Communication protocol between a transceiver unit and transponders or transceivers associated with said unit

• US 6,470,045 B1
• Filed: 09/10/1998
• Issued: 10/22/2002
• Est. Priority Date: 09/11/1997
• Status: Expired due to Term

• Current Assignee: EM Microelectronic - Marin SA (The Swatch Group AG)
• Original Assignee: EM Microelectronic - Marin SA (The Swatch Group AG)
• Inventors: Fuentes, Vincent
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Bayard, Emmanuel
• Application Number:
  US09/151,803
• Time in Patent Office: 1,503 Days
• Field of Search: 375/219, 375/220, 375/222, 370/282, 370/299, 455/463, 455/524, 455/39, 455/73, 455/88, 455/552, 455/575, 455/90, 340/901, 340/933
• US Class Current: 375/220
• CPC Class Codes: H04L 65/40 Support for services or applications
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04L 7/06 the synchronisation signals differing from the information signals in amplitude, polarity or frequency or length

Abstract

The communication protocol between at least one transceiver unit (communication unit) and transponders or transceivers (transponders) associated with said unit is characterised in that at least one initial command is sent by said unit to generate interaction with said transponders entering its field of action, said initial command having at least partially a coding with a specific time structure which is different from the basic time structure used for encoding said coded data. The specific time structure has greater coding time periods than the coding time periods of the basic time structure. At least one coding period of the specific time structure has a constant characteristic electric value over a time interval greater than the duration of said constant characteristic electric value able to appear in any bit sequence having the basic time structure.

Claims

1. A method of providing communication between at least one electromagnetic signal transceiver unit and transponders or transceivers associated with said unit and arranged for receiving from said unit at least one initial command and for exchanging coded data other than commands with said unit, said method comprising the steps of:

sending said at least one initial command, by said transceiver unit, to generate interaction or to establish communication with said transponders or transceivers entering a field of action of said unit; and

encoding said at least one initial command at least partially with a coding having a specific time structure which is different from a basic time structure used for encoding said coded data.

2. The method according to claim 1, wherein the type of coding used with said specific time structure and said basic time structure is the same, a transitions, provided between a high level and a low level of the electromagnetic coding signal exchanged between said transceiver unit and said transponders or transceivers, being identical for characterising a <

<

0>

>

bit and a <

<

1>

>

bit.

3. The method according to claim 1, wherein said initial command has said specific time structure at least in the initial portion thereof.

4. The method according to claim 1, wherein all the commands sent by said transceiver unit each have at least partially a coding with said specific time structure.

5. The method according to claim 4, wherein all of said commands each have said specific time structure at least in the initial portions thereof.

6. The method according to claim 4, wherein all of said commands are coded with said specific time structure.

7. The method according to claim 5, wherein all of said commands are coded with said specific time structure.

8. The method according to claim 1, further comprising the step of choosing said specific time structure to have a coding time period different from the coding time period of said basic time structure.

9. The method according to claim 8, wherein the coding time period of said specific time structure is greater than the coding time period used in said basic time structure.

10. The method according to claim 9, wherein during at least a first coding time period, said specific time structure has a characteristic electric value which is constant over a time interval greater than all the lengths of time of said characteristic electric value able to appear in any bit sequence with said basic time structure.

11. The method according to claim 10, wherein said time interval is greater than or equal to 2.5 times the coding time period of said basic time structure.

12. The method according to claim 10, wherein said characteristic electric value corresponds to a low level of the electromagnetic coding signal for the commands and data exchanged between said transceiver unit and said transponders or transceivers.

13. The method according to claim 11, wherein said characteristic electric value corresponds to a low level of the electromagnetic coding signal for the commands and data exchanged between said transceiver unit and said transponders or transceivers.