Performing a handover in a heterogeneous wireless network

• US 9,225,449 B2
• Filed: 02/01/2013
• Issued: 12/29/2015
• Est. Priority Date: 05/11/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Heo, Youn Hyoung, Fong, Mo-Han, Zhang, Yujian, Fwu, Jong-Kae
• Primary Examiner(s): Mered, Habte
• Assistant Examiner(s): Islam, Rownak
• Application Number:
  US13/756,665
• Publication Number:
  US 20130301439A1
• Time in Patent Office: 1,061 Days
• Field of Search: 370/331, 370/338, 370/328, 370/332, 370/329, 370/252, 370/310, 455/439, 455/436, 455/437, 455/442
• US Class Current: 1/1
• CPC Class Codes: H04B 1/56 with provision for simultaneous communication in two directions
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0473 taking constraints in layer or codeword to antenna mapping into account
• CPC Class Codes: H04B 7/0486 taking channel rank into account
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04B 7/0647 Variable feedback rate
• CPC Class Codes: H04B 7/065 Variable contents, e.g. long-term or short-short
• CPC Class Codes: H04B 7/26 at least one of which is mobile
• CPC Class Codes: H04J 3/00 Time-division multiplex systems H04J14/00 takes precedence; relay systems H04B7/14; selecting techniques H04Q
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04J 3/26 in which the information and the address are simultaneously transmitted
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/1803 Stop-and-wait protocols
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• CPC Class Codes: H04L 27/2627 : Modulators
• CPC Class Codes: H04L 5/0007 : the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/001 : the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0035 : Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0053 : Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0073 : Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04L 5/0096 : Indication of changes in allocation
• CPC Class Codes: H04L 5/14 : Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 5/1469 : using time-sharing
• CPC Class Codes: H04L 65/00 : Network arrangements, protocols or services for supporting real-time applications in data packet communication real-time or near real-time messaging, e.g. instant messaging [IM] H04L51/04; selective video distribution H04N21/00
• CPC Class Codes: H04L 69/22 : Parsing or analysis of headers
• CPC Class Codes: H04L 69/324 : in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04W 16/14 : Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/02 : Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/10 : Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/00 : Hand-off or reselection arrangements
• CPC Class Codes: H04W 36/0061 : of neighbour cell information
• CPC Class Codes: H04W 36/0088 : Scheduling hand-off measurements
• CPC Class Codes: H04W 36/0094 : Definition of hand-off measurement parameters
• CPC Class Codes: H04W 36/04 : Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 36/16 : Performing reselection for specific purposes
• CPC Class Codes: H04W 36/22 : for handling the traffic
• CPC Class Codes: H04W 4/02 : Services making use of location information
• CPC Class Codes: H04W 4/023 : using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 4/06 : Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 4/16 : Communication-related supplementary services, e.g. call-transfer or call-hold
• CPC Class Codes: H04W 4/70 : Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 4/90 : Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 48/20 : Selecting an access point
• CPC Class Codes: H04W 52/0209 : in terminal devices terminal devices per se H04W88/02
• CPC Class Codes: H04W 52/0212 : managed by the network, e.g. network or access point is master and terminal is slave
• CPC Class Codes: H04W 52/0216 : using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0225 : using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 52/0229 : where the received signal is a wanted signal
• CPC Class Codes: H04W 52/0235 : where the received signal is a power saving command
• CPC Class Codes: H04W 52/0251 : using monitoring of local events, e.g. events related to user activity
• CPC Class Codes: H04W 56/00 : Synchronisation arrangements
• CPC Class Codes: H04W 56/001 : Synchronization between nodes
• CPC Class Codes: H04W 72/02 : Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/044 : based on the type of the allocated resource
• CPC Class Codes: H04W 72/12 : Wireless traffic scheduling
• CPC Class Codes: H04W 72/1215 : for collaboration of different radio technologies
• CPC Class Codes: H04W 72/21 : in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 : in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/27 : between access points
• CPC Class Codes: H04W 72/30 : Resource management for broadcast services
• CPC Class Codes: H04W 72/51 : based on terminal or device properties
• CPC Class Codes: H04W 72/54 : based on quality criteria
• CPC Class Codes: H04W 72/541 : using the level of interference
• CPC Class Codes: H04W 72/542 : using measured or perceived quality
• CPC Class Codes: H04W 72/56 : based on priority criteria
• CPC Class Codes: H04W 76/14 : Direct-mode setup
• CPC Class Codes: H04W 76/18 : Management of setup rejection or failure
• CPC Class Codes: H04W 76/27 : Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 76/28 : Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 88/02 : Terminal devices
• CPC Class Codes: H04W 88/06 : adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/08 : Access point devices
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

