Recently, I read with interest a blog post by Tom Wheeler, Chairman of the Federal Communications Commission of the United States, where he has talked about an imminent move by them to begin examining the feasibility of transitioning the entire Wireline telephone system to an IP- based one. FCC is responding to requests from AT&T to permit trials of an all-IP network in select pockets in the USA .
Traditional wireline carriers are finding the TDM based equipment simply unsustainable in the face of competition, obsolescence, and steep drop in the wireline subscriber base. I don’t have the latest figures but I read that in the US only about 35% of the homes are using any kind of wireline telephony! The rest have simply abandoned it in favour of mobile phones! In the absence of revenue, operators simply don’t have an incentive to maintain TDM equipment and provide wireline services.
The message from the Chairman immediately sent shivers- both of excitement as well as of trepidation- down my spine. This is one heck of a transformation- something which other operators have contemplated and started and stopped and diluted- due to various reasons, not all of which are purely technical.
The technical challenges are, of course, enormous. The call-handling capacity, the availability, the reliability- and all of them tied to legal, life-saving SLAs. But what are the other aspects that make this so difficult?
First- the challenge of security. As the transition to VoIP means that voice is just like any other multimedia service transported over the Internet protocol, the same security challenges arise- and this is an area which is open, well-known. Traditional TDM based switching enjoyed a kind of ‘security-by-obscurity’ – but since the IP standards, protocols and vulnerabilities are by now very well known, the curtains now stand drawn.
Another thing about security is the law-enforcement angle. How does legal interception- aka wiretapping – happen? What do the security agencies do if the users use end-to-end encryption on their conversations? How do they trace calls that threaten national security?
The second challenge is the legal one. Take the 911 emergency services as a big example. This service is tied to some implicit and explicit guarantees of availability and reliability. The state of Tennessee has taken a lead in implementing a ‘Next-gen 911’ using an all-IP call center, and this is a model that has to be tried and tested and guaranteed. How does a digital-911 protect itself from DOS attacks from anarchists, for example?
And then we come to the Regulatory Challenge. In the US, the FCC does not have jurisdiction over the Internet to the same extent that it has over the telecom and cable industry. How does this impact various aspects of carrying the service in the face of competition?
Another major challenge is the Universality aspect. How do we ensure everyone in the country, irrespective of geographical restrictions, has access to reliable voice services at affordable cost?
Technical challenges, of course, remain, but these are always conquerable through evolution. Talking of quality- the traditional TDM telephony has a cutoff at 4KHz – and potentially, IP voice can offer voice services of much higher quality- like “HD” voice. But then the TDM 4KHz has guarantees- in terms of an end-to-end circuit being completely reserved for the duration of the call, but in IP this is a complex matter of QoS and can be affected by network congestion.
But despite the challenges, this is one transformation that has to happen- carriers simply can’t afford to twiddle their thumbs over this any longer. I for one, will be watching the progress of the trials with huge interest!