Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W36/00—Hand-off or reselection arrangements
  • H04W36/0005—Control or signalling for completing the hand-off
  • H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W36/00—Hand-off or reselection arrangements
  • H04W36/14—Reselecting a network or an air interface
  • H04W36/144—Reselecting a network or an air interface over a different radio air interface technology

Definitions

• Wireless communication and in particular, to a wireless device (WD)-specific beam cell are wireless devices (WD)-specific beam cell.
• coverage enhancement can be obtained through various techniques. For example, in a cellular system, coverage enhancement can be obtained through repetition (e.g., using strong encoding/redundancy) of the data for wireless devices (WDs) that have low signal-to-interference-plus-noise ratio (SINR).
• Coverage enhancement techniques may be used to enable wireless devices (WDs), such as Machine-type Communication (MTC) devices and other wireless communication devices to transmit and receive data from a communication system, such as a base station and/or network node, at a greater range. For example, repetition of data over multiple subframes may improve the range and/or reception reliability; but also result in a lower achievable peak throughput, as compared to the peak throughput that could be achieved without using repetition.
• MTC Machine-type Communication
• one of the benefits of using repetition for coverage enhancement is that the azimuthal and elevational angular coverage of a cell can be maintained.
• Coverage enhancement may also be obtained when, for example, a network node makes use of an Advanced Antenna System (AAS).
• AAS Advanced Antenna System
• coverage enhancement can be obtained using beamforming to combine “energy going” (i.e., Downlink (DL)), or “energy coming” (i.e., Uplink (UL)) in/from a specific limited angular span in azimuth and elevation.
• DL Downlink
• UL Uplink
• This allows extended range communication without the use of data repetition (hence at a possible higher raw data rates and therefore higher throughput capacity, as compared to use of repetition) but limits the DL coverage to a limited angular range at any given time.
• using AAS to beamform generally requires that the desired angular range of the beam be known in advance.
• existing techniques for coverage enhancement result in different drawbacks, such as, for example, reduced data throughput, limited angular range of coverage and/or the need for the knowledge of a desired angular range.
• Some embodiments advantageously provide apparatuses and methods that may provide coverage enhancement with improved data rates (e.g., broadband data rates, and/or improved throughput over existing repetition-based coverage enhancement techniques, etc.).
• improved data rates e.g., broadband data rates, and/or improved throughput over existing repetition-based coverage enhancement techniques, etc.
• a method implemented in a network node includes obtaining angular information using a first radio access technology, RAT, the angular information being associated with a wireless device, WD, the first RAT supporting a first coverage area and a first peak spectral efficiency for the WD.
• the method includes determining a beam to be used by a second RAT to support a second coverage area and a second peak spectral efficiency for the WD, the beam being determined for the second RAT being based at least in part on the angular information obtained from the first RAT, the second angular coverage area being narrower than the first coverage area and the second peak spectral efficiency being higher than the first peak spectral efficiency.
• the method includes participating in a handover of the WD from the first RAT to the second RAT.
• At least one cell in the second RAT to which the WD is handed over is a pencil-beam cell and a shape of the pencil-beam cell is based at least in part on the angular information obtained from an initial cell corresponding to the first RAT.
• determining the beam to be used by the second RAT to support the second angular coverage area further comprises determining a shape of a cell corresponding to the second RAT, the shape of the cell defining the second coverage area.
• obtaining the angular information using the first RAT further comprises at least one of receiving a measurement report from the WD, the angular information based at least in part on the measurement report; receiving a signal from the WD and performing a measurement on the signal, the angular information based at least in part on the measurement; and receiving a handover request, the handover request including the angular information.
• participating in the handover of the WD from the first RAT to the second RAT further comprises at least one of: transmitting a radio resource control, RRC, reconfiguration message in the second RAT; and receiving an RRC reconfiguration complete message in that same RAT.
• the first RAT is one of a machine-type communication, MTC, cell and a satellite system.
• the first RAT is a cell having coverage enhancement by data repetition; and the obtaining the angular information using the first RAT further comprising obtaining the angular information using at least one uplink signal transmitted by the WD in the cell having coverage enhancement by data repetition.
• the obtaining angular information using the first RAT further includes receiving at least one uplink signal from the WD via the first RAT ; and estimating an uplink, UL, direction-of-arrival based at least in part on the received at least one uplink signal.
• the participating in the handover of the WD further comprises participating in the handover of the WD from the first RAT to the second RAT as a result of at least one of: data for the WD being present in a data buffer associated with the network node; and an absence of cell candidates capable of supporting broadband coverage to the WD.
• the determined beam is a WD-specific beam.
• the method further includes after the handover of the WD to the second RAT, transmitting downlink and broadcast channels to the WD via the determined beam.
• the method further includes based on an inactivity timer, de-activating the second RAT.
• at least one of: the first coverage area is a wide coverage area; the first coverage area provides 360 degrees of coverage; the second coverage area is a narrow coverage area; and the second coverage area provides at most 120 degrees of coverage.
• a method implemented in a wireless device, WD includes transmitting at least one uplink signal in a first radio access technology, RAT, the first RAT supporting a first coverage area and a first data rate for the WD.
• the method includes receiving a handover signal, the handover signal initiating a handover of the WD from the first RAT to a second RAT, the second RAT supporting a second coverage area and a second data rate for the WD, the second coverage area being narrower than the first coverage area and the second data rate being higher than the first data rate and the second RAT using a beam, the beam being based at least in part on angular information obtained from the at least one uplink signal transmitted in the first RAT.
• At least one cell in the second RAT to which the WD is handed over is a pencil-beam cell and a shape of the pencil-beam cell is based at least in part on the angular information obtained from an initial cell using the first RAT.
• the shape of the pencil-beam cell defines the second coverage area.
• transmitting the at least one uplink signal in the first RAT further comprises at least one of transmitting a measurement report from which the angular information is obtained; and transmitting a signal to be measured by the network node, the angular information based at least in part on the measurement.
• receiving a handover signal further comprises receiving a radio resource control, RRC, reconfiguration message, the RRC reconfiguration message indicating a cell corresponding to the second RAT to which the WD is to be handover over, a shape of the cell based on the obtained angular information.
• RRC radio resource control
• the first RAT is one of a machine-type communication, MTC, cell corresponding to a radio access technology, RAT, and a satellite system.
• the first RAT is a cell having coverage enhancement by data repetition.
