UK Broadband; ADSL, FTTC, FTTP, BT, Openreach and the future

20 Votes

2024-07-15 Published, 2024-10-28 Updated
4028 Words, 21 Minute Read

Richard (Senior Partner)

Richard has been with the firm since 1992 and was one of the founding partners

History

BT started broadband in the UK in 2000/2001 with ADSL, which could provide up to 10Mbps but almost never did instead being limited to 0.5Mbps, 1Mbps and 2Mbps. This limit was primarily due to the terrible state of the cabling in and above ground which had been neglected for decades by BT, much of which hadn't been replaced since the war, and again much of which was aluminium instead of copper because it was much cheaper. However, compared to dial-up, even 512k was a step up and 2Mbps was massive.

ADSL2 began rollout in 2003/2004 by BT, which increased reliability somewhat but didn't increase speed by very much. At this time BT began a renovation of the cable infrastructure and began replacing 50 year old cables with new, albeit slowly.

In 2008 BT (now openreach) began upgrading equipment to ADSL2+, which promised a massive speed increase to a max of 24Mbps, although again almost no one achieved this with most floating somewhere between 10Mbps and 20Mbps. ADSL2+ was introduced because of its ability to operate with poor line quality to improve speeds, but it was shortlived with early FTTC trials starting in 2009 as a way to side-step the still terrible cabling in the ground.

In 2010 Openreach launched FTTC and began the roll out, which promised as much as 80Mbps, but this was initially only provided as 40Mbps simply because this was achievable, whereas 80Mbps was never achievable. FTTC used fibre optic from the exchange to the cabinet, which was the LONG leg of the journey greatly reducing the length of copper (or aluminium) to the premises. By 2012 Openreach was installing *new* wires from the cabinet to the premises for new circuits where existing wire was poor and this meant that the maximum speed was increased to 40Mbps with some customers actually achieving that.

In 2010 Openreach launched FTTP which initially was only in select area's and only for commercial use. Later that same year FTTP was extended to some residential premises in select areas. The rollout was slow to start primarily due to the expense of the equipment and skills gap to install it, but by 2016 Openreach made the commitment to rollout FTTP over any other technology, solidifying this in 2018 by making FTTP the only broadband available in new cabinets.

In 2017 Openreach announced G.Fast, which further enhanced FTTC with speeds up to 300Mbps, and it was initially decided to roll this out in area's where FTTP not immediately viable, or possible, but by the end of 2018 Openreach was scalling back the rollout bringing it to a halt in 2019/2020. In 2023 Openreach officially canned G.Fast and no longer offer it as a service. Existing services will be phased out as FTTP becomes available.

Technology

ADSL

ADSL (Asymmetric Digital Subscriber Line 1) used a technology called DMT (Discrete Multitone) modulation to transmit data over standard copper telephone lines. Here's how ADSL1 worked:

Frequency Division: ADSL used frequency division multiplexing to separate the signal into different frequency bands:
- Voice calls: 0-4 kHz
- Upstream data: 26.075 kHz to 137.825 kHz
- Downstream data: 138 kHz to 1104 kHz
DMT Modulation: The data-carrying frequency bands were further divided into smaller 4.3125 kHz channels. Each channel could carry data independently, allowing the system to adapt to line conditions.
Asymmetric Design: ADSL1 provided faster downstream speeds (up to 8 Mbps) compared to upstream speeds (up to 448 Kbps for residential lines, 832 Kbps for business lines). This asymmetry was designed to suit typical internet usage patterns, where users download more data than they upload.
Splitter Usage: A microfilter (splitter) was used to separate the voice and data signals, allowing simultaneous use of telephone and internet services on the same line.
Distance Dependence: The performance of ADSL1 was heavily dependent on the distance from the telephone exchange. Shorter lines could achieve higher speeds, while connections over 6.5 km typically experienced slower speeds.
Always-On Connection: Unlike dial-up, ADSL1 provided an always-on internet connection, eliminating the need to dial in each time internet access was required.
Shared Bandwidth: ADSL1 was a "best efforts" service, meaning bandwidth was shared among multiple users. This could lead to variable performance, especially during peak usage times.

ADSL1 represented a significant improvement over dial-up internet, offering faster speeds and the ability to use the phone and internet simultaneously. However, its performance was limited by factors such as line quality, distance from the exchange, and the number of users sharing the connection.

