Granted Patent B2

US 12,610,276 · App. 17/900,561 · Granted Apr 21, 2026

Inventors: Irfaan Ahamed Salahuddeen (Acton, MA); Vagish Srinivasamurthy (Bangalore, IN); Purnima Venkata Kompella (Bangalore, IN); Naveen Shanmugaraju (Bangalore, IN)

Assignee: Outdoor Wireless Networks LLC

H04W28/0278H04W72/12H04W80/02

Abstract

Claims (123)

1 . A cloud radio access network (C-RAN), comprising:

a Central Unit (CU);

at least one Distributed Unit (DU);

at least one remote unit (RU), communicatively coupled to the at least one DU via a front-haul network, that exchanges radio frequency (RF) signals with a user equipment (UE) using an air interface;

a controller, implemented in the DU or the CU, communicatively coupled to the at least one RU, the controller forming first Radio Link Control (RLC) protocol data units (PDUs) for a first cell and second RLC PDUs for a second cell based on RLC service data units (SDUs); and

wherein a first at least one processor in the controller performs first Medium Access Control (MAC) scheduling for the first cell based on a first buffer occupancy update to produce a first scheduling decision;

wherein a second at least one processor in the controller performs second MAC scheduling for the second cell based on a second buffer occupancy update to produce a second scheduling decision;

wherein the CU performs Packet Data Convergence Protocol (PDCP) processing, comprising:

receiving Internet Protocol (IP) packets from an IP layer;

removing IP headers from the IP packets;

adding a PDCP header to form the RLC SDUs; and

sending the RLC SDUs to the controller.

2 . The C-RAN of claim 1 , wherein the first at least one processor in the controller further determines the first buffer occupancy update, which indicates a first amount of data waiting in a queue specific to the UE and the first cell;

wherein the second at least one processor in the controller further determines the second buffer occupancy update, which indicates a second amount of data waiting in a queue specific to the UE and the second cell.

3 . The C-RAN of claim 1 ,

wherein the first at least one processor is implemented in a first at least one computing device;

wherein the second at least one processor is implemented in a second at least one computing device physically separate from the first at least one computing device;

wherein the first at least one computing device and the second at least one computing device combine to implement the controller.

4 . The C-RAN of claim 1 ,

wherein the at least one remote unit transmit to the UE from the first cell using a first carrier frequency;

wherein the at least one remote unit transmit to the UE from the second cell using a second carrier frequency.

5 . The C-RAN of claim 1 , wherein the first MAC scheduling and the second MAC scheduling are performed in parallel during at least partially overlapping time periods.

6 . The C-RAN of claim 1 , wherein the first at least one processor in the controller further performs first MAC layer processing to produce first MAC PDUs from the first RLC PDUs;

wherein the second at least one processor in the controller further performs second MAC layer processing to produce second MAC PDUs from the second RLC PDUs.

7 . The C-RAN of claim 1 , wherein the first at least one processor in the controller further:

fragments the first RLC PDUs, based on the first scheduling decision; and

performs first MAC layer processing to produce first MAC PDUs from the fragmented first RLC PDUs.

8 . The C-RAN of claim 1 , wherein the second at least one processor in the controller further:

fragments the second RLC PDUs, based on the second scheduling decision; and

performs second MAC layer processing to produce second MAC PDUs from the fragmented second RLC PDUs.

9 . The C-RAN of claim 1 , wherein the controller further:

initiates a first retransmission in response to receiving a first non-acknowledgement (NACK) from the UE regarding the first RLC PDUs; or

initiates a second retransmission in response to receiving a second non-acknowledgement (NACK) from the UE regarding the second RLC PDUs.

