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Standard Combined BCH (Coded Control Channels - Advanced)

The Standard Combined BCH (Control Channels) are coded channels that are available with Option QFP.To open the Data node, click Data in the tree view. Use the Data window to define the bits in the bursts. The cells displayed in the Data section are determined by the Channel Type for the selected timeslot as defined in the Timeslot window.

There are two kinds of Standard Combined Broadcast Channels (BCH):

• Frequency Correction Channel (FCCH)+Synchronization Channel (SCH)+Broadcast Control Channel (BCCH)+Common Control Channel (CCCH)

• Frequency Correction Channel (FCCH)+Synchronization Channel (SCH)+Broadcast Control Channel (BCCH)+Common Control Channel (CCCH)+Stand-alone Dedicated Control Channel (SDCCH/4(0…3))+Slow Associated Control Channel (SACCH/C4(0…3))

Refer to Multiframe Structure of BCH.

BCH Pre-Defined Carrier Configurations

There are different pre-defined carrier configurations for the BCH:

• GSM BCH + TCH/FS

• GSM BCH + TCH/HS

• GSM BCH + PDTCH

• GSM BCH + TCH/FS + PDTCH

• GSM BCH + TCH/HS + PDTCH

• GSM BCH + Normal Burst

The different BCH configurations require different Carrier setups. Refer to the examples.

Figure: FCCH + SCH + BCCH + CCCH + SDCCH + SACCH

Standard Combined BCH parameter description links:

• FCCH+SCH+BCCH+CCCH

  1. FCCH Contents	2. SCH Contents	3. BCCH Contents	4. CCCH Contents
  FCCH State	SCH State	BCCH State	CCCH State
  FCCH Tail bits	SCH Tail bits	BCCH Tail bits	CCCH Tail bits
  FCCH Fixed bits	SCH Encrypted Bits	BCCH Encrypted Bits	CCCH Encrypted Bits
  FCCH Guard period (n bits)	SCH PLMN color code	BCCH Cell Identity	CCCH Stealing Flags (1+1 bits) (1 bit entry)
  	SCH BTS color code	BCCH Mobile Country Code	CCCH External Training Sequence
  	SCH Initial Frame Number	BCCH Mobile Network Code	SCH Guard period (n bits)
  	SCH Extended Training Sequence	BCCH Location Area Code
  	SCH Guard period (n bits)	BCCH MS_TXPWR_MAX_CCH
  		BCCH Stealing Flags (1+1 bits) (1 bit entry)
  		BCCH External Training Sequence
  		BCCH Guard period (n bits)

• FCCH+SCH+BCCH+CCCH+SDCCH+SACCH

  1. FCCH Contents	2. SCH Contents	3. BCCH Contents	4. CCCH Contents
  FCCH State	SCH State	BCCH State	CCCH State
  FCCH Tail bits	SCH Tail bits	BCCH Tail bits	CCCH Tail bits
  FCCH Fixed bits	SCH Encrypted Bits	BCCH Encrypted Bits	CCCH Encrypted Bits
  FCCH Guard period (n bits)	SCH PLMN color code	BCCH Cell Identity	CCCH Stealing Flags (1+1 bits) (1 bit entry)
  	SCH BTS color code	BCCH Mobile Country Code	CCCH External Training Sequence
  	SCH Initial Frame Number	BCCH Mobile Network Code	SCH Guard period (n bits)
  	SCH Extended Training Sequence	BCCH Location Area Code
  	SCH Guard period (n bits)	BCCH MS_TXPWR_MAX_CCH
  		BCCH Stealing Flags (1+1 bits) (1 bit entry)
  		BCCH External Training Sequence
  		BCCH Guard period (n bits)

  5. SDCCH Contents	6. SACCH Contents
  SDCCH State	SACCH State
  SDCCH Tail bits	SACCH Tail bits
  SDCCH Encrypted Bits	SACCH Validity Check
  SDCCH Stealing Flags (1+1 bits) (1 bit entry)	SACCH Encrypted Bits
  SDCCH External Training Sequence	SACCH Power Control Level
  SDCCH Guard period (n bits)	SACCH Timing Advance
  	SACCH Layer 2 Frame
  	SACCH Spare
  	SACCH SR0
  	SACCH FPC_EPC
  	SACCH Stealing Flags (1+1 bits) (1 bit entry)
  	SACCH External Training Sequence
  	SCH Guard period (n bits)

Change Data Values Button

Click to display a drop-down menu in which you can copy a timeslot configuration from one timeslot to another.

