Long term evolution (LTE) air to ground communication enhancements associated with uplink synchronization
First Claim
1. A method for air to ground uplink synchronization, the method comprising:
- (a) initiating a downlink synchronization of user equipment onboard an aircraft with a ground base station, wherein at least a first antenna and a second antenna are mounted on the aircraft;
(b) computing a range to the ground base station based on a downlink path loss, wherein the downlink path loss is calculated independently for each of the first and second antennas;
(c) selecting an initial time advance value from a set of predetermined time advance values based on the computed range, wherein the initial time advance value is estimated from the antenna having the lowest downlink path loss;
(d) sending a first random access channel (RACH) request with the initial time advance value to the ground base station in a first attempt to synchronize an uplink signal and attach the user equipment to a network;
(e) if the user equipment fails to attach to the network, sending a next RACH request with a next time advance value from the set of predetermined time advance values to the ground base station, in a next attempt to synchronize the uplink signal and attach the user equipment to the network; and
(f) if the user equipment fails again to attach to the network, repeating step (e) until the user equipment is attached to the network with a current time advance value.
1 Assignment
0 Petitions
Accused Products
Abstract
A method for air to ground uplink synchronization comprises initiating a downlink synchronization of user equipment onboard an aircraft with a ground base station; computing a range to the base station based on a downlink path loss; selecting an initial time advance (TA) value from a set of predetermined TA values based on the range; and sending a first random access channel (RACH) request with the initial TA value to the base station in a first attempt to synchronize an uplink signal and attach the user equipment to a network. If the user equipment fails to attach, a next RACH request is sent with a next TA value to the base station, in a next attempt to synchronize the uplink signal and attach the user equipment to the network. If the user equipment fails again to attach, the method is repeated until the user equipment is attached to the network.
-
Citations
13 Claims
-
1. A method for air to ground uplink synchronization, the method comprising:
-
(a) initiating a downlink synchronization of user equipment onboard an aircraft with a ground base station, wherein at least a first antenna and a second antenna are mounted on the aircraft; (b) computing a range to the ground base station based on a downlink path loss, wherein the downlink path loss is calculated independently for each of the first and second antennas; (c) selecting an initial time advance value from a set of predetermined time advance values based on the computed range, wherein the initial time advance value is estimated from the antenna having the lowest downlink path loss; (d) sending a first random access channel (RACH) request with the initial time advance value to the ground base station in a first attempt to synchronize an uplink signal and attach the user equipment to a network; (e) if the user equipment fails to attach to the network, sending a next RACH request with a next time advance value from the set of predetermined time advance values to the ground base station, in a next attempt to synchronize the uplink signal and attach the user equipment to the network; and (f) if the user equipment fails again to attach to the network, repeating step (e) until the user equipment is attached to the network with a current time advance value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A computer program product, comprising:
a non-transitory computer readable medium having instructions stored thereon executable by a processor to perform a method for air to ground uplink synchronization, the method comprising; (a) initiating a downlink synchronization of user equipment onboard an aircraft with a ground base station, wherein at least a first antenna and a second antenna are mounted on the aircraft; (b) computing a range to the ground base station based on a downlink path loss, wherein the downlink path loss is calculated independently for each of the first and second antennas; (c) selecting an initial time advance value from a set of predetermined time advance values based on the computed range, wherein the initial time advance value is estimated from the antenna having the lowest downlink path loss; (d) sending a first random access channel (RACH) request with the initial time advance value to the ground base station in a first attempt to synchronize an uplink signal and attach the user equipment to a network; (e) if the user equipment fails to attach to the network, sending a next RACH request with a next time advance value from the set of predetermined time advance values to the ground base station, in a next attempt to synchronize the uplink signal and attach the user equipment to the network; and (f) if the user equipment fails again to attach to the network, repeating step (e) until the user equipment is attached to the network with a current time advance value.
-
9. A system for air to ground uplink synchronization, the system comprising:
-
a processor onboard an aircraft; and a non-transitory computer readable medium having instructions stored thereon executable by the processor to perform a method comprising; (a) initiating a downlink synchronization of user equipment onboard the aircraft with a ground base station, wherein at least a first antenna and a second antenna are mounted on the aircraft; (b) computing a range to the ground base station based on a downlink path loss, wherein the downlink path loss is calculated independently for each of the first and second antennas; (c) selecting an initial time advance value from a set of predetermined time advance values based on the computed range, wherein the initial time advance value is estimated from the antenna having the lowest downlink path loss; (d) sending a first random access channel (RACH) request with the initial time advance value to the ground base station in a first attempt to synchronize an uplink signal and attach the user equipment to a network; (e) if the user equipment fails to attach to the network, sending a next RACH request with a next time advance value from the set of predetermined time advance values to the ground base station, in a next attempt to synchronize the uplink signal and attach the user equipment to the network; and (f) if the user equipment fails again to attach to the network, repeating step (e) until the user equipment is attached to the network with a current time advance value. - View Dependent Claims (10, 11, 12, 13)
-
Specification