Telefonaktiebolaget Lm Ericsson (publ)

Sebastian Euler

Jonas Sedin

Xingqin Lin

Olof Liberg

Henrik Rydén

Helka-Liina Määttänen

Helka-Liina Määttanen

Björn Hofström

Talha Khan

Mattias Bergström

Magnus Åström

Emre Yavuz

Zhenhua Zou

Stefan Eriksson Löwenmark

Icaro L J Da Silva

Johan Rune

Yi-Pin Eric Wang

Shiwei Gao

Siva Dharshan Muruganathan

Gino Masini

Martin Israelsson

Vijaya Yajnanarayana

Mattias BERGSTRÖM

Helka-Liina MÄÄTTÄNEN

Chao He

Helka-Liina MÄÄTTANEN

According to some embodiments, a method performed by a wireless device comprises: receiving a broadcast of full ephemeris data for a serving cell satellite, the broadcast of full ephemeris data occurring at a first periodicity; determining a position of the serving cell satellite based on the full ephemeris data; receiving a broadcast of delta ephemeris data for the serving cell satellite, the broadcast of delta ephemeris data occurring at a second periodicity more frequent than the first periodicity; and determining a position of the serving cell satellite based on the full ephemeris data and the delta ephemeris data.

Ephemeris data signaling-delta over time

According to certain embodiments, a method performed by a wireless device comprises receiving Assisted-Global Navigation Satellite System (A-GNSS) information in system information broadcast by a network, receiving signals from a set of GNSS satellites (the set of GNSS satellites comprises at least three GNSS satellites), and determining a location of the wireless device using the A-GNSS information and information received in the signals from the set of GNSS satellites. The method further comprises determining Doppler time and frequency offsets compared to a network satellite. The Doppler time and frequency offsets are determined based on the location of the wireless device. The method further comprises initiating a connection process with the network satellite by transmitting a random access signal with pre-compensated time and frequency, the pre-compensated time and frequency based on the determined Doppler time and frequency offsets.

GNSS data in non-terrestrial network system information

A method () performed by a wireless device () includes obtaining a remaining service time (T) associated with a first satellite or first spot beam. Based on the remaining service time, the wireless device determines whether to initiate a connection with the first satellite or first spot beam.

Power efficient non-terrestrial network connection establishment

A method, system and apparatus are disclosed. In one or more embodiments, a network node for communicating with a wireless device is provided. The network node includes processing circuitry configured to receive measurement capability information of a wireless device where the measurement capability information indicates an ability to perform a global navigation satellite system, GNSS, measurement. The processing circuitry is further configured to determine a GNSS measurement gap configuration during which the wireless device is to perform at least one GNSS measurement during at least one GNSS measurement gap where the GNSS measurement gap configuration is based at least in part on the received measurement capability information, and indicate the GNSS measurement gap configuration to the wireless device.

GNSS measurement gaps

Methods performed by base stations and wireless devices for reducing RSRP and/or RSRQ measurements are disclosed. A method performed by a base station comprises indicating to a wireless device whether or not to perform cell selection and/or reselection measurements based on certain criteria. A method performed by a wireless device comprises determining whether or not to perform cell selection and/or reselection measurements based on certain criteria. Also disclosed are base stations and wireless devices configured to perform the methods.

UE procedures for reducing RSRP/RSRQ measurement in RRC idle mode and inactive state

Embodiments include methods for operating a network node in a non-terrestrial network (NTN) that utilizes one or more polarization modes for serving one or more cells. Such methods include transmitting, to one or more user equipment (UEs), an indication of at least one polarization mode configured for use in a first cell of the first NTN. The at least one polarization mode can be indicated in various ways, both explicitly and implicitly. Such methods also include transmitting and/or receiving one or more signals or channels in the first cell according to one or more configured polarization modes including the at least one indicated polarization mode. Other embodiments include complementary methods for operating UEs, as well as network nodes and UEs configured to perform such methods.

Methods for configuring polarization modes in a non-terrestrial network (NTN)

Methods and apparatus for obtaining a frequency offset corresponding to a Doppler shift of transmission and/or reception frequencies between a wireless device and a network node. In one embodiment a method is performed by a wireless device for operating in a non-terrestrial network, NTN, the NTN having at least one network node and a communication satellite, wherein the at least one network node is one of a terrestrial base station and a satellite base station or satellite gateway, the method includes obtaining a frequency offset corresponding to a Doppler shift of transmission and/or reception frequencies between the wireless device and the network node and applying the frequency offset to an uplink transmission to the network node.

