TalkTalk may have blazed the path for telephone and broadband bundles, but with Sky now in second place for the title of largest retail broadband provider in the UK they have an increasingly loud voice with regards to how Ofcom regulates the market and in particular the growing market for Next Generation Access via Openreach FTTC and FTTP products.
The current situation is that Openreach have full control of the DSLAM that resides in the green street cabinet, and the only control the provider has is a choice from three products (40/2, 40/10 or 80/20) and whether the line should be run with Standard, Stable or Speed based DLM options. Openreach control the backhaul to a handover node (usually a larger exchange) where providers can pick up the traffic from Openreach directly or rent a BT Wholesale based backhaul to a larger Point of Presence (POP - ~20 around the UK)
Any communications provider with code powers does have the option of what is called sub-loop unbundling, which allows them to place their own cabinet near to an existing telephone cabinet and install their own VDSL2 based hardware. This is essentially how Digital Region in South Yorkshire operate (3.5% of UK homes) and a number of smaller providers have much smaller footprints.
It appears as a response to the Wholesale Broadband Access Market review by Ofcom that Sky is looking for something in between these two options. Sky in its response is calling for the ability to actually rent and control a VDSL2 line card port in the Openreach cabinet to give them more control and the ability to offer unique products. This technique is called SLU bitstream (sub-loop unbundled bitstream) and as well as controlling the port and thus the DLM extra options for backhaul where they can pick up bandwidth directly at the cabinet are explored.
For those wondering what sort of things Sky might be wanting to do, consider the current price premium for fibre based services, and how people with a very tight budget are holding back from upgrading. If a provider was able to offer a 25 Mbps down and 5 Mbps up FTTC based service for £7 extra a month it might encourage take-up, another option is that with port control the provider can control the interleave depth and thus keep latency low, as at present some people are upgrading from ADSL2+ services with low latencies of 10ms to find that FTTC while giving faster downloads and uploads has higher latency in the region of 20 to 30ms depending on what the mysterious Openreach decides to use for interleaving levels.