NETWORK FIELD OF INVENTION:

The present invention relates to improved teleclock receiver utilizing mobile telephone network. More particularly, present invention relates to an improved process using microcontroller to receive data from GPRS modem with data enabled SIM card. The time service via telephone line, Teleclock Service for users who demand a low accuracy (say of order of few seconds) time, is very useful but requires a physical landline connection. An improved Teleclock receiver makes use of Mobile Telephone network instead of landline telephone network.

BACK GROUND AND PRIOR ART:

Time service via telephone has been started to serve the need of users who are happy to have time within few seconds' accuracy. The time service via telephone line is named as Teleclock Service. For users who demand a low accuracy (say of order of few seconds) time, the service via telephone line is very useful. A wired connection (as the name implies) requires a physical wire to be pulled to the desired location of the network jack. The major drawback of telephone, which required a physical landline connection in order to communicate, is now resolved by mobile telephone network. Hence an improved Teleclock receiver makes use of Mobile Telephone network instead of landline telephone network. The landlines phone requires a twisted pair cable from the telephone exchange to our home and it is a fixed location phone once installed it can be used from that location only while the mobile phone can be used while moving. Hence now National Standard Time can be accessed anywhere without any wired landline telephone line which is very useful.

The same transmitting set up is used for the normal landline Teleclock system and for Mobile Teleclock. The only change is in the receiver model of Teleclock. The improved Teleclock receiver receives data through wireless mobile telephone network.

The receiver has the provision of dialing the telephone number of the line dedicated for this service manually by pressing a switch or automatically at a pre programmed time.

The frequency of automatic dialing is normally once in a day but may be increased or decreased on the user's demand. Through dialing, the receiver receives the data corresponding to the "ST'V sets its own time accordingly and disconnects itself. The frequency of the crystal oscillator is so accurate that by dialing once in a day, the receiver may maintain the time Within few seconds of "ST" always without any telephone line connection. And hence even if the users are remotely located with no telephone line connection can now get "ST" wirelessly. The users who are located outside Delhi, and want to avail Teleclock Service, are not able to dial Teleclock transmitter number unless and until they have STD facility enabled in their instrument. No such additional facility is required in Mobile Teleclock receiver. Reference may be made to United States Patent No. 6,091,804, titled: Device useful as a master/slave clock for transmitting standard time over a telephone network and a telephone network incorporating the device for transmitting and receiving standard time wherein disclosed is a device capable of transmitting or receiving time data in the master clock or slave clock modes respectively over standard telephone networks is a microprocessor based system with an independent clock and a time display unit. In the slave clock mode, the device can automatically dial the master clock to have its time corrected. This is a complete transmitter and receiver set. This device is an extension of the receiver model mentioned in above patent. In the previous patent (referring patent # 6,091,804, figure 4), receiver side has a master/slave clock (block 8) which is connected to telephone network via a modem (referring patent # 6,091,804, block 9). The improved Teleclock receiver has a REAL TIME CLOCK CHIP (RTC chip), a microcontroller chip and a Wireless modem (refer figure 4). In the previous patent (referring patent # 6,091,804, figure 5), flow chart of the main program is shown which is improved to a great extent. Initialization of GPRS modem, option for either manual or automatic dialing teleclock transmitter number is not provided in the previous patent, Teleclock receiver tries to connect with Teleclock transmitter for a maximum number of 5 times and not for any unknown wait period as done in the previous patent, moreover the reliability of received data is checked which is not done in the previous patent # 6,091,804 of Teleclock. The setting RTC time and displaying the Standard Time ("ST") is also not done in the previous patent.

The drawback of the earlier system is that it needs a physical connection to a telephone line to receive "ST". From the hitherto known prior art it is seen that there is a definite need to provide improved Teleclock receiver utilizing mobile telephone network.

OBJECTS OF THE INVENTION:

The main object of the present invention is to receive national Standard Time ("ST") without landline telephone connection which obviates the drawback of the hitherto known prior art as detailed above.

Another object of the present invention is to make national Standard Time ("ST") available in moving vehicles and any such systems where landline telephone connection is not possible.

