Methods and systems for representing errors
Disclosed are systems, devices and methods for transmission of messages between wireless transceiver devices including fields representing values such as, for example, a range between devices, time of transmission of a message or time of receipt of a previous message. In particular embodiments, message may also comprise fields to express a maximum error in values representing range, time of transmission of a message or time of receipt of a previous message.
1. A method, at a first wireless station (STA), comprising:
determining, at the first STA, a maximum time of departure (TOD) error as an exponent in five bits or less, wherein the maximum TOD error is capable of expressing the maximum TOD error as large as 1.073741824 msec;
transmitting to a second STA, via a wireless transceiver, a fine timing measurement (FTM) message comprising at least a TOD field and at least one other field, the at least one other field expressing the maximum TOD error in five bits or less; and
synchronizing a first clock state of the first STA with a second clock state of the second STA based at least in part on the maximum TOD error and TOD information regarding a TOD of a message at the first STA.
2. The method of claim 1 , wherein the FTM message is transmitted in response to receipt of a FTM request message transmitted by a second STA.
3. The method of claim 1 , wherein the FTM message further comprises a time of arrival (TOA) field and at least one other field expressing a maximum TOA error in five bits or less, the at least one other field being capable of expressing the maximum TOA error as large as 1.073741824 msec.
4. The method of claim 3 , wherein the at least one other field being capable of expressing the maximum TOA error as small as 1.0 psec.
5. The method of claim 1 , wherein the at least one other field is further capable of expressing the maximum TOD error as small as 1.0 psec.
6. The method of claim 1 , wherein synchronizing the first clock state of the first STA with the second clock state of the second STA based at least in part on the maximum TOD error and the TOD information comprises determining a clock offset based on timing information included in a plurality of FTM messages.
7. A first wireless station (STA), comprising:
a wireless transceiver to transmit messages to and receive messages from a wireless communication network; and
one or more processors coupled to the wireless transmitter, the one or more processors being configured to:
determine a maximum time of departure (TOD) error as an exponent in five bits or less, wherein the maximum TOD error is capable of expressing the maximum TOD error as large as 1.073741824 msec;
initiate transmission of a fine timing measurement (FTM) message to a second STA through the wireless transceiver comprising at least a TOD field and at least one other field, the at least one other field expressing the maximum TOD error; and
synchronize a first clock state of the first STA with a second clock state of the second STA based at least in part on the maximum TOD error and TOD information regarding a TOD of a message at the first STA.
8. The first STA of claim 7 , wherein the FTM message is transmitted in response to receipt of a FTM request message transmitted by a second STA.
9. The first STA of claim 7 , wherein the FTM message further comprises a time of arrival (TOA) field and at least one other field expressing a maximum TOA error in five bits or less, the at least one other field being capable of expressing the maximum TOA error as large as 1.073741824 msec.
10. The first STA of claim 9 , wherein the at least one other field being capable of expressing the maximum TOA error as small as 1.0 psec.
11. The first STA of claim 7 , wherein the at least one other field is further capable of expressing the maximum TOD error as small as 1.0 psec.
12. A first wireless station (STA), comprising:
means for receiving a fine timing measurement (FTM) request message;
means for determining a maximum time of departure (TOD) error as an exponent in five bits or less, wherein the maximum TOD error is capable of expressing the maximum TOD error as large as 1.073741824 msec;
means for transmitting an FTM message to a second STA in response to the FTM request message comprising at least a TOD field and at least one other field, the at least one other field expressing the maximum TOD error; and
means for synchronizing a first clock state of the first STA with a second clock state of the second STA based at least in part on the maximum TOD error and TOD information regarding a TOD of a message at the first STA.
13. The first STA of claim 12 , wherein the FTM message is transmitted in response to receipt of a FTM request message transmitted by a second STA.
14. The first STA of claim 12 , wherein the FTM message further comprises a time of arrival (TOA) field and at least one other field expressing a maximum TOA error in five bits or less, the at least one other field being capable of expressing the maximum TOA error as large as 1.073741824 msec.
15. The first STA of claim 14 , wherein the at least one other field being capable of expressing the maximum TOA error as small as 1.0 psec.
16. The first STA of claim 12 , wherein the at least one other field is further capable of expressing the maximum TOD error as small as 1.0 psec.
17. A non-transitory storage medium having computer-readable instructions stored thereon which are executable by a processor of a first wireless station (STA) to:
determine a maximum time of departure (TOD) error as an exponent in five bits or less, wherein the maximum TOD error is capable of expressing the maximum TOD error as large as 1.073741824 msec; and
initiate transmission of a fine timing measurement (FTM) message to a second STA through a wireless transmitter comprising at least a TOD field and at least one other field, the at least one other field expressing the maximum TOD error; and
synchronize a first clock state of the first STA with a second clock state of the second STA based at least in part on the maximum TOD error and TOD information regarding a TOD of a message at the first STA.
18. The non-transitory storage medium of claim 17 , wherein the FTM message is transmitted in response to receipt of a FTM request message transmitted by a second STA.
19. The non-transitory storage medium of claim 17 , wherein the FTM message further comprises a time of arrival (TOA) field and at least one other field expressing a maximum TOA error in five bits or less, the at least one other field being capable of expressing the maximum TOA error as large as 1.073741824 msec.
20. The non-transitory storage medium of claim 19 , wherein the at least one other field being capable of expressing the maximum TOA error as small as 1.0 psec.
21. The non-transitory storage medium of claim 17 , wherein the at least one other field is further capable of expressing the maximum TOD error as small as 1.0 psec.