Frequency offset in non-terrestrial networks

A method is performed by a wireless device for communication in a non-terrestrial network, NTN, comprising at least a first non-terrestrial network node and a second non-terrestrial network node. The method includes determining an estimated location of the wireless device. The method further includes obtaining first location information associated with the first non-terrestrial network node and second location information associated with the second non-terrestrial network node. The method further includes calculating an estimated signal time arrival difference based on the location of the wireless device, the first location information, and the second location information. The method further includes using the estimated signal time arrival difference to provision an NTN-specific synchronization signal/physical broadcast channel, SS/PBCH, block measurement timing configuration, NTN-SMTC.

Detection of neighboring satellites in wireless communication systems

Embodiments include methods for radio link monitoring (RLM) by a user equipment (UE) in a combined terrestrial and satellite wireless communication network. Such methods include, during a discontinuity in a connection between a UE and a terrestrial network node (TNN), performing RLM of the connection based on a second configuration. Such methods also include, before and/or after the discontinuity, performing RLM of the connection based on a first configuration. The connection includes a first link between the UE and a satellite and a second link between the satellite and the TNN. The discontinuity includes a link switch in at least one of the first link and the second link. The RLM before, during, and after the discontinuity can include various first, second, and third operations, respectively. Embodiments also include complementary methods performed by a TNN, as well as UEs and TNNs configured to perform operations corresponding to such methods.

Configuring radio link monitoring (RLM) for moving radio access network (RAN)

A system, method and non-transitory computer readable media for facilitating reduced signaling load with respect to UE location reporting in a non-terrestrial network (NTN) environment () interoperable with one or more terrestrial cellular communications networks. In one embodiment of an index-based location reporting scheme, a UE () may receive () a list of reference locations from a network node (), each identified with an index. Responsive to receiving the list of reference locations, the UE () may report to the network node () an index or a subset of indices of one or more reference locations that match a specific reporting criterion. In an example implementation, reporting of index-based location information by the UE () may be configurably triggered, e.g., periodically or in response to the occurrence of a particular event, condition, etc.

System and method for facilitating index-based positioning in a non-terrestrial network

The present disclosure relates to a method performed by a UE for enabling GNSS measurements. The UE and a network node are included in a NR communications network, and the NR communications network includes a NTN component. The UE performs a GNSS measurement according to a rule and using a GNSS receiver included in the UE. At least one of a UE position and an absolute time is an output of the GNSS measurement or is derivable from the GNSS measurement.

UE, network node and method for enabling GNSS measurements

A network node of a wireless communication network provides information to a User Equipment (UE) that allows the UE to adapt it radio measurements with respect to the network, to account for 'link changes.' Link changes are service-link and/or feeder-link changes arising from motion by the satellite(s) included in the Radio Access Network (RAN) portion of the network. The UE uses the provided information to adapt its radio measurements in conjunction with the link changes. Among the several advantages of accounting for satellite link changes in the manner contemplated are any one or more of reduced signaling going between the UE and the network, reduced battery consumption at the UE, mitigation of the effects of the link changes on the radio measurements, avoidance of spurious measurements, and an effective “automation” of the timed changeover by the UE to new measurement configurations, coincident with the occurrence of link changes.

User equipment, network node and methods therein for handling a moving radio access network

A method performed by a first network node () for enabling a second feeder link () to be established between a second network node () and an airborne or orbital communication node () in non-terrestrial communications network () to handle wireless devices () being served by the airborne or orbital communication node () is provided. The first network node () is handling the wireless devices () served by the airborne or orbital communication node () over a first feeder link () between the first network node () and the airborne or orbital communication node (). The method comprises determining () that the wireless devices served by the airborne or orbital communication node () are to be handled by the second network node () over the second feeder link (). Also, the method comprises initiating () the second feeder link () to be established between the second network node () and the airborne or orbital communication node (). Further, a first network node () for enabling a second feeder link () to be established between a second network node () and an airborne or orbital communication node () in non-terrestrial communications network () to handle wireless devices () being served by the airborne or orbital communication node () is also provided. A second network node and a method therein, as well as, computer programs and carriers are further provided.

Network nodes and methods therein for enabling a switch between feeder links for an airbourne or orbital communication node in a non-terrestrial communications network

A method is performed by a wireless device. The method includes receiving, from a network, an indication for the wireless device to prepare for a change from a first ground station to a second ground station. Each of the first ground station and the second ground station is configured to communicate with the wireless device via one or more satellites. The method further includes preparing to change from the first ground station to the second ground station. The method further includes communicating with the second ground station via the one or more satellites.

Radio access network mobility in non-geosynchronous satellite systems

A method and one or more network nodes for use in a wireless communication network to determine whether a wireless device is aerial. The one or more one or more network nodes communicate with the wireless device to instruct to report one or more metrics of wireless device parameters. The one or more network nodes receives from the wireless device a report of the metrics and then compares the reported metrics to terrestrial metrics to determine whether the wireless device is aerial.

Growing community of inventors

Storvreta, Sweden

Sebastian Euler