Signaling TA-offset in NR
A method performed by a wireless device for determining a timing advance (TA) offset in a new radio (NR) network is described herein along with associated network devices and systems. An exemplary method includes obtaining an indication of whether a carrier frequency of the NR network coexists with a carrier frequency of a long term evolution (LTE) network, determining, based on whether the carrier frequency of the NR network coexists with carrier frequency of the LTE network, a TA offset for uplink transmission; and transmitting an uplink transmission using the determined TA offset.
1. A method performed by a wireless device for determining a timing advance (TA) offset in a new radio (NR) network, the method comprising:
obtaining, by signalling from a network node, an indication of whether a carrier frequency of the NR network coexists with a carrier frequency of a long term evolution (LTE) network;
determining, based on the indication, a TA offset for uplink transmission, wherein the TA offset depends on a duplex mode of a frequency band of the carrier frequency of the NR network; and
transmitting an uplink transmission using the determined TA offset.
2. The method of claim 1 , wherein the carrier frequency of the NR network coexists with the carrier frequency of the LTE network in that NR and LTE are deployed on the same frequencies using time division duplexing.
3. The method of claim 1 , wherein the duplex mode is one of: a frequency division duplex (FDD) or a time division duplex (TDD).
4. The method of claim 1 , wherein:
the signalling includes an explicit TA offset value; and
determining the TA offset comprises using the explicit TA offset value.
5. The method of claim 1 , wherein the carrier frequency of the NR network is not a TDD network and the TA offset is equal to zero.
6. The method of claim 1 , wherein the NR network is a TDD network, the carrier frequency of the NR network is below a threshold value, the NR network does not coexist with an LTE network, and the TA offset is equal to a first value greater than 0.
7. The method of claim 1 , wherein the NR network is a TDD network, the carrier frequency of the NR network is above a threshold value, the NR network does not coexist with an LTE network, and the TA offset is equal to a second value greater than 0.
8. The method of claim 1 , wherein the NR network is a TDD network, the carrier frequency of the NR network is above a threshold value, the NR network coexists with an LTE network, and the TA offset is equal to a third value greater than 0.
9. The method of claim 8 , wherein the threshold value is 6 GHz and the TA offset is 20 vs.
10. The method of claim 1 , wherein the uplink transmission is a random access to a cell on the carrier frequency of the NR network.
11. The method of claim 1 , wherein TA offset relates uplink transmission timing with respect to downlink transmission timing in a cell belonging to the carrier frequency of the NR network.
12. A method performed by a network node for signalling a timing advance (TA) offset to a wireless device in a new radio (NR) network, the method comprising:
sending an indication of a timing advance (TA) offset for a carrier frequency of the NR network to the wireless device, wherein the TA offset depends on whether the carrier frequency of the NR network coexists with a carrier frequency of a long term evolution (LTE) network and the TA offset depends on a duplex mode of a frequency band of the carrier frequency of the NR network; and
receiving an uplink transmission using the indicated TA offset.
13. The method of claim 12 , wherein the network node comprises co-located NR and LTE base stations.
14. The method of claim 12 , wherein the duplex mode is one of: a frequency division duplex (FDD) and a time division duplex (TDD).
15. The method of claim 12 , wherein the indication of the timing offset comprises an explicit indication of an amount of time.
16. The method of claim 15 , wherein the NR network is not a TDD network and the TA offset is equal to zero.
17. The method of claim 15 , wherein the NR network is a TDD network, the carrier frequency of the NR network is below a threshold value, the NR network does not coexist with an LTE network, and the TA offset is equal to a first value greater than 0.
18. The method of claim 15 , wherein the NR network is a TDD network, the carrier frequency of the NR network is above a threshold value, the NR network does not coexist with an LTE network, and the TA offset is equal to a second value greater than 0.
19. The method of claim 15 , wherein the NR network is a TDD network, the carrier frequency of the NR network is above a threshold value, the NR network coexists with an LTE network, and the TA offset is equal to a third value greater than 0.
20. The method of claim 12 , wherein the indication of the timing offset comprises an indication of whether the carrier frequency of the NR network coexists with an LTE network.
21. The method of claim 12 , wherein the uplink transmission is a random access to a cell on the carrier frequency of the NR network.
22. The method of claim 12 , wherein TA offset relates uplink transmission timing with respect to downlink transmission timing in a cell belonging to the carrier frequency of the NR network.
23. A wireless device for determining a timing advance (TA) offset in a new radio (NR) network, the wireless device comprising:
processing circuitry configured to perform operations comprising:
obtaining, via signalling from a network node, an indication of whether the NR network is a time division duplex (TDD) network, a carrier frequency of the NR network, and whether the NR network coexists with a long term evolution (LTE) network,
determining, based on whether the NR network is a TDD network, the carrier frequency of the network, and the indication, a TA offset for uplink transmission, and
transmitting an uplink transmission using the determined TA offset; and
power supply circuitry configured to supply power to the wireless device.
24. A base station for signalling a timing advance (TA) offset to a wireless device in a new radio (NR) network, the base station comprising:
processing circuitry configured to perform operations comprising:
sending an indication of a TA offset to the wireless device, wherein the TA offset depends on whether a carrier frequency of the NR network coexists with a carrier frequency of a long term evolution (LTE) network and the TA offset depends on a duplex mode of a frequency band of the carrier frequency of the NR network, and
receiving an uplink transmission using the indicated timing offset; and
power supply circuitry configured to supply power to the wireless device.