Data Node Parameters

Use the Data window to define the bits in the bursts. The cells displayed in the Data section are determined by the burst type (Timeslot Type) for the selected timeslot as defined in the Timeslots window. In the window shown above, Timeslots 0 is set up for a data cell with a Broadcast Channel (BCH) Burst.

1. FCCH contents

FCCH State

State is always ON. This setting is not editable.

FCCH Tail bits

Tail Bits (3+3 bits)

Tail bits are set by the software at 000. This setting is not editable.

FCCH Fixed bits

Choice: PN9| PN15 | User

Default: User X"000...000"

This is a 142 bits field.

FCCH Guard period (n bits)

The software sets the Guard period (bits). This setting is not editable.

Figure: Guard Period Lengths Between Different Timeslots

2. SCH contents

SCH State

State is always ON. This setting is not editable.

SCH Tail bits

Tail Bits (3+3 bits) are set by the software at 000. This setting is not editable.

SCH Encrypted Bits

Choice: STD | PN9| PN15 | User Defined Bits

Default: STD

If the data source is STD (standard) then the PLMN (Pubic Land Mobile Network) color code, BTS (Base Transeiver Station) color code and frame number will be used to generate the SCH (Synchronization Channel) data source.

SCH PLMN color code

Choice: 0 to 7

Default: 1

This sets the value of the Public Land Mobile Network (PLMN) for the waveform.

SCH BTS color code

Choice: 0 to 7

Default: 0

The Base Transeiver Station (BTS) color code is broadcasted on SCH. The TSC (Training Sequence Code) that is used on the downlink channel has a logical relationship to the BTS. If the BTS color code is 0, then TSC0 should be used in BCCH and CCCH; if BTS color code is 1, then TSC1 should be used in BCCH and CCCH.

Table 1: BTS color code and TSC values

SCH Initial Frame Number

Range: 0 to 2715647

Default:1

Initial Frame Number is used to calculate the first initial SCH frame. The frame number is incremental. The frame number is used to generate T1, T2 and T3 which are parts of the original data of the encrypted bits for Synchronization Channel (SCH).

The Frame Number is only sent on SCH. And it is sent 5 times every 51 frames.

SCH Extended Training Sequence

Choice: PN9 |PN15 | User Defined Bits

Default: X"B962040F2D45761B" (64 bits)

Enter 64 bits to use for the fixed bits of the extended training sequence bits.

SCH Guard period (n bits)

The software sets the Guard period (bits). This setting is not editable.

Figure: Guard Period Lengths Between Different Timeslots

3. BCCH contents

BCCH State

Choice: On | Off

Default: Off

Double-click or use the drop-down menu to set the channel state. If state is On, GMSK burst shall be used; If the state is Off, Dummy burst shall be used.

BCCH Tail bits

Tail bits (3+3 bits) are set by the software at 000. This setting is not editable.

BCCH Encrypted Bits

Choice: STD | PN9| PN15 | User Defined Bits

Default: STD

If the data source is set to STD (standard) then System Information Type 3 message will be sent on BCCH.

BCCH Cell Identity

Range: 0 to 65535

Default: 0

Enters a value to set the cell identity.

BCCH Mobile Country Code

Range: 0 to 999

Default: 1

Enter a value to set the Mobile Country Code where the base station is located.

BCCH Mobile Network Code

Range: 0 to 99

Default: 1

Enter a value to set the Mobile Network Code.

BCCH Location Area Code

Range: 0 to 65535

Default: 1

Enters a value to set the Location Area Code.

BCCH MS_TXPWR_MAX_CCH

Range: 0 to 31

Default: 0

Enter a value to set the MS_TXPWR_MAX_CCH value.

The BCCH MS_TXPWR_MAX_CCH field is the binary representation of the "power control level" mentioned in 3GPP TS 45.005. This value corresponds to the maximum TX (Transmitter) power level a MS (Mobile Station) may use when accessing on a Control Channel (CCH). Refer to 3GPP TS 45.008.

BCCH Stealing Flags (1+1) (1 bit entry)

Stealing Flag for BCCH. It is always 1. This setting is not editable.

BCCH External Training Sequence

Choice: TSC0 to TSC7 or User Defined Bits

Default: TSC0

Select TSC0 to TSC7 or User Defined Bits to use for the training sequence bits.

The training sequences are defined as follows:

BCCH Guard period (n bits)

The software sets the Guard period (bits). This setting is not editable.

