eceiver to recreate the original payload and to detect the loss of any intermediate fragments. A connection may be in only one fragmentation state at any time instant. On loss of any fragment, the receiver discards all SDU fragments on the connection until a new SDU fragment or a non-fragmented SDU is detected. For ARQ connections, the fragments are transmitted in sequence. The sequence number assigned to each ARQ PDU that carries MAC SDU fragments allows the receiver to recreate the original payload and to detect the loss of any intermediate fragments. For management connec- tions, the FEH header in the MAC PDU provides information about the control message fragment. The sequence number in FEH is used for sequencing the control message fragments and the fragmentation control bits in the FEH header are used to tag the control message fragments with respect to their position in the parent control message. Only one control message can be in the fragmentation state at any given time. The sequence number, assigned to each management connection PDU carrying a control message fragment, allows the receiver to recreate the original payload and to detect the loss of any intermediate fragments. On loss of any fragment, the receiver waits for the lost control message fragments until a new control message fragment or a new non-fragmented control message is detected. Multiple MAC SDUs may be packed into a single MAC PDU. The support of packing and unpacking is mandatory in IEEE 802. 16m entities; however, it is up to the transmitting side whether to pack a group of MAC SDUs into a single MAC PDU. The packing and fragmentation mechanisms for both the non-ARQ and ARQ connections are specified in the IEEE 802. 16m specification [2]. A MAC PDU may contain a packed sequence of variable-length MAC SDUs. It must be noted that 7.3 MAC PDU formation non-fragmented MAC SDUs and MAC SDU fragments may both be present in the same MAC PDU. The MAC appends a PEH header or an MEH header to the MAC PDU. The fragmentation control bits are set 