/or controllers on a first frequency and a second radio transceiver for communicating with the master transceiver on a second frequency.

Description of Drawings

In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein:-

FIG 1 is an annotated block diagram of an application specific integrated circuit (ASIC) mounted on a printed circuit board and constituting the interface device of a first aspect of the invention and referred to herein as a Wireless All-purpose Secure Communications Interface Module (WASCIM); FIG 2 illustrates the WASCIM in an annotated typical data radio block diagram; FIG 3 illustrates a typical radio network in accordance with the invention;

FIG 4 illustrates a typical time slots/data frame allocation utilised in the radio network in accordance with the invention;

FIG 5 is a block diagram of the bio-recognitioπ/passive tag system of the present invention; FIG 6 illustrates the relative location of a passive tag reader and a bio-recognition station;

FIG 7 illustrates the sequence of events during an access cycle of the bio-recognition system of the present invention;

FIGS a to 10 illustrate various practical embodiments of the present invention in a discrete environment such as a high rise building; FIG 1 1 illustrates the connectivity between Zone Interface Modules (ZIMs) arranged throughout a captured radio network, WASCIMs and a building Network management Portal (NMP);

FIG 12 is a schematic illustration of an NMP;

FIG 13 is an annotated block diagram illustrating another preferred embodiment of a WASCIM;

FIG 14 illustrates the interaction of a typical field of WASCIMs with a ZIM and an NMP;

FIG 15 illustrates a typical radio field with WASCIMs communicating with their closest ZIM and the ZIM retransmitting priority signals as called up in a pre-arranged time slot loading format by the NMP, and FIG 16 is a typical interface layout within a building providing a secure access energy control system.

Description of Preferred Embodiment of Invention

Various preferred embodiments of the several aspects of the invention will now be described with reference to the drawings some of which are annotated for ease of interpretation.

The description is conveniently divided under the headings WASCIM, Captured Radio Network

(CRN), Network Management Portal (NMP), Bio-Recognition/Passive Tag and Captured intelligent

Network (CiN).

WASCIM

The WASCIM functions may be provided in part by a microprocessor having specialised electronic functions. These functions include power supply, wakeup timer for low power applications, the precise time reference synchronised to the Master's transmissions, MSK modulation and data recovery, frequency synthesis of transmit and receive frequencies, analog and digital interfaces including pulse counting, serial interfaces to Bio Recognition and Passive tag stations, and serial interfaces to intelligent input outputs. The latter may be RS 232 or RS 485 signal levels.

While these electronic functions may be provided by discrete circuits, significant advantages may be provided by implementing the circuits in an ASIC. The microprocessor, its memory circuits (RAM, EPROM, and EEPROM) and its input output circuits may be provided on the ASIC. Application of the ASIC to a generic microprocessor may also be advantageous. The microprocessor aspect of the electronic functions are known technologies. The application specific circuits provided in one preferred embodiment of the ASIC are now described with reference to annotated FIG 1. The functions and characteristics of the interface unit are preferably incorporated in an

ASIC mounted on a small PCB. This constitutes the WASCIM.

The function of the WASCIM is to send brief batches of information in an encrypted form having full address information that is decoded at the base station. Protection is provided against high electrical and magnetic noise, error detection and correction particularly in the presence of highly reflective radio paths.

Within a discrete environment such as a highrise building for example, there are a variety of units with totally different and unrelated functions and systems required to operate. The system uses dynamic master controlled response time, by using time slot allocations, so as to provide maximum use and efficiency of the radio spectrum. This allows reuse of different systems in close proximity to each other and even in the same building.

Preferred features of the ASIC include the following :- Microprocessor based for flexible applications. User application specific software downloadable and stored. Time reference. Time slot generation, application and synchronisation (slave).

Efficient realtime compression of serial data. Error detection and forward error correction. Row column inversion for burst noise protection. Digital, analog and serial interface. MSK radio interface.

Low power modes - time synchronised wakeup. Reference will now be made in more detail to a number of the components in the WASCIM.

Voltage Controlled Oscillator. The ASIC provides the voltage controlled oscillator required to provide a precise short-term frequency reference locked to the Master Station. In addition to frequency reference this block may provide the slot timing to the microprocessor for data transmission. Discrete electronics may be used to lift this processing load from the microprocessor where it may be provided in alternative concepts. This block may be stabilised by an extemal quartz crystal. The crystal oscillator of this block may provide the microprocessor clock. Data Radio Interface.

This block provides MSK or QMSK modulation and data recovery for the data radio. Including these specialised circuits on the ASIC and optimising them for the application provides major savings in component count, reduces the cost and improves the reliability and performance of the system. Frequency Synthesiser.

This block provides the receiver local oscillator and the transmit frequency generation. Inclusion of this block in the ASIC allows sharing of the crystal oscillator with the frequency reference, microprocessor timing, and synthesiser. Direct control of the synthesiser to meet the frequency agility requirements of the system may also be simplified by inclusion of this block in the ASIC.

Analog Interface.

These circuits may be matched the signal level, noise immunity, isolation, and accuracy required by the WASCIM applications. Integration may provide economic implementation of special combinations of characteristic, which may otherwise be prohibitive in a small low cost unit.

Digital Interface.

These circuits may be matched the signal level, noise immunity, isolation, and input/output types required by the WASCIM applications. The types may include pulse-counting inputs and pulse regenerated outputs. Integration may provide economic implementation of special combinations of characteristic, which may otherwise be prohibitive in a small low cost unit. This interface may provide expansion using low cost generally available devices.

Serial Interface.

The Bio Recognition stations and the Passive Tag stations (to be described subsequently with reference to FIGS 5 to 10) require serial interfaces at a Slave. The serial interface may also provide connection to intelligent input output devices. Master units may require serial interfaces to control computer and broad band communications bearers.

Provision of a number of serial interfaces and their driver receiver circuits are typically expensive in component count and space requirements. Integration of these circuits may provide lower cost, high reliability and allow flexibility in the number and type of signal levels accommodated by the serial ports at a Master or Slave. For example at one Slave the ASCI may be soft configured to provide a RS-232 serial port for a Bio Recognition Station while at another it may be soft configured to provide a RS-485 to communicate with a number of intelligent input /output devices connected to a multi-drop cable pair. Power Supply.

Provision of the power supply on the ASIC provides obvious saving in component count and distribution to the WASCIM circuit blocks. Timer.