Figure: Guard Period Lengths Between Different Timeslots

4. CCCH contents

CCCH State

Choice: On | Off

Default: Off

Double-click or use the drop-down menu to set the channel state. If state is On, GMSK burst shall be used; if the state is Off, Dummy burst shall be used.

CCCH Tail bits

Tail Bits (3+3 bits) are set by the software at 000. This setting is not editable.

CCCH Encrypted Bits

Choice: PN9 | PN15 | User Defined Bits

Default: PN9

Click the Details button in this cell to open the Data Source Selection window.

Select Import, Export, Insert PN9, Insert PN15 or User Defined Bits to use for the encrypted bits.

CCCH Stealing Flags (1+1) (1 bit entry)

Stealing Flag for CCCH. It is always 1. This setting is not editable.

CCCH External Training Sequence

Choice: TSC0 to TSC7 or User Defined Bits

Default: TSC0

Select TSC0 to TSC7 or User Defined Bits to use for the training sequence bits.

The training sequences are defined as follows:

CCCH Guard period (n bits)

The software sets the Guard period (bits). This setting is not editable.

Figure: Guard Period Lengths Between Different Timeslots

5. SDCCH contents (FCCH+SCH+BCCH+CCCH+SDCCH+SACCH only)

SDCCH State

Choice: On | Off

Default: Off

Double-click or use the drop-down menu to set the channel state. If state is On, GMSK burst shall be used; if the state is Off, Dummy burst shall be used.

SDCCH Tail bits

Tail bits (3+3 bits) are set by the software at 000. This setting is not editable.

SDCCH Encrypted Bits

Choice: PN9 | PN15 | User Defined Bits

Default: PN9

Click the Details button in this cell to open the Data Source Selection window.

Select Import, Export, Insert PN9, Insert PN15 or User Defined Bits to use for the encrypted bits.

SDCCH Stealing Flags (1+1) (1 bit entry)

Stealing Flag for SDCCH. It is always 1. This setting is not editable.

SDCCH External Training Sequence

Choice: TSC0 to TSC7 or User Defined Bits

Default: TSC0

Select TSC0 to TSC7 or User Defined Bits to use for the training sequence bits.

The training sequences are defined as follows:

SDCCH Guard period (n bits)

The software sets the Guard period (bits). This setting is not editable.

Figure: Guard Period Lengths Between Different Timeslots

6. SACCH contents (FCCH+SCH+BCCH+CCCH+SDCCH+SACCH only)

SACCH State

Choice: On | Off

Default: Off

Double-click or use the drop-down menu to set the channel state. If state is On, GMSK burst shall be used; If the state is Off, Dummy burst shall be used.

SACCH Tail bits

Tail Bits (3+3 bits) are set by the software at 000. This setting is not editable.

SACCH Encrypted Bits

Choice: STD | PN9 | PN15 | User Defined Bits

Default: STD

If the data source is set to STD, SACCH contents will be generated by user settings.

SACCH Validity Check

Choice: Valid | Invalid

Default: Valid

If Invalid is selected, a wrong CRC will be generated so that MS cannot decode the SACCH correctly.

SACCH Power Control Level

Range: 0 to 31

Default: 15

Enter a value to set power control level.

SACCH Timing Advance

Range: 0 to 255

Default: 0

Enter a value to set timing advance for mobile station (MS).

SACCH Layer 2 Frame

Choice: PN9 | PN15 | User Defined Bits

Default: PN9

This is the content of the 21 octets field in downlink SACCH block structure.

SACCH Spare

SACCH spare bit is always 0. This setting is not editable.

SACCH SR0

SACCH SR0 bit is always 0. This setting is not editable.

SACCH FPC_EPC

SACCH FPC_EPC bit is always 0. This setting is not editable.

SACCH Stealing Flags (1+1) (1 bit entry)

You can enter 1 (control channel burst) or 0 (data channel burst). This setting is not editable.

SACCH External Training Sequence

Choice: TSC0 to TSC7 or User Defined Bits

Default: TSC0

Select TSC0 to TSC7 or User Defined Bits to use for the training sequence bits.

The training sequences are defined as follows:

SACCH Guard period (n bits)

The software sets the Guard period (bits). This setting is not editable.

Figure: Guard Period Lengths Between Different Timeslots

Related Topics

Multiframe Structure of BCH

Waveform Generation Log

Advanced Downlink TDMA

Timeslot (Advanced)