• the method further includes performing the handover of the WD from the first RAT to a second RAT as a result of at least one of: data for the WD being present in a data buffer associated with a network node; and an absence of cell candidates capable of supporting broadband coverage to the WD.
• the beam is a WD- specific beam.
• the method further includes after the handover of the WD to the second RAT, receiving downlink and broadcast channels via the beam.
• the first coverage area is a wide coverage area; the first coverage area provides 360 degrees of coverage; the second coverage area is a narrow coverage area; and the second coverage area provides at most 120 degrees of coverage.
• a network node configured to communicate with a wireless device, WD.
• the network node includes processing circuitry.
• the processing circuitry is configured to cause the network node to obtain angular information using a first radio access technology, RAT, the angular information being associated with a wireless device, WD, the first RAT supporting a first coverage area and a first data rate for the WD.
• RAT radio access technology
• the processing circuitry is configured to cause the network node to determine a beam to be used by a second RAT to support a second coverage area and a second data rate for the WD, the beam being determined for the second RAT based at least in part on the angular information obtained from the first RAT, the second coverage area being narrower than the first coverage area and the second data rate being higher than the first data rate.
• the processing circuitry is configured to cause the network node to participate in a handover of the WD from the first RAT to the second RAT.
• At least one cell in the second RAT to which the WD is handed over is a pencil-beam cell and a shape of the pencil-beam cell is based at least in part on the angular information obtained from an initial cell corresponding to the first RAT.
• the processing circuitry is further configured to cause the network node to determine the beam to be used by the second RAT to support the second coverage area by being configured to cause the network node to determine a shape of a cell corresponding to the second RAT, the shape of the cell defining the second coverage area.
• the processing circuitry is further configured to cause the network node to obtain the angular information using the first RAT further by being configure to cause the network node to at least one of: receive a measurement report from the WD, the angular information based at least in part on the measurement report; receive a signal from the WD and perform a measurement on the signal, the angular information based at least in part on the measurement; and receive a handover request, the handover request including the angular information.
• the processing circuitry is further configured to cause the network node to participate in the handover of the WD from the first RAT to the second RAT by being configured to cause the network node to at least one of: transmit a radio resource control, RRC, reconfiguration message; and receive an RRC reconfiguration complete message.
• the first RAT is one of a machine-type communication, MTC, cell, and a satellite system. In some embodiments of this aspect, the first RAT is a cell having coverage enhancement by data repetition. In some embodiments of this aspect, the processing circuitry is further configured to cause the network node to obtain the angular information using the first RAT by being configured to cause the network node to: receive at least one uplink signal from the WD via the first RAT; and estimate an uplink, UL, direction-of-arrival based on the received at least one uplink signal.
• the processing circuitry is further configured to cause the network node to participate in the handover of the WD by being configured to participate in the handover of the WD from the first RAT to the second RAT as a result of at least one of: data for the WD being present in a data buffer associated with the network node; and an absence of cell candidates capable of supporting broadband coverage to the WD.
• the determined beam is a WD-specific beam.
• the processing circuitry is further configured to cause the network node to after the handover of the WD to the second RAT, transmit downlink and broadcast channels to the WD via the determined beam.
• the processing circuitry is further configured to cause the network node to based on an inactivity timer, de-activate the second RAT.
• the first coverage area is a wide coverage area; the first coverage area provides 360 degrees of coverage; the second coverage area is a narrow coverage area; and the second coverage area provides at most 120 degrees of coverage.
• a wireless device configured to communicate with a network node.
• the WD includes processing circuitry.
• the processing circuitry is configured to cause the WD to transmit at least one uplink signal in a first radio access technology, RAT, the first RAT supporting a first coverage area and a first data rate for the WD.
• RAT radio access technology
• the processing circuitry is configured to cause the WD to receive a handover signal, the handover signal initiating a handover of the WD from the first RAT to a second RAT, the second RAT supporting a second coverage area and a second data rate for the WD, the second coverage area being narrower than the first coverage area and the second data rate being higher than the first data rate and the second RAT using a beam, the beam being based at least in part on angular information obtained from the at least one uplink signal transmitted in the first RAT.
• At least one cell in the second RAT to which the WD is handed over is a pencil-beam cell and a shape of the pencil-beam cell is based at least in part on the angular information obtained from an initial cell using the first RAT.
• the shape of the pencil- beam cell defines the second coverage area.
• the processing circuitry is further configured to cause the WD to transmit the at least one uplink signal in the first RAT by being configured to cause the WD to at least one of transmit a measurement report from which the angular information is obtained; and transmit a signal to be measured by the network node, the angular information based at least in part on the measurement.
• the processing circuitry is further configured to cause the WD to receive a handover signal by being configured to cause the WD to receive a radio resource control, RRC, reconfiguration message, the RRC reconfiguration message indicating a cell corresponding to the second RAT to which the WD is to be handover over, a shape of the cell based on the obtained angular information.
• RRC radio resource control
• the first RAT is one of a machine-type communication, MTC, cell, and a satellite system.
• the first RAT is a cell having coverage enhancement by data repetition.
• the processing circuitry is further configured to cause the WD to perform the handover of the WD from the first RAT to a second RAT as a result of at least one of: data for the WD being present in a data buffer associated with a network node; and an absence of cell candidates capable of supporting broadband coverage to the WD.
• the beam is a WD- specific beam.
• the processing circuitry is further configured to cause the WD to after the handover of the WD to the second RAT, receive downlink and broadcast channels via the beam.
• the first coverage area is a wide coverage area; the first coverage area provides 360 degrees of coverage; the second coverage area is a narrow coverage area; and the second coverage area provides at most 120 degrees of coverage.
• FIG. 1 is a schematic diagram of an exemplary network architecture illustrating a communication system connected via an intermediate network according to the principles in the present disclosure
• FIG. 2 is a block diagram of a network node in communication with a wireless device over an at least partially wireless connection according to some embodiments of the present disclosure
• FIG. 3 is a flowchart of an exemplary process in a network node for Obtainer unit according to some embodiments of the present disclosure
• FIG. 4 is a flowchart of an exemplary process in a wireless device for Handover (HO) unit according to some embodiments of the present;
• FIG. 5 is a schematic diagram of another exemplary network architecture according to some embodiments of the present disclosure.
• FIG. 6 is a flowchart of yet another exemplary processes that may be implemented by a WD and/or a network node according to some embodiments of the present disclosure.
• FIG. 7 is a flowchart of yet another exemplary process including an inter-RAT handover process according to some embodiments of the present disclosure.