10 . A method performed by a controller in a C-RAN comprising a Central Unit, at least one Distributed Unit (DU), the controller implemented in the DU or the CU, and at least one remote unit (RU) that wirelessly communicates with a UE, the method comprising:

forming, based on Radio Link Control (RLC) service data units (SDUs), first RLC protocol data units (PDUs) for a first cell and second RLC PDUs for a second cell;

performing, using a first at least one processor, first Medium Access Control (MAC) scheduling for the first cell based on a first buffer occupancy update to produce a first scheduling decision; and

performing, using a second at least one processor, second MAC scheduling for the second cell based on a second buffer occupancy update to produce a second scheduling decision;

performing, in the CU, Packet Data Convergence Protocol (PDCP) processing, comprising:

receiving Internet Protocol (IP) packets from an IP layer;

removing IP headers from the IP packets;

adding a PDCP header to form the RLC SDUs; and

sending the RLC SDUs to the controller.

11 . The method of claim 10 , further comprising:

determining, using the first at least one processor, the first buffer occupancy update, which indicates a first amount of data waiting in a queue specific to the UE and the first cell; and

determining, using the second at least one processor, the second buffer occupancy update, which indicates a second amount of data waiting in a queue specific to the UE and the second cell.

12 . The method of claim 10 ,

wherein the first at least one processor is implemented in a first at least one computing device;

wherein the second at least one processor is implemented in a second at least one computing device physically separate from the first at least one computing device;

wherein the first at least one computing device and the second at least one computing device combine to implement the controller.

13 . The method of claim 10 , further comprising:

transmitting, from the at least one RU, to the UE from the first cell using a first carrier frequency; and

transmitting, from the at least one RU, to the UE from the second cell using a second carrier frequency.

14 . The method of claim 10 , wherein the first MAC scheduling and the second MAC scheduling are performed in parallel during at least partially overlapping time periods.

15 . The method of claim 10 , further comprising:

performing, using the first at least one processor, first MAC layer processing to produce first MAC PDUs from the first RLC PDUs; and

performing, using the second at least one processor, second MAC layer processing to produce second MAC PDUs from the second RLC PDUs.

16 . The method of claim 10 , further comprising:

fragmenting, using the first at least one processor, the first RLC PDUs, based on the first scheduling decision; and

fragmenting, using the first at least one processor, first MAC layer processing to produce first MAC PDUs from the fragmented first RLC PDUs.

17 . The method of claim 10 , further comprising:

fragmenting, using the first at least one processor, the second RLC PDUs, based on the second scheduling decision; and

fragmenting, using the first at least one processor, second MAC layer processing to produce second MAC PDUs from the fragmented second RLC PDUs.

18 . The method of claim 10 , further comprising:

initiating a first retransmission in response to receiving a first non-acknowledgement (NACK) from the UE regarding the first RLC PDUs; or

initiating a second retransmission in response to receiving a second non-acknowledgement (NACK) from the UE regarding the second RLC PDUs.

19 . A base station, comprising:

at least one remote unit (RU) that exchanges radio frequency (RF) signals with a user equipment (UE) using an air interface; and

a controller communicatively coupled to the at least one RU, the controller configured to:

form, at an upper RLC entity, first RLC protocol data units (PDUs) for a first cell and second RLC PDUs for a second cell based on Radio Link Control (RLC) service data units (SDUs);

determine, by at least one lower RLC entity, at least one buffer occupancy update indicating a first amount of data waiting in a queue specific to the first cell and the UE and a second amount of data waiting in a queue specific to the second cell and the UE;

wherein a first at least one processor in the controller, implementing a first lower RLC entity, determines the first amount of data; and

wherein a second at least one processor in the controller, implementing a second lower RLC entity, determines the second amount of data;

wherein the base station performs Packet Data Convergence Protocol (PDCP) processing, comprising:

receiving Internet Protocol (IP) packets from an IP layer;

removing IP headers from the IP packets;

adding a PDCP header to form the RLC SDUs; and

sending the RLC SDUs to the controller.

20 . The base station of claim 19 , wherein the base station is a cloud radio access network (C-RAN), comprising:

the at least one RU;

at least one Distributed Unit (DU) communicatively coupled to the at least one RU via a front-haul network; and

a Central Unit (CU), wherein the controller is implemented in the DU or the CU.