Yet another object of the present invention is to dial the teleclock transmitter number either manually or automatically, once a day or depending upon the user's request. Still another object of the present invention is to confirm the correctness of received data and to select only the confirmed data.

SUMMARY OF THE INVENTION:

Accordingly, the present invention provides an improved Teleclock receiver utilizing mobile telephone network , referred to fig. 2 comprising combination of 11 blocks, wherein block 4 represents GPRS modem, which receives signals via its antenna as an input, the output of the block 4 being connected to block 5 which represents the converter circuit for conversion of serial signals to TTL signals and vice versa signal conversion, the output of block 5 being TTL signal connected to block 6 which is a microcontroller IC programmed by software, said Block 6 (microcontroller) accessing data from block 7 which is a real time clock chip which receives input signals from block 6, block 8 being an EEPROM IC, its output being an input to block 6 and vice versa, block 9 being control switch of modem controls the operation of Block 4 (GPRS modem) receives input from block 6 (microcontroller) and block 14 which is a modem power supply, output of block 9 being connected to block 4 (GPRS modem), again output of block 6 being connected to inputs of block 11 (status indicator) and block 12 (display unit), block 10 providing optionally push button switches for manual inputs being connected to block 6 (microcontroller) and block 13 representing power supply circuit being connected in parallel to blocks 5,6,7,8, 10, 11 andl2. In one embodiment of the present invention, characterized in the central processing unit used is a microcontroller

In yet another embodiment of the present invention, characterized in the microcontroller is used to receive data from GPRS modem with data enabled SIM card.

In yet another embodiment of the present invention, characterized in the GPRS modem is used to receive the time data from teleclock transmitter. In yet another embodiment of the present invention, wherein the software is embedded in the microcontroller programmed by a computer Language comprising the steps of:

a. turning the power on;

b. turning the modem switch on glows the modem LED after power is turned on;

c. Initializing the GPRS modem after modem is turned on and setting the counter to zero (0);

d. pressing switch for dialing or automatic dialing request is read on a display unit (provision of automatic dialing once in a day which can be programmed is available);

e. checking whether connection of receiver with teleclock transmitter is established or not via GPRS modem;

f. receiving time data via GPRS modem from teleclock transmitter when connection is established and "connect" LED glows;

g. checking reliability of received time data;

h. updating Real Time Clock chip (RTC) time with the received time data after successful reliability check;

i. displaying national "ST" by receiver and disconnecting the modem; j. in case connection is failed establishment in step (e) with teleclock transmitter then increasing counter by 1 further checking if dial is less than 5,

k. going back to step (e) when counter is less than 5;

1. displaying connection "failed" in the display unit when counter is not less than 5 further disconnecting the modem; m. discarding the current data and again dialing the teleclock transmitter when failing the reliability check on received data.

In yet another embodiment of the present invention software used is capable of deciphering correct data particularly in the presence of noise which is prevalent in the signal through GPRS modem.

In yet another embodiment of the present invention the software used is capable of setting the REAL TIME CLOCK Chip with the received data.

In yet another embodiment of the present invention the EEPROM (Block 8) used contains the software as main program comprising the steps as given in claim 5 for the receiver by enabling the initializing process, setting the time if required, activating the interrupts and thereafter receiving the data checking for locking if required.

In yet another embodiment of the present invention a mobile telephone network is being used for receiving standard time comprising of mobile Teleclock receiver which is being connected wirelessly to said mobile telephone network through a GPRS modem.

In yet another embodiment of the present invention the RTC Chip (1) sets its time according to Standard Time ("ST") received which is controlled by microcontroller IC (3), GPRS modem (2) dials Teleclock transmitter number and receives data of corresponding standard time and gives it to microcontroller IC (3) which decoded the information and sets Real Time Clock of mobile Teleclock for display.

In yet another embodiment of the present invention the converter circuit for conversion of serial signals to TTL signals and vice versa converts the serial data from modem (4) into TTL signals compatible to the microcontroller IC(6) and vice versa.

