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8. The Access Model
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This section sets out to describe the methodology and assumptions behind the access
model and describes the changes that have been made in the revised Hybrid Model to
reflect the increasing importance of sub-loops and DSLAMs at the street cabinet
resulting from the transition to Next Generation Access (NGA).
8.1 The Access Network in Denmark
The access network connects the end user with central equipment in the core network.
Subsequently, the related costs primarily depend on the number of subscribers, and
less so on the volume of traffic. Consistent with this, access can alternatively be
defined as those services which allow the subscriber to send and receive traffic.
Both definitions suggest that the access network includes all costs for cable and
trenching associated with subscriber lines between the customer premises and the
concentrator. These definitions also suggest that the access network includes
analogous costs for other lines, such as those for public call boxes between the
customer premises and the concentrator. Furthermore, the definitions suggest that the
access network includes the line card within the concentrator/DSLAM and potentially
other subscriber related costs. This is consistent with the first definition, since line
card requirements are driven by the number of subscribers or, more accurately, by the
subscriber requirements for lines. It is also consistent with the second definition since
the line card is essential to sending and receiving traffic. However, for ease of
modelling, line cards have been included in the core model rather than the access
model. The costs associated with these items are then allocated to the relevant access
products in the consolidation model. In this sense, it is important to realise that the
access network is not the same as the access increment.
A schematic representation of TDC’s access network is provided in Figure 8.1 below.
Figure 8.1: Schematic outline of Local Access Network
Customer Site
Customer
Building
ExistingRCU site
RCU
eqquipmt
PDP
PDP
RCU
ASM
equipment
PDP
Primary
DistribnPoint
(PDP)
Secondary
DistribnPoint
(SDP)
SDP
Ducting/Trench
join?
Customer Site
MUX ?
SDP
SDP
Customer
Building
Customer Site
Customer
Building
exit from
street duct
Road
Customer Site
Customer
Building
Assets within the access network include:
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the final drop wire to the customer’s premises (although the cost associated with
this drop wire, or its activation, might be captured through the connection charge);
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the trenching (in some cases ducted) between the final connection point and the
remote or host concentrator/DSLAM;
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radio systems, cable and optical fibre in this part of the network;
Date: 30.11.2009
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