A MACRO-ASSISTED MULTI-CONNECTIVITY SCHEME IN MULTI-RAT CELLULAR SYSTEMS

• US 20170303286A1
• Filed: 04/15/2016
• Published: 10/19/2017
• Est. Priority Date: 04/15/2016
• Status: Active Grant

• Current Assignee: HFI Innovation, Inc. (MediaTek, Inc.)
• Original Assignee: MediaTek, Inc.
• Inventors: Sang, Aimin Justin, Zhang, Yuanyuan
• Granted Patent: US 10,045,360 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• 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 72/542 using measured or perceived quality
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states

Abstract

A novel Macro-assisted Multi-Connectivity (MC) mobility scheme for UEs traversing clusters of (mmWave) small cells (small-BS or SBS) under the coverage of the same 5G or LTE Macro-cell (macro-BS or MBS) is proposed. It keeps the same Control/User split scheme and C-Plane anchor at MBS, same as in LTE Dual Connectivity (DuCo or DC), yet extending DuCo with a multi-connectivity split bearer user plane. For example, MBS adopts a multi-way packet data convergence protocol (PDCP) bearer split based on routing weighted by channel quality, SBS'"'"'s resource availability, etc. with or without inter-BS flow control. Utilizing the MC user plane, a macro-assisted make-before-break MC mobility can be enabled.

Claims

1. A method comprising:

establishing a radio resource control (RRC) connection with a macro base station (MBS) by a user equipment (UE) in a heterogeneous network having a macrocell served by the MBS and overlaying smallcells served by smallcell base stations (SBSs);

establishing a multi-connectivity (MC) multi-way split bearer U-plane for simultaneous data transmission with one or more base stations; and

performing macro-assisted make-before-break MC mobility by using the multi-way split bearer.

2. The method of claim 1, wherein UE monitors and reports dynamic channel states to the MBS for a routing or a scheduling decision of loading traffic onto different sub-bearers of the multi-way split bearer.

3. The method of claim 1, wherein the UE reorders PDCP layer packets for a single downlink flow that arrives at the UE from one or more base stations.

4. The method of claim 1, wherein the UE splits PDCP layer packets for a single uplink flow that is destined to the MBS through one or more base stations.

5. The method of claim 1, wherein the UE adopts a dynamic weighted based U-plane routing and scheduling for the multi-way split bearer.

6. The method of claim 1, wherein the make-before-break MC mobility involves switching between (N-1)-way and N-way of the multi-way split bearer, wherein N is an integer that is greater than one.

7. The method of claim 1, wherein the UE uses the multi-way split bearer to aggregate multi-cell bandwidth at PDCP layer for packets from one flow but through different base stations.

8. A User Equipment (UE) comprising:

a control plane handler that establishes a radio resource control (RRC) connection with a macro base station (MBS) in a heterogeneous network having a macrocell served by the MBS and overlaying smallcells served by smallcell base stations (SBSs);

a user plane handler that establishes a multi-connectivity (MC) multi-way split bearer U-plane for simultaneous data transmission with one or more base stations; and

a mobility circuit that performs macro-assisted make-before-break MC mobility by using the multi-way split bearer.

9. The UE of claim 8, wherein UE monitors and reports dynamic channel states to the MBS for a routing or a scheduling decision of loading traffic onto different sub-bearers of the multi-way split bearer.

10. The UE of claim 8, wherein the UE reorders PDCP layer packets for a single downlink flow that arrives at the UE from one or more base stations.

11. The UE of claim 8, wherein the UE splits PDCP layer packets for a single uplink flow that is destined to the MBS through one or more base stations.

12. The UE of claim 8, wherein the UE adopts a dynamic weighted based U-plane routing and scheduling for the multi-way split bearer.

13. The UE of claim 8, wherein the make-before-break MC mobility involves switching between (N-1)-way and N-way of the multi-way split bearer, wherein N is an integer that is greater than one.

14. The UE of claim 8, wherein the UE uses the multi-way split bearer to aggregate multi-cell bandwidth at PDCP layer for packets from one flow but through different base stations.

15. A method comprising:

establishing a radio resource control (RRC) connection with a user equipment (UE) by a macro base station (MBS) in a multi-RAT network having a microwave macrocell served by the MBS and overlaying smallcells served by smallcell base stations (SBSs);

establishing a multi-connectivity (MC) multi-way split bearer U-plane together with the SBSs for providing simultaneous data transmission to the UE; and

performing macro-assisted make-before-break MC mobility for the UE by using the multi-way split bearer.

16. The method of claim 15, wherein the MBS collects dynamic channel states for making a routing or a scheduling decision of loading traffic onto different sub-bearers of the multi-way split bearer.

17. The method of claim 15, wherein the MBS exchanges signaling carrying weighting information with the SBSs and the UE for a weighted traffic splitting/merging at the packet data convergence protocol (PDCP) layer.

18. The method of claim 17, wherein the PDCP layer packets routing/merging occurs for a single uplink flow that is destined to the MBS through one or more base stations.

19. The method of claim 17, wherein the PDCP payer packets scheduling/splitting occurs for a single downlink flow that arrives at the UE through one or more base stations.

20. The method of claim 15, wherein the MBS supports SBS addition or removal from the multi-way split bearer through RAN and the core network signaling to enable the multi-way bearer splitting or merging.

21. The method of claim 15, wherein the make-before-break MC mobility involves switching between (N-1)-way and N-way of the multi-way split bearer, wherein N is an integer that is greater than one.

22. The method of claim 21, wherein the multi-way split bearer switching is based on channel quality, resource availability, network policy, UE preference, and traffic loads.