Annex B: Example of the Downlink Channel Descriptor (DCD) Message


In Chapter 9, were given the global parts of a DCD message, a MAC management message that describes the PHY characteristics of the downlink channel. This example of a DCD message contains the descriptions of two downlink burst profiles respectively identified by DIUC 0101 (hexadecimal: 5) and DIUC 1010 (hexadecimal: A). In this Annex the full details of this message are given, using OFDM (WiMAX) PHYsical interface specifications.

The construction of this message is based on Tables 233 and 358 and, more generally, on Section 11.4 of the IEEE 802.16-2004 specification. Some of the numerical values chosen may not be completely based on practical considerations (e.g. BSID, whose definition is not exhaustive in the standard). 802.16e added new parameters to the DCD message (mainly for the handover process) that are not included in this example.

Open table as spreadsheet

Field content

Field length

Field name

Description

01

8b (fixed)

MAC Management Message Type

01 is the value for DCD

04

8b (fixed)

Downlink Channel ID

Arbitrarily chosen by the BS

01

8b (fixed)

Configuration Change Count

Indicates a change versus previous DCD message (01 is an assumption)

Start of the Downlink Burst Profile Description for DIUC value = 0101 (hexadecimal: 5). This part is TLV encoded.

01

8b (fixed)

Downlink_Burst_Profile Type

Downlink_Burst_Profile Indicator

44 (decimal: 67)

8b (fixed)

Downlink_Burst_Profile Length

67 bytes for the overal Downlink_Burst_Profile of DIUC = 0101

0

4b (fixed)

Reserved

Set to zero

05

4b (fixed)

DIUC value

This value of DIUC will be associated with the Downlink Burst Profile and Thresholds defined in the following

Open table as spreadsheet

Start of Channel Encodings values for DIUC value = 0101 (hexadecimal: 5). This part is TLV encoded.

01

1 byte (fixed)

Type for Downlink_Burst_Profile encoding

The number of bytes in the overall object, including embedded TLV items

01

1 byte

Length for Downlink_Burst_Profile encoding

See Rule for TLV Length

44 (decimal: 67)

1 byte

Value for Downlink_Burst_Profile encoding

67 bytes for the overall Downlink_Burst_Profile of DIUC = 0101

02

1 byte (fixed)

Type for BS EIRP encoding

The BS Transmitted Power (effective isotropic radiated power)

01

1 byte

Length for BS EIRP encoding

See Rule for TVL Length

1E

1 byte

Value for BS EIRP encoding

Signed in units of 1 dBm (see Note 1 at the end of annex B)

06

1 byte (fixed)

Type for Downlink channel number encoding

Used for license-exempt operation only

01

1 byte

Length for Downlink channel number encoding

 

09

1 byte (fixed)

Value for Downlink channel number encoding

The Channel Number (Channel Nr), an 8-bit value, allows the calculation of the channel centre frequency for license-exempt frequency bands

07

1 byte (fixed)

Type for TTG (Transmit/receive Transition Gap) encoding

Expressed in Physical Slot

01

1 byte

Length for TTG (Transmit/receive Transition Gap) encoding

 

2D

1 byte

Value for TTG (Transmit/receive Transition Gap) encoding

148 Physical Slots

08

1 byte (fixed)

Type for RTG (Receive/transmit Transition Gap) encoding

Expressed in Physical Slot

01

1 byte

Length for RTG (Receive/transmit Transition Gap) encoding

 

2D

1 byte

Value for RTG (Receive/transmit Transition Gap) encoding

84 Physical Slots

09

1 byte (fixed)

Type for Initial Ranging Maximal Received Signal Strength at BS encoding

RSSIR, max: Initial Ranging Maximal Received Signal Strength at BS

02

1 byte

Length for Initial Ranging Maximal Received Signal Strength at BS encoding

 

FFE4

2 bytes

Value for Initial Ranging Maximal Received Signal Strength at BS encoding

Signed in units of 1 dBm (see Note 1 below). FFE4= -28dBm (10−5.8 W)

A (decimal: 10)

1 byte (fixed)

