A first communication device wirelessly coupled to a second communication device. The first communication device includes a first receiver, a message processor, and a first transmitter. The first receiver is configured to receive first signals corresponding to a first number of communication devices, where the second communication device is one of the communication devices, and is also configured to measure first strengths of the first signals. The message processor is configured to determine that a second number of the communication devices can be processed by the first communication device according to the first strengths measured. The first transmitter is configured to transmit one or more first messages to the second communication device indicating the second number.