large scale wireless solution.
Intended Audience
It is assumed that the reader has both an understanding of the BDUK project and a basic working knowledge of Ethernet based Network architecture. It is also assumed that the reader is conversant with, and sympathetic to, the difficulties faced by many users who are unable to connect to an Internet service, delivered over traditional underground mediums, which can not satisfy their needs in terms of speed and resilience.
10
MARKET DIMENSION
The ultimate objective of the BDUK program is to increase the available bandwidth to all business and residential properties in the UK. The attenuation of the electrical signals passed over copper bearers connecting millions of properties around the UK to their local telephone exchanges is the root cause of the problem. These cables were never designed to propagate switched digital modulation protocols over such distances and as such have been the bottleneck for so many. Over the course of the programme, BTOR have worked to move the optical path closer to the customers by installing additional street cabinet’s, backhauled to the exchange by Fibre, and have moved the multiplexers into these new cabinet further reducing the cable length from the customers to the first optical path.
Clearly there is a significant cost associated all with this engineering work, especially at a national scale, and there are many scenarios where communities are just too far from their local exchange to commercially justify the civils work required to connect their new proposed PCP back to the telephone exchange.
Around the UK there are tens of thousands of properties in this situation, for reasons born from commercial or technical complexities, their local community will not be benefitting from the underground investment program and as such are open to other technologies such as FWA.
Project Area
We have been commissioned by DCM&S to investigate the installation of a Pilot project with the goal of investigating the installation of a platform to deliver NGA access speeds in a “last 10%” area and to glean knowledge and information and share it on our journey. After very lengthy discussions with the Welsh Government it was decided that Monmouthshire would be the focus of our activities and deployment.
Monmouthshire is a county on the South East corner of Wales bordering Gloucestershire and Herefordshire. It has a population of around 91,300 and its land mass is approximately 850 Km². It enjoys rolling hills and picturesque valleys with 6 major towns, the largest being Abergavenny forming the main conurbation clusters.
This illustration shows the projection of NGA coverage at the end of 2016. The grey area in this image represents forecasted NGA coverage by one or more service providers and as you can see this covers at least 90% of the county. The white areas however indicate the last 10% where no service provider will be offering NGA services and it is in these areas where the feasibility study has taken place. These white areas, for many varying and unique reasons, will not benefit from the Superfast Cymru deployment or any other BDUK investment and it is these “NGA White”
areas where we plan to deploy our NGA and Superfast infrastructure.
11 Subscriber Base
According to the Welsh Government there are approximately 1696 properties in these white areas and we will need to cover as much of that as we possibly can to build up the potential revenues, and as such the sustainability. These 1696 properties will be a mixture of individual buildings, small new developments and farm buildings, most of which will have a very real need for the infrastructure.
This heat map image illustrates the disparate and random nature of the distribution of target properties in a typical NGA White area and goes some way to illustrate the difficulties faced by network designers dealing with these type of projects. The circles on this map of Abergavenny show the number of properties in NGA White areas by size and colour. Small green dots represent 1 or 2 properties in a unique postcode and large red dots are 50+, again in a unique postcode.
When the heatmap is studied the reader can see that the town itself is well served and is clearly included in the NGA deployment plans but it is the surrounding areas which have been excluded. The challenge for a FWA operator is to deploy a platform which encompasses and includes as many of the small green dots as possible. It is often the case that the small hamlets and individual properties are nestled deep inside small valleys and burns and will never be able to
connect to a terrestrial FWA solution and in those cases a satellite solution is their only option.
12
TECHNICAL DESIGN
Assumptions Made
As this is a feasibility study only at this stage, we have been forced into making several bold assumptions regarding not only the design and shape of the platform but also the subscriber base and uptake. This was due to a lengthy delay understanding where this Pilot Project would take place.
Where there are infrastructure sites identified we are assuming that we will be able to conclude negotiations with not only the land owner, but also the Local Planning Authority for permission to build a structure at each site. It is likely that some of the sites will not come to fruition and we will need to organise an alternative however providing not too many sites fail to complete, this should not change the shape of the topology or the commercials significantly.
As discussed in the lessons learned, radio does not respect political boundaries or postcodes, it does not understand the boundary of the NGA White area and although this project will focus in the White areas illustrated above, it will no doubt attract customers outside this boundary but are in fact well within range of the service. For the purposes of this document and its context of learning for the reader, the report will concentrate solely on the uptake within the 1696 identified NGA White properties available to this project and the network design will of course reflect this. The reality is such that the project will attract significant more customers than this. However, our boundary is firmly placed within the NGA White areas illustrated in the grey and white county map on the previous pages.
In terms of our customer uptake predictions and expectations, we will use 18% of the target area, as this figure is quoted by many credible sources as being the average figure across the UK.1 The actual uptake may be higher than this as the current speeds in the area are very slow and no doubt we will experience a minor surge in orders as soon as the marketing message begins to penetrate the target area.
When calculating the extended number of properties covered by the actual and incidental radio coverage we sought clarification from Shared Resource Service Wales as to the number of properties in every postcode in Monmouthshire, and used this in our calculation of the total number of properties covered by the platform. In areas outside of Monmouth, we assumed there was an average of 15 properties per postcode, 12 residential and 3 businesses in our calculations.
