US 9,813,969 B2
In-flight cellular communications system coverage of mobile communications equipment located in aircraft
Joakim Axmon, Kavlinge (SE); Peter Alriksson, Horby (SE); Bjorn Ekelund, Bjarred (SE); and Bengt Lindoff, Bjarred (SE)
Assigned to TELEFONAKTIEBOLAGET LM ERICSSON (publ), Stockholm (SE)
Filed by Telefonaktiebolaget L M Ericsson (publ), Stockholm (SE)
Filed on Nov. 3, 2015, as Appl. No. 14/931,057.
Prior Publication US 2017/0127332 A1, May 4, 2017
Int. Cl. H04W 4/00 (2009.01); H04W 36/32 (2009.01); H04B 7/185 (2006.01); H04W 4/04 (2009.01); H04W 16/28 (2009.01); H04W 72/04 (2009.01); H04W 36/00 (2009.01)
CPC H04W 36/32 (2013.01) [H04B 7/18506 (2013.01); H04W 4/04 (2013.01); H04W 16/28 (2013.01); H04W 36/00 (2013.01); H04W 72/0406 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A method of providing cellular telecommunications system service to a user equipment situated in a first aircraft that is in-flight, wherein the method is performed by a first network node of a terrestrial cellular telecommunications system, the method comprising:
periodically acquiring, via an aircraft navigation broadcast receiver, acquired navigation information transmitted from the first aircraft, wherein the acquired navigation information comprises:
an identity of the first aircraft;
a position of the first aircraft;
an altitude of the first aircraft; and
a time value indicating when the position of the first aircraft was determined;
maintaining a first link between the first network node and the user equipment by transmitting beam steered, Doppler shift compensated downlink signals, and by performing beam steered reception of uplink signals, wherein beam steering is directed toward the first aircraft based on the periodically acquired navigation information, and wherein Doppler shift compensation is based on one or more determinations of relative velocity between the first aircraft and one or more first antenna nodes associated with the first network node, and is adapted to compensate for a Doppler shift experienced by the user equipment such that the user equipment experiences a nominal carrier frequency when receiving transmissions from the one or more first antenna nodes;
detecting that the first aircraft will be leaving a first coverage area that is served by the one or more first antenna nodes and will be entering a second coverage area that is served by one or more second antenna nodes, and responding by causing the one or more second antenna nodes to provide a second link between the user equipment and the one or more second antenna nodes using a same cell identifier and a same frequency allocation to the user equipment as are being used for the first link so that handover from the one or more first antenna nodes to the one or more second antenna nodes is carried out without informing the user equipment.