Schmid SHDSL - Multi-pair operation

Watson SHDSL Router
Operating Manual
Watson-SHDSL-Router-Manual.doc
Version 1.0-03
PSDs which in turn can lead to higher interference to other DSL systems in the same cable binder,
e.g. ADSL, ADSL2, ADSL2+.
The linerate rate, i.e. the data rate available to the application is calculated as follows:
[
]
)(
)(
/
893
41
64
Λ
Λ
pairpertimeslotsofnumbern
pairswireofnumberm
skbitnmLinerate
=
=
××=
Note: n = 3 … 36 for Watson SHDSL router
The physical DSL synchronization rate per pair is
[
]
)/./(
)(
/
EOCskbitincludingskbitOverheadSHDSLOH
timeslotsofnumbern
skbitOHnSyncrate
238
893
64
=
=
+×=
Λ
Note: n = 3 … 36 for Watson SHDSL router
The sync rate determines the DSL reach. Decreasing the sync rate increases DSL reach and vice
versa. The linerate rate has no influence on the DSL reach.
3.5.2 Multi-pair operation
Watson SHDSL router supports multi-pair operation. This allows aggregation of individual DSL wire
pairs for higher speeds or increased reach at a given speed. Watson SHDSL router supports two
different multi-pair aggregation methods: the IEEE 802.3ah EFM PAF and the ETSI / ITU-T SHDSL
M-pair mode.
EFM PAF allows to configure different linerate on the different DSL wire pairs with a maximum lin-
erate ratio of 1 to 4. It is also resilient to DSL wire pair failure. If one pair fails the link is maintained
using the other pairs. The data service is running at a lower speed, but is kept uninterrupted.
The SHDSL M-pair mode is used for backwards compatibility reason when Watson SHDSL router is
connected to Watson Ethernet plug-in (SZ.866.V654) as showed in . In this mode each
wire pair of Watson SHDSL router must be configured with the same linerate. If one pair fails then
the entire link must be restarted.
Figure 2-1
A multi-pair DSL link is called a span. Watson SHDSL router has only one span. The span can have
1, 2, 3 or 4 DSL wire pairs.
The following naming conventions is used in multi-pair operation on Watson SHDSL router:
DSL ports within the span are named 1, 2, 3 and 4. Depending on the number of wire pairs
within the span the DSL ports 2, 3 or 4 might not be used.

 Physical wire pairs available at the DSL connector are named a, b, c and d (see Table 3-1 for
the DSL connector pin assignment).
Depending on the configuration of Watson SHDSL router the following combinations are possible:
default
DSL ports Wire pairs
1 1 (a1, a2)
2 1, 2 (a1, a2), (b1, b2)
3 1, 2, 3 (a1, a2), (b1, b2), (c1, c2)
4 1, 2, 3, 4 (a1, a2), (b1, b2), (c1, c2), (d1, d2)
Table 3-1: Naming of DSL ports and wire pairs
3-10 Revision: 2007-05-24