Method and apparatus for spread spectrum communications
First Claim
1. A method for communicating between a first station and a second station over a plurality of communication channels, the first station including a first transmitter and a first receiver and the second station including a second transmitter and a second receiver, the second receiver at the second station sequentially monitoring each of the channels in the plurality of communication channels for communication signals transmitted by the first transmitter at the first station for a predetermined period of time, the method comprising the steps of:
- a) initiating the establishment of a link of communication channels between the first station and the second station, each of the communication channels of the link being characterized by a predetermined set of spread spectrum parameters, each parameter taking a value in a range of values such that the communication reliability of a communication channel changes monotonically as the value of the corresponding parameter changes from one extreme of the range to the other extreme of the range;
b) determining whether the link is established between the first station and the second station;
c) if the link is not established, broadcasting communication signals from the first transmitter to the second receiver over a first one of the plurality of communication channels for a period of time equal to the total period of time over which the second receiver monitors the channels in the plurality of communication channels;
d) if the link is not established after performing step c), changing one of the parameters in at least one of the predetermined sets of spread spectrum parameters at the first station and returning to step b);
e) if the link is established after performing step c), changing the one of the parameters in the at least one of the predetermined sets of spread spectrum parameters at the second station;
f) monitoring the spread spectrum parameters associated with each channel in the plurality of communication channels to determine which channel in the plurality of communication channels is characterized by spread spectrum parameters, at least one of which has a critical value that establishes a communication reliability that is the smallest possible greater than a predetermined communication reliability between the first station an the second station;
g) transmitting a communication signal from the first station to the second station, the communication signal including information identifying which channel in the plurality of communication channels has a spread spectrum parameter that has a critical value; and
h) causing the first and second transmitters and the first and second receivers to change to the channel in the plurality of communication channels that has the spread spectrum parameter that has a critical value.
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Accused Products
Abstract
A method and apparatus for providing spread spectrum communications. The apparatus starts with designated spread spectrum communications parameters, such as default transmitted power level, pseudo-noise (PN) sequence, PN sequence length, and frequency channel, having values which are chosen to ensure that spread spectrum communications can be carried out between a first station and a second station. The apparatus of the invention then changes the values of the spread spectrum communications parameters to the minimum values necessary to provide a given level of communications reliability. If the conditions facing the spread spectrum communication system change so that communications reliability falls below the given level, the apparatus resets the values of the spread spectrum communications parameters to the default levels and begins again to change their values to provide the given level of communications reliability. If the apparatus establishes that communications can reliably be carried out with narrowband communications techniques, the apparatus changes the parameters to provide narrowband communications at the minimum acceptable power level.
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Citations
23 Claims
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1. A method for communicating between a first station and a second station over a plurality of communication channels, the first station including a first transmitter and a first receiver and the second station including a second transmitter and a second receiver, the second receiver at the second station sequentially monitoring each of the channels in the plurality of communication channels for communication signals transmitted by the first transmitter at the first station for a predetermined period of time, the method comprising the steps of:
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a) initiating the establishment of a link of communication channels between the first station and the second station, each of the communication channels of the link being characterized by a predetermined set of spread spectrum parameters, each parameter taking a value in a range of values such that the communication reliability of a communication channel changes monotonically as the value of the corresponding parameter changes from one extreme of the range to the other extreme of the range; b) determining whether the link is established between the first station and the second station; c) if the link is not established, broadcasting communication signals from the first transmitter to the second receiver over a first one of the plurality of communication channels for a period of time equal to the total period of time over which the second receiver monitors the channels in the plurality of communication channels; d) if the link is not established after performing step c), changing one of the parameters in at least one of the predetermined sets of spread spectrum parameters at the first station and returning to step b); e) if the link is established after performing step c), changing the one of the parameters in the at least one of the predetermined sets of spread spectrum parameters at the second station; f) monitoring the spread spectrum parameters associated with each channel in the plurality of communication channels to determine which channel in the plurality of communication channels is characterized by spread spectrum parameters, at least one of which has a critical value that establishes a