A timer to provide wakeup for low power consumption applications may be integrated with the frequency reference and slot generation circuitry to ensure the operation of the timer is synchronised to the requirements to maintain reference lock and receive slot broadcasts.

The contribution of the above blocks in the WASCIM/ASIC provide for efficient power consumption, space requirements, and cost.

FIG 1 is annotated to facilitate understanding and conveniently indicate the relationship between the various components within WASCIM 11 which include power supply 12, RAM 13, flash EPROM 14, EEPROM 15 and CPU 16 (which may all be external to the ASIC), Input/output 17, timer 18, radio transceiver 25, data radio interface 19, frequency synthesiser 20, time reference voltage control oscillator 21 , analog interface 22, digital interface 23, and data interface 24.

Similarly, FIG 13 is annotated to facilitate understanding and conveniently indicate the relationship between the various components within WASCIM 113 which include ASIC 114, power supply 115, serial data passive tag interface 116, data interface fingerprint interface 117, data radio interface 118, compression module 119, time reference VCO 120, microprocessor 121 , data protocol 122, serial input/output 123, analog interface 124, radio transceiver 125 and remote equipment interface connections 126. It will be appreciated that the function of a WASCIM is to add intelligence to devices that have none, and to embrace all the equipment in the building into a common management system. This is regardless of the equipments particular state of intelligence or software compatibility. It can interface with - Serial input/output, Analogue, Voltage, Current, normally open, normally closed contacts, Serial data passive Tag, Data interface Bio-metrics. The WASCIM is different to ordinary radio data traffic in at least some of the following features:-

It provides high integrity, fast response, low-powered, short-range communications, because it uses its own data language, which allows it to operate in obstructed & highly reflective radio environments. It permits high frequency reuse by using a narrow band FM radio capture and provides error detection & correction in burst noise.

It provides dynamic master controlled response times by use of time slot master control with slaves deriving time reference from master broadcast.

There is efficient time & spectrum use for status reporting, by priority change of state reporting with periodic health checks.

High throughput of serial data devices (bio-recognition or TAG) is provided by data compression, multiple time slot allocation and dynamic priority hold of status traffic during transfer of serial data.

Low powered, short-range (100 meters) communication status devices may be battery powered.

Low cost, miniature case & ease of integration into a wide range of OEM products.

Captured Radio Network (CRN)

The wireless communications system constitutes another aspect of the present invention and is specifically suited for use in difficult radio environments, where sensors and controlled devices are distributed throughout a large site or building.

Preferred features of the data radio system of the present invention will now be discussed with reference to FIGS 2 to 4. These features include the following:- Narrow band FM capture. High Integrity, short range. Electrical & Magnetic noise resistance.

Error correction & Detection in presence of burst noise with Row column inversion technique.

Interface through dynamic master controlled response times; Time slot allocation; Time slot occupancy; Slaves derive time reference from master broadcasts plus high through-put data.

Efficient time and spectrum use.

Low power consumption because system powered fore ended.

FIG 3 illustrates a typical radio system in accordance with this aspect of the invention. The system uses one or more Master stations 38, each Master 38 communicating with a number of Slave stations 35,36,37. Where a slave (37) may be shielded by shielding 39 from a Master station 38 another slave (36) may be used to repeat the message to the shielded slave 37.

The radio system transfers data by Minimum Shift Keying on a class licensed frequency, the capture effect of the frequency modulation allowing each receiver to be captured by the operating transmitter. While low power is used, the system is designed so that the wanted transmitter is stronger than other transmitters, which may be on the same frequency. This occurs due to the shielding the local environment provides to outside transmitters and by matching the transmit power, aerials, and distance between transmitters and receivers.

This approach provides efficient use of the class licence frequencies and allows reuse of frequencies even within the site, yet provides the level of integrity required by these systems.

A number of Zone Interface Modules (ZIMs) provide a reliable secure interface capability with all equipment fitted with a WASCIM wherever it is located within the building. The ZIMs are the programmed radio link to the Main Base Station Radio Transceiver. If interference blocks one path, the WASCIM communicates through to the next ZIM available. In the event of burst noise or site RF interference blocking the radio path, the Base station can divert and read any output signal through another zone interface. In a worst case, the base station puts the system on temporary hold until the spectrum is clear if it cannot read all signals clearly.

The Captured Radio Network (CRN) together with full error correction in the data software, provides a secure high integrity network adapted to address typical interference problems found with using radio.

FIG 2 is a block diagram which has been annotated to facilitate understanding and indicate the relationship between the various components in a typical data radio network which includes

WASCIM ASIC 11 having power supply and switch 12, input/output 17, data radio interface 19, frequency synthesiser 20, reference oscillator and timing reference voltage control oscillator 21 , TX

VCO 27, buffer 28, PA 29, TRX switch 30, RF amplifier 31, mixer 32 and IF amplifier 33.

Preferred features of the radio system include the following:-

The main base station is constantly scanning all ZIMs in the system.

Any WASCIM that has communicated its signal to ZIM will await ongoing transfer and instruction. The main Base station has a constant poled data stream set up between all ZIM.

Signals are compressed and packaged according to priority and transmitted to base in a pre-ordained priority.

Pre-arrange software actions the un-compressed signals. The system of the present invention utilises time slots for the exchange of data between the Master and Slave and vice versa.

These time slots are precise timed by the use of highly accurate clock (eg. Global

Positioning System [GPS] clock) feed to the Master. The slave units derive their timing from the

Master transmissions and maintain the exact frequency by a Voltage Controlled Oscillator (VCO) locked to the highly stable crystal clock in the slave. The crystal clock provides short-term stability while the VCO allows preservation of the Master's timing.

Each transmission from Master to Slave and Slave to Master occurs in a pre-allocated slot. The Master dynamically allocates the slot allocations. The Master broadcasts at the beginning of a cycle of time slots. This broadcast informs the Slave of the Slots in which they are to transmit. The Master uses the un-allocated slots.

Depending on the amount of data to be communicated (eg. dependent on the activity of the Slaves Input/Outputs), the number and timing of the slot is allocated in each successive cycle by the Master.

A Slave is only enabled to transmit if it receives a broadcast allocating it a time slot, the message is error free, and the Slave has synchronised its internal clock to the Master.

FIG 4 illustrates a number of time slots in a cycle. In an early slot the slot allocations are broadcast. A data frame may be transmitted in a time slot. The data frame is similar to other MSK data radio systems in that it contains a Lead In of alternative data bits, a unique Frame Flag,

Station Address, Data, a 16-bit cyclic redundancy check character, and a closing Frame Flag. The Lead-in provides reference timing to the Slave and assists in data recovery at the Master.