• coverage enhancement such as, an extended, wider cell coverage range can be obtained through repetition; however, this results in a relatively low achievable data rate.
• coverage enhancement such as, an extended cell range can be obtained through beamforming; however, a drawback here is that this requires knowledge of the desired angular range of the beam (which may not be available).
• IoT Intemet-of-Things
• MTC-type devices that use coverage enhancement through repetition
• conventional cellular devices such as cell phones
• networks and WDs are configured to either use high capacity transmissions when in the coverage of a typical cellular system, or IoT/MTC-type transmissions using repetition for coverage enhancement when not in the coverage of the typical cellular system.
• IoT/MTC-type of transmission e.g., coverage enhancement through data repetition
• some embodiments of the present disclosure provide for a process and/or arrangement to identify a proper beam (e.g., pencil beam directed to the WD) to use for extended range communication, between a network node and WD, through channel state information (e.g., WD angular information, direction-of- arrival, etc.) acquired e.g., in advance from a wide area coverage communication (e.g., UL channel in an MTC cell that uses repetition for coverage enhancement).
• a proper beam e.g., pencil beam directed to the WD
• channel state information e.g., WD angular information, direction-of- arrival, etc.
• a wide area coverage communication e.g., UL channel in an MTC cell that uses repetition for coverage enhancement.
• the wide area coverage communication does not require directional information and can therefore be used directly to obtain angular information.
• the downlink directional information can be obtained from the wide area coverage communication, through direction-of-arrival estimation, assuming some level of uplink/downlink directional reciprocity, or from DL channel state information signaling/feedback from the WD, made using the wide area coverage communication.
• radio resources can be used more efficiently for DL and/or UL, by using a WD-specific pencil-beam in the specific direction of the WD, and which may eliminate the drawback of reduced throughput since repetition may no longer be used for coverage enhancement.
• NB-IoT Narrowband-IoT
• LTE-M Long Term Evolution Cat-Mi
• an initial low throughput communication made using NB-IoT/LTE-M can be used to obtain angular/directional information allowing for the use of a more spectrally efficient communication with the remote WD using a dedicated beam (e.g., dedicated pencil- beam).
• a dedicated beam e.g., dedicated pencil- beam.
• a remote WD can obtain initial access to the network using a wide coverage area cell (e.g., MTC cell) (which is capable of reaching remote WDs).
• MTC cell wide coverage area cell
• a more spectrally efficient communication can then be initiated (e.g., initiating handover of the WD from the low throughput MTC cell to a higher throughput WD-specific beam cell) using an appropriate pencil beam.
• Some embodiments may not require Line-of-Sight (LoS) from the network node to the WD, but instead, that the angular distribution of the incoming signal (e.g., UL) be somewhat narrow and that the directional information be somewhat reciprocal in the downlink and uplink, as is often the case.
• the joining term, “in communication with” and the like may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example.
• electrical or data communication may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example.
• Coupled may be used herein to indicate a connection, although not necessarily directly, and may include wired and/or wireless connections.
• network node can be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio node such as MSR BS, multi-cell/multicast coordination entity (MCE), relay node, integrated access and backhaul (IAB), donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS),
• BS base station
• wireless device or a user equipment (UE) are used interchangeably.
• the WD herein can be any type of wireless device capable of communicating with a network node or another WD over radio signals, such as wireless device (WD).
• the WD may also be a radio communication device, target device, device to device (D2D) WD, machine type WD or WD capable of machine to machine communication (M2M), low-cost and/or low-complexity WD, a sensor equipped with WD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (IoT) device, or a Narrowband IoT (NB-IOT) device etc.
• D2D device to device
• M2M machine to machine communication
• M2M machine to machine communication
• Tablet mobile terminals
• smart phone laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles
• CPE Customer Premises Equipment
• IoT Internet of Things
• NB-IOT Narrowband IoT
• radio network node can be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell/multicast Coordination Entity (MCE), IAB, relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH).
• RNC evolved Node B
• MCE Multi-cell/multicast Coordination Entity
• IAB Multi-cell/multicast Coordination Entity
• RRU Remote Radio Unit
• RRU Remote Radio Unit
• RRH Remote Radio Head
• pencil-beam may indicate a beam directed to a particular WD direction and/or having a shape based on angular information obtained according to one or more of the techniques in the present disclosure.
• a pencil-beam is meant to roughly have the shape of a narrow cone and is formed by “bundling” from all antennas the power associated with a specific azimuth and elevation using appropriate beamforming weights on each antennas for a given time-frequency resource.
• the phrase “WD-specific beam” may indicate a beam and/or cell whose shape and/or direction is determined according to angular information corresponding to a particular WD according to one or more of the techniques in the present disclosure. It should be understood that, while the WD-specific beam may be tailored to the WD, the resulting cell may, in some embodiments, also be used by other WDs than the WD involved in setting the cell shape/determining the beam.
• a cell may be generally a communication cell, e.g., of a cellular or mobile communication network, provided by a node.
• a serving cell may be a cell on or via which a network node (the node providing or associated to the cell, e.g., base station or eNodeB) transmits and/or may transmit data (which may be data other than broadcast data) to a WD, in particular control and/or user or payload data, and/or via or on which a WD transmits and/or may transmit data to the node;
• a serving cell may be a cell for or on which the WD is configured and/or to which it is synchronized and/or has performed an access procedure, e.g., a random access procedure, and/or in relation to which it is in a RRC_connected or RRC_idle state, e.g., in case the node and/or WD and/or network follow the LTE-standard.
• One or more carriers e.g., up
• At least one uplink (UL) connection and/or channel and/or carrier and at least one downlink (DL) connection and/or channel and/or carrier e.g., via and/or defining a cell, which may be provided by a network node, in particular a base station or eNodeB.
• An uplink direction may refer to a data transfer direction from a terminal to a network node, e.g., base station and/or relay station.
• a downlink direction may refer to a data transfer direction from a network node, e.g., base station and/or relay node, to a terminal.
• UL and DL may be associated to different frequency resources, e.g., carriers and/or spectral bands.
• a cell may comprise at least one uplink carrier and at least one downlink carrier, which may have different frequency bands.
• a network node e.g., a base station or eNodeB, may be adapted to provide and/or define and/or control one or more cells, e.g., an MTC cell and/or a conventional cell.
• the term “signaling” used herein may comprise any of: high-layer signaling (e.g., via Radio Resource Control (RRC) or a like), lower-layer signaling (e.g., via a physical control channel or a broadcast channel), or a combination thereof.
