Techniques for Reusing existing duct infrastructure

Some observations... Process of increasing bandwidth needs goes on (e.g. 3D HD

television) DSL techniques reach their limit Threat of a ‘Digital divide’ already reality Green Theme gets more & more attention also in the Teleco

Industry Hesitation to invest in FTTH: how to guarantee an

acceptable ROI for investors?

An all Fiber network is the future proof answer but how?

Further observations Telco regulators (Arcep, CMT, Ofcom, ...) driven by EU

policies force incumbent operators to open their duct infrastructure

Where a balanced frame work for duct sharing is implemented creating own duct infrastructure in a brownfield environment is stopped (e.g. France)

Reduced Capex leads to an explosion in FTTH initiatives (e.g. France)

CAPEX of Greenfield FTTH Deployments

Source: FTTH Handbook 2010 v.3.1

How to share ducts ?

Having an existing duct infrastructure = Gold in the ground!

Remaining duct capacity must be used in an optimal way, get rid of wasting space!

Cable over cable installs

Cable over cable installs The cable of a new operator is pulled over the existing cable(s) in

a duct

+ cheapest solution if it works

- high friction is generated during a pull due to high COF (coefficient of friction) between cable jackets

- Can lead to burn through of a cable jacket - Can lead to exceeding the maximum allowed pulling forces on a

cable and potential fiber damage- Difficult and risky to replace a cable - Does not result in a maximum fill ratio of the duct

Subducting with rigid sub ducts

The main duct is subducted with several Rigid sub ducts Can be traditional ‘big’ sub ducts to sub duct a ‘big’ main duct (e.g. 100 mm

duct with 4x 32 mm sub ducts Can be more recent smaller ducts (e.g. 50 mm HDPE) with mini ‘sub’ ducts

+ cable can installed by different techniques (pulling, blowing)+ installed cable can be replaced easily

- works only well in empty ducts of an existing duct infrastructure - in overlay applications high friction is generated during the pull of the

(mini) sub ducts due to the high COF between the sub duct(s) and the existing cable(s)

- does not allow to maximize the capacity of the duct

Sub ducting with Flexible sub ducts

The main duct is subducted with several Flexible subducts For all sizes of main ducts

+will maximize the capacity of an existing duct infrastructure+best solution for overlay applications +installed cable can be replaced easily

-less suitable for long distance applications (> 2000 m)

Examples form the field FTTF

Examples from the field FTTF (Continued)

Examples from the Field Elbe Tunnel (Hamburg )

Examples from the field

Examples form the field City of Luxembourg

Thank You