The Frame Flag indicates the start of the data frame and provides timing reference to maintain a Slave's VCO. The Station Address indicates the source and destination of the data transmission. A 16 bit CRC to provide error-checking follows the data. The closing Frame Flag confirms the end of the frame and assists slaves to maintain their frequency reference. The data frame allows the Slave to indicate to the Master its Health status, the amount of data to be transferred (and thus allow additional slots to be allocated in the next cycle), and to forecast its next slot requirement based on its current activity.

In the system either a Master or Slave unit is transmitting. This allows the time reference to be maintained and allows the maximum throughput when all slots are occupied by "live" data. The latter occurs because the system is precisely timed and data is continually being transmitted by the

Master or a Slave. A long lead-in is not required, as the Data Receivers in the system already are synchronised. Only sufficient time for the transmitter to stabilise on key-up is required.

The above approach overcomes the inefficiency (often up to 50% of the channel time) taken while receivers stabilise and synchronise to the data timing. Other features of the radio system of the present invention include the following:- Where a Slave is shielded from the Master, the Slave obtains its reference timing from other Slave transmissions. The data to and from this Slave may be repeated via other Allocated slaves. The Slot allocation provides for the Repeater Slave to advise the Shielded Slave of its Slot Allocation and multiple Slots are allocated to allow the additional Slave transmissions. The system provides high data integrity due to the time slot allocation strategy, the data frame structure, and the error checking.

For systems where data packets exceed 10 bytes (typical of the outlined application) additional integrity is provided by forward error checking and row/column translation during transmission and reception. This technique employs various different techniques to match row/column to - time slots - and adds a higher level of encryption to the data packages.

The continuous transmission with precise time reference and synchronisation together with FM capture and error checking, forward error correction and retrying of corrupted frames provides high Noise Immunity.

The nature of the application is such that high data volumes and rapid response times are not required by all stations at all times. The unique dynamic allocation of time slots accommodates regular health reporting, high periods of change of state activity and also facilitates priority handling of emergency signals regarding essential services such as fire and gas alarms.

The Master controls the reporting strategy. In addition to providing an ability for it to respond to Slave requirements, a Master's strategy may be controlled by the need to obtain selective information form the network (eg. repetitively poll a Slave if its data is of particular importance).

Further frequency agility can be achieved by using 2 or 3 frequencies in the same class licence band (use the same radio, aerials, etc). A fall back strategy, if interference is identified by the Master and/or Slaves, is to listen on another frequency for the timing and slot allocation broadcast.

The main radio base station supplies constant de-compressed data stream to the CBS where the data is processed according to the pre-programmed Building Management System.

Individual sensors typically have only one or two status bits that only occasionally change

(eg fire detector is normally OK and goes into alarm only in a fire). The sensor may develop a health status. This status may be required by the control system on a daily or hourly basis. It may be appropriate that the health status be requested while the data needs to be reported immediately on a change of state.

Some sensors such as environment control sensors output an analogue value of 8 to 12 bits that may change by one bit every minute or two. Where the value is slowly changing, quite low reporting rates may be appropriate or it may be more appropriate for the central unit to request the data. Where the value is more rapidly changing or where it changes from slowly varying to rapidly varying, reporting on a percentage change or reporting more often may be necessary. Access control panels (eg Fingerprint) have data which may consist of a frame 9f 100 to 200 characters sent for each identification which may be up to twenty times a minute per sensor. As seen for illustrative purposes in FIGS 8 to 10, a number of sensors may be required at major entry points. Typically each floor of the building has similar sensors and controlled devices. The data from each floor may typically be concentrated and passed to a central point or number of central points for processing or reporting. With reference to FIG 8 which has been annotated to facilitate understanding, there is illustrated a typical discrete environment within a high rise building for example, in which floorings 50 separate the building space into levels transected by a vertically extending fire resistant backbone bearer 51. ZIM 52 is fixed to the ceiling of one level and communicates with WASCIM 54 associated with tag reader 159 and bio-recognition reader 55 located at main door 56. ZIM 53 is fixed to the ceiling of another level and communicates with WASCIM 57 associated with tag reader 158 located at internal door 58. ZIMs 52 and 53 communicate via bearer 51 and bearer interface 59 with computer base station 60.

With reference to FIG 9 which has been annotated to facilitate understanding, there is illustrated another typical discrete environment within a high rise building for example, in which floorings 61 separate the building space into levels transected by a vertically extending fire resistant backbone bearer 62. ZIM 63 is fixed to the ceiling of one level and communicates with WASCIM 65 associated with pressure mat 66 supporting a safe 66 and with WASCIM 68 associated with infra-red detector 69 located at door 70. ZIM 64 is fixed to the ceiling of another level and communicates with WASCIM 70 associated with window 71 and with WASCIM 62 associated with infra-red detector 73 located at door 74. ZIMs 63 and 64 communicate via bearer 62 and radio interface 75 with computer base station 76.

With reference to FIG 10 which has been annotated to facilitate understanding, there is illustrated another typical discrete environment within a high rise building for example, in which floorings 76 separate the building space into levels transected by a vertically extending fire resistant backbone bearer 77. ZIM 78 is fixed to the ceiling of one level and communicates with WASCIM 80 associated with pressure mat 82 supporting a safe 81, and with WASCIMs 88 and 92 located at main door 91 and associated with tag reader 89 and bio-recognition reader 90, and with infra-red detector 93 respectively. ZIMs 78 and 79 communicate via bearer 77 and radio interface 96 with computer base station 97. Some plant controls may be located on each floor. Major plant is typically concentrated at one or two locations in the building. When concentrated, the amount of data from all sources may be very large and the bandwidth of the channel to provide the required response time for the system may be large.

The system of the present invention is less applicable in providing communications for the concentrated data. Conventional wide bandwidth communication bearers such as coaxial cables, optical fibres or twisted copper pairs may economically provide the centralised bearer. Building design, even in older buildings, may provide for the installation of centralised power and communications services.

