Telcos the world over have been desperate to retire ancient circuit switched infrastructures and migrate their ageing fixed voice calling services to the broadband networks now accessed by nearly all their customers.
This has met resistance not so much ironically on the voice front but through various legacy data services that are hitched to the technical idiosyncrasies of the PSTN (Public Switched Telephone Network). This includes fax machines, old telephony PBX switches, emergency services, telecare, home security alarms, payment terminals and monitoring systems, developed when the PSTN was the only remote communications option and also provided power in the event of a mains’ failure. Devices in these categories were either installed by service providers or purchased by consumers, raising slightly different issues in each case.
Meanwhile use of landlines for voice calling is plummeting, having halved over the last six years, while the number of homes with them has fallen from well over 90% at the turn of the millennium to under 50% in many developed countries now. At the same time, quite apart from the boom in mobile which is now the sole means of voice communications for many, there has been the rise of voice over IP services such as Skype and Viber.
This does not mean the need for fixed line voice calling is going away but it is being migrated to broadband, bringing improved quality and added functions, providing those legacy services are catered for. There is also the issue of ensuring migration is as painless and transparent as possible, especially for senior citizens who may never have embraced the Internet or mobile communications in any case.
Countries have faced very similar issues, but have been migrating fixed voice calling to broadband at different paces, so that the laggards can learn from the leaders. Germany and Switzerland are two of the leaders having embarked on their migration several years ago. They have found that, rather like the Millennium bug red herring in the run up to 2000, fears that legacy devices would malfunction over Voice over IP (VoIP) connections have been greatly exaggerated. In many cases devices have continued working normally without any intervention being necessary.
Where problems do occur, normal function can often be restored by changing device settings, which has worked for fax machines. In some other cases the equipment either needed an adapter or replacing altogether, raising the issue of who pays. In Germany, Switzerland and some other countries such as New Zealand where this has arisen, the costs are shared between the end user and provider of the service where that is relevant, with neither party naturally being happy with the arrangement.
For that reason, the incumbent operators in Germany and New Zealand tried to sweeten the pill by providing a test center for providers of devices and these legacy services to assess firstly whether their equipment works on an IP network and then work out what to do. Some countries provide recommendations, as the French regulator has done.
One of the issues is reliability and availability, given that the old PSTN was immune from both internet and power outages. The Swiss incumbent Swisscom has moved to minimize risk of outages for critical services by insisting that devices used for safety of life applications, such as medical alarms, have dual communications using both the cellular and fixed line VoIP networks.
Some countries such as the UK are only now considering PSTN migration and the regulator there, Ofcom, has just published an industry document, “The future of fixed telephone services”, outlining lessons drawn from other countries’ experiences. This identifies four categories of migration, the first being voluntary where the user moves to a VoIP product or service to gain the more advanced functionality on offer. The second category is coincidental where the user moves from the PSTN to a VoIP service without realizing this has happened, as in many cases where FTTH (Fiber to The Home) is deployed, making the PSTN redundant.
The third so called passive category is similar, but here the communications provider moves the user to an all-IP network quite transparently with the VoIP service emulating any aspects of the PSTN predecessor needed to maintain services. The final category is the forced one where the user has to act to preserve voice access. This last category is where regulators and service providers have to collaborate to minimize impact on the last users left on the PSTN.
For that reason, most countries have not imposed deadlines for PSTN switch off in the way they did say for analog cable, so that there is time to execute the forced migrations. There are one or two exceptions, such as France, which has set 2030 for PSTN closure. However France is actually taking a relaxed approach because most countries, including the UK, aim to complete the migration process in just four or five years with some forced migration. France is hoping that its 12-year migration period which began in 2018 will mean it can rely on voluntary and coincidental migration, rather than forced migration.
Meanwhile the US is in a league of its own through having an almost unique telecoms structure, just as it does for TV, which throws out some challenges of its own. One of these, which does not seem to crop up so much elsewhere, is the “rural call completion problem”. This has roots in economics more than technology and arises because in rural areas of the country both long distance and wireless carriers normally pay higher charges to the local telephone company to complete the call circuits than they do to their urban counterparts. In the past this was done to reflect the higher costs incurred extending service to more remote premises.
This means that for a long distance or wireless carrier to complete one of its subscriber’s calls to a resident in a rural area, it must first switch the call to the local exchange serving that resident and then pay a charge to that local carrier.
A problem has arisen more recently because in order to minimize these charges, some long-distance and wireless carriers have used third-party “least-cost routing” services to terminate these rural calls at the lowest cost possible. Some of these services fail to meet minimum performance requirements with a significant incidence of total call failure. This whole problem would be made worse by VoIP migration and so the regulator, the FCC, has stepped in, leading Congress to pass Improving Rural Call Quality and Reliability Act of 2017. This was followed in April 2018 by the Second Report and Order and Third Further Notice of Proposed Rulemaking to seek comment on implementing the new law. All this has slowed down the process of VoIP migration, highlighting how what at first sight seems like a relatively straightforward question of catering for diminishing legacy services can get stuck in a groove. But it also emphasizes the importance of catering for universal provision and ensuring a basic level of reliable service for all citizens.