Type for Channel Switch Frame Number encoding

Used for license-exempt operation only. In the case of DFS (Dynamic Frequency Selection), the new channel to be used is deduced by using this Channel Switch Frame Number

03

1 byte

Length for Channel Switch Frame Number encoding

See Rule for TLV length

000003

3 bytes

Value for Channel Switch Frame Number encoding

+3

C (decimal: 12)

1 byte (fixed)

Type for Downlink centre frequency encoding

The centre of the frequency band in which a base station (BS) or SS is intended to transmit in kHz

04

1 byte

Length for Downlink centre frequency encoding

 

0036 5240

4 bytes

Value for Downlink centre frequency encoding

00365240 (0000,0000,0011,0110,0101,1111,1110,1010)=3560000 kHz (3.56 GHz)

D (decimal: 13)

1 byte (fixed)

Type for Base Station ID encoding

The Base Station ID is a 48-bit long field identifying the BS (not the MAC address)

06

1 byte

Length for Base Station ID encoding

 

AE54AA 123456

6 bytes

Value for Base Station ID encoding

The Base Station ID is programmable. The MS 24 bits must be used as the operator ID. A random value has been chosen here

E (decimal: 14)

1 byte (fixed)

Type for Frame Duration Code encoding

The Frame Duration Code values are given in the standard

01

1 byte

Length for Frame Duration Code encoding

 

03

1 bytes

Value for Frame Duration Code encoding

The code corresponding to 8 ms (see Table 232 of 802.16-2004)

F (decimal: 15)

1 byte (fixed)

Type for Frame Number encoding

The Frame Number is a modulo 212 number (a 12-bit-number) which is increased by one for every frame

03

1 byte

Length for Frame Number encoding

 

A0B1EE

3 bytes

Value for Frame Number encoding

The frame number of the frame containing the DCD message

94th (decimal: 148)

1 byte (fixed)

Type for MAC version encoding

Specifies the version of IEEE 802.16 to which the message originator conforms

01

1 byte

Length for MAC version encoding

 

04

1 byte

Value for MAC version encoding

Indicates conformance with IEEE Std 802.16-2004

Open table as spreadsheet

Start of Burst Profile Encoding values for DIUC value = 0101 (hexadecimal: 5). This part is TLV encoded.

01

1 byte (fixed)

Type for Frequency encoding

Downlink frequency of this burst profile in kHz

04

1 byte

Length for Frequency encoding

 

0036 5FEA

4 bytes

Value for Frequency encoding

00365FEA (0000,0000,0011,0110,0101,1111,1110,1010)=3563 500 kHz (3.5635 GHz)

96 (decimal: 150)

1 byte (fixed)

Type for FEC Code encoding

Provides the modulation and the coding scheme of the burst profile

01

1 byte

Length for FEC Code encoding

 

03

1 byte

Value for FEC code encoding

This value corresponds to 16-QAM modulation and Reed-Solomon CC, coding rate = 1/2

97 (decimal: 151)

1 byte (fixed)

Type for DIUC mandatory exit threshold encoding

CINR (Carrier-to-Interference-and-Noise Ratio) used for burst profile (or equivalently DIUC) selection. In 0.25 dB units.

01

1 byte

Length for DIUC mandatory exit threshold encoding

 

30 (decimal: 48)

1 byte

Value for DIUC mandatory exit threshold encoding

Corresponds to 48 × 0.25 dB = 12 dB

98 (decimal: 152)

1 byte (fixed)

Type for DIUC mandatory entry threshold encoding

CINR (Carrier-to-Interference-and-Noise Ratio) used for burst profile (or equivalently DIUC) selection. In 0.25 dB units.

01

1 byte

Length for DIUC mandatory entry threshold encoding

 

36 (decimal: 54)

1 byte

Value for DIUC mandatory entry threshold encoding

Corresponds to 54 × 0.25 dB = 13.5 dB

99 (decimal: 153)

1 byte (fixed)

Type for TCS_enable encoding

The TCS (Transmission Convergence Sublayer) is an optional mechanism for the OFDM PHY (8.1.4.3)

   

0 = TCS disabled

   

1 = TCS enabled 2255 = Reserved

01

1 byte

Length for TCS_enable encoding

 

1

1 byte

Value for TCS_enable encoding

1 = TCS enabled

Open table as spreadsheet

Start of Downlink Burst Profile Description for DIUC value = 1010 (hexadecimal: A). This part is TLV encoded.