Design Summary
In terms of each element of the network, dedicated capacity fibre connectivity will be brought to key infrastructure nodes, thereafter, IP transit will be delivered across the region via licensed Point-to-point Microwave radios connecting a network of Prime Node and Secondary repeater PoPs, each of which will include Point To Multipoint wireless infrastructure, transmitting 360 degrees sectors.
Fixed line connectivity to the end user (FTTC, FTTDP and FTTP) has been disregarded since the proposed solution is a more flexible architecture for both retail and wholesale purposes; it will provide Superfast Services (of up to 50MB) across the widest possible geographic area and will also offer the best value for money. It will also offer a hybrid network that is not only capable of supporting contended residential broadband services, but also offers high capacity dedicated links (Internet access and Leased line), resilient connections and Public Sector Capacity.
1Source - http://www.ispreview.co.uk/index.php/2013/12/uk-comes-top-major-eu-countries-superfast-broadband.html
13 Its effectiveness is such that coverage will reach even the most challenging areas; areas where only ‘basic’
broadband (2MB) is expected in fixed line terms, will be capable of superfast speeds thanks to AB Internet’s network.
In terms of delivering service levels to the community, for all Fibre and Point-to-Point licensed wireless connectivity, all links are delivered to a minimum of 99.99% availability on the transmission path with an 8 working hour restoration of service. Additionally, each infrastructure PoP will have either redundant or fully sustainable power supplies. Access layer wireless availabilities are designed around 99.85% availability but this is a design parameter, and is not contractually enforced SLA with the end user. All repairs to the end user are made on a best efforts basis.
The solution provides the fastest possible mechanism for service rollout, with no threat from unsecured wayleaves and complex ‘digs’, yet provides a platform for future growth and migration to optical paths to the end user, as and when this is commercially viable.
Delivery of IP transit via fibre to select nodes will
Ensure extremely high capacities with soft upgrade paths Be delivered to multiple points for capacity uplift and resilience
Provide a dedicated layer 2 connection to core peering points (no double transit) Distribution of the IP transit regionally via licensed wireless will:
Ensure high capacities (multi Gigabit) Provide high availability (up to 99.999%) Offer the possibility of true resilience Provide the lowest cost of MB per mile.
Final delivery of broadband service via 5.8GHz PtMP radio will:
Provides Superfast broadband speeds at a cost per property passed significantly lower than any fixed line alternatives
Provide services of up to 50MB to the end user. (residential)
Provide a connection with room for growth (Radio units capable of 100MB throughput)
Establish a scalable business case (with upgrade to fibre services should the business case justify it) Establish a sustainable business case
Why is Wireless So Good?
Fixed Wireless Access networks work particularly well in all locations and geo-types. Rather than looking at where it works well, it is probably better to consider its strengths and then document how this fits well with the proposed AB Internet project. Positive benefits include:
A. Reach
Fixed Wireless Access networks will generally comprise of two types of wireless infrastructure; Fully Licensed Point-to-point and light licensed Point to Multipoint equipment. Point-to-point links can be established up to 50km in a single ‘hop’, or a multiple chain of ‘hops’ and at the node of each of these hops, a PtMP wireless access layer can provide ubiquitous superfast coverage across 360 degrees and up to 15Km in radius form the hub; that’s over 700km2 per access layer PoP.
B. Rapid
14 With no way-leaves to secure (or to threaten) the project and no complex (and costly) trenching & ducting work, superfast wireless services can be deployed very quickly and cost effectively. Taking the example of two villages, 5km apart; village A has a Superfast service and Village B is in an intervention area, if Village A has a wireless based service, customers in Village B can be connected the next day, and if superfast fibre is at Village A, then B can be connected in less than a month.
Using the same metrics as Reach the 700km² area is enabled all at the same time.
C. Resilient
Wireless makes a particularly effective means of resilience and business continuity through path, power and bearer resilience.
All these benefits are applicable across the Geo-types, but it is those benefits of A and B that make a Fixed Wireless Access network particularly relevant for the deployment of sustainable superfast services in the most remote and difficult to reach rural areas. It is in these challenging landscapes and environments that AB Internet has carved a proven track record of delivering the fastest possible services to the most rural customers. It is in these areas that current FTTC or FTTP or even FTTDP services remain very expensive in terms of Cost Per Premises Past and yet the inverse is so for FWA Networks.
AB Internet has successfully deployed such networks in the most remote parts of The UK including mountainous areas such as Snowdonia, and open rolling countryside in Lincolnshire. Using this experience, the metric for average minimum numbers per PoP to ensure sustainability are 40 or more subscribers for a large village PoP and 10 or more for a small ‘repeater’ PoP in another part of a village or a small hamlet. However, it should be remembered that large PoP’s are typically deployed to cover areas rather than specific villages or hamlets. In this sense, that critical mass of 40 subscribers now applies to the ‘700km²PoP’ model
Some network operators will deploy services at extremes of range and in ‘Near Line of Sight’ scenarios to drive down cost. AB is not an advocate of either of these methodologies as it only compromises service quality and leads to problems at a later stage. The second issue; Line of Sight is the main limitation of FWA networks, it means that service can only be provided to a customer or site whose premises can actually see the PoP. The most common assumption is that ‘…the flatter the land, the better’ but this is not always the case; hills and mountains provide excellent vantage points, obviating the need to build large mast structures. Usually, LOS obstructions are more of a very local nature and involve trees or buildings obstructing the line of sight.
