Method for sharing bandwidth using reduced duty cycle signals and media access control
A method is provided for transmitting data. A first device generates a first signal having a first duty cycle, comprising a first gated-on portion and a first gated-off portion in a time slot; and a second device generates a second signal having second duty cycle, comprising a second gated-on portion and a second gated-off portion in the same time slot. The first gated-on portion is generated during a first segment of the time slot and the first gated-off portion is generated during a second segment of the time slot, while the second gated-on portion is generated during the second segment and the second gated-off portion is generated during the first segment. Media access control (MAC) can be used to further define positions within time slots and provide error correction, power control, and the like. A preamble can be transmitted at an increased power level to facilitate acquisition.
1. A method for increasing signal power associated with a plurality of radio transmissions from a plurality of ultra wideband (UWB) transmitters operating in accordance with a UWB protocol, the method comprising:
dividing a transmission period into a plurality of superframes;
dividing each of the superframes into a plurality of regular time slots;
dividing each of the plurality of regular time slots into a plurality of nominal time slots;
dividing each of the nominal time slots into at least a first allocated portion and a second allocated portion;
assigning a first wireless device to transmit first wireless transmissions during the first allocated portion in each of the plurality of nominal time slots;
assigning a second wireless device to transmit second wireless transmissions during the second allocated portion in each of the plurality of nominal time slots;
setting a first transmission duty cycle for the first wireless device during each of the plurality of nominal time slots to be less than one hundred percent;
setting a second transmission duty cycle for the second wireless device during each of the plurality of nominal time slots to be less than one hundred percent;
setting a first power level for the first wireless device such that the first power level multiplied by the first transmission duty cycle is less than or equal to a desired power threshold;
setting a second power level for the second wireless device such that the second power level multiplied by the second transmission duty cycle is less than or equal to the desired power threshold;
transmitting the first wireless transmissions from the first wireless device within the first allocated portion of each of the plurality of nominal time slots according to the first radio transmission duty cycle and the first power level; and
transmitting the second wireless transmission from the second wireless device within the second allocated portion of each of the plurality of nominal time slots according to the second transmission duty cycle and the second power level,
wherein a sum of the first duty cycle and the second duty cycle is less than or equal to one hundred percent, and
wherein the first allocated portion and the second allocated portion in the time slot do not overlap in time.
2. The method in accordance with claim 1 , wherein each of the nominal time slots is no greater than about 1 millisecond in duration.
3. A method in accordance with claim 1 , further comprising aggregating information associated with the first and second radio transmissions from the UWB protocol to each of the plurality of nominal time slots in accordance with a MAC protocol.
4. The method in accordance with claim 1 , wherein the UWB protocol includes a preamble associated with an aggregated data packet, the preamble being transmitted at a power level greater than the increased power level.
5. The method in accordance with claim 1 , further comprising aggregating information associated with the respective first and second wireless transmissions from one or more frames associated with the UWB protocol to each of the plurality of nominal time slots based on one or more parameters associated with a physical (PHY) layer of the UWB protocol.
6. The method in accordance with claim 1 , wherein:
the UWB protocol includes a preamble associated with an aggregated data packet and one or more of a header having a device address, a payload, a transmit power level, and an automatic gain control (AGC) value, and
each of the one or more of the header having a device address, the payload, the transmit power level, and the AGC value are associated with each of the plurality of nominal time slots.
7. The method in accordance with claim 6 , wherein the first power level is set for the first device according to the AGC value.
8. The method in accordance with claim 1 , wherein the UWB protocol includes an IEEE 802.15.3-based protocol.
9. The method in accordance with claim 1 , further comprising:
dividing each of the plurality of nominal time slots into at least first through N th allocated portions;
assigning third through N th devices to transmit during third through N th allocated portions in each of the plurality of nominal time slots;
setting third through N th transmission duty cycles for the third through N th devices, respectively, during each of the plurality of nominal time slots to each be less than one hundred percent;
setting third through N th power levels for the third through N th UWB devices such that one of the third through Npower levels multiplied by a respective one of the third through N th transmission duty cycles is less than or equal to the desired power threshold; and
transmitting the wireless transmissions from the third through N th devices within the respective third through N th allocated portions of the nominal time slot according to the third through N th duty cycles and the third through N th power levels,
wherein a sum of the first through N th duty cycles is less than or equal to one hundred percent, and
wherein none of the first through N th allocated portions in the nominal time slot overlap in time.
