Title: Communication System The present invention relates to a communication system.
When a parent or guardian is out in public places with one or more children, it can be difficult to allow children freedom to move around without fear of them becoming lost or abducted.
Similarly when skiing, children can become lost from their parent or guardian.
It has been know to provide a device which senses when a child moves away from a parent or guardian more than a predetermined distance. Such a device may typically comprise a GPS and receiver in a master unit worn by the parent or guardian, and a GPS and transmitter in a slave.
unit worn by a child. The slave unit transmits the child's position to the master unit which sends off an alarm when a child moves away from a parent or guardian more than a predetermined distance. A problem with such devices is that they do not allow the parent or guardian to communicate with a child, and the slave unit can easily be removed from a child by an abductor.
The invention seeks to provide a communication device which avoids the above difficulties.
According to the present invention there is provided a communication system comprising: a) a master unit adapted to be worn by a first person, b) at least one slave unit each adapted to be worn by a second or other persons, c) proximity sensor circuit means in the master unit and the or each slave unit to generate an alarm signal in the master unit when the distance between a master unit and slave unit is more than a predetermined distance, and d) voice communication circuit means in the master unit and the or each slave unit to allow voice communication between the master unit and slave units, in use the master unit alerting the first person when the distance between the first person and a second or other person is more than a predetermined distance, and the device allowing voice communication between the first person and a second or other person.
Preferably the voice communication circuit means allows voice communication between two or more persons with slave units. Preferably the voice communication circuit means includes a termination tone to advise the receiver of a voice communication that the sender of a voice communication has finished speaking.
Preferably the device includes alert circuit means in the master unit and each slave unit to allow a person with a master unit to attract the attention of a person with a slave unit or vice versa. The alert circuit means may include a noise generator or vibrator. The noise generator may be a tone or melody.
Preferably the proximity sensor circuit means in the or each slave unit transmits a code at regular intervals and an alarm signal is generated in the master unit if the transmitted code received signal strength falls below a predetermined level providing an indication of the distance between a master unit and slave unit.
Preferably the proximity sensor means and voice communication circuit means in a master unit and first and second slave units allow voice communication between the master unit and two or more slave units, but allows the master unit to sense when the distance between a master unit and first slave unit is more than a predetermined distance independently of when the distance between a master unit and second slave unit is more than a predetermined distance. The proximity sensor means and voice communication circuit means in a master unit and first and second slave units may include digital coding squelch system to pair a master unit and slave unit on a frequency channel.
Preferably the master unit and the or each slave unit is housed in a housing with a wrist strap so that a master unit and a slave unit can be worn on the wrist. The master unit and slave unit may further comprise a time display optionally with a time alarm. Preferably the or each slave unit includes a sensor to generate an alarm signal for the master unit if the slave unit is removed from a person, such as from a person's wrist. Preferably the housing has a removable face plate whereby interchangeable face plates can be provided to change the cosmetic appearance of the master unit and/or the or each slave Unit.
The master unit and the or each slave unit may include a GPS.
The master unit and the or each slave unit may include SMS type messaging communication.
An embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 shows a perspective view of a master and slave unit, and Figures 2A,2B,2C,2D show circuit diagrams.
Referring to Figure 1 there is shown a communication system 1.
System I comprises a master unit 1OA adapted to be worn by a first a first person, such as a parent or guardian, and at least one slave unit lOB adapted to be worn by a second or other persons, such as children. Master unit IOA is identical to slave unit lOB in appearance but both their functions in use are different.
Master unit 1 OA and slave unit I OB look similar to a watch and has a housing 11. A wrist strap, to secure housing 11 to a wrist, is formed from two straps 12A,12C, A buckle 12B is provided at a free end of strap 12A, and apertures 12D are provided in strap 12C to engage with the buckle 12B.
An aerial 13 is provided which can rotate relative to the housing so it is either in a discrete first position adjacent strap 1 2A as shown, or can be raised to a second position projecting away from housing 11 to improve its transmission and reception performance.
A display screen 14 is provided on housing 11 along with six control buttons 15A,15B,15C,15D,15E,15F. A microphone and loudspeaker 16 is also provided in the housing.
Display screen 14 displays the time and other information as required, e.g. relating to the function of the unit 1 OA, 1 OB or messages.
