Idle mode for digital subscriber line
First Claim
1. A method for implementing an idle mode in a digital subscriber line communication system, including the steps of:
- (a) generating an idle mode modulated symbol once for each idle mode;
(b) repeatedly transmitting the idle mode modulated symbol from a first modem to a second modem.
6 Assignments
0 Petitions
Accused Products
Abstract
A system and method for generating and repetitively transmitting a single modulated symbol during idle periods in user data in a digital subscriber line (DSL) communication system. The modulated symbol to be transmitted is selected such that its spectral properties match those of user data modulated symbols. For an asynchronous DSL system, and variants thereof, a preferred idle symbol is the "superframe" synchronization symbol. A separate modulated symbol would indicate the end of the idle state. In the preferred embodiment, the end-of-idle symbol is the idle symbol shifted by a 180° phase shift. In a preferred embodiment, the transmitter in a DSL modem would calculate the idle state modulated symbol once at the start of the idle period and then simply repeat this symbol until the end of the idle period, in which case the transmitter would invert the final idle symbol. At the receiver, an idle state modulated symbol detector and phase detector are implemented. Symbol detection can be performed in the time-domain for faster and easier detection, requiring little processing power. Upon detection of a 180° phase shift of the idle symbol, the receiver would exit the idle mode. The invention includes method, apparatus, and computer program implementations.
132 Citations
54 Claims
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1. A method for implementing an idle mode in a digital subscriber line communication system, including the steps of:
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(a) generating an idle mode modulated symbol once for each idle mode; (b) repeatedly transmitting the idle mode modulated symbol from a first modem to a second modem. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for implementing an idle mode in a digital subscriber line communication system, including the steps of:
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(a) providing data representing an idle mode modulated symbol once for each idle mode; (b) transforming such data into a single idle mode modulated symbol; (c) repeatedly transmitting the single idle mode modulated symbol from a first modem to a second modem during the idle mode. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method for implementing an idle mode in a digital subscriber line communication system, including the steps of:
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(a) generating an idle mode modulated symbol once for each idle mode; (b) repeatedly transmitting the idle mode modulated symbol from a first modem to a second modem; and (c) exiting the idle mode by transmitting an exit symbol from either modem to the other modem.
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18. A computer program, residing on a computer-readable medium, for implementing an idle mode in a digital subscriber line communication system, including instructions for causing a computer to:
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(a) generate an idle mode modulated symbol once for each idle mode; (b) repeatedly transmit the idle mode modulated symbol from a first modem to a second modem. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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26. A computer program, residing on a computer-readable medium, for implementing an idle mode in a digital subscriber line communication system, including instructions for causing a computer to:
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(a) provide data representing an idle mode modulated symbol once for each idle mode; (b) transform such data into a single idle mode modulated symbol; (c) repeatedly transmit the single idle mode modulated symbol from a first modem to a second modem during the idle mode. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33)
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34. A computer program, residing on a computer-readable medium, for implementing an idle mode in a digital subscriber line communication system, including instructions for causing a computer to:
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(a) generate an idle mode modulated symbol once for each idle mode; (b) repeatedly transmit the idle mode modulated symbol from a first modem to a second modem; and (c) exit the idle mode by transmitting an exit symbol from either modem to the other modem.
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- 35. Modem circuitry for implementing an idle mode in a digital subscriber line communication modem, the circuitry having a generator for generating an idle mode modulated symbol once for each idle mode and a coupled transmit circuit for repeatedly transmitting the idle mode modulated symbol when connected to a receiver modem.
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43. Modem circuitry for implementing an idle mode in a digital subscriber line communication modem, wherein the circuitry:
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(a) provides data representing an idle mode modulated symbol once for each idle mode; (b) transforms such data into a single idle mode modulated symbol; (c) repeatedly transmits the single idle mode modulated symbol to a coupled receiver modem during the idle mode. - View Dependent Claims (44, 45, 46, 47, 48, 49, 50)
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51. A modem circuit for implementing an idle mode in a digital subscriber line communication modem, including circuitry for:
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(a) generating an idle mode modulated symbol once for each idle mode; (b) repeatedly transmitting the idle mode modulated symbol from a first modem to a second modem; and (c) exiting the idle mode by transmitting an exit symbol from either modem to the other modem.
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52. A method for implementing an idle mode in a digital subscriber line communication system, including the steps of:
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(a) providing a non-time-varying idle mode symbol once for each idle mode; (b) repeatedly transmitting the single idle mode symbol from a first modem to a second modem during the idle mode.
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53. A computer program, residing on a computer-readable medium, for implementing an idle mode in a digital subscriber line communication system, including instructions for causing a computer to:
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(a) provide a non-time-varying idle mode symbol once for each idle mode; (b) repeatedly transmit the single idle mode symbol from a first modem to a second modem during the idle mode.
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54. Modem circuitry for implementing an idle mode in a digital subscriber line communication modem, wherein the circuitry:
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(a) provides a non-time-varying idle mode symbol once for each idle mode; (b) repeatedly transmits the single idle mode symbol from a first modem to a second modem during the idle mode.
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Specification