In still another embodiment of the present invention the microcontroller IC (6) controls the RTC (7), EEPROM (8), Status Indicators (11), Display Unit (12) and modem control switch (9). When RTC (7) is set, microcontroller (6) disconnects modem (4) by sending a signal to control switch (9) of modem. In still another embodiment of the present invention the switches (10) are used to provide manual input to microcontroller IC (6).

In still another embodiment of the present invention the display unit is combination of LED and LCD display. These are used to display the current time and the status of different mode of operation.

In still another embodiment of the present invention the power supply circuit provides regulated DC voltage to modem control switch (9) and a power supply circuit (13) being connected in parallel to converter circuit (5) for conversion of serial signals to TTL signals and vice versa, microcontroller (6), Real Time Clock Chip (7), EEPROM IC (8), input switches (10), status indicators block (11) and display unit (12).

BRIEF DESCRIPTION OF DRAWINGS:

Figure 1 represents the schematic block diagram of the concept of the improved

Teleclock receiver utilizing mobile telephone network.

Figure 2 represents the functional block diagram of the improved Teleclock receiver utilizing mobile telephone network.

Fig.3 represents the flowchart of the software, of improved teleclock receiver.

Fig.4 represents the comparison of present invention with prior art

Fig.5 represents the flowchart of the software of prior patent (patent no. 6091804)

DETAILED DESCRIPTION:

The improved Teleclock receiver is an inexpensive and advanced solution to access any country national Standard Time (ST) without any dedicated landline telephone connection. Novelty of the present invention has been in terms of receiving national Standard Time (ST) of any country without landline telephone connection, by using General Packet Radio Service (GPRS) Modem with Subscriber Identity Module (SIM) Card in "Data communication mode Enabled".

In the design of the system consists of three main blocks refer Fig.l Block 1 REAL TIME CLOCK CHIP (RTC CHIP), Block 2 (MODEM), Block 3 (MICROCONTROLLER), where (Block 3) microcontroller controls the operation of block 1 (RTC CHIP) and Block 2 (MODEM), the role of the GPRS modem & SIM card with "Data communication mode Enabled" is being key component which is one of the inventive steps of the invention. Also it is accompanied- with special software which is also one of the inventive steps.

The configured system being innovatively simple, the unit becomes inexpensive. In the present invention the improved Teleclock receiver receives data through wireless mobile telephone network refer fig.2 The receiver has the provision of dialing the telephone number of the line dedicated for this service manually by pressing a switch or automatically at a pre programmed time. The frequency of automatic dialing is normally once in a day but may be increased or decreased on the user's demand. Through dialing, the receiver receives the data corresponding to the national "Standard Time" (ST) of the day (in India Indian Standard Time (IST)), sets its own time accordingly, displays it and disconnects itself. In the design of the system consisting of 11 blocks, the role of microcontroller IC is critical being its key component which is one of the inventive steps of the invention. Again the use of Real Time Clock Chip (RTC chip) to set and display the time is an inventive step. Use of TRANSISTOR- TRANSISTOR LOGIC (TTL) to Serial converter IC which converts serial signals to TTL/CMOS (Complementary Metal Oxide Semiconductor Field Effect Transistor) signals and vice versa is an inventive step of the invention. An Electrically Erasable Programmable Read Only Memory (EEPROM) is used to store subroutine program to make the system more flexible is also an inventive step. Development of software to decipher correct data particularly in the presence of noise which is prevalent in the signal through GPRS modem is also an inventive step of present invention.

EXAMPLES:

Example 1: Successful Dialing through Manual Input

Based on working principal a prototype unit of the present invention was made and its working is described below:

Initially power is turned ON and Modem switch is also turned ON, Modem LED glows. The Mobile Teleclock displayed time: 12:31:03. Where as the NATIONAL STANDARD Time (ST) was 12:30:31.

After modem is properly initialized manually pressed Dial switch, Display showed: "12:30:33 Dial".

This is an input to microcontroller IC. Based upon the input microcontroller accesses data of real time clock chip and also calls a program stored in EEPROM. Then microcontroller sends TTL signals for dialing Teleclock transmitter number which are converted to serial mode by TTL to serial to TTL and vice versa converter circuit. These signals are fed to GPRS modem. GPRS modem now dials the number for getting connected to Teleclock transmitter.