01

8b (fixed)

Downlink_Burst_Profile Type

Downlink_Burst_Profile Indicator

44 (decimal: 67)

8b (fixed)

Downlink_Burst_Profile Length

67 bytes for the overal Downlink_Burst_Profile of DIUC = 1010

0

4b (fixed)

Reserved

Set to zero

A

4b (fixed)

DIUC value

This value of DIUC will be associated with the Downlink Burst Profile and Thresholds defined in the following

Open table as spreadsheet

Start of Channel Encodings values for DIUC value = 1010 (hexadecimal: A). This part is TLV encoded.

01

1 byte (fixed)

Type for Downlink_Burst_Profile encoding

The number of bytes in the overall object, including embedded TLV items

01

1 byte

Length for Downlink_Burst_Profile encoding

See Rule for TLV Length

44 (decimal: 67)

1 byte

Value for Downlink_Burst_Profile encoding

67 bytes for the overall Downlink_Burst_Profile of DIUC = 1010

02

1 byte (fixed)

Type for BS EIRP encoding

The BS Transmitted Power (effective isotropic radiated power)

01

1 byte

Length for BS EIRP encoding

See Rule for TLV Length

1E

1 byte

Value for BS EIRP encoding

Signed in units of 1 dBm (see Note 1 below). 1E = 30 dBm (1 W)

06

1 byte (fixed)

Type for Downlink channel number encoding

Used for license-exempt operation only

01

1 byte

Length for Downlink channel number encoding

 

09

1 byte (fixed)

Value for Downlink channel number encoding

The Channel Number (Channel Nr), an 8-bit value, allows the calculation of the channel centre frequency for license-exempt frequency bands

07

1 byte (fixed)

Type for TTG (Transmit/receive Transition Gap) encoding

Expressed in Physical Slot

01

1 byte

Length for TTG (Transmit/receive Transition Gap) encoding

 

3C

1 byte

Value for TTG (Transmit/receive Transition Gap) encoding

148 Physical Slots

08

1 byte (fixed)

Type for RTG (Receive/transmit Transition Gap) encoding

Expressed in Physical Slot

01

1 byte

Length for RTG (Receive/transmit Transition Gap) encoding

 

3C

1 byte

Value for RTG (Receive/transmit Transition Gap) encoding

84 Physical Slots

09

1 byte (fixed)

Type for Initial Ranging Maximal Received Signal Strength at BS encoding

RSSIR, max: Initial Ranging Maximal Received Signal Strength at the BS

02

1 byte

Length for Initial Ranging Maximal Received Signal Strength at BS encoding

FFE6

2 bytes

Value for Initial Ranging Maximal Received Signal Strength at BS encoding

Signed in units of 1 dBm (see Note 1 below). FFe6 = 26 dBm (10−5.6 W)

A (decimal: 10)

1 byte (fixed)

Type for Channel Switch Frame Number encoding

Used for license-exempt operation only. In the case of DFS (Dynamic Frequency Selection), the new channel to be used is deduced by using this Channel Switch Frame Number

03

1 byte

Length for Channel Switch Frame Number encoding

See Rule for TLV Length

000003

3 bytes

Value for Channel Switch Frame Number encoding

+3

C (decimal: 12)

1 byte (fixed)

Type for Downlink centre frequency encoding

The centre of the frequency band in which a base station (BS) or SS is intended to transmit in kHz

04

1 byte

Length for Downlink centre frequency encoding

 

0036 5240

4 bytes

Value for Downlink centre frequency encoding

00365240 (0000,0000,0011,0110,0101,1111,1110,1010) = 3 560 000 kHz (3.56 GHz)

D (decimal: 13)

1 byte (fixed)