Technology for performing a handover in a heterogeneous wireless network (HetNet) is disclosed. One method comprises receiving, at an anchor serving cell in the HetNet, channel measurement reports made by a user equipment (UE) for a plurality of cells. A transmission point change request can be sent, based on the channel measurements for the UE, from the anchor serving cell to a target transmission point. The target transmission point is located in one of the plurality of cells. A transmission point change indicator is sent from the anchor cell to the UE to indicate a change in TP with which the UE will communicate via an air interface, while maintaining a connection to the anchor serving cell.

Claims

1. A method for performing a handover in a heterogeneous wireless network (HetNet), comprising:

receiving, at an anchor serving cell in the HetNet, channel measurement reports made by a user equipment (UE) for a plurality of cells, wherein one or more of the channel measurement reports is initialized using one or more UE-specific Radio-Resource-Control-configured parameters instead of one or more cell-specific parameters that use a physical cell ID of a specific cell, to enable the UE to avoid performing Radio-Resource reconfiguration when a change in transmission point (TP) from the anchor serving cell to a target TP has occurred;

sending a TP change request that is based, in part, on the channel measurements for the UE, from the anchor serving cell to the target TP, wherein the target TP is located in one of the plurality of cells; and

sending a TP change indicator from the anchor serving cell to the UE to indicate the change in TP with which the UE will communicate via an air interface.

2. The method of claim 1, further comprising:

receiving uplink packets, from the UE, at the anchor serving cell via the target TP, wherein the uplink packets are sent from the UE to the target TP via the air interface and forwarded from the target TP to the anchor serving cell; and

sending downlink packets from the anchor serving cell to the target TP for transmission to the UE via the air interface.

3. The method of claim 1, wherein receiving channel measurements further comprises receiving the channel measurements made by the UE using the one or more UE-specific RRC-configured parameters to initialize channel state information reference signals (CSI-RS) to enable handover to occur for the UE from the anchor serving cell to the target TP without requiring Radio Resource reconfiguration to be performed when the change in TP from the anchor serving cell to the target TP has occurred.

4. The method of claim 1, further comprising sending the TP change indicator from the anchor serving cell to the UE using one of downlink control information (DCI), radio resource control (RRC) signaling, and a medium access control (MAC) control element (CE).

5. The method of claim 1, further comprising sending at least one of a master information block (MIB) and a system information block (SIB) from the anchor serving cell to the UE via the target TP.

6. The method of claim 1, further comprising sending at least one of a master information block (MIB) and a system information block (SIB) from the target TP to the UE using a radio resource control (RRC) layer signaling.

7. The method of claim 1, further comprising changing from a source TP to a target TP, comprising:

receiving, at the anchor serving cell in the HetNet, channel measurement reports made by the user equipment (UE) for the plurality of cells;

identifying that a change in TP is to be performed based, in part, on the channel measurement reports; and

sending a TP change request from the anchor serving cell to a source TP that indicates the target TP to enable the source TP to forward the TP change request to the target TP.

8. The method of claim 1, further comprising forming an uplink/downlink data path to the anchor serving cell comprising:

forming an s1 data connection between the anchor serving cell and at least one of a mobile management entity (MME) and a serving gateway (S-GW); and

forming an X2 interface between the anchor serving cell and the target TP to enable data communication between one of the MME and the S-GW with the UE via the target TP, wherein the target TP has a Uu connection with the UE.

9. The method of claim 8, further comprising:

forming a U-plane tunnel between the anchor serving cell and the target TP to enable uplink data forwarding and downlink data forwarding between the anchor serving cell and the target TP; and

forming a c-plane tunnel between the anchor serving cell and the target TP to enable signaling radio bearer (SRB) communication for a downlink and an uplink between the anchor serving cell and the target cell.