Having regard to the illustrations in FIGS 8-12 , 14 and 15 it will be appreciated that the captured radio network in accordance with the present invention uses one or more master radio stations. Each master is constantly communicating, with a number of slave stations called - Zone Interface Modules (ZIMs), or Zone Interface Units as above and with reference to FIGS 8- 10 . Where a zone station may be shielded from a master station another zone slave station may be used to repeat the message to the shielded slave. This system is controlled by the NMP or Network Management Portal (see FIG12) and has a network of slave. ZIMs are Radio transceivers set up in every zone within a site and are normally mounted on the ceiling in an enclosure. Each ZIM is fitted with two radio transceivers, one of which is constantly polled by the NMP. The second is interfaced to all WASCIMs within the zone of the building by a preprogrammed time based coordination system. The ZIM thus has the ability to be doing two functions at once, whilst dividing Metadata into priority signals.

This is seen in FIG 14 which is annotated to facilitate understanding and conveniently indicate the relationship between WASCIMs 127, ZIM 128 (including the ZIM -WASCIM transceiver 129 and the ZIM-NMP transceiver 130) and NMP 131 (including the main radio base station 132 and the software management portal 133). WASCIMs 127 transmit ID, prioritised, encrypted, compressed, error correction Metadata to ZIM 128, and receive command Metadata from ZIM 128. ZIM 128 transmits prioritised Metadata to NMP 131 which transmits time slotted package loading Metadata and command instructions to ZIM 128.

Antennae power for each WASCIM and ZIM is matched and shielded, so that each WASCIM Transceiver is always the dominant signal being transmitting to its adjacent ZIM. Thus rather than sending a broadcast signal in all directions, a matched signal is transmitted to a ZIM by the shielding of the antennae to give a direct path, making it the dominant signal.

The information is gathered by the WASCIM and transposed in a particular way by the ASIC, into a suitable form of Metadata, before it is transmitted through the system.

The system operation is based on a WASCIM reporting to its adjacent ZIM, with ID, Priority, error count and Data. The ZIM reports the first three parts of the package to the NMP and loads the data into priority based memory chips. This can be termed Time cycle 1 - WASCIM to ZIM.

On a second frequency the NMP is also calling up all stored data from each ZIM in an endless stream of time package slots. Any illegal interception of the data stream first has to break the compressed encrypted data. This can be termed Time Cycle 2 - ZIM to NMP.

The Metadata command or message signal streams transmitted do not require a start ID or stop as it is from timed based stored memory and can be a collection of signals from many WASCIM's reporting to the one ZIM.

Consequently, should the information be intercepted it appears as useless garbled encrypted compressed metadata with no common start stop milestones. The preferred medium for the CRN radio system transfers data by Minimum Shift Keying on a class license frequency.

FIG 15 is also annotated to facilitate understanding and conveniently indicate the relationship between a field of WASCIMs 134, a first ZIM (a) 135, a second ZIM 136 and NMP 137 having transmitter 138 and receiver 139. AS is seen in the illustration, ZIM priority seamless data train side band delivers data storage information with the pair of ZIMs (a) and (b) mounted in the same enclosure and the NPM transmitter 138 sending to the receiver of ZIM (b) time slot data loading information by priority.

Re-stated, a ZIM has two radio transceivers on different frequencies to enable it to be talking to WASCIMs receiving or imparting data, whilst the other unit is transmitting WASCIM priority pending traffic and receiving data time slot allocations.

Each ZIM sets up its own captured radio network, and may have up to 50 WASCIMs under its influence. It is constantly scanning for Signals from any WASCIM in its network. It accepts them on a first in first serve basis. On receipt of a signal it will tell the WASCIM to standby until further instructions are sent. The WASCIM will only transmit further information if its status changes yet again. The ZIM can tell the WASCIM to desist from sending any signals till further advised, if there is a more pressing problem and a clear spectrum is required.

A typical General Signal Procedure is as follows:-

1. WASCIM (ID 10001) sends radio signal to ZIM (ID 20201 )

On any alarm or change of state. WASCIM (Id 10001 ) alters its own internal condition to full power and puts out a signal flag, comprising System ID, Priority of message and Sum (length of message in characters).

2. ZIM Rx1( ID 20101) accepts message passing it on to the NMP via ZIM 1Tx1 (ID 20301 ), then asks for balance of message, which it store in memory according to priority.

3. ZIM 1 Rx 1 then scans its Captured Radio Area for more WASCIMs with messages.

4. ZIM 1 Rx 2 (ID 20202) receives timed slot allocation from NMP and re-transmits it through ZIN Tx (203 02) to the WASCIM.

Thus there are two separately timed allocated radio networks working within any one captured radio network area. This can mean there may be dozens throughout a building, but because they are low powered and use separate ID codes, they do not interfere with each other.

Furthermore the unique capture effect of the frequency modulation will allow each receiver to be captured by the operating transmitter. While low power is used, the system is designed so that the wanted transmitter is stronger than other transmitters, which may be on the same frequency. This occurs due to the shielding of antennae in the local environment, which provides an invisible barrier to outside transmitters.

The system constantly monitors the spectrum for burst noise. If interference blocks one signal Path, the WASCIM will communicate through to the next ZIM in its area in a manner similar to mobile phone technology. To reiterate with reference to FIG 12 which illustrates an example of the system of the present invention in a high rise building with levels separated by floors 104, ZIMs 106 are positioned on the ceiling in the upper level and ZIMs 107 are positioned on the ceiling in the lower level. ZIMs 106 communicate with the WASCIM associated with laptop 110- and with the WASCIM associated with door tag reader 109. ZIMs 107 communicate with the WASCIM associated with lighting control relay 111 and with the WASCIM associated with PIR detector 112.

ZIMs 106 and 107 communicate via bearer 105 base station 99.

FIG 16 is annotated to facilitate understanding and conveniently indicate an exemplary relationship between a ZIM 140 and a series of WASCIMs associated respectively with hydraulic alarm panels 141 , fire exit doors 142, tag readers 1 3 and fingerprint units 144 in a security access system 145, sector lighting control relays 146 and 151 , passive infrared detectors 147 on internal doors, air conditioning control panels 148, air conditioning controls and dampers 149, DVD cameras 150 and passive infrared detectors 152 on storage area doors. The data is transmitted via a leeky feeder backbone bearer 153 located in a vertically extending fireproof ducted riser 154 to a main radio base station 157, which links as illustrated with DVD camera interface 157, NMP

156 and security closed circuit TV control 155.

Thus in summary, the captured radio network in accordance with the present invention provides a safe and secure form of transmitting management data in a high-rise building, and includes the following features:-

• In the event of burst noise or site RF interference blocking the radio path, the Base station can divert the signal to read through another zone interface Module.