Type for Base Station ID encoding

The Base Station ID is a 48-bit long field identifying the BS (not the MAC address)

06

1 byte

Length for Base Station ID encoding

 

AE54 123456

6 bytes

Value for Base Station ID encoding

The Base Station ID is programmable. The MS 24 bits must be used as the operator ID. A random value has been chosen here

E (decimal: 14)

1 byte (fixed)

Type for Frame Duration Code encoding

The Frame Duration Code values are given in the standard

01

1 byte

Length for Frame Duration Code encoding

 

04

1 byte

Value for Frame Duration Code encoding

The code corresponding to 10 ms (see Table 232 of 802.16-2004)

F (decimal: 15)

1 byte (fixed)

Type for Frame Number encoding

The Frame Number is a modulo 212 number (a 12-bit-number) which is increased by one for every frame

03

1 byte

Length for Frame Number encoding

 

A0b1EE

3 bytes

Value for Frame Number encoding

The Frame Number of the frame containing the DCD message

94 (decimal: 148)

1 byte (fixed)

Type for MAC, version encoding

Specifies the version of IEEE 802.16 to which the message originator conforms

01

1 byte

Length for MAC version encoding

 

04

1 byte

Value for MAC version encoding

Indicates conformance with IEEE Std 802.16-2004

Open table as spreadsheet

Start of Burst Profile Encoding values for DIUC value = 1010 (hexadecimal: A). This part is TLV encoded.

01

1 byte (fixed)

Type for Frequency encoding

Downlink frequency of this burst profile in kHz

04

1 byte

Length for Frequency encoding

 

0036 5FEA

4 bytes

Value for Frequency encoding

00365FEA (0000,0000,0011,0110,0101,1111,1110,1010) = 3 563 500 kHz (3.5635 GHz)

96 (decimal: 150)

1 byte (fixed)

Type for FEC Code encoding

Provides the modulation and the coding scheme of the burst profile

01

1 byte

Length for FEC Code encoding

 

05

1 byte

Value for FEC Code encoding

This value corresponds to 64-QAM modulation and Reed-Solomon CC, coding rate = 2/3

97 (decimal: 151)

1 byte (fixed)

Type for DIUC mandatory exit threshold encoding

CINR (Carrier-to-Interference-and-Noise Ratio) used for burst profile (or equivalently DIUC) selection. In 0.25 dB units

01

1 byte

Length for DIUC mandatory exit threshold encoding

 

52 (decimal: 82)

1 byte

Value for DIUC mandatory exit threshold encoding

Corresponds to 82 × 0.25 dB = 20.5 dB

98 (decimal: 152)

1 byte (fixed)

Type for DIUC mandatory entry threshold encoding

CINR (Carrier-to-Interference-and-Noise Ratio) used for brust profile (or equivalently DIUC) selection. In 0.25 dB units

01

1 byte

Length for DIUC mandatory entry threshold encoding

 

62 (decimal: 98)

1 byte

Value for DIUC mandatory entry threshold encoding

Corresponds to 98 × 0.25 dB = 24.5 dB

99 (decimal: 153)

1 byte (fixed)

Type for TCS_enable encoding

The TCS (Transmission Sublayer) is an optional mechanism for the OFDM PHY
0 = TCS disabled
1 = TCS enabled 2–255 = Reserved

01

1 byte

Length for TCS_enable encoding

 

1

1 byte

Value for TCS_enable encoding

1 = TCS enabled

Note 1. No specific rule is given in the standard (802.16-2004) for some parameters coding. It is presumed that for N possible combinations (e.g. for 16 bits, 65 536 combinations), the first N/2 combinations (0 to 32767) represent positive numbers while the next 32768 combinations (32768 to 65536) represent negative numbers (two's complement). In order to get ‘-28’, 28 is substracted from the number of combinations (65536) in order to get 65508 (binary: 1111,1111,1110,0100, hexadecimal: FFE4).

Open table as spreadsheet




WiMAX. Technology for Broadband Wireless Access
WiMAX: Technology for Broadband Wireless Access
ISBN: 0470028084
EAN: 2147483647
Year: 2007
Pages: 124

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net