Referring to the overhead penalty imposed by the small size of the asynchronous transfer mode (ATM) cell. Although the ATM cell imposes only 5 octets of overhead, there are only 48 octets of payload, Picocell Macrocell Microcell so the overhead accounts for approximately 10 percent of the cell. Additionally, there is overhead embedded in the payload attributable to Convergence Sublayer and Data Link Layer and Network Layer headers. See also ATM, Convergence Sublayer, Data Link Layer, header, Network Layer, octet, overhead, and payload.