| CPC H04W 56/0015 (2013.01) [H04W 84/042 (2013.01)] | 20 Claims |
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1. A central radio access network (C-RAN) system comprising:
a plurality of base stations, the plurality of base stations comprising:
a plurality of controllers; and
a plurality of radio points;
wherein each of the controllers and the radio points comprises a respective local clock;
wherein each of the radio points is associated with a respective at least one antenna, wherein the plurality of radio points is communicatively coupled to the controllers using a fronthaul network;
wherein the controllers and the plurality of radio points are configured to implement the plurality of base stations in order to provide wireless service to a plurality of user equipment (UEs), each of the controllers configured to perform at least some air-interface Layer 2 processing for one or more of the base stations;
wherein each of the controllers is communicatively coupled to a core network of a wireless service provider over a backhaul network;
wherein each of the controllers is communicatively coupled to a master clock source over the backhaul network;
wherein each of the controllers is configured to:
determine if that controller should serve as a timing master for the controllers and the radio points;
if that controller should serve as the timing master,
serve, by that controller, as the timing master for the controllers and the radio points;
synchronize the local clock of that controller with the master clock source over the backhaul network; and
transmit synchronization messages from that controller over the fronthaul network for reception by the other controllers and the radio points and for use by the other controllers and the radio points in synchronizing the local clocks thereof with the local clock of that controller.
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11. A method of distributing a clock in a central radio access network (C-RAN) system comprising a plurality of base stations, the plurality of base stations comprising a plurality of controllers and a plurality of radio points, wherein each of the controllers and the radio points comprises a respective local clock, wherein each of the radio points is associated with at least one antenna, wherein the plurality of radio points is communicatively coupled to the controllers using a fronthaul network, wherein the controllers and the plurality of radio points are configured to implement the plurality of base stations in order to provide wireless service to a plurality of user equipment (UEs), each of the controllers configured to perform at least some air-interface Layer 2 processing for one or more of the base stations, wherein each of the controllers is communicatively coupled to a core network of a wireless service provider over a backhaul network, and wherein each of the controllers is communicatively coupled to a master clock source over the backhaul network, the method comprising:
determining if a first of the controllers should serve as a timing master for the controllers and the radio points;
if said first controller should serve as the timing master,
serving, by said first controller, as the timing master for the controllers and the radio points;
synchronizing the local clock of said first controller with the master clock source over the backhaul network; and
transmitting synchronization messages from said first controller over the fronthaul network for reception by the other controllers and the radio points and for use by the other controllers and the radio points in synchronizing the local clocks thereof with the local clock of said first controller.
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