• RRC Radio Resource Control
• the signaling may be implicit or explicit.
• the signaling may further be unicast, multicast or broadcast.
• the signaling may also be directly to another node or via a third node.
• Radio measurement used herein may refer to any measurement performed on radio signals. Radio measurements can be absolute or relative. Radio measurement may be called as signal level which may be signal quality and/or signal strength. Radio measurements can be e.g. intra-frequency, inter-frequency, inter-RAT measurements, CA measurements, etc. Radio measurements can be unidirectional (e.g., DL or UL) or bidirectional (e.g., Round Trip Time (RTT), Receive-Transmit (Rx-Tx), etc.).
• RTT Round Trip Time
• Rx-Tx Receive-Transmit
• radio measurements e.g., Time of Arrival (TOA), timing advance, RTT, Reference Signal Time Difference (RSTD), Rx-Tx, propagation delay, etc.), angle measurements (e.g., angle of arrival), power-based measurements (e.g., received signal power, Reference Signals Received Power (RSRP), received signal quality, Reference Signals Received Quality (RSRQ), Signal-to-interference-plus-noise Ratio (SINR), Signal Noise Ratio (SNR), interference power, total interference plus noise, Received Signal Strength Indicator (RSSI), noise power, etc.), cell detection or cell identification, radio link monitoring (RLM), system information (SI) reading, etc.
• TOA Time of Arrival
• RTT Reference Signal Time Difference
• RSTD Reference Signal Time Difference
• Rx-Tx Reference Signal Time Difference
• propagation delay etc.
• angle measurements e.g., angle of arrival
• power-based measurements e.g., received signal power, Reference Signals Received Power (RSRP),
• the inter-frequency and inter-RAT measurements may be carried out by the WD in measurement gaps unless the WD is capable of doing such measurement without gaps.
• measurement gaps are measurement gap id # 0 (each gap of 6 ms occurring every 40 ms), measurement gap id # 1 (each gap of 6 ms occurring every 80 ms), etc.
• the measurement gaps may be configured at the WD by the network node.
• the network configures a WD 22, in particular with the transmission resources.
• a resource may in general be configured with one or more messages. Different resources may be configured with different messages, and/or with messages on different layers or layer combinations.
• the size of a resource may be represented in symbols and/or subcarriers and/or resource elements and/or physical resource blocks (depending on domain), and/or in number of bits it may carry, e.g. information or payload bits, or total number of bits.
• the set of resources, and/or the resources of the sets may pertain to the same carrier and/or bandwidth part, and/or may be located in the same slot, or in neighboring slots.
• control information e.g., handover command
• one or more resources may be considered to be transmitted in a message having a specific format.
• a message may comprise or represent bits representing payload information and coding bits, e.g., for error coding.
• Receiving (or obtaining) control information may comprise receiving one or more control information messages (e.g., an RRC connection reconfiguration message). It may be considered that receiving control signaling comprises demodulating and/or decoding and/or detecting, e.g. blind detection of, one or more messages, in particular a message carried by the control signaling, e.g. based on an assumed set of resources, which may be searched and/or listened for the control information. It may be assumed that both sides of the communication are aware of the configurations, and may determine the set of resources, e.g. based on the reference size.
• receiving control signaling comprises demodulating and/or decoding and/or detecting, e.g. blind detection of, one or more messages, in particular a message carried by the control signaling, e.g. based on an assumed set of resources, which may be searched and/or listened for the control information. It may be assumed that both sides of the communication are aware of the configurations, and may determine the set of resources, e.g. based
• Signaling may generally comprise one or more symbols and/or signals and/or messages.
• a signal may comprise or represent one or more bits.
• An indication may represent signaling, and/or be implemented as a signal, or as a plurality of signals.
• Signaling in particular control signaling, may comprise a plurality of signals and/or messages, which may be transmitted on different carriers and/or be associated to different signaling processes, e.g. representing and/or pertaining to one or more such processes and/or corresponding information.
• An indication may comprise signaling, and/or a plurality of signals and/or messages and/or may be comprised therein, which may be transmitted on different carriers and/or be associated to different acknowledgement signaling processes, e.g. representing and/or pertaining to one or more such processes.
• Signaling associated to a channel may be transmitted such that represents signaling and/or information for that channel, and/or that the signaling is interpreted by the transmitter and/or receiver to belong to that channel. Such signaling may generally comply with transmission parameters and/or format/s for the channel.
• a channel may generally be a logical or physical channel.
• a channel may comprise and/or be arranged on one or more carriers, in particular a plurality of subcarriers.
• a wireless communication network may comprise at least one network node, in particular a network node as described herein.
• a terminal connected or communicating with a network may be considered to be connected or communicating with at least one network node, in particular any one of the network nodes described herein.
• a channel may generally be a logical, transport or physical channel.
• a channel may comprise and/or be arranged on one or more carriers, in particular a plurality of subcarriers.
• a channel carrying and/or for carrying control signaling/control information may be considered a control channel, in particular if it is a physical layer channel and/or if it carries control plane information.
• a channel carrying and/or for carrying data signaling/user information may be considered a data channel, in particular if it is a physical layer channel and/or if it carries user plane information.
• a channel may be defined for a specific communication direction, or for two complementary communication directions (e.g., UL and DL, or sidelink in two directions), in which case it may be considered to have at least two component channels, one for each direction.
• Examples of channels comprise a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), a physical downlink control channel (PDCCH) and a physical uplink shared channel (PUSCH).
• Transmitting in downlink may pertain to transmission from the network or network node to the terminal.
• the terminal may be considered the WD or UE.
• Transmitting in uplink may pertain to transmission from the terminal to the network or network node.
• Transmitting in sidelink may pertain to (direct) transmission from one terminal to another.
• Uplink, downlink and sidelink (e.g., sidelink transmission and reception) may be considered communication directions.
• uplink and downlink may also be used to described wireless communication between network nodes, e.g. for wireless backhaul and/or relay communication and/or (wireless) network communication for example between base stations or similar network nodes, in particular communication terminating at such.
• Configuring a terminal or wireless device (WD) or node may involve instructing and/or causing the wireless device or node to change its configuration, e.g., at least one setting and/or register entry and/or operational mode.
• a terminal or wireless device or node may be adapted to configure itself, e.g., according to information or data in a memory of the terminal or wireless device (e.g., the indication of the resource allocation as discussed above).
