GPON Case Study - Conwy Lodge

The client is the owner/proprietor of “Conwy Lodge Park” based on the outskirts of Conwy town in North Wales. The site commands a superior position on a 100acre site with 360˚ views of Conwy Valley, Llandudno Great Orme, Anglesey, Conwy Castle and Snowdonia National Park. The client has a very clear strategy and a vision for the Luxury Park. His ambition and driving force is behind the significant and on-going developments that makes Conwy Lodge Park such a success. Part of that vision is to have the ability to deliver Super Fast & Ultra Fast Broadband to each and every lodge across the whole site. Clients paying £250-£500k per lodge would not expect anything less. 

To enable every lodge on the park to experience and enjoy as a minimum Super Fast Broadband and have the capability to provide Ultra-Fast Broadband By special request experience Warp Speed Broadband greater than 500Mgbs.

This is broadband connectivity without compromise.

Connection from CO (Central Office) to WAN -WWW is:-

• Variable on demand EAD (Ethernet Access Direct) on 10Gig barer. 
• Technology used to deliver services across the Park is GPON
• Network type - FTTL Fibre To The Lodge 
• Number of users 50 rising to 400.

 

 
GPON is a fibre broadband technology that uses multiplexing to allow multiple customers via optical splitting to share a fibre connection whilst delivering a secure connection and Gigabit+ speeds. GPON has only passive light
transmission components in the access network with active components only in the central office and the customer premise equipment. At the central office the termination point is in Optical Line Terminal Equipment (OLTE). At the customer optical network terminals or ONT is the termination point. Between OLTE and NTE is the passive optical 
network, comprising fibre links and PLC (Planar Lightwave Circuits) passive splitters.


With the price of OLTE/NTE the active component within a GPON system continuing to fall in price, it now looks to be a  cost-effective solution on smaller Campus / Residential environments. We are talking about GPON, so it is also important to point-out that GPON provides 2.5Mbps of bandwidth downstream and 1.25Gbps upstream shared by a maximum of 64 users.

GPON provides a 20 km reach with a 28dB optical budget using class B+ optics with a split ratio of 1:32. This reach can be extended to 30 km by limiting the splitting factor to a maximum of 1:16, or by the help of enhanced optics C+, this optical link can add up to 4 dB to the budget and extend optical reach up to 60 km. The 10G-EPON can also provide 20 km reach with a 29dB optical budget.

To make it easier to understand, below is a simple diagram of GPON.

In FTTH system signals are combined, multiplexed, converted to light signals & interfaced to a single fibre by the Optical Line Terminal (OLT) placed in the exchange. The signals are transported & distributed to the end users, directly or through splitters, where the signals are converted through ONT to electrical signals

Typically GPON system is used with single mode fibre G652 but more recently G657 (Bend insensitive Fibre).

Planning of the ODN (Optical Distribution Network) is critical to a successful GPON deployment. The network needs to be well planned to take into consideration optical budgets bandwidth performance number of clients and distance involved if we are to deliver a good service.

From an infrastructure perspective FTTH networks are very similar in design and layout to the copper network configurations and elements. In comparison, it consists of a Feeder (primary) and Distribution (secondary) network, Fibre Distribution Terminal (Pedestal / Cross connect cabinet), Fibre Access Terminal (Distribution Point) and Drop fibre (buried or aerial service) via a demarcation box.

The park benefits from a lattice of ducts extending across it, typically 100mm plastic ducts. If there is a need to deploy new ducts then this is a relatively easy task for the park owner. He owns the land he has the plant and the skills at his disposal. 

From a planning perspective there are detailed plans approved by Conwy Borough Council which clearly identify what lodges can go where. From this and GIS mapping we are able to generate plans to cover all the services to include Electricity / Water / Gas / Sewer & Communications. On the communications layer we are now able to strategically plan the deployment of pedestals taking into consideration the existing ducting and plot locations and where necessary, the planning of additional ducting. We also take into consideration at this stage the need and flexibility to enable expansion. The park currently has at least 3 phases with a rollout programme over the next 3yrs. 