ADSL2

ADSL2 (Asymmetric Digital Subscriber Line 2) was an improved version of the original ADSL technology, offering several key enhancements:

Higher data rates: ADSL2 could achieve maximum download speeds of up to 12 Mbps, compared to 8 Mbps for ADSL1.
Improved reach: ADSL2 could maintain usable speeds over longer distances from the telephone exchange than ADSL1.
Better noise resistance: ADSL2 had improved capabilities to handle line noise, resulting in more stable connections.
Dynamic rate adaptation: ADSL2 could adjust connection speeds in real-time based on line conditions.
Reduced initialization time: Connection setup time was reduced from about 10 seconds to less than 3 seconds.
Power management: ADSL2 introduced a standby mode to reduce power consumption.
The key technological differences between ADSL2 and ADSL1 were:
- Frequency usage: ADSL2 used the same frequency range as ADSL1 (up to about 1.1 MHz) but utilized it more efficiently.
- Modulation: While both used DMT (Discrete Multitone) modulation, ADSL2 improved the encoding to achieve higher bit rates within the same bandwidth.
- Adaptive capabilities: ADSL2 had more sophisticated algorithms for adapting to line conditions, allowing it to optimize performance and maintain stability.
- Error correction: ADSL2 implemented improved error correction techniques, contributing to its better noise resistance.
- Framing: ADSL2 used more efficient data framing methods, reducing overhead and improving overall throughput.

It's worth noting that while ADSL2 offered these improvements, the actual performance still depended heavily on factors like distance from the exchange and line quality. In some cases, particularly for users far from exchanges, ADSL1 could still perform better than ADSL2.

ADSL2 equipment was designed to be backwards compatible with ADSL1, allowing for easier upgrades and compatibility with existing infrastructure.

FTTC

FTTC (Fibre to the Cabinet) is a broadband technology that combines fibre optic and copper cables to deliver high-speed internet. By using new fibre-optic to carry data to the cabinet, only the much shorter distance from the cabinet to the premises was copper.

In FTTC the fibre optic from the exchange to the cabinet was initially at 1Gbps, later 2Gbps and then 10Gbps, and there could be more than one fibre if needed.

The "last mile" section from the cabinet to the premises was often installed fresh even if there was existing cable simply to avoid the poor quality existing cabling, and even with fresh cable there maximum speed was still limited to 80Mbps even though the equipment in the cabinet could achieve 120Mbps if so configured. It was felt that 80Mbps was more than sufficient and that having too many speeds would complicate ordering and billing. When you consider that being able to order 20Mbps, 40Mbps, 60Mbps, 80Mbps, 100Mbps and 120Mbps, and then having customers not achieving that speed would mean near constant downgrades and credits/refunds which would make it unworkable, instead going for 40Mbps or 80Mbps and you get what you get.

The analogue "last mile" section of the circuit used VDSL (Very high bit rate DSL) which again improved on ADSL2/2+ by

Frequency Bands:
- VDSL uses a wider frequency band than ADSL, typically from 25 kHz to 12 MHz, allowing it to support higher data rates.
- The frequency band is divided into multiple channels, each carrying a portion of the data.
Modulation:
- VDSL employs Discrete Multi-Tone (DMT) modulation, which divides the frequency spectrum into multiple sub-channels, each modulated separately.
- This allows for efficient use of the available bandwidth and better handling of line noise.

Feature	VDSL	ADSL2+
Maximum Download Speed	Up to 52 Mbps (VDSL), 100-300 Mbps (VDSL2)	Up to 24 Mbps
Maximum Upload Speed	Up to 16 Mbps (VDSL), 50-100 Mbps (VDSL2)	Up to 1.4 Mbps
Frequency Range	25 kHz to 12 MHz	Up to 2.2 MHz
Distance Sensitivity	High (best performance within 1,000 meters)	Moderate (effective up to 5,000 meters)
Modulation	DMT (Discrete Multi-Tone)	DMT (Discrete Multi-Tone)
Deployment	Requires fiber to the cabinet (FTTC)	Uses existing copper lines from exchange

G.FAST

G.fast is a broadband technology that enhances the performance of existing copper lines by using higher frequencies, typically 106Mhz to 212Mhz, and can technically deliver up to 1Gbps over short copper lines, although in practise its more reasonable to expect around 200Mbps. G.Fast is only effective on short lines of 500m or less, after which it becomes incresingly less effective. G.fast was the next logical progression of DSL technology, but is no longer avaialble with Openreach focusing their efforts on FTTP.

