DL-MAP Info (802.16 OFDMA)

The DL-MAP Info trace the shows the data results of the DL-MAP Decoding feature. The DL-MAP Info trace is a summary table of the downlink subframe, decoded FCH and decoded DL-MAP downlink map: A MAC message that defines burst start time for both time division multiplex and time division multiple access (TDMA) by a subscriber station (SS) on the downlink. messages. When DL-MAP Decoding is not selected in the current configuration, a “NO DATA” message will show, and the results will be filled with "***" asterisks.

The DL-MAP Decoding parameter must be selected to view the DL-MAP Info trace data results.

The DL-MAP Info trace data results include the decoded FCH parameters, a DL Down Link (forward link: from base station to cell phone)-MAP Status indicator, the decoded DL-MAP parameters, and the decoded DL-MAP_IE messages. A “NO DATA” trace message will show, and the results will be filled with “***” placeholders if DL-MAP decoding is not selected in the current configuration.

Decoded FCH parameters:

FCHType: Normal or FFT128
UsedSubch: A value between [0 thru 63] indicating the used subchannel bitmap.
DLMAPType: Normal or Compressed,
Length: DL-MAP length in slots)
CodingType: Coding used by the DL-MAP; CC and CTC are supported, others may be indicated if specified in the FCH, but subsequent decoded DL-MAP parameters would not be valid)
RepCode: 0=None(1x), 1=2x, 2=4x, 3=6x

Status: DL-MAP Status indicator results

DECODED: Successfully decoded the FCH and the DL-Map messages.
CRC Cyclic Redundancy Check_FAIL: Indicates the DLMAP CRC failed, and further DLMAP parsing was aborted.
FCH_FAIL: Indicates the FCH was not correctly decoded, and therefore DLMAP decoding was not attempted.
PARSE_FAIL: Indicates either the DLMAP CRC check could not be performed (DLMAP PDU (protocol data unit) The data unit exchanged between peer entities of the same protocol layer. On the downward direction, it is the data unit generated for the next lower layer. On the upward direction, it is the data unit received from the previous lower layer. bits not available to compute the CRC), or the DLMAP CRC was validated, but the decoder could not parse the entire DLMAP message. This may be due to DLMAP features of the DUT Device under Test: An acronym used to describe some type of electrical apparatus connected to test instrumentation. The apparatus can range from a single component to a complex subsystem such as a mobile phone, base station or MSC. that are not implemented in the analyzer, or due to invalid implementation of the DLMAP message by the DUT.

Decoded DL-MAP parameters:

FrameLen: Frame length indicated in seconds.
DLSubframe: Length of downlink subframe including preamble, in symbols.
Frame: Frame counter
DCDCount: DCD downlink channel descriptor: A MAC message that describes the PHY characterstics of a downlink channel. counter index to apply when using this DLMAP.
BSID: Unique 12-hex-character value to identify the transmitting base station.
NumIEs: (the total number of IEs counted in the decoded DLMAP)

Decoded DL-MAP_IE list:

The Decoded DL-MAP_IE list, in the lower section of the trace, includes a one-line text summary of each encountered IE (Information Element). The following IE types will be interpreted, other IE types present a textual summary of the basic IE parameters and the first few bytes of the message.