Housing 11 has a removable face plate 17 whereby interchangeable face plates can be provided to change the cosmetic appearance of the master unit and/or the or each slave unit. For example the face plates could support images of cartoon characters for children or different colours for male and female parents and guardians.
A sensor in the form of a spring loaded finger 18 is depressed when the housing 11 is placed on a wrist. If the unit 1OA or lOB is removed (e.g. by an unauthorised third party or a child wanting to remove a unit from the wrist), the finger can spring up as shown and will generate an alarm signal for the master unit through circuit 1 8A. The alarm signal will ensure an audible or other alarm is delivered to the wearer of the master unit lOA, e.g. through speaker 16. Such an alarm signal generated by a slave unit lOB will be transmitted to and received by the master unit IOA. This ensures that a parent or guardian knows that a child is wearing a slave unit unless an alarm is delivered.
A proximity sensor circuit means 19 is provided in the master unit 1OA and the or each slave unit lOB to generate an alarm signal in the master unit when the distance between a master unit and slave unit is more than a predetermined distance. The alarm signal will ensure an audible or other alarm is delivered to the wearer of the master unit bA, e.g. through speaker 16. The proximity sensor circuit means 19 in the or each slave unit transmits a code at regular intervals and an alarm signal is generated in the master unit if the transmitted code received signal strength falls below a predetermined level providing an indication of the distance between a master unit and slave unit.
Voice communication circuit means 20 in the master unit and the or each slave unit to allow voice communication between the master unit and slave unit. The voice communication circuit means 20 allows voice communication between two or more persons with slave units. Also the voice communication circuit means 20 includes a termination tone to advise the receiver of a voice communication that the sender of a voice communication has finished speaking.
The proximity sensor circuit means 19 and voice communication circuit means 20 in a master unit and first and second slave units allow voice communication between the master unit and two or more slave units, but allows the master unit to sense when the distance between a master unit and first slave unit is more than a predetermined distance independently of when the distance between a master unit and second slave unit is more than a predetermined distance. The proximity sensor means and circuit means in a master unit and first and second slave units may include digital coding squelch system to pair a master unit and slave unit on a frequency channel. This allows the wearer of the master unit to be advised if the particular wearer of a slave unit has wondered off more than a predetermined distance whilst still allowing voice communication between a master unit and all slave units.
An alert circuit means 21 in the master unit and each slave unit to allows a person with a master unit to attract the attention of a person with a slave unit or vice versa. The alert circuit means may include a noise generator or vibrator. The noise generator may be a tone or melody.
in use the master unit alerts the wearer of the master unit when the distance between the first person and a second or other person is more than a predetermined distance. The voice communication circuit means 20 allows voice communication between the first person and a second or other person.
It is envisaged that the device may be used by a parent (or guardian) looking after say four children, e.g. in a public venue like a theme park. The parent would wear the master unit and each child would wear a slave unit. Buttons 15A,15B,15C secured to appropriate circuitry would be used to select whether a unit was a master or slave unit and give each slave unit a unique code readable by the master unit.
In normal use the parent can each communicate freely with each other using the microphone and speaker 16 and the voice communication circuit means 20. If desired the aerial can be moved to the second position.
If one child should stray more than a predetermined distance away form the parent, the parent would be advised which child as each slave unit has its unique code. The parent can immediately have voice communication with that child if desired.
If a parent wants to contact a child and that child does not respond to a voice communication, the parent may use the alert circuit means to alert a given child.
Because each slave unit has its unique code a parent can be selective in communicating with or alerting a given child whilst still allowing voice communication between all wearers of master and slave units.
The master unit and the or each slave unit may include a GPS to allow a parent to receive a GPS position of a child.
Also the master unit and the or each slave unit may include SMS type messaging communication to allow parent and children to "text each other".
In addition to displaying the time, each unit may include a time alarm. This feature is useful, for example, to set as a reminder of a meet-up time.
A circuit is shown in Figures 2A to 2E and the master and slave unit1s may operate as follows with each unit being referred to as a "Talkie".
The invention may take a form different to that specifically described above or below.
Further modifications will he apparent to those skilled in the art without departing from the scope of the present invention.
1. Radio Specifications.
1.1 Operating Frequency Band: PMR446 as detailed in UK Interface Requirement 2009' 1.2 Output Power: Maximum Effective Radiated Power 500mW (maximum allowed under PM1R446 specification) Anticipated range up to 3km in open field situation, reducing depending on obstructions.