■ In severe interference periods the base station can put the entire system on temporary hold until the spectrum is clear if it cannot read all signals clearly.

■ Moreover, a unique aspect of the present system is it can also read the local environment at each ZIM.

■ It only offers data when the spectrum is clear for the exchange of data between the

Master and Zone Slave and vice versa therefore there will be many completely autonomous radio zones within one complete CRN embracing the entire building

■ In situations where there is a major security or safety risk developing the system has the ability to freeze all WASCIM non- critical traffic and then direct a pre-programmed alarm, evacuation or tracking program to help counter the threat.

• The approach of the present invention provides efficient use of the class license frequencies and allows reuse of Frequencies even within the site, yet provides the highest level of integrity and security required, by a complete building management systems.

^■ The system uses a total synchronised time packaged to control the flow of Metadata within specific protected local spectrums. The CRN provides a complete building multi zone polled radio network, with its own specific pre-programmed data format.

Network Management Portal (NMP)

The NMP has a Main Radio Base (MRB) station and a Network Management Computer to interface with all internal and external devices including LAN, WAN, WiFi and all other external communication devices necessary. Thus as seen in annotated FIG 11 , in a locker 99 will be located radio base station 100, NMP 101 , graphic display module 102 and a battery and charger 103.

There may be more than one MRB station for the building, this depending on its height and the number of input signal sources. The MRB receives all signal Metadata from its ZIMs and transposes it to Serial data, for the overlaid computer software program to dissect, record and process according to a pre-programmed format set up at installation. WASCIMs to ZIMs is one capture network and ZIMs to NMP in the other. This allows for the system to maximise the re use of the spectrum with a seamless flow of time slot data traffic from ZIMs to the NMP.

Because each location has its WASCIM empowered at start up by the NMP, it is only necessary to send change of state enquiries or commands. The action it will take, is imbedded in its ASIC and microprocessor. Therefore the signals transmitted and received at each location have no immediate meaning outside the system.

An external hacker would experience extreme difficulty attempting to distinguish when a signal starts and stops to any one location, and as it is also encrypted and compressed it is exceedingly difficult to dissect. The NMP is made up of 4 separate sections: the main Radio Base station (MRB), the

Data Processing and application centre, the Firewall and inter connectivity to the outside world, and the main Backup Power Supply and charger. All equipment is mounted on racks in a dustproof, water resistant, metal wall mounted cubicle, with appropriate portals available to all access connection for: - WAN, LAN, Wi-Fi, 802.11 , Telco's and Emergency Services. The NMP is thus the Main Radio Base (MRB) transceiver which receives all incoming signals and transposes them into digital data for recognition, thence transferring them to the data and application section for appropriate action by a pre-programmed set of instructions. Group incoming signals may prompt a different response when the collective data is examined as a whole. The system can then send all outgoing command instructions required to manage the system.

By virtue of its software control the system has five main attributes and reacts as a whole after fully analysing the entire picture and taking into account all the pre programmed data as compared to the following examination of the situation : -

1. Behaviour analysis of individual or group signals, will decide what action, Instruction, or alarm condition response is required. 2. Personality of the system can be a passive processing of all incoming data that it receives, then acknowledges and stores data information. The system also has the ability to aggressively take over the entire system, put non-essential elements on hold and activate a preprogrammed action plan. 3. Rules will be checked and applied to all functions to ascertain if the system needs to turn to a pro-active stance.

4. Language forms the "key" to all transmitted signals. We determine what function each individual WASCIM is connected to and it is pre-programmed with response at start-up. It is then only necessary to transmit encrypted, compressed metadata in each communication. If intercepted it has no meaning to any but the NMP.

5. Sensors form with the essential software, imperative controls that we program to initiate commands to unrelated devices. They turn on and become pro-active in determining the adjacent environment of Sight ( CCTV), Sound (microphones) Touch ( metal detection) and Smell (Gas or explosion sensing). All sensors being essential sources of information required for particular high security locations in alarm conditions, for both action and evacuation plans to be effective.

Bio-Recognition/Passive Tag

FIG 5 is an annotated block diagram illustrating the relationship between two interfaces/data radio transceivers 42 and 43, passive tag reader station 40 and bio-recognition station 41, and a central computer recognition application 44 which receives a tag ID and passes a bio-signature.

FIG 6 illustrates traffic flow along an access corridor 45 where passive tag reader stations 46 and bio-recognition stations 47 control access beyond an access control bamer 48 by controlling operation of door 49.

An "Identification Number" may be fixed where the "ID tags" are permanently allocated, or in higher security applications where multiple access points are used and "signatures" are checked daily or where itinerants' signatures are captured and tags allocated on a casual basis, as the "signature". Each Bio-Recognition "signature" may have a corresponding Passive Tag "identification number". The correspondence between the "signature" and the "identification/"identification number" may be continually allocated or reallocated.

As seen in FIG 6, a typical access control system utilises a one-way traffic flow to assist in Security and Access Control. The invention utilises the Passive Tag to provide a preliminary identification of the person. The lead provided by the traffic flow and the separation of the Passive Tag reader station and the Bio-Recognition station allows the "signature" to be requested and downloaded to the Bio-Recognition station in preparation for the unique match of the "signature" with the person.

The sequence of events during an access cycle is described with reference to FIG 7. A

9600-baud data transfer rate may be readily achieved on a WASCIM radio link. A fourteen character "Identification Number" may be encrypted and passed in a data frame, with forward error correction, not exceeding 300 bits. The "Identification Number" frame may therefore be transferred in less than 50 mS.

A Bio-Recognition "signature of 5000 characters may be similarly encrypted and passed in data frame, with forward error correction, in less than 500 mS. This time being based on five frames with acknowledgment of each frame. Consequently the physical configuration therefore need only provide less than a second transit time.

The bandwidth of the required communications channel may be reduced to enable the communications between the recognition station and the central computer to be carried by a low cost data radio operating on a class licence frequency. The association of a passive tag with a particular identity only requires the recognition pattern for that identity to be passed to the recognition station.

Bio-Recognition systems are based on identifying unique aspects of a person's anatomy and using this "key" to provide recognition with high integrity. The best of these systems require matching of hundreds of thousands of elements. To provide high security, the "key" is typically stored on a central computer and the "image" at the recognition unit is passed to the central computer for comparison with the key. Some systems utilise a hierarchy of comparisons based on critical points. Matching of the higher level points provides a tree search to construct a match and recognition. These approaches require a high bandwidth communications channel between the recognition unit and the computer. Typically, these channels are required to be two way to allow the tree search to occur. Such a system is illustrated in general terms in FIG 5.

