I have been doing a brief polling round with the FMC vendors on the current market size of FMC. I have not interacted with service providers on the subject since they are still very secretive about it. The aggregate feedback I have from vendors is as under:
As of September 2007 ….
Number of FMC (WiFi-GSM) subscribers worldwide: approx 900,000, with UMA based subscribers accounting for the majority
Number of data continuity subscribers: approximately 400,000
Average FMC server capacity shipped each quarter over the last two quarters: 120k sessions for voice and approximately 40k sessions for multimedia continuity. Voice split: 60% UMA, 40% VCC. There is not a lot of capacity being sold these days because vendors already shipped near about 2.5 million sessions capacity for trials.
Leaders: Kineto for voice continuity, Azaire for data continuity
FMC server licenses shipped to enterprises: 60k on a cumulative basis. Average is 10-15k sessions capacity shipped each quarter over the last 2 or 3 quarters. DiVitas has some commercial deployments in this area. Nortel also has a couple.