EoW January 2008

EuroWire – January 2008

english

A novel aerial air-blown

solution for FTTH networks

using pre-terminated fibre

and micro cables

By Anders Björk, Mårten Björs and Peter Lo Curzio, of Ericsson Network Technologies AB, Hudiksvall, Sweden;

and Bill McGavin, Ericsson Communications Ltd, Auckland, New Zealand

1. Introduction

The advent of broadband technology

delivering triple play services has revolu-

tionised the way of modern business and

home entertainment. To the communities

that have these service facilities already,

such services are now just a way of life.

Amajor reason why fibre-based broadband

is not more universal is the high cost of

the civil works for underground building.

Heavily built-up areas and areas that are

located on hard rock terrain are typical

areas that operators try to avoid in their

rollout of broadband services. In such

areas aerial solutions can be an option,

especially in cases where an existing aerial

infrastructure already is in place, eg over-

head power distribution or telephony.

Air-blown fibre and micro cables have been

proven to be very efficient for fibre access

network applications such as Fibre To The

Home (FTTH). When using pre-terminated

fibre, the installation time can be kept to

a minimum compared with conventional

cabling techniques. Furthermore, the

air-blown technique enables a ‘dynamic’

network where fibres can be quickly and

easily added, removed, replaced or re-

routed without expensive civil works.

Aerial air-blown fibre installations have

suffered in the past with regard to the

aesthetics and practical installation.

Modern advances in fibre cable design,

see

[3]

and

[4]

, and installation practices have

totally revolutionised aerial installation

which will be discussed in this paper.

We propose a novel technique for aerial

installation of fibre using air-blown

techniques describing these advances in

both design and installation techniques.

2. Solution Description

The basic aerial air-blown system design is

the same as for a traditionally underground

system. However, some new products had

to be developed, see

section 3

The solution is based on self-supporting

ducts combining pre-terminated air-

blown fibre units as well as air-blown micro

cables. The technology is unique in many

ways:

a single duct assembly can be used

for both the distribution and drop

sections of a FTTH network. By sharing

the same infrastructure for distribution

cables and drop cables in a fibre access

installation, considerable cost savings

can be made. The installation cost for a

single assembly is obviously lower than

installing separate cables for feeder

and drop sections of the network in

parallel

•

it also fully utilises the benefits

of incremental fibre deployment,

allowing new fibre to be installed

quickly and at low cost when needed.

Thus, it is possible to postpone costly

investment in fibre for the future – ‘pay

as you grow’

the solution is equally suitable for

Passive Optical Networks (PON) as

well as Point To Point Networks (P2P).

In fact, both topologies can share the

same physical infrastructure. A PON

network can be upgraded to a P2P

network without additional investment

in ducts

a general requirement for all products

in this concept is small dimensions and

low visual impact. The visual impact

of aerial pollution is a key factor in the

acceptance or rejectionof such solutions

by the community. Communities no

longer allow installations that impact

on their visual rights

•

Figure 1

Pole line with distribution terminal closures on each 5

pole

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