One or more devices comprising: one or more processors; and memory storing instructions that, when executed by the one or more processors, configure the one or more devices to: classify each of a plurality of communication cells associated with a base station as being a forbidden communication cell or a clean communication cell, wherein: up-link transmissions received from a client device are not permitted using a forbidden communication cell, the forbidden communication cell being associated with a first portion of spectrum assigned to the client device that is also available for up-link communications by an incumbent entity; and the up-link transmissions received from the client device are permitted using a clean communication cell associated with a second portion of spectrum assigned to the client device; send, for individual ones of the plurality of communication cells, a broadcast system information message indicating that the individual communication cell is either a forbidden communication cell or a clean communication cell; determine that the client device has identified a clean communication cell and is monitoring the clean communication cell; in response to receiving a request from the client device or an indication that there is data available for the client device to receive, determine that the request is associated with down-link transmissions to the client device; determine that a forbidden cell is available for use for the down-link transmissions to the client device; use the clean communication cell being monitored by the client device for receiving the up-link transmissions from the client device; and use the forbidden communication cell determined to be available for use for sending the down-link transmissions to the client device. one or more processors; and memory storing instructions that, when executed by the one or more processors, configure the one or more devices to: classify each of a plurality of communication cells associated with a base station as being a forbidden communication cell or a clean communication cell, wherein: up-link transmissions received from a client device are not permitted using a forbidden communication cell, the forbidden communication cell being associated with a first portion of spectrum assigned to the client device that is also available for up-link communications by an incumbent entity; and the up-link transmissions received from the client device are permitted using a clean communication cell associated with a second portion of spectrum assigned to the client device; send, for individual ones of the plurality of communication cells, a broadcast system information message indicating that the individual communication cell is either a forbidden communication cell or a clean communication cell; determine that the client device has identified a clean communication cell and is monitoring the clean communication cell; in response to receiving a request from the client device or an indication that there is data available for the client device to receive, determine that the request is associated with down-link transmissions to the client device; determine that a forbidden cell is available for use for the down-link transmissions to the client device; use the clean communication cell being monitored by the client device for receiving the up-link transmissions from the client device; and use the forbidden communication cell determined to be available for use for sending the down-link transmissions to the client device. classify each of a plurality of communication cells associated with a base station as being a forbidden communication cell or a clean communication cell, wherein: up-link transmissions received from a client device are not permitted using a forbidden communication cell, the forbidden communication cell being associated with a first portion of spectrum assigned to the client device that is also available for up-link communications by an incumbent entity; and the up-link transmissions received from the client device are permitted using a clean communication cell associated with a second portion of spectrum assigned to the client device; up-link transmissions received from a client device are not permitted using a forbidden communication cell, the forbidden communication cell being associated with a first portion of spectrum assigned to the client device that is also available for up-link communications by an incumbent entity; and the up-link transmissions received from the client device are permitted using a clean communication cell associated with a second portion of spectrum assigned to the client device; send, for individual ones of the plurality of communication cells, a broadcast system information message indicating that the individual communication cell is either a forbidden communication cell or a clean communication cell; determine that the client device has identified a clean communication cell and is monitoring the clean communication cell; in response to receiving a request from the client device or an indication that there is data available for the client device to receive, determine that the request is associated with down-link transmissions to the client device; determine that a forbidden cell is available for use for the down-link transmissions to the client device; use the clean communication cell being monitored by the client device for receiving the up-link transmissions from the client device; and use the forbidden communication cell determined to be available for use for sending the down-link transmissions to the client device.