1.3 Operating Frequencies: There are 8 frequency channels for PMR446: Channel 1. 446.0062 5 Channel 2. 446.01875 Channel 3. 446.03 125 Channel 4. 446.04375 Channel 5. 446.05625 Channel 6. 446.06875 Channel 7. 446.08125 Channel 8. 446.09375 1.4 Channel Coding.
Channel coding will be by a Digitally Coded Sub-audio signal with 26 code pairs split to facilitate 2 wander off alarms.
With 8 frequency channels and 26 codes there will be 208 unique combinations.
1.5 Wander Off alarm.
Child units will transmit their code for 0.25 seconds every 10 seconds, Parent units will monitor received signal strength and frequency of coded transmissions.
1.6 Remove alarm.
II
Child units will sound an alarm and send an alarm message to the Parent unit if they are removed. To facilitate this a switch will detect when the Child unit is being worn.
2. Electrical Specifications.
Rechargeable Lithium Ion battery power with recharging socket.
Recharge time approx 6 hours.
Battery Life greater than 24 hours in standby, 2 hours of talk time.
Recharge power supply 200mA 6V, CE marked.
3. Construction, Display and Controls.
Talkie' has 6 buttons: On/Off (0/I) Menu Adjust up (+) Adjust down (-) Talk/OK AlertlAlarm Display is backlit, the display lights when any key is pressed and remains lit for 5 seconds afterwards.
Talkie' will be splash proof but not waterproof.
Built in aerial with adjustable direction.
Switch to detect if Talkie' is removed.
Approximate dimensions as Talkie' layout figure.
4. Operation.
See Talkie' layout and sample displays also.
4.1 Charging the battery.
The mains adaptor is used to charge the Talkie' battery. When the charger is connected the battery symbol will flash until charging is complete at which time it will stop flashing.
As the battery is used the bars in the battery symbol will extinguish one by one indicating the remaining capacity of the battery. When the battery is close to running out the battery symbol will start to flash.
When the radio section is off the battery usage is minimised. When the radio is on more power is consumed. When the radio is receiving a signal and sounds are being heard the battery consumption is higher, likewise when the Talk button is pressed or VOX causes radio transmission the battery consumption is higher.
4.2 Time display.
When Talkie' is first powered the radio section will be off and the display will show the starting time of 00:00 Talkie' will usually show the time whether the radio section is on or off. During certain functions the time display will be used to show other items but the internal clock will continue to run.
4.2.1 Time adjust.
To adjust the time with Talkie' radio section turned off: * Press the Menu button for 2 seconds until the hours start flashing.
* Adjust the hours using the + and -buttons, when correct press the Menu button to store the hours and the minutes will start flashing.
* Adjust the minutes using the + and -buttons, when correct press the Menu button to store the minutes and Talkie' returns to normal use.
4.3 Clock alarm function.
Talkie' has an alarm feature which can be set to sound at any time of day. This feature is useful, for example, to set as a reminder of a meet-up time.
When the alarm time is reached Talkie' will beep, with the alarm icon flashing, until the Alarm button is pressed to cancel it.
The alarm feature works whether the radio section is on or off.
4.3.1 Setting the Alarm.
To adjust the alarm time with Talkie' radio section turned off: * Press the Alarm button for 2 seconds and the alarm icon will show and the hours start flashing. The initial time in the alarm will be the same as the last alarm that was set.
* Adjust the alarm hours using the + and -buttons, when correct press the Alarm button to store the hours and the minutes will start flashing.
* Adjust the alarm minutes using the + and -buttons, when correct press the Alarm button to store the minutes and return to normal use.
The alarm icon will be on to show that the alarm is active.
4.3.2 Un-setting the Alarm.
To unset the alarm with Talkie' radio section turned off: * Press the Alarm button for 2 seconds and the alarm icon will clear.
* The Talkie' will return to normal use.
The alarm icon will now be off to show that the alarm is not active.
4.4 Turning on the radio section.
When Talkie' is in standby, with the radio section turned off, the display will show the time, the battery level and PARENT or CHILD.
The radio section is turned on and off using the 0/I button as follows: * Press and hold the 0/I button for 2 seconds to turn the radio section on or off. When the radio turns on or off the time display will show On or Off for 2 seconds to confirm.