• Configuring a node or terminal or wireless device by another device or node or a network may refer to and/or comprise transmitting information and/or data and/or instructions to the wireless device or node by the other device or node or the network, e.g., allocation data (which may also be and/or comprise configuration data) and/or scheduling data and/or scheduling grants.
• Configuring a terminal may include sending allocation/configuration data to the terminal indicating which modulation and/or encoding to use.
• a terminal may be configured with and/or for scheduling data and/or to use, e.g., for transmission, scheduled and/or allocated uplink resources, and/or, e.g., for reception, scheduled and/or allocated downlink resources. Uplink resources and/or downlink resources may be scheduled and/or provided with allocation or configuration data.
• WCDMA Wide Band Code Division Multiple Access
• WiMax Worldwide Interoperability for Microwave Access
• UMB Ultra Mobile Broadband
• GSM Global System for Mobile Communications
• functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes.
• the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices.
• all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
• FIG. 1 a schematic diagram of a communication system 10, according to an embodiment, such as a 3GPP-type cellular network that may support standards such as LTE and/or NR (5G), which comprises an access network 12, such as a radio access network, and a core network 14.
• the access network 12 comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas 18).
• Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20.
• a first wireless device (WD) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16c.
• a second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16a. While a plurality of WDs 22a, 22b (collectively referred to as wireless devices 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node 16. Note that although only two WDs 22 and three network nodes 16 are shown for convenience, the communication system may include many more WDs 22 and network nodes 16.
• a WD 22 can be in simultaneous communication and/or configured to separately communicate with more than one network node 16 and more than one type of network node 16.
• a WD 22 can have dual connectivity with a network node 16 that supports LTE and the same or a different network node 16 that supports NR.
• WD 22 can be in communication with an eNB for LTE/E-UTRAN and a gNB for NR/NG-RAN.
• a network node 16 is configured to include an Obtainer unit 32 which is configured to cause the network node 16 to obtain angular information using a first radio access technology, RAT, the angular information being associated with a wireless device, WD 22, the first RAT supporting a first coverage area and a first data rate for the WD 22; determine a beam to be used by a second RAT to support a second coverage area and a second data rate for the WD 22, the beam being determined for the second RAT based at least in part on the angular information obtained from the first RAT, the second coverage area being narrower than the first coverage area and the second data rate being higher than the first data rate; and participate in a handover of the WD from the first RAT to the second RAT.
• RAT radio access technology
• a wireless device 22 is configured to include a Handover (HO) unit 34 which is configured to transmit at least one uplink signal in a first radio access technology, RAT, the first RAT supporting a first coverage area and a first data rate for the WD 22; and receive a handover signal, the handover signal initiating a handover of the WD 22 from the first RAT to a second RAT, the second RAT supporting a second coverage area and a second data rate for the WD 22, the second coverage area being narrower than the first coverage area and the second data rate being higher than the first data rate and the second RAT using a beam, the beam being based at least in part on angular information obtained from the at least one uplink signal transmitted in the first RAT.
• HO Handover
• a network node 16 provided in a communication system 10 and including hardware 58 enabling it to communicate with the WD 22.
• the hardware 58 may include a communication interface 60 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 10, as well as a radio interface 62 for setting up and maintaining at least a wireless connection 64 with a WD 22 located in a coverage area 18 served by the network node 16.
• the radio interface 62 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers.
• the hardware 58 of the network node 16 further includes processing circuitry 68.
• the processing circuitry 68 may include a processor 70 and a memory 72.
• the processing circuitry 68 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions.
• the processor 70 may be configured to access (e.g., write to and/or read from) the memory 72, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).
• volatile and/or nonvolatile memory e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).
• the network node 16 further has software 74 stored internally in, for example, memory 72, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 16 via an external connection.
• the software 74 may be executable by the processing circuitry 68.
• the processing circuitry 68 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by network node 16.
• Processor 70 corresponds to one or more processors 70 for performing network node 16 functions described herein.
• the memory 72 is configured to store data, programmatic software code and/or other information described herein.
• the software 74 may include instructions that, when executed by the processor 70 and/or processing circuitry 68, causes the processor 70 and/or processing circuitry 68 to perform the processes described herein with respect to network node 16.
• processing circuitry 68 of the network node 16 may include Obtainer unit 32 configured to perform one or more of the network node methods and/or arrangements discussed in this disclosure, such as, those described with reference to the flowchart depicted in FIG. 3.
• the communication system 10 further includes the WD 22 already referred to.
• the WD 22 may have hardware 80 that may include a radio interface 82 configured to set up and maintain a wireless connection 64 with a network node 16 serving a coverage area 18 in which the WD 22 is currently located.
• the radio interface 82 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers.
• the hardware 80 of the WD 22 further includes processing circuitry 84.
• the processing circuitry 84 may include a processor 86 and memory 88.
• the processing circuitry 84 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions.
• the processor 86 may be configured to access (e.g., write to and/or read from) memory 88, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).
• memory 88 may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).
• the WD 22 may further comprise software 90, which is stored in, for example, memory 88 at the WD 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the WD 22.
• the software 90 may be executable by the processing circuitry 84.
• the software 90 may include a client application 92.
• the client application 92 may be operable to provide a service to a human or non-human user via the WD 22. In providing the service to the user, the client application 92 may receive request data and provide user data in response to the request data.
• the client application 92 may interact with the user to generate the user data that it provides.
• the processing circuitry 84 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by WD 22.
• the processor 86 corresponds to one or more processors 86 for performing WD 22 functions described herein.
• the WD 22 includes memory 88 that is configured to store data, programmatic software code and/or other information described herein.
• the software 90 and/or the client application 92 may include instructions that, when executed by the processor 86 and/or processing circuitry 84, causes the processor 86 and/or processing circuitry 84 to perform the processes described herein with respect to WD 22.
• the processing circuitry 84 of the wireless device 22 may include a HO unit 34 configured to configured to perform one or more of the WD methods and/or arrangements discussed in this disclosure, such as, those described with reference to the flowchart depicted in FIG. 4.
• the inner workings of the network node 16 and WD 22 may be as shown in FIG. 2 and independently, the surrounding network topology may be that of FIG. 1.
• Network infrastructure may determine the routing, which it may be configured to hide from the WD 22 or from a service provider, or both.
• the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).
• FIGS. 1 and 2 show various “units” such as Obtainer unit 32, and HO unit 34 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry.
