Low-Latency Inter-eNodeB Coordinated Multi-Point Transmission

Abstract

Systems and methods are disclosed for supporting multi-point transmission. In one embodiment, a system for downlink multi-point transmission are disclosed, comprising: a first base station in radio frequency proximity to a user device and with a established control connection with the user device; a second base station also in radio frequency proximity to the user device; and a coordinating node coupled to the first and the second base station for coordinating transmissions to the first and the second base station to the user device, the coordinating node configured to: select the second base station based on selection criteria, the selection criteria including latency of each base station and perceived signal strength of each base station at the user device; and send scheduling instructions to each of the first and the second base stations to transmit data to the user device.

1 . A system for downlink multi-point transmission, comprising:
 a first base station in radio frequency proximity to a user device and with an established control connection with the user device;   a second base station also in radio frequency proximity to the user device connected to a core network via the first base station in a mesh network; and   a coordinating server coupled to the first and the second base station for coordinating transmissions to the first and the second base station to the user device, the coordinating server configured to:   select the first base station to send downlink signals to a User Equipment (UE); and   select the second base station to receive uplink signals from the UE,   wherein the coordinating server is situated between, and is configured to act as a gateway between, a plurality of radio access nodes and an operator core network, the plurality of radio nodes including the first and the second base station.   
     
     
         2 . The system of  claim 1  wherein the second base station is physically closer to the coordinating server than the first base station. 
     
     
         3 . The system of  claim 1  wherein the first base station is a macro base station. 
     
     
         4 . The system of  claim 3  wherein the second base station is a micro base station. 
     
     
         5 . The system of  claim 1  wherein the first base station communicates with the coordinating server via an X2 protocol. 
     
     
         6 . The system of  claim 1  wherein the second base station communicates with the coordinating server via an X2 protocol. 
     
     
         7 . The system of  claim 1  wherein the first base station communicates with the UE via a Uu protocol. 
     
     
         8 . The system of  claim 7  wherein the second base station communicates with the UE via a Uu protocol. 
     
     
         9 . The system of  claim 4  wherein a virtual cell ID is used to enable use of the macro base station and the micro base station as a single base station. 
     
     
         10 . The system of  claim 4  wherein as the UE moves, a different micro base station is used for receiving uplink signals from the UE. 
     
     
         11 . The system of  claim 10  wherein selection of a different micro base station for receiving uplink signals from the UE is performed by the coordinating server.