boundary may be greater than about four bytes for example about eight bytes further the frame may be aligned with the increased word boundary by increasing the length of the fields in the frames the increased field lengths may also be used to accommodate more values addresses or identifiers to support more onus 120 more data flows or both fig2 illustrates an embodiment of a downstream gtc frame 200 the downstream gtc frame 200 may comprise downstream data transmitted from the olt 110 to any of the onus 120 for instance over a downstream channel for instance the downstream gtc frame 200 may broadcasted by the olt 110 and comprise payload data as well as network control and management information each onu 120 may receive the downstream gtc frame 200 and identify the corresponding data assigned to the onu 120 using some addressing information such as an onu identifier onu id the downstream gtc frame 200 may comprise a physical control block downstream pcbd 210 and a downstream payload 220 which may be a gem payload as described below the pcbd 210 may comprise a plurality of fields such as a physical synchronization psync 211 an identification ident 212 a physical layer operations administration and maintenance ploam downstream or ploamd 213 a bit interleaved parity bip 214 a payload length downstream plend 215 and an upstream bandwidth map us bwmap 216 the psync 211 may comprise a fixed pattern that precedes the remaining fields in the pcbd 210 this pattern.