A number of passive tag systems have been developed. In these systems, the tag is excited by a sensor station. The excited tag broadcasts its identification, which is received and the tag identified by the sensor station.

By combining these two technologies, the bandwidth of the required communications channel may be reduced to enable the communications between the recognition station and the central computer to be carried on a low cost data radio operating on a class licence frequency.

The association of the passive tag with a particular identity only requires the recognition pattem for that identity to be passed to the recognition station. The communications bandwidth is reduced considerably and the continuous two-way communication required by the tree search is not required. Potentially the time required to achieve recognition is significantly reduced. This factor is important in reducing the delays at recognition stations or reducing the number of recognition stations required for a specified delay or throughput.

The approach of the present invention avoids the need for high bandwidth radio systems, physical cabling between the recognition station and the central computer, provides flexibility in the location of recognition stations and provides high reuse and efficiency in the use of radio spectrum. In the present system a person approaching the sensor station uses a card in lieu of the ubiquitous person identification number (PIN). The card may be a passive tag or a smart card and there approaches as to how we interface these systems include:-. 1. Between the card and reader. 2. Between the Identity recognition unit through our CRN to the NMP. Using passive tags

On approach, the surrounding reader field excites the tag which then broadcasts its identification, which is received and the tag identified by the sensor station is transferred to the Bio-recognition unit (BRU), which calls up the template prior to the finger being placed on the glass platen of the BRU. On signal acceptance our system can transfer the transaction as Metadata through the CRN to main base station. This ensures the highest security.

Using a bio-metric smart card One approach has the bio-recognition embedded in the card and when swiped and compared to an attached reader BRU, on signal acceptance the transaction is transferred as Metadata through the CRN to main base station. This ensures the highest security level while protecting the ID from War driving hackers.

Using a radio Smart Card with passive tag

This approach is to have a miniature radio embedded in the card to transmit its identification information, when in close proximity to the reader and excited by an attached tag. The reader transmits radio signal to the card to handshake and download Identity information before re-transmitting Metadata transaction data through the CRN to the NMP. This approach also ensures the highest security Level while protecting the ID from War driving hackers.

Using a radio Smart Card with local initiation

In this approach a miniature radio is embedded in the card. When the card is in close proximity to a door reader, it picks up an intermittent turn-on signal from the appropriate door reader. The reader transmits a low powered radio signal to the card to handshake and download Identity information before re-transmitting Metadata transaction data through the CRN to the NMP. This ensures the highest security. The person carrying the card can then be tracked through the building.

By combining any of these technologies, the bandwidth of the required communications channel may be reduced to enable the communications between the recognition station and the central computer to be carried by a low cost data radio operating on a class license frequency. The association of a card or tag with a particular identity only requires the recognition pattern for that identity to be passed to the recognition station. A variety of different Types of cards may be used as the Identifying Key and a variety of solutions for each different card enhance operational effectiveness.

Thus a passive card is also used at the reading points as the ID key. A radio link between the passive card and the Bio-metric reader substantially increases the speed of the process of Identifying the holder of the card without the necessity of conducting a tree search. If using a Radio Card, the holder of the card is identified by pulse door transmitters on entry to the building and at each different zone within a building. It is also used at the reading points as the ID key.

Captured intelligent Network (CiN)

It will be appreciated that a CRN provides the physical architecture required to physically interface with the recipient object and to secure and transmit management level data via its secure wireless mechanism. This in turn leads to what may be described as a captured intelligent network (CiN) which provides and enables new forms of process automation, detection and data reporting for any type of physical item, mechanical object, electronic component or computerised system.

A CiN can be regarded as providing a decision processing engine for a CRN which allows all CRN devices to feed and draw information from a single management and processing platform which itself can also be remotely accessed and remotely managed and can also act as a command and reporting portal for computer application to CRN connectivity.

A CiN processes and manages all of the commands and data for a CRN network and transforms and processes this data so that it is capable of feeding a virtual reality simulation of the zone covered by the CRN. It does this to the extent that the virtual world objects, properties and logistics can be kept in near to real time synchronization with the real world objects, properties and logistics. The real world objects can also be remotely controlled and managed using their virtual reality counterparts.

A CiN can itself be regarded as the process of managing the component parts of a CRN and providing together with the retrofitable WASCIM a generic method of collecting, sampling and managing data from devices that provide not only critical business information but also near to real time environmental and movement information.

A CiN can provide the necessary data for the interactive virtual simulation and manipulation of any environmental condition, object, item or process without the need in many cases to redesign the original component.

A CiN is a collection of CRN data, CRN protocols, CRN software and CRN procedures and management that securely enables an external system or application with access to monitor, interface with and control any object fitted with a WASCIM operating inside a CRN.

A CiN allows all objects operating in a CRN to participate in a collaborative automation management and reporting system. The WASCIMs are the external agents to the system, and can act independently - although they are programmed by, report to and are securely asccessible via the CiN and its host, the NMP. The CiN gives the CRN its instructions and manages the overall flow of traffic between the CRN networks and the external systems. A CRN can be regarded as a new type of data network that uses a new form of data protocol. The CiN can be regarded as providing the bridge between the protocol of the CRN and those of traditional computer networks.

Attributes and characteristics of a CiN include the following:-

1. A CiN facilitates the overall remote automation of objects fitted with a WASCIM operating in a CRN.

2. A CiN enables the unified integration, control and management of diverse real world items, specifically those items that currently have no external data reporting facilities or do not communicate or interface with traditional computing platforms.

3. A CiN provides bi-directional interfaces for the virtual simulation of and virtual remote control of totally dissimilar real world objects.

4. A CiN provides the information necessary to generate a near to real time virtual simulation and interface with any physical object operating in a CRN.

a. The data necessary to generate the virtual copy of the real world and WASCIM fitted objects is a combination of:

i. the known configuration, behaviour and appearance of the WASCIM fitted items ii. the movement history of the WASCIM fitted items iii. the activity, alarm and sensor history of the WASCIM fitted items iv. the known and possible interaction of all CRN items with regard to their current neighbouringitems v. the known configuration of the building: its dimensions, entrances and exits; its floors, walls, windows and spaces. b. Because a CRN is constantly sampling the environment the collection of data can be reliably and dynamically automated from any WASCIM-fitted device to match an applications need. It is also possible to build up enough data to accurately feed a virtual reality interface to real world objects in near real time, c. A CiN creates a control link between dissimilar real world objects and corresponding intelligent virtual software based objects enabling the interaction and participation of those objects in an overall management suite.