• FIG. 3 is a flowchart of an exemplary process in a network node 16 for providing a WD-specific beam cell according to some embodiments of the present disclosure.
• One or more Blocks and/or functions and/or methods performed by the network node 16 may be performed by one or more elements of network node 16 such as by Obtainer unit 32 in processing circuitry 68, processor 70, radio interface 62, etc. according to the example method.
• the example method includes obtaining (Block S134), such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, angular information using a first radio access technology, RAT, the angular information being associated with a wireless device, WD 22, the first RAT supporting a first coverage area and a first data rate for the WD 22.
• Block S134 such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, angular information using a first radio access technology, RAT, the angular information being associated with a wireless device, WD 22, the first RAT supporting a first coverage area and a first data rate for the WD 22.
• the method includes determining (Block S136), such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, a beam to be used by a second RAT to support a second coverage area and a second data rate for the WD 22, the beam being determined for the second RAT being based at least in part on the angular information obtained from the first RAT, the second coverage area being narrower than the first coverage area and the second data rate being higher than the first data rate.
• the method includes participating in (Block S138), such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, a handover of the WD 22 from the first RAT to the second RAT.
• At least one cell in the second RAT to which the WD 22 is handed over is a pencil-beam cell and a shape of the pencil-beam cell is based at least in part on the angular information obtained from an initial cell corresponding to the first RAT.
• determining the beam to be used by the second RAT to support the second coverage area further includes determining, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, a shape of a cell corresponding to the second RAT, the shape of the cell defining the second coverage area.
• obtaining the angular information using the first RAT further comprises at least one of receiving, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, a measurement report from the WD, the angular information based at least in part on the measurement report; receiving a signal from the WD 22 and performing a measurement on the signal, the angular information based at least in part on the measurement ; and receiving, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, a handover request, the handover request including the angular information.
• participating in the handover of the WD from the first RAT to the second RAT further includes at least one of: transmitting, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, a radio resource control, RRC, reconfiguration message; and receiving, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, an RRC reconfiguration complete message.
• the first RAT is one of a machine-type communication, MTC, cell and a satellite system.
• the first RAT is a cell having coverage enhancement by data repetition; and the obtaining the angular information using the first RAT further comprising obtaining, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, the angular information using at least one uplink signal transmitted by the WD in the cell having coverage enhancement by data repetition.
• the obtaining angular information using the first RAT further includes receiving, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, at least one uplink signal from the WD 22 via the first RAT; and estimating, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, an uplink, UL, direction-of-arrival based at least in part on the received at least one uplink signal.
• the participating in the handover of the WD 22 further comprises participating in, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, the handover of the WD 22 from the first RAT to the second RAT as a result of at least one of: data for the WD 22 being present in a data buffer associated with the network node 16; and an absence of cell candidates capable of supporting broadband coverage to the WD 22.
• the determined beam is a WD-specific beam.
• the method further includes after the handover of the WD to the second RAT, transmitting, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, downlink and broadcast channels to the WD 22 via the determined beam.
• the method includes based on an inactivity timer, de activating, such as via Obtainer unit 32, processing circuitry 68, processor 70 and/or radio interface 62, the second RAT.
• the first coverage area is a wide coverage area; the first coverage area provides 360 degrees of coverage; the second coverage area is a narrow coverage area; and the second coverage area provides at most 120 degrees of coverage.
• FIG. 4 is a flowchart of an exemplary process in a wireless device 22 related to a WD-specific beam cell provided according to some embodiments of the present disclosure.
• One or more Blocks and/or functions and/or methods performed by WD 22 may be performed by one or more elements of WD 22 such as by HO unit 34 in processing circuitry 84, processor 86, radio interface 82, etc.
• the example method includes transmitting (Block S140), such as via HO unit 34, processing circuitry 84, processor 86 and/or radio interface 82, at least one uplink signal in a first radio access technology, RAT, the first RAT supporting a first coverage area and a first data rate for the WD.
• Block S140 transmitting
• the method includes receiving (Block S142), such as via HO unit 34, processing circuitry 84, processor 86 and/or radio interface 82, a handover signal, the handover signal initiating a handover of the WD 22 from the first RAT to a second RAT.
• the second RAT supports a second coverage area and a second data rate for the WD 22.
• the second coverage area is narrower than the first coverage area and the second data rate is higher than the first data rate and the second RAT uses a beam, the beam being based at least in part on angular information obtained from the at least one uplink signal transmitted in the first RAT.
• At least one cell in the second RAT to which the WD is handed over is a pencil-beam cell and a shape of the pencil-beam cell is based at least in part on the angular information obtained from an initial cell using the first RAT.
• the shape of the pencil-beam cell defines the second coverage area.
• transmitting the at least one uplink signal in the first RAT further comprises at least one of: transmitting, such as via HO unit 34, processing circuitry 84, processor 86 and/or radio interface 82, a measurement report from which the angular information is obtained; and transmitting a signal to be measured by the network node 16, the angular information based at least in part on the measurement.
• receiving a handover signal further comprises receiving, such as via HO unit 34, processing circuitry 84, processor 86 and/or radio interface 82, a radio resource control, RRC, reconfiguration message, the RRC reconfiguration message indicating a cell corresponding to the second RAT to which the WD is to be handover over, a shape of the cell based on the obtained angular information.
• RRC radio resource control
• the first RAT is one of a machine-type communication, MTC, cell corresponding to a radio access technology, RAT, and a satellite system.
• the first RAT is a cell having coverage enhancement by data repetition.
• the method further includes performing the handover of the WD 22 from the first RAT to a second RAT as a result of at least one of: data for the WD 22 being present in a data buffer associated with a network node 16; and an absence of cell candidates capable of supporting broadband coverage to the WD 22.
• the beam is a WD-specific beam.
• the method further includes after the handover of the WD 22 to the second RAT, receiving, such as via HO unit 34, processing circuitry 84, processor 86 and/or radio interface 82, downlink and broadcast channels via the beam.
• at least one of: the first coverage area is a wide coverage area; the first coverage area provides 360 degrees of coverage; the second coverage area is a narrow coverage area; and the second coverage area provides at most 120 degrees of coverage.
• three types of cells from a given transmission/reception point e.g., at network node 16
• AAS angle-of-arrival
• UL signals UL signals
• MTC cell e.g., LTE-M, New Radio (NR)-M, etc.
• NR New Radio
• CE Coverage enhancement
• Conventional cell e.g., LTE, NR, etc.
