Nortel Networks DCT1900 manual Speech Processing Unit SPU-S REX-BRD0017 or Rofnb 157 16/3, Spu

Technical Product Manual - DCT1900

System Description, Radio Exchange Boards

4.4Speech Processing Unit - SPU-S (REX-BRD0017 or ROFNB 157 16/3)

The SPU interfaces between a LTU/DTU and a CLU/SLU. Every SPU board contains eight Speech Processing Channels (SPC, see Figure 4-2). Every SPC handles the speech processing for one call. When a call is initiated, either by a Portable Telephone or by an incoming call, an SPC is assigned to the call.

The main functions of the board are:

z64 kbit/s PCM to 32 kbit/s ADPCM transcoding and vice versa

zDTMF generation and dial tone detection

zEcho control

BC

SPC	Peripheral
8	P8

		Peripheral
	SPC
1		P1

Fig.4-2 SPU

System-DCT1900/R8/mw	4-3
© 2000-2005