10. A device for increasing signal power associated with a plurality of radio transmissions from a plurality of ultra wideband (UWB) transmitters operating in accordance with a UWB protocol, the device comprising:
means for dividing a transmission period into a plurality of superframes;
means for dividing each of the superframes into a plurality of regular time slots;
means for dividing each of the plurality of regular time slots into a plurality of nominal time slots;
means for dividing each of the nominal time slots into at least a first allocated portion and a second allocated portion;
means for assigning a first wireless device to transmit first wireless transmissions during the first allocated portion in each of the plurality of nominal time slots;
means for assigning a second wireless device to transmit second wireless transmissions during the second allocated portion in each of the plurality of nominal time slots;
means for setting a first transmission duty cycle for the first wireless device during each of the plurality of nominal time slots to be less than one hundred percent;
means for setting a second transmission duty cycle for the second wireless device during each of the plurality of nominal time slots to be less than one hundred percent;
means for setting a first power level for the first wireless device such that the first power level multiplied by the first transmission duty cycle is less than or equal to a desired power threshold;
means for setting a second power level for the second wireless device such that the second power level multiplied by the second transmission duty cycle is less than or equal to the desired power threshold;
means for transmitting the first wireless transmissions from the first wireless device within the first allocated portion of each of the plurality of nominal time slots according to the first radio transmission duty cycle and the first power level; and
means for transmitting the second wireless transmission from the second wireless device within the second allocated portion of each of the plurality of nominal time slots according to the second transmission duty cycle and the second power level,
wherein a sum of the first duty cycle and the second duty cycle is less than or equal to one hundred percent, and
wherein the first allocated portion and the second allocated portion in the time slot do not overlap in time.
11. The device of claim 10 , wherein each of the nominal time slots is no greater than about 1 millisecond in duration.
12. The device of claim 10 , further comprising means for aggregating information associated with the first and second radio transmissions from the UWB protocol to each of the plurality of nominal time slots in accordance with a MAC protocol.
13. The device of claim 10 , wherein the UWB protocol includes a preamble associated with an aggregated data packet, the preamble being transmitted at a power level greater than the increased power level.
14. The device of claim 10 , further comprising means for aggregating information associated with the respective first and second wireless transmissions from one or more frames associated with the UWB protocol to each of the plurality of nominal time slots based on one or more parameters associated with a physical (PHY) layer of the UWB protocol.
15. The device of claim 10 , wherein:
the UWB protocol includes a preamble associated with an aggregated data packet and one or more of a header having a device address, a payload, a transmit power level, and an automatic gain control (AGC) value, and
each of the one or more of the header having a device address, the payload, the transmit power level, and the AGC value are associated with each of the plurality of nominal time slots.
16. The device of claim 15 , wherein the first power level is set for the first device according to the AGC value.
17. The device of claim 10 , wherein the UWB protocol includes an IEEE 802.15.3-based protocol.
18. The device of claim 10 , further comprising:
means for dividing each of the plurality of nominal time slots into at least first through N th allocated portions;
means for assigning third through N th devices to transmit during third through N th allocated portions in each of the plurality of nominal time slots;
means for setting third through N th transmission duty cycles for the third through N th devices, respectively, during each of the plurality of nominal time slots to each be less than one hundred percent;
means for setting third through N th power levels for the third through N th UWB devices such that one of the third through N th power levels multiplied by a respective one of the third through N th transmission duty cycles is less than or equal to the desired power threshold; and
means for transmitting the wireless transmissions from the third through N th devices within the respective third through N th allocated portions of the nominal time slot according to the third through N th duty cycles and the third through N th power levels,
wherein a sum of the first through N th duty cycles is less than or equal to one hundred percent, and
wherein none of the first through N th allocated portions in the nominal time slot overlap in time.