FTTP

Openreach's FTTP (Fibre to the Premises) technology involves running fibre optic cables directly from the exchange to individual homes and businesses. This completely avoids any existing wiring and of course removes any speed restrictions based on this. FTTP currently provides speeds up to 1Gbps, but is technically able to provide speeds up to 30Gbps or more. There is no dependency on having cabinets in the street or wires in the ground and since its a 'passive' network, the actual cabinets that are needed can be tiny in size, and actually are often installed on telegraph poles with a long term plan to remove street cabinets.

Even though technically FTTP can provide significant speeds, in the UK, Openreach heavily contends customers so that, a single 2.5Gbps fibre port (OLT) is shared between 32 customers, and sometimes as many as 64 customers. Openreach are upgrading OLT's to increased this to 10Gbps between 32 customers (up to 64 customers) but this isn't easily tracked.

Regardless, the actual maximum speed at the customer's ONT (Optical Network Termination) depends on how much contention there is, the capabilities of the OLT/PON and ONT, and the limits imposed by the broadband vendor. Just becase you're connected to a 10Gbps PON doesn't mean you can have 10Gbps or 2Gbps or any other combination. The original ONT's provided by Openreach can only support speeds up to 1Gbps.

Broadband Vendors

Have you ever wondered how you can have broadband from GEN, and BT using the same infrastructure?

Its actually quite simple. The Openreach infrastructure is responsible for data transmission between the exchange and the customer, once at the exchange traffic is transferred over BT's backhaul network to your broadband providers POP (where they interconnect to BT's network) and from there the traffic flows over the providers network. Mostly. In some cases, there are hybrid peering agreements where broadband traffic terminates on one vendors network and is then routed to another, and possibly another. BT's WBMC Shared is an example of this and can be significantly cheaper than WBC. Hybrid peering increases performace by routing internet traffic directly to the internet bypassing the vendors network, and then only hitting the vendors network for vendor specific services, like email, SDWAN, SSO, etc.

LLU

For broadband providers with a large enough wallet, it is possible to circumvent the BT Backhaul network and transfer data directly to your own network by having a network termination in the exchange. This is expensive, but provides greater flexibility and control. Some providers started to rollout LLU during ADSL2, but as BT reduced the price of backhaul and offered more 'options' it became less favourable.

Traffic Shaping

Smart Traffic shaping has enabled residential broadband providers to 'manage' customers that are placing a higher than average demand on their network by delaying, slowing, or factoring excessive traffic to maintain an average service level. Residential broadband providers contend connections more, meaning that customers sharing a circuit 'feel' the impact of a heavy user more than businesses. Let's assume that a 2.5Gbps fibre circuit is shared between 32 households, then that doesn't mean that each will get 78Mbps of bandwith, because traffic isn't like that. Let's assume that every one of those 32 customers has the full 1Gbps service, and that two of them are downloading torrents at the full 1Gbps at the same time. That will means that 500Mbps is all that's left for the other 30 customers. Its rarely like this, but you start to see how contention can cause laggy performance especially at those peak times. Sharing only 2.5Gbps between 32 1Gbps circuits means that if everyone was downloading at the same time, they'd each only get 8% of their purchased bandwidth. I know, but in reality even contending at 32:1 performs 'ok' in a residential setting, and traffic shaping successfully slows down those heavy users to allocate bandwidth more fairly.

Business vs Residential

A Broadband Vendor, when using Openreach, and other networks like Virgin, are able to specify the contention as a factor of the OLT. That is, whilst residential vendors are happy at 32:1 or more contention, business vendors are (generally) not, but we can't all afford to provide 1:1 for £100/pcm. Instead we try and work to a more sensible contention giving each business a far larger share of the 2.5Gbps OLT, and we can reduce this further if needs be, anything up to 1:1 assuming the customer is willing to pay for it and the vendor can support it. However, broadband and FTTP is not the most suitable service for businesses who need low contention, low latency circuits, and private circuits fit this use case much better. With a private circuit you're getting 1:1 and if you order a 1Gbps private circuit, then all 1Gbps is yours to do with as you please. Private circuits are also synchronous, meaning that its 1Gbps download and 1Gbps upload which again suits business use cases better than FTTP which is asynchronous.

