How are exchanges connected?

Very random question today as i've been walking in the Peaks. Lot's of mini exchanges in villages that have now been upgraded to Fibre, but where do they go?

Do these smaller, rural exchanges connect to bigger ones close by? What kinda fibre cables run under the roads? Is it 10GB etc?

Any Superfast broadband in the area (FTTP/FTTC) likely bypasses the small exchanges completely and go to larger headend exchanges.
ADSL services may use microwave or fibre using SDH fibre systems, and PSTN could be microwave, SDH/PDH or even some old copper DLS for really small sites.
If they really are small exchanges there wont be anything like 10Gbs, maybe as little as 34Mbits for ADSL services, unless there is an LLU operator that's chucked in 100mbit or 1gb for unbundling.

How far can FTTP go in terms of bypassing the smaller exchanges 10 miles, 50 miles etc ?

In reply to a post by mwarby:

How far can FTTP go in terms of bypassing the smaller exchanges 10 miles, 50 miles etc ?

Around 20km using the standard deployment method.

They can increase this distance by using Subtended Head Ends, making it more like 20km from where they install the S.H.E (ideally next to an existing Huawei FTTC cabinet).

mwarby

Technically 50-60 miles, but usually much less than this.

Exchanges use different transmission tech for different services. So PSTN ( Voice) will still be on SDH or even PDH using multiple 2Mb, sometimes over copper in small exchanges.

As Witchunt says exchanged based ADSL could be 34Mb (SDH) or Ge ( Multiples) Bigger exchanges may have 10Ge for LLU backhaul. VDSL could be Ge (Multiples) from each Cab bypassing the local exchange to a Head end. FTTP is 2.5Ge bck to the Head end.

From Head end to core is now likely to be 10Ge (Multiples) or 40Ge in larger sites.

Leased lines most lcan be anything from 2Mb to 155Mb for old TDM circuits or 100Mb to 10Gb for ethernet

Looks like in some areas, everything will be FTTP, which may mean those exchanges are a thing of the past.

Edited by mwarby (Thu 15-Oct-20 21:43:04)

In reply to a post by mwarby:

Looks like in some areas, everything will be FTTP, which may mean those exchanges are a thing of the past.

Future sale of 5000+ copper exchange sites, might dent that little pension pot issue

In reply to a post by Pheasant:

In reply to a post by mwarby:

Looks like in some areas, everything will be FTTP, which may mean those exchanges are a thing of the past.

Future sale of 5000+ copper exchange sites, might dent that little pension pot issue

Most (maybe all) exchanges are rented anyway.

https://www.egi.co.uk/news/bt-to-end-3700-telephone-...

So it will improve their profitability won't directly reduce their pension deficit.

Edited by Andrue (Fri 16-Oct-20 08:16:14)

In reply to a post by Pheasant:

might dent that little pension pot issue

In fairness to BT the pension shortfall has been reducing over recent years because of lump sum payments from BT

Pension Shortfall
June 2017 - £11.2bn
June 2018 - £8.3bn
June 2019 - £7.7bn

Between now and 2030 they will make additional payments of no less than £700m each year

Edit: Changed 'Shortfall Reductions' to 'Pension Shortfall' as it could be misleading.

Edited by dect (Fri 16-Oct-20 13:47:34)

Cheers for the detail there. must admit it was a bit of a throw away remark on my part. All good.