5.8.3.7 Sequence Control field In data frames, the Sequence Control field contains the information necessary to identify the MSDU or MMPDU sequence number. The information in this field has the format depicted in Fig. 5.8.3.7.1. Bits 4 to 15 identify the packet sequence number, while bits 0 to 3 are reserved for possible future extensions of the protocol functionality such as packet fragmentation support. This same information is used by the receiving station and placed in the Ack Info field of a subsequent frame used for package acknowledgment. 5.8.3.8 Reserved field This field contains 16 bits which are reserved for future references in an extension of the MAC protocol. 5.8.3.9 Body field The Frame Body is a variable length field that contains information specific to individual frame types and subtypes as defined in subclause 5.8.4. The minimum frame body is 0 octets. The maximum length frame body is defined by the maximum length (MSDU + ICV + higher layer overhead), where ICV stands for integrity check value. 5.8.3.10 Frame check sequence (FCS) field The FCS field is a 32-bit field containing a 32-bit CRC. The FCS is calculated over all the fields of the MAC header and the Frame Body field. These are referred to as the calculation fields. The FCS is calculated the following standard generator polynomial of degree 32: G(x) = + + + + + + + + + + + + + + 1 x32 x26 x23 x22 x16 x12 x11 x10 x8 x7 x5 x4 x2 x The FCS is the ones complement of the sum (modulo 2) of the following: a) The remainder of × (x31 + + + + + 1) divided (modulo 2) by G(x), where xk x30 x29 x2 x …+ is the number of bits in the calculation fields, and k
5.8.3.7 Sequence Control field In data frames, the Sequence Control field contains the information necessary to identify the MSDU or MMPDU sequence number. The information in this field has the format depicted in Fig. 5.8.3.7.1. Bits 4 to 15 identify the packet sequence number, while bits 0 to 3 are reserved for possible future extensions of the protocol functionality such as packet fragmentation support. This same information is used by the receiving station and placed in the Ack Info field of a subsequent frame used for package acknowledgment. 5.8.3.8 Reserved field This field contains 16 bits which are reserved for future references in an extension of the MAC protocol. 5.8.3.9 Body field The Frame Body is a variable length field that contains information specific to individual frame types and subtypes as defined in subclause 5.8.4. The minimum frame body is 0 octets. The maximum length frame body is defined by the maximum length (MSDU + ICV + higher layer overhead), where ICV stands for integrity check value. 5.8.3.10 Frame check sequence (FCS) field The FCS field is a 32-bit field containing a 32-bit CRC. The FCS is calculated over all the fields of the MAC header and the Frame Body field. These are referred to as the calculation fields. The FCS is calculated the following standard generator polynomial of degree 32: G(x) = x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1 The FCS is the ones complement of the sum (modulo 2) of the following: a) The remainder of xk × (x31 + x30 + x29 + …+ x2 + x + 1) divided (modulo 2) by G(x), where k is the number of bits in the calculation fields, and
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