Spectrum Efficiency for Uplink Wireless Communications

• US 20170265191A1
• Filed: 03/11/2016
• Published: 09/14/2017
• Est. Priority Date: 03/11/2016
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Ahmed, Wessam Afifi, Rantala, Enrico-Henrik, Torkildson, Eric, Choudhury, Sayantan, Tuomaala, Esa Juhani
• Granted Patent: US 11,019,621 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 74/0875 with assigned priorities based access

Abstract

A wireless network having one or more access points and one or more stations may improve spectrum efficiency for uplink transmissions by assigning a plurality of stations to a channel (or subchannel), each with a different priority. A channel may be assigned to a first station with the first priority, a second station with a second priority, and so on (e.g., instead of assigning the channel to just one station). An access point may transmit information indicative of the channel assignments, priorities, and other information used by stations to perform uplink transmissions. If a station with the highest priority receives the data from the access point, it may start transmission. A station with a lower priority may listen, during a listening period, to the same channel and determine whether the higher priority station started transmission during the listening period. If the higher priority station did not start transmission during the listening period, the lower priority station may transmit uplink data to the access point.

Claims

1. A method comprising:

receiving, by a first station from an access node, information indicative of an assignment of a reservation period on a frequency channel to the first station and a second station;

listening, by the first station, for a transmission on the frequency channel from the second station to the access node during the reservation period;

if the transmission on the frequency channel from the second station to the access node did not occur, transmitting, by the first station, data to the access node on the frequency channel during the reservation period; and

if the transmission on the frequency channel from the second station to the access node did occur, preventing transmission, by the first station, of data to the access node on the frequency channel during the reservation period.

2. The method of claim 1, wherein the reservation period comprises a transmission opportunity in a wireless local area network.

3. The method of claim 1, wherein the assignment indicates that the reservation period is assigned to the second station with a first priority, and wherein the reservation period is assigned to the first station with a second priority lower than the first priority.

4. The method of claim 1, wherein the transmitting the data comprises transmitting the data at a predetermined time delay from a start of the reservation period.

5. The method of claim 1, wherein the listening is performed in response to the first station receiving a trigger frame from the access node.

6. The method of claim 1, wherein the assignment of the reservation period is received in a trigger frame from the access node.

7. The method of claim 1, wherein the frequency channel comprises a subchannel of a Wi-Fi channel, the method further comprising:

determining a start time of a transmission of payload data on at least one other subchannel of the Wi-Fi channel,

wherein the transmitting the data to the access node comprises initiating transmission of a preamble at the start time of the transmission of the payload data on the at least one other subchannel.

8. The method of claim 7, further comprising:

setting a length of the preamble to a length of an integer number of data symbols of the payload data transmitted on the at least one other subchannel.

9. The method of claim 1, wherein the frequency channel comprises a subchannel of a Wi-Fi channel, and wherein the data comprises a preamble and payload data, and wherein the transmitting the data to the access node comprises:

transmitting, by the first station, the preamble, wherein the preamble is shorter than a preamble transmitted on at least one other subchannel of the Wi-Fi channel; and

after transmitting the preamble, initiating transmission, by the first station, of the payload data at a same time as transmission of payload data on the at least one other subchannel is initiated.

10. The method of claim 1, further comprising:

receiving, by the first station from the access node, an indication of a listening period within the reservation period, wherein the listening, by the first station, for the transmission on the frequency channel occurs during at least a portion of the listening period.

11. The method of claim 10, wherein a determination that the transmission on the frequency channel from the second station to the access node did not occur comprises a determination that the second station did not initiate data transmission to the access node during the listening period.

12. The method of claim 10, wherein receiving the indication of the listening period comprises receiving the indication of the listening period within a trigger frame received from the access node.

13. An apparatus comprising:

at least one processor; and

at least one memory including computer program code,

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to perform;

receiving, from an access node, information indicative of an assignment of a reservation period on a frequency channel to the apparatus with a first priority and a second apparatus with a second priority;

if the first priority is lower than the second priority, listening for a transmission on the frequency channel from the second apparatus to the access node during the reservation period; and

if the transmission on the frequency channel from the second apparatus to the access node did not occur, transmitting data to the access node on the frequency channel during the reservation period.

14. The apparatus of claim 13, wherein the transmitting the data comprises transmitting the data at a predetermined time delay from a start of the reservation period.

15. The apparatus of claim 13, wherein the listening is performed in response to the apparatus receiving a trigger frame from the access node.

16. The apparatus of claim 13, wherein the frequency channel comprises a subchannel of a Wi-Fi channel, and wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to perform:

determining a start time of a transmission of payload data on at least one other subchannel of the Wi-Fi channel,

wherein the transmitting the data to the access node comprises initiating transmission of a preamble at the start time of the transmission of the payload data on the at least one other subchannel.

17. The apparatus of claim 13, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to perform:

receiving, from the access node, an indication of a listening period within the reservation period, wherein the listening for the transmission on the frequency channel occurs during at least a portion of the listening period.

18. The apparatus of claim 17, wherein a determination that the transmission on the frequency channel from the second apparatus to the access node did not occur comprises a determination that the second apparatus did not initiate data transmission to the access node during the listening period.

19. A method comprising:

assigning a reservation period on a frequency channel to a first station with a first priority and a second station with a second priority lower than the first priority;

transmitting, by an access node and to at least the first station and the second station, a trigger frame, wherein the trigger frame comprises an indication of the first priority, an indication of the second priority, and an indication of the reservation period on the frequency channel; and

after transmitting the trigger frame, receiving, by the access node, data from the second station on the frequency channel during the reservation period.

20. The method of claim 19, wherein the data received from the second station is based on a determination that a transmission on the frequency channel from the first station to the access node during the reservation period did not occur.

21. The method of claim 19, further comprising:

transmitting, to the second station, a listening period indicating a length of time for the second station to listen to data transmissions by the first station on the frequency channel during the reservation period.

22. The method of claim 19, further comprising:

determining a proximity of the first station to the second station,

wherein assigning the reservation period on the frequency channel to the first station and the second station is performed in response to a determination that the proximity of the first station to the second station is less than a threshold proximity.