Satellite Switching in Non-Terrestrial Networks
A wireless device may receive, from a first satellite, a system information block comprising one or more configuration parameters indicating a first time for determining transmission of uplink signals via a cell, a second time when the cell stops serving an area, and ephemeris information of the first satellite. The first satellite may be a serving satellite. The wireless device may transmit, to the first satellite via the cell, a first uplink signal using a timing advance value, wherein the timing advance value is determined using the ephemeris information of the first satellite. The wireless device may switch, after the first time, a service link from the first satellite to a second satellite. The wireless device may not transmit, via the cell, an uplink signal between the first time and the second time.
1 . A wireless device comprising:
one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the wireless device to:
receive, from a first satellite, a system information block comprising one or more configuration parameters indicating:
a first time for determining transmission of uplink signals via a cell;
a second time when the cell stops serving an area; and
ephemeris information of the first satellite, wherein the first satellite is a serving satellite;
transmit, to the first satellite via the cell, a first uplink signal using a timing advance value, wherein the timing advance value is determined using the ephemeris information of the first satellite;
switch, after the first time, a service link from the first satellite to a second satellite; and
not transmit, via the cell, an uplink signal between the first time and the second time.
2 . The wireless device of claim 1 , wherein the wireless device is global navigation satellite system (GNSS) capable.
3 . The wireless device of claim 1 , wherein the cell is a non-terrestrial network (NTN) cell.
4 . The wireless device of claim 1 , wherein the first satellite forwards the system information block from an NTN gateway to the wireless device.
5 . The wireless device of claim 1 , wherein the second satellite is the serving satellite after switching the service link.
6 . The wireless device of claim 1 , wherein the uplink signal comprises a request message for uplink radio resources.
7 . The wireless device of claim 1 , wherein the ephemeris information of the first satellite indicates at least one of:
a position of the first satellite; or
a velocity of the first satellite.
8 . A method comprising:
receiving, by a wireless device from a first satellite, a system information block comprising one or more configuration parameters indicating:
a first time for determining transmission of uplink signals via a cell;
a second time when the cell stops serving an area; and
ephemeris information of the first satellite, wherein the first satellite is a serving satellite;
transmitting, by the wireless device to the first satellite and via the cell, a first uplink signal using a timing advance value, wherein the timing advance value is determined using the ephemeris information of the first satellite;
switching, by the wireless device and after the first time, a service link from the first satellite to a second satellite; and
not transmitting, by the wireless device and via the cell, an uplink signal between the first time and the second time.
9 . The method of claim 8 , wherein the wireless device is global navigation satellite system (GNSS) capable.
10 . The method of claim 8 , wherein the cell is a non-terrestrial network (NTN) cell.
11 . The method of claim 8 , wherein the first satellite forwards the system information block from an NTN gateway to the wireless device.
12 . The method of claim 8 , wherein the second satellite is the serving satellite after switching the service link.
13 . The method of claim 8 , wherein the uplink signal comprises a request message for uplink radio resources.
14 . The method of claim 8 , wherein the ephemeris information of the first satellite indicates at least one of:
a position of the first satellite; or
a velocity of the first satellite.
15 . A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of a wireless device, cause the wireless device to:
receive, from a first satellite, a system information block comprising one or more configuration parameters indicating:
a first time for determining transmission of uplink signals via a cell;
a second time when the cell stops serving an area; and
ephemeris information of the first satellite, wherein the first satellite is a serving satellite;
transmit, to the first satellite via the cell, a first uplink signal using a timing advance value, wherein the timing advance value is determined using the ephemeris information of the first satellite;
switch, after the first time, a service link from the first satellite to a second satellite; and
not transmit, via the cell, an uplink signal between the first time and the second time.
16 . The non-transitory computer-readable medium of claim 15 , wherein the wireless device is global navigation satellite system (GNSS) capable.
17 . The non-transitory computer-readable medium of claim 15 , wherein the cell is a non-terrestrial network (NTN) cell.
18 . The non-transitory computer-readable medium of claim 15 , wherein the first satellite forwards the system information block from an NTN gateway to the wireless device.
19 . The non-transitory computer-readable medium of claim 15 , wherein the second satellite is the serving satellite after switching the service link.
20 . The non-transitory computer-readable medium of claim 15 , wherein the ephemeris information of the first satellite indicates at least one of:
a position of the first satellite; or
a velocity of the first satellite.