Packet Ieee80211DataFrame

File: src/inet/linklayer/ieee80211/mac/Ieee80211Frame.msg

C++ definition

Format of the 802.11 data frame

Usage diagram:

The following diagram shows usage relationships between types. Unresolved types are missing from the diagram.

Inheritance diagram:

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Extends:

Name	Type	Description
Ieee80211DataOrMgmtFrame	packet	Common base class for 802.11 data and management frames

Known subclasses:

Name	Type	Description
Ieee80211DataFrameWithSNAP	packet	802.11 data frame with the 8-byte SNAP header (AA AA 03, 00 00 00, <2-byte EtherType>)

Fields:

Name	Type	Description
byteLength
type	short	type and subtype
address4	MACAddress	optional field, exists when toDS and fromDS are true
qos	uint16	TODO nobody uses this currently, only its parts like tid below...
ackPolicy	int	FIXME in real life this is part of the optional qos field above...
tid	uint8	FIXME in real life this is part of the optional qos field above...
aMsduPresent	bool	8.2.4.5.9 A-MSDU Present subfield FIXME in real life this is part of the optional qos field above...
address3	MACAddress
fragmentNumber	short
sequenceNumber	uint16
transmitterAddress	MACAddress	aka address2
toDS	bool
fromDS	bool
retry	bool
moreFragments	bool
duration	simtime_t	TODO: rename to durationField (levy)
AID	short	"id" (Association ID) in the Duration/ID field (-1=no ID)
receiverAddress	MACAddress	aka address1
MACArrive	simtime_t	FIXME remove it, technical data, used inside of MAC module

Source code:

//
// Format of the 802.11 data frame
//
packet Ieee80211DataFrame extends Ieee80211DataOrMgmtFrame
{
    //  The presence of the Address 4 field is determined by the setting of the To DS and From DS subfields of
    //  the Frame Control field (see below). The QoS Control field is present when the QoS subfield of the Subtype
    //  field is set to 1 (8.3.2.1 Data frame format)
    //  FIXME: byteLength is not a constant value (DATAFRAME_HEADER_MINLENGTH / 8 = 28).
    //  For example, with Address 4 and without QoS the correct length is 34 bytes.
    //  Without Address 4 and QoS the correct value is indeed 28.
    //  With Address 4 and QoS the correct value is indeed 36.
    byteLength = DATAFRAME_HEADER_MINLENGTH / 8;
    type = ST_DATA;         // or ST_DATA_WITH_QOS
    MACAddress address4;    // optional field, exists when toDS and fromDS are true
    uint16 qos;             // TODO nobody uses this currently, only its parts like tid below... 
    int ackPolicy @enum(AckPolicy); //FIXME in real life this is part of the optional qos field above...
    uint8 tid; //FIXME in real life this is part of the optional qos field above...
    bool aMsduPresent = false; // 8.2.4.5.9 A-MSDU Present subfield FIXME in real life this is part of the optional qos field above...
}

//TODO this can be introduced when the SNAP header 
//packet Ieee80211QoSDataFrame extends Ieee80211DataFrame
//{
//    type = ST_DATA_WITH_QOS;
//    byteLength = (DATAFRAME_HEADER_MINLENGTH + QOSCONTROL_BITS) / 8;
//    int ackPolicy @enum(AckPolicy); //FIXME in real life this is part of the optional qos field above...
//    uint8 tid;
//    // TODO: other QoS control field parts
//}