What is Vectoring and Vectoring on Huawei DSLAM Device？

As mention for Huawei DSLAM device MA5616 MA5600 or MA5600T, many customers will check if it supports vectoring. What is vectoring, and which device and ADSL or VDSL service cards support vectoring? This article will explain and introduce vectoring of Huawei DSLAM.

What is Vectoring?

Vectoring is a VDSL2 based technology that uses far-end crosstalk cancellation to increase the line rate. ITU-T released the standard G.993.5 in April 2010. It is used for copper wire VDSL2, and doesn’t involve optical access, ADSL2+ and other DSL technology.

Vectoring mainly eliminates the influence of far-end crosstalk (FEXT) on the line rate, and has no effect on other external source interference. Vectoring technology has emerged as a means of delivering high bandwidth over existing copper infrastructure by extracting more value from it, without investing in an extensive fiber roll-out.

The influence of crosstalk

• The line rate of VDSL2 depends on the attenuation of the cable and the noise interference, the louder noise on the line under same distance, the higher noise margin must be set, which leads to line rate decreasing.
• The twisted pair cable was originally designed for telephone voice transmission. Factors such as unshielded, high density of a large number of lines, and differences in high and low frequency coupling determine the existence of crosstalk in twisted-pair cables and affect each other to a certain extent.
• Crosstalk is interference that caused by signal coupling between wire pairs. It is divided into near-end crosstalk (NEXT) and far-end crosstalk (FEXT). For VDSL2, it uses a frequency band of 0~30MHz and is mainly used for short-distance transmission, that  makes far-end crosstalk (FEXT) be the most main noise interference.
• Actual measured data shows that crosstalk will reduce the VDSL2 line rate by about 50%.

What is the fundamental of Vectoring?

1, Use downlink precoding and uplink joint reception technology to achieve crosstalk cancellation

2, Through interaction between device and CPE, the crosstalk vector information in the line is obtained, and then large-scale and complex real-time matrix calculation (it is The origin of the name Vectoring) is performed to obtain the “inverted” crosstalk and superimpose it on the VDSL2 signal.

3, In the process of data transmission, “inverted” crosstalk and crosstalk in the line cancel with each other, so that the impact of crosstalk on the line is minimized, and access bandwidth is greatly increased.

Vectoring Classified by architecture: BLV SLV and NLV

1, Board level vectoring (BLV)

BLV characteristics are as follows:

• Vectoring processing chip is integrated on one board, the backplane and system architecture remain unchanged;
• Limited capacity, only supports a one board Vectoring, 24-48 lines;
• Need new Vectoring user boards.

2, System level vectoring (SLV)

SLV characteristics are as follows:

• Vectoring processing chip is integrated on one board
• Large capacity, supports several Vectoring boards, generally less than 200 lines; does not support cross-device Vectoring
• A high-speed connection is required between the user board and the VP board, and backplane needs to be redesigned
• Need new backplane, VP board and Vectoring board

3, Node level vectoring

 

NLV characteristics are as follows:

• Two SLV devices jointly implement vectoring.
• An NLV system supports multiple vectoring service boards that totally connect to up to 384 VDSL2 lines.
• The two SLV devices share data using a high-speed cable. In addition, clock synchronization must be enabled on both devices.

 

Which Huawei DSLAM devices support Vectoring function?

Huawei MA5616 MA5603T MA5600 can support vectoring and vectoring service board, but MA5600 does not support.

To implement vectoring, the device needs to be equipped with all parts (Chassis, control board, backplane, VP board and even the terminal device, Vectoring-supported Huawei terminals include HG612, HG622, HG630, and HG658) that support this feature, below is mapping table between the vectoring processing board with other boards.

Product	Board Type	Board Name	Remarks	Corresponding Outdoor Cabinet
MA5603T	Control board	SCUB SCUN SCUK	Supports SLV only.	S300
	Backplane	H802MABO	None
	VP board	H806VPEA	Installed in slot 12 fixedly.
	VDSL2 board	H80BVCMM H80DCCPE H80DVCPD H80DVCPE H80DVCPM	The H80BVCMM board is a 48-channel VDSL2 over POTS access service board. The H80DCCPE board is a 64-channel VDSL2&POTS Combo Board with built-in splitter. The H80DVCPD board is a 64-channel VDSL2 over POTS access service board. The H80DVCPE board is a 64-channel VDSL2 over POTS access service board, equipped with a built-in splitter. The H80DVCPM board is a 64-channel VDSL2 over POTS access service board.
MA5600T	Control board	SCUB SCUN SCUK	Supports SLV only.	N/A
	Backplane	H802MABC H803MABC	None
	VP board	H806VPGA	Consistently installed in slot 8 and slot 11.
	VDSL2 board	H80BVCMM H80DCCPE H80DVCPD H80DVCPE H80DVCPM	The H80BVCMM board is a 48-channel VDSL2 over POTS access service board. The H80DCCPE board is a 64-channel VDSL2&POTS Combo Board with built-in splitter. The H80DVCPD board is a 64-channel VDSL2 over POTS access service board. The H80DVCPE board is a 64-channel VDSL2 over POTS access service board, equipped with a built-in splitter. The H80DVCPM board is a 64-channel VDSL2 over POTS access service board.
MA5616	Control board	H831CCUE	Supports SLV and NLV.	S200/S100 NOTE: The S200 cabinet is recommended because it supports a maximum of 192 lines. The S100 cabinet supports only 96 lines due to the limitation of heat dissipation.
	Daughter board	UP2CA/UP2AA	None
	Backplane	H831MABB	None
	VP board	H836VPBA H836VPDA	H836VPBA: A daughter board for SLV; attached to the power board. H836VPDA: A daughter board for NLV; attached to the power board.
	VDSL2 board	H83BVCMM H83BVCLE H83BVCLF	H83BVCMM: A 48-channel VDSL2 access service board. H83BVCLE/H83BVCLF: 32-channel VDSL2 access service board.
	Power board	H831PAVDA H832PDVAA H832PDNAA	H831PAVDA: An AC power board for SLV. H832PDVAA: A DC power board for SLV. H832PDNAA: A DC power board for NLV.