• regular/conventional coverage with high data rates and high call capacity deployed in and for densely populated areas
• regular mobile devices in regular/planned coverage area.
• ‘Pencil-beam cell’ o Generally, characterized by long-range but narrow coverage, for a more reasonably high data rate (as compared to CE through repetition); o Typical use case: WDs 22 with high data rate capability at remote areas (covered by a wide coverage area system, such as an MTC cell, but not by a conventional cell); ⁇ Network node 16 can transmit/receive messages and/or data at a reasonably high data rate to/from these WDs 22 (as compared to throughput when using repetition); and/or o Use of a pilot signal (e.g., MTC-type, dedicated signal) for AoA/AoD measurement.
• a pilot signal e.g., MTC-type, dedicated signal
• the carrier on which a wide coverage area cell (e.g., MTC cell) is present may be ON’ all the time, while a pencil-beam cell may be activated/de activated dynamically, as needed and/or desired, and may be oriented towards a specific azimuth and elevation direction (e.g., direction based on WD angular information obtained from UL signals in the MTC cell).
• the wide coverage area cell e.g., e.g., MTC cell, LTE-M cell, etc.
• the coverage area cell for WDs 22 that are quite remote (e.g., rural or non-highly populated areas, outside of conventional cell coverage area, etc.).
• the set of possible pencil-beam cells may be considered as capacity booster cells, which may be activated dynamically, such as, for example, when needed to provide higher data rates to remote WDs 22, when requested and/or as otherwise useful.
• the pencil beam cell may be considered to provide a narrower coverage area (e.g., 120 degrees) to the WD 22, but with higher data rates, as compared to data rates for the wide coverage area cell (e.g., 360 degrees), which may utilize repetition for coverage enhancement.
• the criteria used to determine when to establish and/or activate a pencil beam cell (e.g., pencil beam NR cell) for the WD 22 is related to the presence of data in a data buffer at the network node 16 side and/or the WD 22 side when connected to the wide coverage area cell and/or the absence of other “conventional” (e.g., LTE or NR) cell candidates.
• the network node 16 and/or WD 22 may identify the presence of data in the data buffer for DL and/or UL channels, respectively.
• the network node 16 and/or WD 22 may use signals transmitted in the wide coverage area cell to obtain angular information about the WD 22 and use such angular information to activate a WD-specific pencil beam cell and initiate handover of the WD 22 from the wide coverage area cell to the activated WD- specific pencil beam cell.
• all downlink and broadcast channels are transmitted to the WD 22 via the beam, which beam may be determined and/or selected based on the obtained angular information.
• all uplink channels may be transmitted to the network node 16 from the WD 22 via a beam determined and/or selected based on the obtained angular information.
• the specific pencil beam to use may be determined using direction-of-arrival and/or angle-of-arrival information derived from UL signals transmitted by the WD 22.
• the specific beam to use may be determined according to the LTE-M uplink direction-of-arrival information estimated using a method, such as, projecting the signal received at the elements of the AAS (e.g., radio interface 62) on the steering vector of the possible pencil beams and selecting the one associated with the largest resulting power.
• a method such as, projecting the signal received at the elements of the AAS (e.g., radio interface 62) on the steering vector of the possible pencil beams and selecting the one associated with the largest resulting power.
• Other methods for obtaining angular information and/or determining a beam to be used for the WD-specific beam cell may be used in other embodiments.
• the WD 22 may receive an inter-RAT handover signal/command from e.g., the network node 16.
• the inter-RAT handover command may be, for example, via radio resource control (RRC) signaling (e.g., RRC connection reconfiguration message).
• RRC radio resource control
• the WD 22 may then find the newly activated pencil-beam cell during its cell search and connect procedure, allowing the WD 22 to transmit/receive the data e.g., from the data buffer.
• the WD 22 may synchronize to the pencil-beam cell, obtain system information and/or perform a random-access procedure to access and/or connect to the pencil-beam cell.
• an inactivity timer in e.g., network node 16 can be configured to switch off the pencil- beam cell if, e.g., no data has been transmitted to or from the WD 22 for e.g., a predetermined time period.
• the inactivity timer may be set to the predetermined time period and may count down when there is no activity in the pencil-beam cell and when the inactivity timer reaches, for example, 0, the network node 16 may de-activate the pencil-beam cell.
• the WD 22 would then fall back to a condition for which a subsequent cell search by the WD 22 would likely provide access again to the wide coverage area cell (e.g., LTE-M cell). This process may repeat if it is again determined that use of the pencil-beam cell may be useful for the WD 22 (e.g., data is detected in the data buffer).
• the wide coverage area cell e.g., LTE-M cell
• FIG. 5 illustrates an embodiment in which the communication (e.g., UL signalling, DL signalling, etc.) is between a WD 22 and a network node 16 that is a terrestrial base station.
• FIG. 5 also illustrates a communication between the WD 22 and a network node 16 that is a non-terrestrial base station (satellite).
• Some embodiments including a satellite implementation may be performed in one of the following two ways: (1) the satellite is the network node 16, or (2) the satellite is the WD 22.
• the techniques used in the satellite context are similar to what is described herein in a cellular network context.
• the satellite uses a RAT with wide angular coverage (covering a wide earth area) allowing to find a WD 22 on the earth surface or elsewhere in the sky/space, and then another RAT with a pencil-beam to provide higher peak spectral efficiency for the identified WD 22.
• the cellular network node 16 is the same as the non satellite implementation and the satellite is the WD 22.
• the WD 22 broadcasts a non-directional transmission with enough repetitions to be detected at the network node 16 given that, at this preliminary stage, the network node 16 may have no priori information to use in order to set up a directional beam for the detection of the uplink signal (some level of directivity could also be used in the WD 22 transmission if the WD 22 has the capabilities).
• (transmitter) TX beamforming can be quite different from (receiver) RX beamforming in the sense that TX beamforming generally needs to have knowledge about the beamforming weights ahead of the beamforming operation while RX beamforming can actually “try” different sets of weights by applying the weights on the signals received at the antennas and use the set of weights which are seen as “best”.
• the techniques in the present disclosure relate to adapting the angular coverage of the second RAT assuming that the first RAT was able to establish communication using coverage enhancement, such as coverage enhancement through repetition. That coverage enhancement through repetition is not only used in the downlink channels but may also be used in the uplink channels. However, it is also possible for the first RAT to not only use coverage enhancement through repetition for the uplink, but also provide RX beamforming at the network node 16 (by obtaining a proper beamforming weight a posteriori). TX beamforming at the WD 22 could also be used in the uplink for the first RAT if the WD 22 has this capability. The WD 22 would aim a beam in a direction corresponding roughly to the direction that the WD 22 estimated as the direction of arrival for the downlink broadcast channel.