5. A CiN provides a common control and management interface for a. dissimilar equipment with dissimilar protocols b. detection and movement information for assets and personnel c. data reporting and device command infrastructures d. unified alarm and sensor management e. unified environmental sensing f. unified remote automation. g. a bridge between CRN devices and traditional LANs and applications

A CiN enables the provision of real time data ready to feed a near real time virtual reality simulation of a real physical environment, its contained objects and its population, enabling a virtual reality system to be able to match many of the properties of a real world environment in a near real time simulation that can also be used to interact with and control the real environment.

a. This feature extends the practical use of virtual reality systems to include the near to real time visualization, control and management of any type of device or object that is fitted with a WASCIM operating in a CRN.

7. A CiN enables the provision of a complete audit trail of an entire building, its environmental conditions, its population and their movement, its physical contents and their status, position and management.

8. A CiN enables the provision of a single platform for use by emergency services for the interrogation and management of an entire building or site in an emergency situation.

a. The Cin has ability to feed and manage information with regards to population location, fire and gas detection, access and security, physical asset tracking and population tracking all from a safe position long after cabled systems have failed.

b. This feature will significantly improve the number of possibilities available for the effective management and swift resolution of emergency situations in hi-rise buildings and sites protected by a CRN.

It will further be appreciated that the various aspects of the present invention have a number of advantages over known communication systems and methods, and components therefor. These include the following :-

WASCIM is a reliable, fast, high integrity integration module, for a large variety of system uses. This makes it particularly suitable for easy integration of a wide range of other manufactures products. This unit can be plugged into any device from which it is necessary to provide a data interface, or to which we wish to send control signals. It may be a lighting control relay, air conditioning damper unit, a security device, fire/smoke detector or access control unit and such items can be integrated into a common low cost communication network. The Features of the WASCIM allow it to be used as a single purpose communication format, to be attached to almost any device and when programmed, can provide a high quality, error corrected, encrypted data interface. When many WASCIMs are used with low powered radio links they form part of a complete integrated data transfer system. For all applications requiring mixed bearer data transfer the WASCIM can be used as the data language of choice. A radio transceiver is used as the wireless medium when two-way communications are required.

The wireless system is particularly applicable to use in high-rise building for access & Energy management, fire detection & evacuation systems and all types of alarm or security systems. Its main attribute is it diversity, which makes it applicable to the above and well as many other uses where high integrity short range communications with fast response times are required.

In known building control systems cost is often prohibitive to provide hardwired systems. Even where hardwired systems may be provided, a number of sensors may need to be combined to minimise the complexity and cost of the wiring. The combining of sensors often means that the data which is available from individual sensors is generalised and may not be as effective (eg. for firefighting). The wireless system of the present invention provide flexible, expandable solutions where the amount of data to be transferred is small or the number of sensors is large.

The allocation of licensed frequencies is becoming more difficult with the reuse range between users allocated the same frequency and service being decreased and lower levels, if any, of protection being guaranteed by the allocating authorities. That is the onus is similarly falling on the users to coexist with other users. In this environment the license fees are generally increasing. Licensed frequency bands and their applicable service are not well aligned. The regulations and equipment approval specifications vary widely (although some alignment is progressing) throughout the world. Typically equipment needs to re-tested to the local regulations and approved in each global region or country. This is an expensive and time consuming exercise which often limits the development and marketing or radio based systems. Infrared and visible wireless systems offer wider bandwidth than radio but requires sophisticated techniques to avoid interference between devices and signals from natural and man-made sources. Inductive and power borne systems have limited bandwidth and are subject to high levels of interference in the environment described above. The communications system of the present invention provides improved functionality in high-rise buildings and other similar discrete environments.

When radio is used as the medium for transmitting this information, all units are low powered (less than 100 mw, unlicensed band). Low power consumption status devices may be battery powered for extended periods. This provides efficient use of class license radio spectrum with high frequency reuse by narrow band FM capture.

Advantages of the bio-recognition/passive tag system of the present invention will be seen to include the following:-

The communications bandwidth is reduced considerably and the continuous two- way communication that is required by the tree search is not needed. Potentially the time to achieve a recognition is significantly reduced. This factor is important in reducing delays at recognition stations.

The number of recognition stations can be reduced for a specific throughput. This approach avoids the need for high bandwidth, making it eminently suitable for a high integrity radio system.

There is no physical cabling between the recognition station and the central base station that can be tampered with.

It provides complete flexibility in location of recognition stations. The system provides high reuse and efficiency in the use of radio spectrum. The "link" timing (even allowing re-transmission of some frames) is be more favourable, thus increasing people throughput, compared to that of reading and matching time in the standard Bio-Recognition station.

There is considerable hardware cost savings, together with ease and speed of installation. It has the advantages of equipment portability for even temporary venues that require high levels of security.

Because of the special features attributed to the "Radio Timed Coding Format" and the variable column data transfer, a high level of encryption is imparted to the base system. It is therefore difficult for illegal operatives to circumvent data cable between the door and the Base station. Even higher levels of encryption can be obtain if required, by issuing a new passive tag daily, from a card dispenser on entry to the first perimeter door. A new card every day, with new electronic address, makes it exceedingly difficult for the system to be circumvented.

It will of course be realised that whilst the above has been given by way of an illustrative example of this invention, all such and other modifications and variations hereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of this invention as is herein set forth.

Claims

The claims defining the invention are as follows:-

1. An interface device constituting a slave transceiver programmable to receive and/or transmit remote commands and/or data from and/or to master transceivers and monitors and/or controllers within a discrete environment, said interface device including:- means for transferring modulated data between said slave transceivers and said master transceiver, wherein said modulated data is transferred in time slots.

2. An interface device as claimed in claim 1 , wherein said data is prioritised time packaged metadata.

3. An interface device as claimed in claim 1 , wherein said means for transferring modulated data includes a radio transceiver.

4. An interface device as claimed in claim 3, wherein said means for transferring modulated data includes a first radio transceiver for communicating with the monitors and/or controllers on a first frequency and a second radio transceiver for communicating with the master transceiver on a second frequency.