When the radio section is on the display will show the radio channel plus code and the radio speaker volume as well as the time, battery level and PARENT or CHILD plus A or B. 4.5 Setting the radio channel and code The radio channel and code are set when the Talkie' radio section is turned on as follows: * Press the Menu button briefly (less than 2 seconds), Cl-IAN is displayed in the time area and the channel number will start flashing.
* Adjust the channel using the + and -buttons, when correct press the Menu button to store the channel.
* CODE is displayed in the time area and the code number will start flashing.
* Adjust the code number using the + and -buttons, when correct press the Menu button to store the channel and return to normal operation.
The channel number is the PMR446 radio frequency channel between 1 and 8.
The code number is the Digital Coded Squelch code and is between 0 and 26 with A or B designation. Code 0 is a unique code which tells the radio section to ignore the coding and therefore any radio transmission on the chosen channel will be heard independent of any coding it has. When code 0 is selected a Parent Talkie' will not monitor for wander off alarm signals and a Child Talkie' will not transmit any wander off alarm signals.
A Parent Talkie' will show only the code number between 0 and 26 whilst a Child Talkie' will show the code number plus the A or B designation. The A or B designation is used to allow a Parent Talkie' to monitor two different Child Talkies' for Wander Off alarm whilst still allowing talking between all three.
4.6 Communicating using the radio.
To communicate using the radio all Talkie' radio sections have to be on and all must be on the same frequency and code.
To transmit press and hold the Talk button whilst speaking. When talking is finished release the Talk button and Talkie' resumes monitoring allowing others to respond.
When Talkie' is transmitting the TX icon is displayed and when receiving the RX icon is displayed.
If VOX control is set then Talkie' transmits as soon as speaking starts and stops transmitting 2 seconds after speaking stops. When VOX control is active the VOX icon is displayed and the TX icon displays when transmission activates. See VOX control (section 4.11.1) for further instructions.
Talkie' incorporates squelch so that during normal use static hiss is not heard when there is no radio signal being received. This can be overridden using the monitor function (section 4.10).
If the receiving person does not respond to talking, perhaps because of background noise, then the transmitting person can send an Alert ring melody to the receiver. Briefly press the Alert/Alarm button and Talkie' will send the Alert signal, which lasts about 2 seconds, at maximum volume to the receivers. The receiving person can then answer. The ring melody can be changed from the radio menu (section 4.11.2) so that different Talkies' can be identified.
4.7 Adjusting the radio volume.
The volume of the radio speaker can be adjusted. Even on minimum volume the radio will still be audible.
To adjust the volume with the Talkie' radio section turned on press the + button to increase the volume or the -button to reduce the volume. The volume of the speaker is shown by the volume level bars.
4.8 Wander Off Alarm Each Talkie' can be set to be a Parent or a Child unit under the radio menu (section 4.11.5).
When set as a Parent unit it monitors the wander off signals of Child units checking that they are suitably strong and that they are regularly received. When Talkie' is a Child unit it sends wander off signals at regular intervals (0.25 seconds of transmission every 10 seconds). If the Parent Talkie' finds that signals are missing or weak then it will sound an alarm and display ALM' in the time area. Parent and Child units must be set to the same frequency and code for the wander off alarm to work.
If the wander off alarm sounds the parent can use the Talkie' radio to call their children by pressing the Talk button which will also reset the alarm for a short while to allow parent and child to meet up. If the radio signal remains missing or weak then the alarm will sound again.
The Wander Off alarm sensitivity can be adjusted under the radio menu (section 4.1 1.6). The setting should be adjusted to suit the environment and circumstances. With the sensitivity set high the alarm will sound when the child moves a short way away whilst with low sensitivity the child can go further before the alarm sounds. If Talkie' is being used in an area with obstructions then the range will be shorter than when it is being used in an open area so the sensitivity can be adjusted to suit if needed.
The Wander Off alarm can be turned off by setting the sensitivity to OF.
4.9 Scanning radio channels.
Talkie' can be set to scan the 8 frequency channels to check for other transmissions. This might be useful to help choosing which channel to select at busy times. When scanning codes are ignored, Talkie' just checks for any transmissions on the channel.
Scanning is initiated as follows: * Press Talk and + buttons at the same time. Talkie' will start scanning the 8 channels one at a time, monitoring each channel for a fraction of a second. During scanning the time display will show SCAN and the channel display will show the number of the channels as they are scanned. If a signal is received the scanning will pause to monitor the signal and continue scanning again 2 seconds after the transmission ceases.