• the WD 22 may transmit a signal in one direction at a time and sweep over time to extend its reach even more so than e.g., with only repetitions. It should be noted that the above concept could also be modified to include an initial phase for which the network node 16 may transmit an MTC signal to provide an initial direction to the WD 22. As an example, in a 3 GPP- specific implementation, this may be performed using the LTE-M RAT.
• the network node 16 can estimate direction-of-arrival from the uplink signal and configure and activate the WD-specific beam cell with a very narrow (e.g., 120 degrees or less) cell beam width that is associated with e.g., a directional pencil- beam to provide downlink and uplink communications for the WD 22 in a more spectrally efficient way for subsequent transmissions/receptions.
• the network node 16 can then instruct the WD 22, using the first RAT (e.g., LTE-M RAT), to perform a handover from e.g., the LTE-M cell to the WD-specific pencil-beam cell (which was just configured and activated for the WD 22).
• the first RAT e.g., LTE-M RAT
• FIG. 6 illustrates a flowchart of another exemplary process according to the techniques in the present disclosure.
• the network node 16 provides a wide coverage area cell (Block S200).
• the WD 22 may perform an initial access of the wide coverage area cell (Block S202).
• the network node 16 estimates AoA information using e.g., UL signal from the WD 22 in the wide coverage area cell (Block S204).
• the network node 16 configures and/or activates the WD-specific pencil-beam cell tailored to the AoA information (Block S206).
• the network node 16 initiates and/or participates in an inter-RAT handover of the WD 22 from the wide coverage area cell to the WD-specific pencil-beam cell (Block S208).
• the WD 22 may then perform a handover procedure to switch to the WD-specific pencil-beam cell (Block S210).
• a beam tuning phase could be triggered to periodically adjust the steering of the beam at the network node 16 using a form of local beam sweeping and feedback from the WD 22. It should be noted that it is contemplated that some embodiments of the present disclosure may provide for the WD 22 also trying to use transmit/receive beamforming if the WD 22 has beamforming capabilities (e.g., multiple antennas). In such embodiments, the tuning/tracking of beams may be made with coordination from the network node 16 and the WD 22.
• FIG. 7 is a flowchart of yet another exemplary process including an inter-RAT handover process according to some embodiments of the present disclosure.
• the WD 22 is shown RRC connected to the handover (HO) source (e.g., network node 16a).
• the HO source e.g., eNB-MTC
• the WD 22 may then perform measurements according to the measurement configuration.
• the WD 22 transmits a measurement report to the HO source.
• the measurement report may include the measurement information requested and/or based on the measurement configuration.
• the HO source may determine and/or derive cell/beam information from the measurement report and/or UL measurements.
• the HO source may transmit an HO request to the HO target (e.g., network node 16b).
• the HO request may include cell/beam information obtained from UL measurements and/or from the measurement report.
• Cell/beam information may be obtained from UL measurements according to one or more known direction of arrival estimation techniques. For example, in one embodiment, a “beamscan” technique may be used, which includes trying candidate receiver (RX) beamforming weight vectors and selecting the one which results in the highest output power. This could directly provide the beam that should be used for the pencil-beam cell. Another approach could provide angular values in azimuth and elevation that you could then be mapped to the most appropriate beam candidate.
• Cell/beam information may be obtained from measurement reports according to one or more techniques.
• downlink reference symbols are transmitted by the network node 16 in different time-frequency locations with different DL beamforming weights, and the WD 22 reports the identity of the one(s) which is(are) received with the best signal-to-interference-plus-noise ratio (SINR).
• SINR signal-to-interference-plus-noise ratio
• the HO target (e.g., eNB -pencil-beam) may send an HO request acknowledgement to the HO source.
• the HO target e.g., eNB -pencil-beam
• the HO target may wait for the pencil-beam cell to be discovered by the WD 22.
• the HO source transmits an RRC reconfiguration message to the WD 22.
• the HO source may determine that the WD 22 has discovered the pencil-beam cell by “gambling” that the WD 22 has discovered the pencil beam cell given that the HO source has let enough time pass for the HO target to configure and activate the pencil- beam cell and that the new pencil beam cell has had sufficient time to send the broadcast/synchronization channels and for the WD 22 to detect and synchronize to the cell.
• the HO source will then receive confirmation that its gamble was correct if the RRC Connection Reconfiguration for the inter-RAT handover to the pencil-beam cell is successfully completed.
• the HO source may determine that the WD 22 has discovered the pencil-beam cell using other techniques as well.
• the WD 22 may apply the RRC reconfiguration and/or perform a random access procedure to connect to the HO target. For example, in step S266, the WD 22 may transmit an initial context setup response; in step S268, the HO target may transmit a random access response to the WD 22; in step S270, the WD 22 may transmit a RRC reconfiguration complete message to the HO target. In stepS272, the WD 22 is RRC connected to the HO target.
• FIG. 7 shows the HO source and HO target as being separate nodes, the principles are also applicable to a single network node running two RAT s/cells according to the principles in this disclosure.
• some embodiments may include one or more of the following: An inter-RAT handover mechanism from a system supporting wide-area coverage through the use of repetitions, to a system supporting higher spectral efficiency through the use of a WD-specific pencil-beam cell.
• the pencil-beam cell being tailored to the WD location obtained from an azimuth and elevation angle of arrival (AoA) estimate obtained from the signal received from the WD on the wide-area coverage system.
• AoA azimuth and elevation angle of arrival
• the concepts described herein may be embodied as a method, data processing system, computer program product and/or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and/or functionality described herein may be performed by, and/or associated to, a corresponding module, which may be implemented in software and/or firmware and/or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that can be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices.
• These computer program instructions may also be stored in a computer readable memory or storage medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.
• the computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
• Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Java® or C++.
• the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language.
• the program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer.
• the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
• LAN local area network
• WAN wide area network
• Internet Service Provider for example, AT&T, MCI, Sprint, EarthLink, MSN, GTE, etc.

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• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Mobile Radio Communication Systems (AREA)

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• 2019
  • 2019-08-02 WO PCT/IB2019/056623 patent/WO2021024016A1/en unknown
  • 2019-08-02 EP EP19779968.7A patent/EP4008127A1/de not_active Withdrawn

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