EnGenius EWS660AP User Manual page 38

Client Limits: Limits the total number of clients.
Aggregation: Merges data packets into one packet. This option reduces the number of packets, but also increases packet sizes.
AP Detection: AP Detection can select the best channel to use by scanning nearby areas for Access Points.
Distance: Specifies the distance between the Access Points and clients. Note that longer distances may drop higher speed
connections.