* When Talk or Menu button is pushed Talkie' will stop scanning and revert to the programmed channel and code.
4.10 Monitoring radio channel.
Talkie' can be set to monitor the set channel with squelch suppressed and the code ignored. This way any weak transmissions on that channel can be heard. This might be useful if a Talkies' are at long range or the signal is weak due to obstructions. If there are no transmissions on the channel then just background static hiss will be heard.
Monitor is initiated as follows: * Press Talk and -buttons at the same time. Talkie' will start monitoring the channel.
During monitoring the time display will show MON and the channel display will show the number of the channel.
* When Talk or Menu button is pushed Talkie' will stop monitoring and revert to the programmed channel and code.
4.11 Radio setting menu.
A number of settings can be adjusted under the radio settings menu. To change the settings, with Talkie' radio section turned on, press and hold the Menu button for 2 seconds to access the first item on the menu. To move from one menu item to the next briefly press the Menu button again or to exit from the menu after changing an item press the Talk button.
4.11.1 VOX control setting.
When adjusting the VOX control setting Vo' is displayed in the hours area and the VOX sensitivity (OF or I to 7) is flashing in the minutes area.
Adjust the VOX setting using the + and -buttons, when correct press the Menu or Talk button to store the setting.
A setting of OF turns off the VOX control, whilst a setting of I is the least sensitive increasing to a setting of 7 which is the most sensitive.
Adjust the setting to suit the environment, if Talkie' transmits due to background noise then reduce (he sensitivity, if Talkie' is slow to start then increase the sensitivity.
The VOX icon will be displayed when the radio section is switched on and a setting of I or more has been chosen.
4.11.2 Alert melody setting.
When adjusting the Alert melody setting AL' is displayed in the hours area and melody number (1 to 4) is flashing in the minutes area.
* Choose the Alert melody using the + and -buttons, when + or -is pressed the new melody is played for the user to hear. When the desired Alert melody is set press the Menu or Talk button to store the setting.
There are 4 melodies to choose from and this enables each user to have their own identification.
4.11.3 Roger Beep setting.
When adjusting the Roger Beep setting rb' is displayed in the hours area and ON or OF is flashing in the minutes area.
* Use the + and -buttons to turn the Roger Beep on or off. When the setting is right press the Menu or Talk button to store the setting.
When Roger Beep is on Talkie' adds a beep-beep tone to the end of every transmission to let the listeners know that they may now transmit. When Roger Beep is off no sound is added and the talker is, by convention, expected to say over' to indicate that they have finished.
4.11.4 Key Tone setting.
When adjusting the Key Tone setting to' is displayed in the hours area and ON or OF is flashing in the minutes area.
* Use the + and -buttons to turn the Key Tone on or off. When the setting is right press the Menu or Talk button to store the setting.
When Key Tone is on every time a key is pressed Talkie' gives a short beep, when off no beeps are made, key presses are silent.
4.11.5 ParentlChild setting.
When adjusting the Parent/Child setting PC' is displayed in the hours area and P for parent or C for child is flashing in the minutes area, the PARENT or CHILD icon is also flashing * Use the + and -buttons to change the Parent/Child setting. When the setting is right press the Menu or Talk button to store the setting.
When Talkie' is a Parent unit it monitors the wander off signals, when Talkie' is a Child unit it sends wander off signals (section 4.8).
4.11.6 Wander Off sensitivity setting (Parent unit only).
When adjusting the Wander Off sensitivity setting SE' is displayed in the hours area and the sensitivity (OF or 1 to 7) is flashing in the minutes area.
* Adjust the Wander Off sensitivity setting using the + and -buttons, when correct press the Menu or Talk button to store the setting.
A setting of OF disables the wander off alarm, whilst a setting of us the least sensitive increasing to a setting of 7 which is the most sensitive.
4.12 Removal Alarm.
Each Talkie' can be set to be a Parent or a Child unit under the radio menu (section 4.11.5).
When Talkie' is a Child it will sound an alarm and send out an alarm message if it is removed from the wrist. The alarm will stop when the Talkie' is put back on. The Parent unit will receive the alarm signal and display rALM' in the time area. Parent and Child units must be set to the same frequency and code for the removal alarm to work.