AB internet overcomes line of sight limitations by:
1. Detailed RF propagation modelling at an early stage; nominating site locations that give ubiquitous coverage and where possible, overlapping wireless coverage to provide alternative bearings on a regional scale, creating alternative path options.
2. Building a number of small local ‘village’ PoPs to give multiple local options for clear LOS
3. Deploying its unique ‘Eco-PoPs’ which allows AB to install PoPs on the highest and most remote hills which would not be economically viable if powered by a REC supply. They also provide a fully sustainable and reliable power supply.
Proximity to Other Competing Superfast Networks
Wireless adheres to physics, not to postcodes or cabinet locations. It is inevitable then that the proposed network, (in terms of design or incidental coverage) will overlap existing superfast capacity. Whilst there will be no intent in design to overlap NGA Black or Grey areas for commercial purposes, this will be a simple fact of FWA deployment. However, this overlap is actually of benefit to the project as a whole: where there is already
15 a Superfast deployment, there is almost always BTOR plant which we can use to connected to our core network.
Deployment by AB and the Wider Marketplace
Deployment in remote rural areas has challenges associated with the scale of deployment. AB Internet will use its experience of rolling out remote rural networks by:
1. In the survey stage, using its core surveying team and aerial survey platform to ensure the largest area can be covered in the shortest and most economical time
2. Deployment of villages and hamlets by group, rather than by house
3. The use of key subcontractors that AB has an existing relationship with (Arqiva and T James) to add extra capacity at the core install phase.
4. The use of local installation sub contractors (for client end) volume deployment
5. Resellers and Service partners (wholesale channels) will also do I&C as well as maintenance work in the local area.
6. For wholesale partners who interconnect with AB at our peering locations, no physical installation work is needed; AB Internet will effect layer 2 connectivity; the partner merely makes the connection at Layer 3 and above.
The Proposed Core Network
Our network deployments are designed from the outset to be scalable and to plug into our national platform, regardless of the number of network segments, subscribers or services, and for it to conform to all the relevant and latest telecommunications peering, interconnecting and exchanging protocols to ensure the greatest possible interoperability between us, our transit providers and our wholesale partners.
Our national network is carried throughout the UK over the well renowned high availability Cogent platform, and we peer at both Telehouse Redbus Sovereign in London and IFL2 in Manchester to deliver our transit to our subscribers and interconnect with our partners.
16 Local Topography Considerations
In order for us to design the core network to connect to our national platform we must first consider the local topography. Monmouthshire has many rolling hills and meandering rivers as can be seen from the topological survey shown here with the Brecon Beacons to the west dominating the landscape and the Wye Valley meandering down the English Welsh border to the East.
FWA networks are best suited to landscapes with hills, as these vantage points give engineers the opportunity to span great distances with licensed high capacity microwave links and can install the Access Layer equipment at great heights to ensure the deepest penetration into the market place.
Fortunately, the potential market place footprints are located near high ground and we can take advantage of that, not only to exploit the maximum coverage but also to allow us to link all the infrastructure sites together.
Top Level Topology and Site Identification
In order to determine the shape of the topology, the designer must look at the footprint of the demand and overlay this information onto the topography information. In doing so we can glean an early insight into where the network nodes need to be located. In this case the NGA White areas are located in or near:
o Abergavenny o Monmouth o Chepstow o Caldicot o Caerleon
We can now use this information to determine approximately where each of the nodes need to be built. At the very top level we can see a ring forming around the areas of demand. It is always best to look for circular routes, as the lower level network infrastructure can use rings to re-route traffic in the event of a site failure.
In this case we are fairly lucky in that there is high ground near most of the areas of concern. There are a number of factors to consider when selecting sites:
Commercials
Careful consideration needs to be taken over the commercials of a site. Most Mobile Operator Locations (MOLO’s) are prohibitively expensive to rent space on as their owners’ commercial models work in a
17 fundamentally different way to an ISP’s. Whereas they will be able to justify a significant figure for aperture rental on a another operators structure because they will have up to 1000 subscribers using a site, we will often have only 20-50 customers associated with a site commanding the same ARPU. A typical mobile operator or agent will charge somewhere in the region of £5000 to rig, and £2500-£6000 per annum to rent the required space on an existing commercial tower. That cost, together with the fact that there may only be
17 fundamentally different way to an ISP’s. Whereas they will be able to justify a significant figure for aperture rental on a another operators structure because they will have up to 1000 subscribers using a site, we will often have only 20-50 customers associated with a site commanding the same ARPU. A typical mobile operator or agent will charge somewhere in the region of £5000 to rig, and £2500-£6000 per annum to rent the required space on an existing commercial tower. That cost, together with the fact that there may only be