When connection established, GPRS modem starts receiving data serially from Teleclock transmitter and connect LED glows. GPRS modem sends the data received to serial to TTL and vice versa converter circuit. This device converts serial signal into TTL signals compatible for microcontroller IC. Microcontroller again calls a program from EEPROM. Data is checked for its reliability. Data found reliable. So real time clock chip (RTC) is reset to the data received from Teleclock transmitter and this current time data signal is given to the display unit which displayed as: 12:30:42 nationaP'ST", which is same as Standard Time.

Then Microcontroller sends a control signal to modem switch to turn it OFF. Example 2: Unsuccessful Dialing through Manual Input

Again when manually dial (push button switch) is pressed, the time displayed by Mobile Teleclock was 13:11:28. This is an input to microcontroller IC. Based upon the input microcontroller accesses data of real time clock chip and also calls a program stored in EEPROM. Then microcontroller sends TTL signals for dialing Teleclock transmitter number which are converted to serial mode by TTL to serial to TTL and vice versa converter circuit. These signals are fed to GPRS modem. GPRS modem now dials the number for getting connected to Teleclock transmitter

It showed: "13: 11: 28 Dial "

Signal strength was very less.

So GPRS modem sends signals regarding "connection could not be established" to serial to TTL/CMOS and vice versa converter circuit. This device converts serial signal into TTL signals compatible for microcontroller IC. Microcontroller again calls a program from EEPROM and checks for the attempts made. Microcontroller tried five times to get connected with Teleclock transmitter. But when no connection was established between receiver and transmitter, microcontroller sends a control signal to modem switch to turn it OFF and sends control signal to display unit which After 45 seconds it displayed "13:12:13 Fail". Example 3: Successful Dialing through Automatic Input

The receiver system of the present invention is preprogrammed to dial teleclock transmitter number automatically once in a day (which can be changed as per user's requirement) Microcontroller generated a signal to dial teleclock transmitter number at the preprogrammed time which is 10:21:03.

Mobile teleclock dialed automatically

Display shows: "10:21:03 Dial"

Microcontroller accesses data of real time clock chip and also calls a program stored in EEPROM. Then microcontroller sends TTL signals for dialing Teleclock transmitter number which are converted to serial mode by TTL to serial to TTL/CMOS and vice versa converter circuit. These signals are fed to GPRS modem. GPRS modem now dials the number for getting connected to Teleclock transmitter.

When connection established, GPRS modem starts receiving data serially from Teleclock transmitter and connect LED glows. GPRS modem sends the data received to serial to TTL/CMOS and vice versa converter circuit. This device converts serial signal into TTL signals compatible for microcontroller IC. Microcontroller again calls a program from EEPROM. Data is checked for its reliability. Data found reliable. Real time clock chip (RTC) is reset to the data received from Teleclock transmitter and this current time data signal is given to the display unit.

Display shows: "10:21:16 Standard Time "ST".

Microcontroller sends a control signal to modem switch to turn it OFF.

The above examples are given by way of illustration of the improved Teleclock receiver utilizing mobile telephone network of the present inventions in actual practice and should not be constructed to limit the scope of the present invention

ADVANTAGES OF THE PRESENT INVENTION:

1. Teleclock receiver is equipped with Built in clock with 1 ppm crystal so that

Teleclock receiver does not differ by a second in 10 days.

2. This is a Microcontroller based system so that the system is reprogrammable.

3. It has inbuilt battery to maintain time even on power failure so that current time is not lost.

4. Synchronized within one second of nation's standard time "ST"

5. Built in GPRS modem. 6. Auto Dialing / Manual Dialing facility.

7. Serial output in RS 232C to drive slave clocks, IRIG B option may also be made available.

8. improved Teleclock receiver utilizing mobile telephone network should have GSM SIM card with "data communication mode enabled"

9. The service is flexible for any GSM service provider.

10. An Improved Teleclock receiver of the present invention will find a large industrial usage viz.

a) Police patrolling Vans

b) Personal Vehicles

c) Outstation Places where STD facility is not available

d) Remote Locations where telephone lines may not be available