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6 auxiliary security header field, 7 mac service data unit (msdu), 8 mac footer (mfr) fields – Rainbow Electronics AT86RF231 User Manual

Page 84

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84

8111A–AVR–05/08

AT86RF231

8.1.2.6

Auxiliary Security Header Field

The Auxiliary Security Header specifies information required for security processing and has a
variable length. This field determines how the frame is actually protected (security level) and
which keying material from the MAC security PIB is used (see IEEE 802.15.4-2006, section
7.6.1). This field shall be present only if the Security Enabled subfield b3, see

Section 8.1.2.3

“Frame Compatibility between IEEE 802.15.4-2003 and IEEE 802.15.4-2006” on page 83

, is set

to one. For details of its structure, see IEEE 802.15.4-2006, section 7.6.2. Auxiliary security
header.

8.1.2.7

MAC Service Data Unit (MSDU)

This is the actual MAC payload. It is usually structured according to the individual frame type. A
description can be found in IEEE 802.15.4-2006, section 5.5.3.2.

8.1.2.8

MAC Footer (MFR) Fields

The MAC footer consists of a two-octet Frame Checksum (FCS), for details refer to

Section 8.2

“Frame Check Sequence (FCS)” on page 85

.