The 10 that Established VoIP (Part 5: 3GPP)

In order to justify our choice for selecting 3GPP among the 10 most influential organizations in VoIP history, we have to start with answering two straightforward questions: (1) How far is 3GPP responsible for drafting IMS blueprint, and (2) What role has IMS played in promoting VoIP?

Question 1 is easy to answer. 3GPP as a forum is wholly and solely responsible for drafting the IMS blueprint. There was no particular member (out of the usual suspects there such as Nokia, Ericsson, Motorola, but also companies like Huawei, LG, and RIM) whose contribution to IMS was the outweighing one. As with other standardization forums, 3GPP standards were developed by consensus. IMS standardization was a concerted effort. It would be fair to say that the credit should go to 3GPP as a forum of members rather than an individual member.

Before attempting to answer question 2, it is important to note that IMS is based on SIP, and IP in general. As such, promoting IMS, directly promotes VoIP. Prior to IMS, VoIP and NGN in general had been around for a long time but no one had done much standardization work around it. IMS represents the first industry wide NGN technical standardization. And IMS acceptance represents VoIP acceptance. So our question 2 then rephrases itself as follows: How far has IMS been deployed in the industry. Answer to that question will determine the importance of 3GPP contribution so far.

We have heard of over hundred IMS service provider trials worldwide but no service provider in the world can claim to have deployed a fully IMS compliant network serving all its customers. Nevertheless what is important is the momentum IMS has gained in terms of service provider trials and vendor compliance. For the last three years no one in the industry has questioned the fact that move toward VoIP is irreversible. Having said that, only 5 percent of the world telecom voice networks has migrated to IP. And yet VoIP already represents a major paradigm shift in communications industry. Likewise, the IMS blueprint implementation (although IMS blueprint is far from 100% complete) also seems irreversible now. This is reflected in the long term commitment to IMS from the vendors as well as the service providers.

I hope to have convinced you so far that (1) 3GPP as a forum of members should be given the credit for drafting IMS rather than giving credit to an individual forum member, and (2) IMS standardization is a major industry development that directly promotes VoIP.

Let us now move over a slightly lighter discussion on IMS and 3GPP. IMS was originally meant for cellular networks. Even in the late nineties it seemed inevitable that networks would migrate over to packet switched architecture. So that was the motivation for the IMS blueprint. IMS was all done within 3GPP as cellular activity until about three years ago when ETSI, the ITU and ATIS of North America started discussing NGN together. NGN had been around for a long time but no one had done much standardization work around it. There was no reason to reinvent the wheel. 3GPP had all the ground work. The committee decided to‘re-use’ the IMS spec. The decision was firmly supported by ETSI TISPAN which was the most advanced NGN standardization group at the time.

A vast majority of IMS specification was network orientated and was access independent. So it was equally applicable to fixed networks. Indeed it is now being re-used in PSTN and cable networks. And of course equipment providers prefer to supply the same piece of equipment to various different operators. It was particularly in the interest of equipment providers to use a standard that could be replicated in both wireless and wireline world.

There will be a detailed write up on 3GPP’s contribution in VoIP/IMS in the paper when it is published. I will conclude here by mentioning two more reasons why we selected 3GPP among ‘The 10 that Established VoIP’. One is the nature of standardization itself in competitive markets. In simpler old days of monopoly telecom operators, it took bureaucrats in Geneva or Washington a few meetings to decide upon the standards. In an IT oriented competitive market, standards are decided by the market share. It is the kind of culture that has evolved over time. Standards therefore take a long time to iron out, and at times the whole process can create market deficiencies and bottlenecks. The fact that 3GPP got all major forums and service providers to agree upon IMS specifications, is quite an achievement.

And lastly: You may well ask why 3GPP and why not the likes of IETF and ITU. Well, the latter two have also made major contributions to VoIP, but (1) IMS is much more significant a development than say G.729 and MGCP standards, and (2) ITU did not, for instance, play as important a role in promoting a certain codec as compared to the role 3GPP played in IMS acceptance; And likewise IETF did not play as important a role in SIP and MGCP specs as compared to the role 3GPP played in IMS specs.