Current plans to close down the fixed Public Switched Telephone Network (PSTN) need a major rethink. We are in danger of a major misstep
Current plans to close down the fixed Public Switched Telephone Network (PSTN) need a major rethink. We are in danger of a major misstep which render our two-way public and other communications systems useless if we lose mains power.
When the PSTN was conceived we built in power resiliency
When mobile phones and the supporting infrastructure were later developed and rolled out, power resiliency was not built in so it is the case today that if the power goes off in your locality your mobile phone will most likely not work.
As broadband Internet systems were developed again power resiliency was not much in mind, there has been a significant roll out of powered modems in the street wiring cabinets, the home routers have no power backup and although you may have a laptop computer that works for a while on batteries, there will be no working broadband network when the local power is down
As the PSTN evolved over the years power resiliency diminished somewhat and the use of DECT phones which do not work when the power is down did not help here either. However, it is possible today to connect a wired phone when your power is down and find the system working a deal of the time when you have a local power outage.
If we move the PSTN to the Broadband Internet Infrastructure as is being proposed we will reduce the power resiliency further and introduce more risks due to the IP network which will be then carrying the voice traffic as well. This is because hacking IP Networks is well established activity and its very hard to compromise the PSTN in the same way. So even if we had power, we could find all the fixed line voice communication not working because of attacks on the IP infrastructure from criminals or hostile countries
So, imagine the scenario, the Power fails, your fixed phone is down, mobile back up does not work because the mobile network node is down, the TV does not work, mains powered radios are down, maybe local radio is down… You cannot contact emergency services (999), you do not know what is going on, you cannot cook, your heating is not working, you are 70 years old ill and cannot talk to your family
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We need to do something here; we need to think about providing a Critical Network Infrastructure
This does not mean that we have to keep the existing PSTN but we should certainly not be in the process of closing it down until we have considered all the CNI aspects and developed a reasonable plan to prevent the scenario I have illustrated here.
Over the past weeks a number of very experienced communications experts with decades of experience have discussed the current plans for the PSTN removal and we find that they have not considered all the implications. ?It is time to reconsider before the nightmare scenario above becomes a reality
I have asked them to repost this to their contacts with any comments they wish to attach.
Addendum
It is important to note here that the issues of the resilience of our UK communications networks extend beyond the PSTN although the PSTN currently helps to mitigate them. I can imagine many teenagers looking at their mobile phones forlornly when the mains power is out and the mobile network and Internet networks are off line, but the situation here affects us all, there is too much risk today that we are cut off from emergency services, and the ability to contact each other in times of trouble
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Senior Director Business Development Europe - 5G Enterprise Networks at Microsoft
2 年Cannot agree more Brian.
Voice & Converged Services - Principal Consultant at BT
2 年Hi Brian! Are you suggesting that in order to close the PSTN, that the availability of the Uk mobile voice service should be improved, eg by providing a battery back- up at base stations? There would of course be a significant cost impact associated with doing this and the services are of course very different ( ie fixed v mobile). I would suggest that Industry & Regulatiry agreement would be needed, so as to affect any such change. To date I am unaware of any such justification as having been reached. Rather there is now an evolving International ip network based solution being deployed, enabling PSTN closure Internationally, eg supported in part by the existing mobile solutions, without enhanced mobile service availability. One of course also needs to rememember that eg UK mobile coverage doesn’t equate to that of the installed base of the PSTN. So even with enhanced mobile reliability, this would not enhance voice service availability of for ALL of the existing PSTN customers coincident with PSTN closure/ migration to a replacement service.
Voice & Converged Services - Principal Consultant at BT
2 年An interesting post. Hopefully reassuringly, the principal concerns raised have definitely been thoroughly investigated by my former employer (BT) and Industry and then widely shared eg with Industry bodies and the UK Regulator. Benchmarking has also taken place Internationally. There is a battery back-up option available, in the BT Future Voice (PSTN replacement solution for the analogue voice service). It is fully recognised that for people who might be described as being vulnerable, that this is a potentially useful option, in the event of mains power failure. Admittedly there are still issues relating to eg the period of battery back up possible, the battery life and battery replacement which mean that any PSTN replacement solution will be different compared to a comparable PSTN solution. Additionally again from a BT (PSTN - analogue) solution perspective, resilience to DOS attacks has been fully considered with mitigations detailed and employed in the solution being deployed. From an Industry perspective UK standards (NICC) again define best practice. One also has to recognise that in the overwhelming majority of cases mobile services now act as a PSTN back-up. Cost effectiveness of solution is also a key consideration.
Programmable Telecoms / Communications Expert
2 年Hi Brian Levy, I was talking about this in my CXTech newsletter today, https://alanquayle.com/2022/03/cxtech-week-13-2022/. For some customers, Verizon moved to digital voice 14 years ago. The US has low landline penetration compared to the UK, 15% versus 73%. All the storms of the past decade mean back-up generators are common in some areas of the US. An extreme solution, not applicable to the UK. I reviewed some of the FTTH planning work from the mid-90s. It's a complex?cultural and infrastructure change issue. BT's 2025 deadline is going to slip. The weather is only going to get more stormy. BTW through the major 2011 and 2012 storms the mobile network kept on working over the 2 weeks without power, just it was rather congested initially. The mobile network in our area has back-up power all the way down to the base stations.
Don't the mobile base stations have emergency power? Last I saw one I was convinced it did, but that was a while ago.