communication reliability that is the smallest possible greater than a predetermined communication reliability between the first station an the second station; g) transmitting a communication signal from the first station to the second station, the communication signal including information identifying which channel in the plurality of communication channels has a spread spectrum parameter that has a critical value; and h) causing the first and second transmitters and the first and second receivers to change to the channel in the plurality of communication channels that has the spread spectrum parameter that has a critical value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus for communicating between a first station and a second station over a plurality of communication channels, the first station including a first transmitter and a first receiver and the second station including a second transmitter and a second receiver, the second receiver at the second station sequentially monitoring each of the channels in the plurality of communication channels for communication signals transmitted by the first transmitter at the first station for a predetermined period of time, the apparatus comprising:
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means for initiating a link of communication channels between the first station and the second station, each of the communication channels of the link using a predetermined set of spread spectrum parameters, each parameter taking a value in a range of values such that the communication reliability of a communication channel changes monotonically as the value of the corresponding parameter changes from one extreme of the range of the other extreme of the range; means for determining whether the link is established between the first station and the second station; means for broadcasting communication signals from the first transmitter to the second receiver over a first one of the plurality of communication channels for a period of time equal to the total period of time over which the second receiver monitors the channels in the plurality of communication channels, if the link is not established; means for changing one of the parameters in at least one of the predetermined sets of spread spectrum parameters at the first station if the link is not established; means for changing the one of the parameters in the predetermined set of spread spectrum parameters in the at least one of the predetermined sets of spread spectrum parameters at the second station; means for monitoring the spread spectrum parameters associated with each channel in the plurality of communication channels to determine which channel in the plurality of communication channels is characterized by spread spectrum parameters, at least one of which has a critical value that establishes a communication reliability that is the smallest possible greater than a predetermined communication reliability between the first station and the second station; means for transmitting a communication signal from the first station to the second station, the communication signal including information identifying which channel in the plurality of communication channels has a spread spectrum parameter that has a critical value; and means for causing the first and second transmitters and the first and second receivers to change to the channel in the plurality of communication channels that has the spread spectrum parameter that has a critical value. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. An apparatus for communicating between a first station and a second station over a plurality of communication channels, the second receiver at the second station sequentially monitoring each of the channels in the plurality of communication channels for communication signals transmitted by the first transmitter at the first station for a predetermined period of time, the first station including a first transmitter and a first receiver and the second station including a second transmitter and a second receiver, the apparatus comprising:
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a first circuit to initiate a link of communication channels between the first station and the second station, each of the communication channels of the link being characterized by a predetermined set of spread spectrum parameters, each parameter taking a value in a range of values such that the communication reliability of a communication channel changes monotonically as the value of the corresponding parameter changes from one extreme of the range to the other extreme of the range; a second circuit to determine whether the link is established between the first station and the second station; a transmitter circuit to broadcast communication signals from the first transmitter to the second receiver over a first one of the plurality of communication channels for a period of time equal to the total period of time over which the second receiver monitors the channels in the plurality of communication channels, if the link is not established; a third circuit to change one of the parameters in at lest one of the predetermined sets of spread spectrum parameters at the first station if the link is not established; a fourth circuit to change the one of the parameters in the at least one of the predetermined sets of spread spectrum parameters at the second station; a fifth circuit to monitor the spread spectrum parameters associated with each channel in the plurality of communication channels to determine which channel in the plurality of communication channels is characterized by spread spectrum parameters, at least one of which has a critical value that establishes a communication reliability that is the smallest possible greater than a predetermined communication reliability; a first transmitter circuit to transmit a communication signal from the first station to the second station, the communication signal including information identifying which channel in the plurality of communication channels has a spread spectrum parameter that has a critical value; and a sixth circuit to cause the first and second transmitters and the first and second receivers to change to the channel in the plurality of communication channels that has the spread spectrum parameter that has a critical value. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
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Specification