5. An interface device as claimed in claim 2, wherein said modulated data is frequency modulated.

6. An interface device as claimed in claim 5, wherein said interface device is adapted:- to monitor and discern connected multi-facet signals from a master transceiver; to formulate a pre-programmed signal response for transmission to a master transceiver; to convert said response to a compressed digital prioritised package; to monitor the availability of in-coming time synchronised packages, and to transmit an interference-free response to a master transceiver so positioned in the discrete environment to provide interference-free transmission between the interface device and said master transceiver.

7. An interface device as claimed in claim 6, wherein said interface device includes a printed circuit board on which is mounted an application specific integrated circuit including:- microprocessor means programmable by application specific software; memory means for storing said application specific software; timing means; means for generating, allocating and synchronising said time slots, and input/output means including at least some of data radio interface means, analog interface means, digital interface means, voltage interface means, current interface means, voltage free contact means, signal sensor means and serial interface means.

8. A method of receiving and/or transmitting remote commands and/or data from and/or to master transceivers and monitors and/or controllers within a discrete environment, said method iπcludiπg:- transferring modulated data between said master transceivers and said slave transceivers, wherein said modulated data is transferred in time slots.

9. A method as claimed in claim 8, wherein said data is prioritised time packaged metadata.

10. A method of receiving and/or transmitting remote commands and/or data from and/or to master transceivers and monitors and/or controllers within a discrete environment, said method including:- providing an interface device constituting a programmable slave transceiver including means for transferring modulated data between said slave transceivers and said master transceiver, wherein said modulated data is transferred in time slots; monitoring and discerning connected multi-facet signals from a master transceiver; formulating a pre-programmed signal response for transmission to a master transceiver; converting said response to a compressed digital prioritised package; monitoring the availability of in-coming time synchronised packages, and transmitting an interference-free response to a master transceiver so positioned in the discrete environment to provide interference-free transmission between the interface device and said master transceiver.

11. A method as claimed in claim 10, wherein said data is prioritised time packaged metadata.

12. A radio network for communication within a discrete environment, said radio network including:- a base control facility, a plurality of zone transceivers and a plurality of site transceivers associated with monitors and/or controllers in said discrete environment; said base control facility communicating to and from said zone transceivers, and said zone transceivers communicating to and from said base facility and to and from said site transceivers; said base control facility and said zone transceiver when transmitting constituting master transceivers, and said zone transceiver when receiving and said site transceivers constituting slave transceivers; and means for transferring modulated data between said master transceivers and said slave transceivers, wherein said modulated data is transferred in time slots.

13. A radio network as claimed in claim 12, wherein said data is prioritised time packaged metadata.

14. A radio network as claimed in claim 13, wherein said means for transfening modulated data includes a first radio transceiver for communicating with the monitors and/or controllers on a first frequency and a second radio transceiver for communicating with the master transceiver on a second frequency.

15. A method of radio communication within a discrete environment, said method including:- establishing a communication network having a base control facility, a plurality of zone transceivers and a plurality of site transceivers associated with monitors and/or controllers in said discrete environment; said base control facility communicating to and from said zone transceivers, and said zone transceivers communicating to and from said base facility and to and from said site transceivers; said base control facility and said zone transceiver when transmitting constituting master transceivers, and said zone transceiver when receiving and said site transceivers constituting slave transceivers; and transferring modulated data between said master transceivers and said slave transceivers, wherein said modulated data is transferred in time slots.

16. A method as claimed in claim 15, wherein said data is prioritised time packaged metadata.

17. A method of radio communication as claimed in claim 15, wherein said modulated data is transferred by minimum shift keying (MSK).

18. A method of radio communication as claimed in claim 17, wherein a time slot includes a lead-in time frame providing reference timing to a slave transceiver and facilitating data recovery at a master transceiver.

19. A method of radio communication as claimed in claim 18, wherein a time slot includes a data frame whereby a slave transceiver indicates to a master transceiver its status, the amount of data to be transferred and the estimated requirement for the next time slot.

20. A method of radio communication as claimed in claim 19, wherein said master transceivers constantly poll said slave transceivers.

21. A method of radio communication as claimed in claim 19, wherein interference monitoring means monitors interference or noise on the radio transmission spectrum within the discrete environment, and wherein said master transceivers do not allocate a time frame for a transmission from a slave transceiver upon detection of said interference or noise.

22. A method of radio communication as claimed in claim 15, wherein a slave transceiver is enabled to transmit data to a master transceiver if it receives a broadcast from a master transceiver allocating a time slot to said slave transceiver, if the message received in said broadcast is error free and if said slave transceiver is synchronised with the time slots and data frame of said master transceiver.

23. A bio-recognition system for controlling access at locations within a discrete environment, said system including:- sensing means at said locations for sensing a bio-recognisable feature of a person or object requiring access to or within the discrete environment; conversion means for converting the sensed bio-recognisable feature into sensed bio- recognisable data; an interface device at said locations constituting a slave transceiver programmable to receive and/or transmit remote commands and/or data from and/or to master transceivers within the discrete environment, said interface device including means for transferring modulated data between said slave transceivers and said master transceivers, wherein said modulated data is transferred in time slots, and passive identification means for each said person or object, said identification means being excitable proximate a location within the discrete environment for transmission of an identification of the person or object to said interface device; whereby authorised bio-recognisable data of a person or object which is stored in a cental control facility is transmitted therefrom to an interface device at a location upon excitation at said location of the passive identification means of said person or object for comparison at said location with said sensed bio-recognisable data.

24. A bio-recognition system as claimed in claim 23, wherein said data is prioritised time packaged metadata.

25. A method of controlling access at locations within a discrete environment, said method including:- sensing at said locations a bio-recognisable feature of a person or object requiring access to or within the discrete environment; converting the sensed bio-recognisable feature into sensed bio-recognisable data; providing an interface device at said locations constituting a slave fransceiver programmable to receive and/or transmit remote commands and/or data from and/or to master transceivers within the discrete environment, said interface device including means for transferring modulated data between said slave transceivers and said master transceivers, wherein said modulated data is transferred in time slots, and exciting passive identification means for said person or object proximate a location within the discrete environment for transmission of an identification of the person or object to said interface device; transmitting authorised bio-recognisable data of a person or object which is stored in a cental control facility therefrom to said interface device at said location upon excitation of the passive identification means of said person or object, and comparing said authorised bio-recognisable data with said sensed bio-recognisable data at said location.

26. An method as claimed in claim 25, wherein said data is prioritised time packaged metadata.