Business vendors do not generally use traffic shaping, although they do use hybrid routing, not only to route internet traffic away from their core networks, but also to configure and establish software defined WAN, or SDWAN, which is essentially a 'virtual' private circuit between a companies sites, allowing traffic to flow as-if they were directly connected. SD-WAN, which is essentially a hardware based VPN is quite a popular service especially for companies with more than one site, joining their LAN's allows for file, data, voice, and video sharing between distinct buildings.

Service Levels

Business customers NEED better service than the usual 2 to 5 days to repair a broadband circuit in the UK, and to achieve this we, and any other good business ISP has to pay Openreach (or Virgin etc) a monthly fee for every circuit to jump the queue for faults. I'm not going to say what this charge is because it changes regularly but its not insignificant over the life of a connection. Another apporach is disperate connectivity which is achieved by bringing in one circuit over, for example, Openreach and another one from, for example, Virgin Media. Both circuits are delivered to a router capable of load balancing and fault tollerance which then ensures that internet connectivity will be maintained if either circuit fails. This is more expensive than the queue jumping charge, but it guarantees connectivity even in the event of a failure, which for some companies is worth the extra. We, for example use routers that can handle 2 circuits as standard, but can supply equipment capable of supporting 4 or 8 circuits, load balanced with redundancy if needed, and this sort of service is what sets business ISPs apart from residential ISPs who also sell to business.

Monopoly

Openreach, is still a BT company, and its part of BT, meaning that BT who themselves provide broadband have a distinct advantage over everyone else, even though they pretend they don't. Since Openreach is the only way to provide broadband to the majority of customers, all broadband vendors are forced to use them unless alternatives are available. That means we're forced to pay the same price as everyone else which reduces competition significantly.

There are alternatives, some of which have significant coverage like Virgin Media, and others who are slowly growing, and of course 5G promised broadband speeds through the airwaves. Ultimately, for any one broadband provision there are generally several options, which is why GEN, for example, don't have a online ordering process for broadband. Instead we take the address details and then a specialise will look at all the options for a given location, which involves looking at openreach capacity, virgin, 4GLTE, 5G, Satellite, private circuit and other technologies like WiMax or Microwave, and with smart equipment several of these can be combined to provide even more bandwidth with automatic redundancy for high uptime and service levels. As the market continues to diverge, business broadband will become more segmented with some providers sticking with Openreach whilst others readily embrace emerging networks providing more choice and performance.

Recap

ADSL, ADSL2/2+, and VDSL involve transmitting data over copper (or otherwise) wires in the ground, or above ground. This analogue section severly limits the maximum speed but these technologies are adept at handling poor quality lines to obtain the best possible rates.

FTTP involves fibre optic from the exchange to the customer, no boxes, no copper (or otherwise) just fibre. This is far more reliable, far faster and is much cheaper to install and maintain. In the future FTTP will continue to increase bandwidth and broadband vendors will keep pace with faster packages

Openreach is working hard to withdraw ALL wires in the ground/above ground as soon as possible, and they are doing this in several ways.

They have taken away our ability to provision new ADSL, ADSL2/2+ and FTTC on any exchange where FTTP is available.
For exchanges that do not have FTTP, they have limited our options to SOGEA which is FTTC but without the telephone line component.
For anyone with a analogue telephone line, they have increased the line rental significantly and stepped up marketing away from analogue.
They will no longer accept orders for a 'telephone line', and to make it awkward to continue will no longer process any change of ownership, change or address or any other changes to telephone line services.

This approach is effective, but not really in the spirit of things. If they want people to move, offer it for free, don't force people into it by making the other options untenable. In my opinion.

