Page 826 - 5G Basics - Core Network Aspects

2 Transport aspects

The subcarrier parameter fields for the respective OLR types are different and are specified as follows.

The format descriptor L(iQf) designates a fixed point format with wordlength of L bits, with the binary point
just to the right of the "i"-th most significant bit (including the sign bit if signed integer), and f bits are
allocated behind the binary point (i.e., L=i+f). Letter Q is a syntax-separator.

The format descriptor L M ML(iQf) E LE/B designates a floating point format with total wordlength L. It has
mantissa wordlength of ML bits, with the binary point just to the right of the i-th most significant bit
(including the sign bit if signed integer), and f bits are allocated behind the binary point (i.e., ML=i+f). The
exponent is always unsigned and has wordlength LE. The exponent has unity gain when its value equals B.
Letters M, Q and E are syntax-separators.

In below fields, the LSB of a parameter shall be mapped to the lowest bit number in the field assigned to
that parameter.

For OLR commands of OLR request type 1.
Each subcarrier parameter field shall be formatted as shown in Table 11-10.

Table 11-10 – Subcarrier parameter field format for OLR type 1

Bit Length Parameter Format
(bits)
3-0 4 bi (Notes 1 and 2) Unsigned integer
NOTE 1 – The values of b i for subcarriers that are in the specified range but not part of the MEDLEY set shall be included. They
shall be set to zero by the transmitter and ignored by the receiver.
NOTE 2 – The values of b i shall follow each other in ascending order of subcarrier index (not re-ordered).

Two subcarrier parameter fields shall be packed into one byte as shown in Table 11-11.

Table 11-11 – Packing of subcarrier fields into bytes for OLR type 1
Byte MSB LSB

k bi+1 [3:0] bi [3:0]

If the number of subcarriers is odd, the four MSBs in the last byte is set to 0000.
The scalar gain d_SRA or d_TIGARESP shall be formatted as fixed point 5(1Q4) unsigned.
The valid values that are allowed to be used within this format, shall be:

(0.5 ≤ d_SRA ≤ 1) and (0.5 ≤ d_TIGARESP ≤ 1)
NOTE – Possible values are 8/16, 9/16, … ,16/16 corresponding to backoff levels in dB of –6.02, –5.00,
–4.08, –3.25, –2.50, –1.80, –1.16, –0.56, and 0.00.

For OLR commands of OLR request type 2, each subcarrier parameter field shall be formatted as shown in
Table 11-12.

Table 11-12 – Subcarrier parameter field format for OLR type 2

Bit Length (bits) Parameter Format

3-0 4 bi Unsigned integer
15-4 12 gi 12(1Q11) unsigned
27-16 12 subcarrier index i Unsigned integer
Packing of the subcarrier parameter field into bytes shall be as shown in Table 11-13. Bytes of the
subcarrier parameter field shall be transmitted in the order of increasing indices, i.e., byte k is the first
transmitted byte.

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