Therefore it is important to have sufficient capacity in the network. Typically all ground works (ducts) are complete for all three phases, additional tubes and fibre can be added as we move through the phases and align ourselves with demands. 

We need to get a Fibre connection from the CO to the Client, this is achieved via a lattice of multi microtube and OSP Cabinets (Pedestals). So we now have a physical tube connection from the CO to the demarcation box. Typically we will have a primary fibre from the CO ODF terminating at the OSP pedestal where we will split the fibre either 16 or 32. This will enable 16-32 client connections. We have a tube running from the Pedestal to each property terminating at a demarcation box. The network from the CO to the demarcation box is Passive - PON (Passive Optical Network) Each pedestal has a minimum of 4 primary fibres from the CO. Giving capacity, flexibility and redundancy. These additional fibres may also be used for other activities associated with the park such as CCTV / Barrier control / NPR etc.

Traditional methods are used to deploy the tubes. These are pulled in via draw ropes to each location. Specific tubes are dropped off and terminated via inline connectors and extension tubes. This continues and is replicated across the site. When an OSP is deployed with terminated tubes and secure, we are now ready to Blow EPFU (Enhance Performance Fibre Units) down the tubes. This will entail primary and secondary fibres. All primary fibres are blown from the CO. However, all secondary fibres are blown from the OSP to client location. All fibre connections are fusion spliced.

During the planning process we worked closely with a number of potential suppliers of Optical Connectivity products. But it was Micos range of products that provided a cost effective solution for our particular FTTL (Fibre To The Lodge) network. The Micos product range is stocked and distributed through Cable Management Warehouse (CMW). The CMW technical services fibre division provided on the ground support for product selection installation, test and commission.

External Optical Closure – SNM 288
Optical closure designed for placement of up to 288 fibres. Wall mounted with good fibre management for splice and patch. Easy removal of ODF to enable easy access and splicing of fibres. Two of these units are installed at the old reception area. Unit 1 to feed the primary fibre to the GPON pedestals the 2nd unit to provide primary fibres to a new fibre distribution centre. An added complication here was the need for the SNM 288 to be on Umbilical Cord/s, waiting erection of new Central Office.

Optical Overground Closure – SNM 48/72/144
Optical closure designed to terminate and manage 48/72/144 fibres. Quick easy deployment with duct access underground. Ideal for bringing in and securing feeder and distribution tubes. Easy removal of ODF to enable easy access and splicing of fibres.

Demarcation box-ORM3
External demarcation box complete with splice tray and fibre management. Accepts 3/5mm tubing presents customer connection via armoured patch cord.

Optical Splitters PLC (Planar Lightwave Circuits)
PLC splitters with SCAPC connectors for reduced back reflection. Used a combination of 4/8/16 way splits. The 4 & 8 way splits used at the head end with the 16 fibre downstream for client splits.

Armoured Patch Cord
Simplex SCAPC patch cord with spiral steel armour to protect against rodent attack EPFU (Enhance Performance Fibre Unit) G657 fibre unit both 4 & 12 used for both primary and secondary connections. Easy to strip good blowing performance.

LCAPC Pigtails (900u)
Small form factor connector higher packing density in CO / ODF. APC for reduced reflection. Easy strip buffer.

SCAPC Pigtails (900u)
Active and PLC splitters are supplied in SCAPC hence the need for SCAPC pigtails. APC for reduced reflection. Easy strip buffer.

GPON technology has the flexibility to develop and migrate as demands grow within a campus/village small convocation environment. It also has the added advantage to better manage and stage capital expenditure, aligned with a project programme. 

GPON Technology continues to develop and evolve giving rise to improved functionality, better control and it is more accessible and manageable. The cost per OLTE port is very competitive given that 1 port can deliver services to 64-128 clients.

It is important that we ultimately understand what the client expects. If the client is investing £500K in a Luxury Holiday Lodge then we must have the capability to provide Ultra-Fast broadband, there can be no compromise.

Download the case study in pdf format.