10. A user equipment (UE) operable to perform a handover in a heterogeneous wireless network (HetNet), having computer circuitry configured to:

communicate using one or more physical channels of the UE configured to be initialized using one or more UE-Specific Radio-Resource-control-configured parameters, wherein the one or more UE-Specific Radio-Resource-control-configured parameters are used instead of one or more cell-specific parameters that use a physical cell ID of a specific cell to enable the UE to avoid performing Radio-Resource reconfiguration when a change in transmission point (TP) from an anchor serving cell to a target TP has occurred;

receive a TP change indicator at the UE from the anchor serving cell indicating the target TP for an air interface with the UE;

send uplink data from the UE to the target TP using the one or more physical channels to enable the target TP to forward the uplink data to the anchor serving cell for communication to a core network; and

receive downlink data at the UE from the target TP without having to perform radio resource reconfiguration when the change in TP from the anchor serving cell to the target TP has occurred, wherein the downlink data is sent from the core network to the TP via the anchor serving cell.

11. The computer circuitry of claim 10, having circuitry further configured to:

receive the transmission point change indicator at the UE using one of downlink control information (DCI), radio resource control (RRC) signaling, and a medium access control (MAC) control element (CE).

12. The computer circuitry of claim 10, having circuitry further configured to:

identify carrier-specific resource signal (CRS) resource element (RE) position for the target TP, when CRS is associated with the target TP; and

receiving physical downlink shared channel (PDSCH) resource elements not used for the CRS resource elements (Res).

13. The computer circuitry of claim 10, having circuitry further configured to perform radio link monitoring and uplink power control based on channel state information (CSI) reference signal (RS) information corresponding to the target TP.

14. The computer circuitry of claim 10, having circuitry further configured to send a physical random access channel (PRACH) preamble to the target TP to perform uplink synchronization with the target TP when the target TP includes a different receiving point (RP) than the anchor serving cell.

15. The computer circuitry of claim 10, having circuitry further configured to perform radio link monitoring and uplink power control using a channel state information reference signal (CSI-RS) of the target TP.

16. The computer circuitry of claim 15, having circuitry further configured to change a synchronization reference using the CSI-RS of the target TP.

17. The computer circuitry of claim 10, having circuitry further configured to send channel measurements made by the UE using channel state information reference signals (CSI-RS) to enable handover to occur for the UE from the anchor serving cell to the target TP while continuing to use a radio resource control (RRC) layer configured by the anchor serving cell.

18. The computer circuitry of claim 10, wherein the UE includes at least one of an antenna, a touch sensitive display screen, a speaker, a microphone, a graphics processor, an application processor, internal memory, a non-volatile memory port, and combinations thereof.

23. The UE of claim 10, wherein the one or more physical channels of the UE configured to be initialized using one or more UE-Specific Radio-Resource-control-configured parameters include one or more of:

a physical downlink shared channel (PDSCH), an enhanced physical downlink control channel (E-PDCCH), a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), or a sounding reference signal (SRS).

19. A heterogeneous network (HetNet) handover device in a target transmission point (TP), comprising:

a TP change module configured to receive a TP change request from an anchor serving cell for a user equipment (UE), wherein the UE is configured to communicate using one or more physical channels of the UE, and wherein the physical channels of the UE are configured to be initialized using one or more UE-Specific Radio-Resource-control-configured parameters instead of one or more cell-specific parameters that use a physical cell ID of a specific cell to enable the UE to avoid performing radio resource reconfiguration when a change in TP from the anchor serving cell to the target TP has occurred;

a downlink data forwarding module configured to receive downlink information from the anchor serving cell that is sent from a core network (CN);

an air interface module configured to send the downlink information to the UE and receive uplink information from the UE using the one or more physical channels via an air interface between the UE and the target TP;

an uplink forwarding module configured to send the uplink information to the anchor serving cell for communication to the CN to enable the UE to communicate with the CN via the target TP without having to perform radio resource reconfiguration when the change in TP from the anchor serving cell to the target TP has occurred.

20. The HetNet handover device of claim 19, further comprising a buffer module configured to buffer packets from the anchor serving cell.

21. The HetNet handover device of claim 19, wherein the downlink data forwarding module is further configured to receive the downlink information from the anchor serving cell via X2 interface.

22. The HetNet handover device of claim 19, wherein the downlink information is received from at least one of a mobile management entity (MME) and a serving gateway (S-GW) to the anchor serving cell via an S1 connection.

24. The HetNet handover device of claim 19, wherein the one or more physical channels of the UE configured to be initialized using one or more UE-Specific Radio-Resource-control-configured parameters include one or more of:

a physical downlink shared channel (PDSCH), an enhanced physical downlink control channel (E-PDCCH), a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), or a sounding reference signal (SRS).