Fiber allocation and the Demand Model

Every address in a fiber project needs to know two things: how many fibers it should get, and which tier of the network they should come from. A single-family home might need one drop fiber, while a large apartment building or a hospital is better served directly from further up the network.

You don’t set these values on each address. Instead:

Each address has an AddressType, such as SFU for a single-family home or LMDU for a large apartment building.
The Demand Model in your architecture sets the tier and number of fibers for each address type.
FOND applies the Demand Model to every address when it generates your plan or design.

To change how an address is served, change its AddressType or change the Demand Model. You can’t edit the tier or the number of fibers on an individual address.

This applies to Fiber Planner and Fiber Design projects.

Where to find the Demand Model

The Demand Model is part of your architecture. You set it up straight after the network architecture settings.

Demand Model settings

Each row in the Demand Model is a fiber allocation for one address type:

Setting	What it does
Address Type	The value in the address’s AddressType field that this row applies to
Description	A short note on what kind of address this is, to help you and your team
Tier	The tier the fibers come from: Drop, Distribution or Feeder
NumFibers	How many fibers to provide, as a whole number of 0 or more. 0 means the address isn’t served.
Default	Applies this row to any address whose type isn’t in the Demand Model. You can have only one default, and it can’t be deleted.
Exclude type	Leaves addresses of this type out of the plan or design completely

Unserved addresses

Addresses with NumFibers set to 0, and addresses of an exluded type, aren’t served. They don’t count toward your subscription’s premises.

Address types that aren’t in the Demand Model

If an address has a type that isn’t in the Demand Model, FOND tells you which type is missing and applies the default row to those addresses. If that’s not what you want, add a row for the missing type.

Which tier should I use?

As a general rule, the larger the address, the further up the network it should be served from.

Tier	What FOND builds at the address	Typical address types
Drop	A service location served by drop cables, one per fiber. Fibers are split at both the distribution and drop tiers.	Homes, duplexes, small businesses
Distribution	A drop dedicated hub, served by a distribution cable (or a drop hub tail cable in connectorized architectures).	Small and medium apartment buildings, medium commercial buildings
Distribution + bypass splitters	A drop unsplit hub, served by a distribution cable.	Large apartment complexes, large commercial sites, institutions
Feeder	A distribution dedicated hub, served by a feeder cable.

As you can see, an address type classified using Distribution + bypass splitters and one with Feeder will receive the same fiber capacity. The difference between the two is the device placed at the address location and the cable feeding it.

What if a drop-tier address needs a lot of fibers? FOND uses your architecture to serve it sensibly. For example, it might place a drop dedicated hub at the address instead of running many drop cables.

How many fibers?

For addresses served from the Distribution or Feeder tier, work out the number of fibers from the number of units the address contains (X):

Distribution tier: fibers = X ÷ drop split ratio, rounded up. For example, with a 1:4 drop split, 6 fibers serve up to 24 units.
Feeder tier: fibers = X ÷ overall split ratio, rounded up. For example, with a 1:32 overall split, 8 fibers serve up to 256 units.
Distribution bypass splitters: Use the same method as an address served by the Feeder tier.

The standard Demand Model

New architectures start with a standard Demand Model, which you can change to suit your network. It is always recommended that you revise this to be suitable for your architecture.

Address Type	Description	Examples	Tier	NumFibers
SFU	Single-family residence	Single-family homes	Drop	1
DPX	Residential duplex	Two-family residences	Drop	2
TPX	Residential triplex	Three-family residences	Drop	3
QPX	Residential quadplex	Four-family residences	Drop	4
SMDU	Small multi-dwelling unit (5–9 units)	Apartment buildings	Distribution	1
MMDU	Medium multi-dwelling unit (10–99 units)	Apartment buildings	Distribution	2
LMDU	Large multi-dwelling unit (100+ units)	Apartment complexes	Feeder	2
SCU	Small commercial unit	Retail stores, offices, farms	Drop	1
MCU	Medium commercial unit	Office buildings, hotels, medical clinics	Distribution	1
LCU	Large commercial unit	Shopping malls, multi-story offices, arenas	Feeder	1
INSTITUTION	High-bandwidth facilities	Schools, colleges, hospitals, museums	Feeder	1
GOVT	Government offices and facilities	Administration offices, military sites	Distribution	1
PUBLIC	Public buildings	Community centers, municipal facilities	Drop	1
DNS	Do not serve	Vacant, exempt or forest land	-	-

The SFU Address Type is also the Default treatment for addresses with a type that does not match any of the above values.

Addresses that are already classified

Addresses you import with Area Select already have an AddressType from the table above. FOND classifies them mainly by the parcel’s land use. That means the standard Demand Model works straight away, with no extra setup.

Area Select classifications are a starting point. It’s worth checking them, especially for large or buildings or parcels.

Using your own address data

If you upload your own addresses, add an AddressType field (text) and fill it in with the types in your Demand Model. Addresses with no AddressType, or with a type that isn’t in the Demand Model, get the default allocation.