MPDU - 802.11ac

This section enables you to configure the MAC header, set the length and type of payload data, and choose to have an FCS added to the packet.

MPDU Index	User File
A-MPDU_Subframe_Length	User File Length
MPDU Length	MAC Header
Data Type	MAC FCS
PN9 Seed	Increment Sequence Number
PN15 Seed	Sequence Number Increment by: (Frames)
Data Length	Increment Fragment Number

MPDU Index

Displays the index for each MPDU. This cell cannot be edited.

A-MPDU Subframe Length

Coupling: Only available when Aggregated MPDU is set to ON.

Displays the number of octets in the current A-MPDU subframe, which is composed of MPDU and Padded MPDU Delimiters.

If the current MPDU is not the last one, its length can not be shorther than Minimum MPDU Start Spacing, otherwise MDPU delimiters will be padded after the current MPDU. If the current MPDU is the last one, its A-MPDU Subframe Length is equal to its MPDU Length plus the length of one MPDU Delimiter (4 octets).

MPDU Length

Displays the number of octets in current MPDU, which is comprised of MSDU, MAC Header and MAC FCS.

Prior to N7617B version 1.12.0.0, this was named MAC Frame Length.

Data Type

Use this cell to select the payload data source. The user data of the frame can contain the following data:

All 0s

PN9

PN15

User file

The user file must be in binary form. The least significant bit (LSB) of the first byte in the user data file will be the first bit of the user payload; the LSB of the second byte in the user file will be the ninth bit of the user payload, and so on. If User file is selected as the Data Type, the value displayed in the Data Length field will be equal to the length of the user's data file, up to the maximum data length.

PN9 Seed

Range: 0 to 511

Default: 511

Specify a seed in decimal format to generate a PN9 data sequence. The LSB of the seed comes out first. For example, if you enter a seed value of 10 (1010 in binary), the first 9 bits of the PN9 sequence are 0 1 0 1 0 0 0 0 0, with an increasing index from left to right. For more information, see PN Sequence Generation.

PN15 Seed

Range: 0 to 32767

Default: 32767

Specify a seed in decimal format to generate a PN15 data sequence. The LSB of the seed comes out first. For example, if you enter a seed value of 10 (1010 in binary), the first 15 bits of the PN15 sequence are 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0, with an increasing index from left to right. For more information, see PN Sequence Generation.

Data Length

Use this cell to set the number of data bytes in a frame. The value is limited by MPDU Length.

User File

Click the button in this cell to select a user file as the data source.

User File Length

This cell displays the number of data bytes in the user file when it is selected as the payload data source.

MAC Header (Adjustable for Advanced Capability Only)

Click the button in this cell to open the MACHeaderDialog (see the dialogs below), which enables or disables pre-pending the MAC header to the data payload. You can select General, RTS, or CTS MAC frame format by clicking the down arrow in the top right corner of the MacHeaderDialog. You can set the desired data in each of the individual fields for each format. You can also disable these fields if the data is no longer desired by clearing the Mac Header (hex) checkbox.

MAC FCS (Adjustable for Advanced Capability Only)

Use this cell to enable or disable appending the MAC FCS to the data payload. The FCS is automatically calculated by the software if this cell is enabled. Note: When the MAC header is not selected, then the FCS is applied to just the payload.

This cell is adjustable only for the Advanced Capability. In the Basic Capability, it is automatically set to OFF.

Increment Sequence Number (Applicable for Advanced Capability Only)

Use this cell to enable or disable incrementing the Sequence Number within the Sequence Control field in the MAC Header. When it is turned ON, the Sequence Number increments by one after each user-specified interval of new frames. For an example of how incrementation works, see Incrementing Sequence and Fragment Numbers.

Sequence Number Increment by: (Frames) (Applicable for Advanced Capability Only)

The number of frames you set in this cell determines when the Sequence Number within the Sequence Control field in the MAC Header is incremented. For an example of how incrementation works, see Incrementing Sequence and Fragment Numbers.

This cell is only applicable for the Advanced Capability.

Increment Fragment Number (Applicable for Advanced Capability Only)

Use this cell to enable or disable incrementing the Fragment Number within the Sequence Control field in the MAC Header. When it is turned ON, the Fragment Number increments by one after every assignment of a new frame. This field uses the Increment Sequence Number by: (Frame) value as the upper limit. When the upper limit is reached, incrementation wraps back to zero. For an example of how incrementation works, see Incrementing Sequence and Fragment Numbers.