21 . The base station of claim 19 , wherein the controller is further configured to:

perform, based on the at least one buffer occupancy update, first Medium Access Control (MAC) scheduling for the first cell to produce a first scheduling decision and second MAC scheduling for the second cell to produce a second scheduling decision.

22 . The base station of claim 21 ,

wherein the first MAC scheduling is performed in a first at least one processor implementing a first per-cell MAC scheduler;

wherein the second MAC scheduling is performed in a second at least one processor implementing a second per-cell MAC scheduler.

23 . The base station of claim 21 , wherein the controller fragments at least one of the following:

the first RLC PDUs based on the first scheduling decision; and

the second RLC PDUs based on the second scheduling decision.

24 . The base station of claim 19 , wherein a first at least one processor in the controller further:

performs first MAC layer processing to produce first MAC PDUs based on the first RLC PDUs.

25 . The base station of claim 19 , wherein a second at least one processor in the controller further:

performs second MAC layer processing to produce second MAC PDUs based on the second RLC PDUs.

26 . The base station of claim 19 , wherein the controller further:

initiates a first retransmission in response to receiving a first non-acknowledgement (NACK) from the UE regarding the first RLC PDUs; or

initiates a second retransmission in response to receiving a second non-acknowledgement (NACK) from the UE regarding the second RLC PDUs.

27 . A method performed by a controller in a base station comprising the controller and at least one remote unit (RU) that wirelessly communicates with a UE, the method comprising:

forming, at an upper RLC entity, first RLC protocol data units (PDUs) for a first cell and second RLC PDUs for a second cell based on Radio Link Control (RLC) service data units (SDUs);

determining, by at least one lower RLC entity, at least one buffer occupancy update indicating a first amount of data waiting in a queue specific to the first cell and the UE and a second amount of data waiting in a queue specific to the second cell and the UE;

wherein the first amount of data is determined using a first at least one processor in the controller that implements a first lower RLC entity; and

wherein the second amount of data is determined using a second at least one processor in the controller that implements a second lower RLC entity;

performing Packet Data Convergence Protocol (PDCP) processing, comprising:

receiving Internet Protocol (IP) packets from an IP layer;

removing IP headers from the IP packets;

adding a PDCP header to form the RLC SDUs; and

sending the RLC SDUs to the controller.

28 . The method of claim 27 , wherein the base station is a cloud radio access network (C-RAN), comprising:

the at least one RU;

at least one Distributed Unit (DU) communicatively coupled to the at least one RU via a front-haul network; and

a Central Unit (CU), wherein the controller is implemented in the DU or the CU.

29 . The method of claim 27 , further comprising:

performing, based on the at least one buffer occupancy update, first Medium Access Control (MAC) scheduling for the first cell to produce a first scheduling decision and second MAC scheduling for the second cell to produce a second scheduling decision.

30 . The method of claim 29 , further comprising:

performing the first MAC scheduling using a first at least one processor that implements a first per-cell MAC scheduler; and

performing the second MAC scheduling in a second at least one processor that implements a second per-cell MAC scheduler.

31 . The method of claim 29 , further comprising fragmenting at least one of the following:

the first RLC PDUs based on the first scheduling decision; and

the second RLC PDUs based on the second scheduling decision.

32 . The method of claim 27 , further comprising performing first MAC layer processing to produce first MAC PDUs based on the first RLC PDUs.

33 . The method of claim 27 , further comprising performing second MAC layer processing to produce second MAC PDUs based on the second RLC PDUs.

34 . The method of claim 27 , further comprising:

initiating a first retransmission in response to receiving a first non-acknowledgement (NACK) from the UE regarding the first RLC PDUs; or

initiating a second retransmission in response to receiving a second non-acknowledgement (NACK) from the UE regarding the second RLC PDUs.

Assignments (9)

Priority Claims (1)

Continuity (1)

References Cited (6)