The Public Switched Telephone Network (PSTN) that has provided telephony services for many decades is being retired across the world along with the copper wires that crisscross cities, towns and the countryside connecting homes and businesses.
PSTN services are being replaced by voice over IP (VoIP) services delivered over broadband connections which eventually will depend entirely on optical fibre rather than copper.
Some countries such as Germany, Norway and Sweden have already switched off their PSTN while others such as Denmark, New Zealand and the UK plan to end PSTN services at or before the end of this decade (the UK will end its PSTN services in 2027). Other countries such as the USA and Canada are transitioning to VoIP services but without an official deadline.
VoIP over fibre broadband has many advantages for service providers: PSTN equipment is old and so is becoming unreliable. Copper networks also require much more maintenance than those based on optical fibre. It is estimated that the recycling of redundant copper cables in the UK will result in a two billion pounds windfall over the next decade for the network’s owner. VoIP services over fibre can be provided with less equipment, physical space and sites than the PSTN allowing the selling off of redundant exchange buildings.
There are advantages to customers as well, particularly business users. VoIP services provide higher quality calls and greater flexibility with call rerouting facilities.
However, the transition to VoIP services does have to take into account that some existing attached equipment such as burglar and fire alarms rely on copper PSTN connections. Unlike a PSTN connection, VoIP over broadband stops working during a mains power failure (backup batteries may be provided but these have a limited power feed duration). This is especially a problem for customers in those rural areas where mobile coverage is poor and so may not be able to make an emergency call.
PTT’s online courses Introduction to Telephony and Voice over IP provide a detailed explanation of the features and operation of VoIP telephony for those responsible for the provision of VoIP services.

Optical fibre cables carry Internet traffic around the globe and provide us with broadband connections to our homes and businesses. But those same cables have an important role apart from high speed communications.
A technique known as distributed acoustic sensing (DAS) can detect changes in environment around those cables and indicate where those disturbances are occurring. For example, DAS applied to a submarine cable can detect vibrations caused by trawling and dredging or nefarious activities of states wishing to disrupt international communications.
A water company in the UK is using Openreach’s fibre broadband cables to detect vibrations caused by water leaks. AI assisted machine learning is used to pinpoint the exact location and distinguish between other causes of vibration such as traffic or roadworks.
DAS works by monitoring optical pulses as they are reflected back from natural microscopic inhomogeneities in the glass – an effect known as Rayleigh scattering. Changes in the refractive index of the fibre caused by vibrations affecting the cable create changes in the phase of the reflected signal. The time taken for the affected signal to return gives an indication of the position of the event.
Rayleigh scattering is just one of the topics explained in PTT’s online course “Optical fibre principles“. This course is an indispensable primer for those joining the telecoms sector to maintain the broadband connections we all rely on.

The telecommunications sector is facing a labour shortage and a technical skills gap. The situation can only worsen over time as it is estimated that over 60% of the telecoms engineering work force in the UK are past the age of 50. Apart from the inevitable shrinkage in the workforce, remaining staff may not have kept up to date with the radical technological changes that have affected the industry in this century.

These challenges are exacerbated by the pressure to expand the coverage and capabilities of fibre broadband access due to customer expectations, increasing competition, and government targets.

The solution comes in two parts: re-skilling the existing workforce and recruiting and training young people.

Apprenticeships provide a structured, all-encompassing method of inducting new staff. Governments in the EU and UK actively encourage apprenticeships with financial inducements and other support especially for small and medium enterprises (SMEs).

The UK’s Telecoms Field Operative apprenticeship scheme is designed for those who will build and maintain fixed line broadband access networks. PTT has developed a range of online courses that cover the knowledge objectives of that apprenticeship standard. This unique resource provides training delivery flexibility and reduced costs that benefit employers and training providers while ensuring teaching is of a consistent high quality.

The latest PTT online course “Working in access networks” joins those PTT courses already providing targeted, relevant training for field operatives.