FAQ - Openreach Industry Secrets

Can my ISP expedite an install?: Yes we can, it's an option on the wholesale portal but there is a charge involved.
Can my ISP expedite a fault fix?: Yes and No. If your ISP is paying a premium for support then all faults are expedited, otherwise it's down to how ameniable the Openreach Area manager is.
Can my ISP make my circuit faster, or slower?: Yes, we can control 'profiles' which tell the circuit how fast to sync, but also the system itself makes changes to handle line quality. for FTTP however, the system is fixed at what we set.
I have a 'slow' circuit and my ISP tells me it's within the range, are they not able to sort it?: Yes, they can, but quite often Openreach will make a charge of £160 to come out and fix it, if it is already within the expected performance window. Most residential ISP's don't do this because they can't then charge the customer, but business ISP's can and do.
Does everyone pay the same price to Openreach for the service?: Yes, generally everyone using WBC pays the same. There are rumours that BT don't but they are just that and there's no confirmation. The only ISP's who pay more/less are LLU providers who do not use BT's backhaul service.
Can I transfer my circuit to another provider?: Yes, but the process is fraught with issues. It's better and won't leave you without internet, to order a new circuit from your new provider and terminate the existing one.
Why are the contracts 12 and 24 months?: Well, there are two reasons, firstly to install a new circuit costs between £100 and £160 for broadband, and then the ISP has to supply the router, which typically costs them another £25, so at the outset they are in the hole for £125 to £185 that they need to recoup monthly from the customer. The case is different for proper business ISPs like GEN, becase we do charge for an install and in most cases the equipment is leased as part of the service, mainly because it's very much more expensive at £200+vat for our entry level routers, up to £2000+ for the multi-wan or specialist routers, but also because the equipment is 'managed' which means we monitor and maintain it for the duration, which in some cases means changing the hardware out every year or two for newer technologies.
Can I terminate mid contract if my broadband doesn't work?: Yes, but you must give your provider a reasonable chance to resolve the issue. If you have, and they still are unable to fix it, then most ISP's will let you out of any contract, because quite obviously you ordered a service and they can't supply it. There is a regulator for this kind of thing, OFCOM (https://www.ofcom.org.uk) who have an entire complaints section, but please give your provider a chance before heading to OFCOM.
The engineer says it's my wiring, it isn't fixed and I've been charged?: Openreach are responsible for the circuit up to and including your Master Socket. Any internal wiring is not their problem, but, your provider should have asked you to remove the faceplace (therefore isolating any internal wiring) and tested again. This is standard practice. If you then have an engineer come to your premises, and find that there's no issue with the line, and instead the fault is local, then you can and will be charged for that engineer, becuase your provider will be charged for that engineer. Because of this 'charging' by Openreach for engineering no fault visits, many residential ISPs will simply refuse to send an engineer unless the circuit is down, which is a shame.
Why do I need a new contract for an upgrade?: In BTWholesale land, an upgrade IS a new circuit, and the provider is then on the hook for that circuit, and in some cases, probably many cases will need to ship out more equipment. For this reason, an upgrade is treated as a new service and your 12 or 24 month contract begins at that point. It is worth mentioning that some residential ISPs have an entire team dedicated to offering custoemrs 'free' upgrades to secure another 12 or 24 month contract, and it's called 'recontracting' in the business.

This FAQ hopefully answers some questions, and I can only speak to our own experience with BTW, WBC and Openreach, other providers may have other experiences, and some providers use API's to integrate with BTW which can limit their abilities to perform some functions, so please consider this.

The Future

In 2024, we are already being included in Openreach briefings regarding high speeds and improved technology, and indeed the fibre being deployed between the exchange and premises, which is single mode, is technically capable of carrying 1Pbps leaving room for much expansion. The proposed future servics are suggesting 1.8Gbps will be possible for residential customers at some point in the medium term, and for business customers there's a possibility of 10Gbps, but we'll have to wait and see how this shapes up in the coming months and years.

With virtually limitless potential for Openreach fibre, and the proliferation of alternatives such as Wimax, Microwave, 5G, Satellite and private broadband infrastrucutre, the future for UK consumers and businesses alike is bright.

GEN

GEN, as the UK's oldest Business ISP has been involved in the connectivity business for 30+ years, and we are NOT limited to Openreach. If you need flexible reliable connectivity with a service level guarantee then feel free to ask us for a quotation (Services / Connectivity from the top Menu).

20 Votes

Comments (1)

Nigel wing · 2024-07-25 16:18 UTC
Well, that explains a lot. Thank you for the detailed article