In its most recent monthly assessment of global IP multimedia subsystem deployments, inCode Wireless suggested that most carriers are taking a best-of-breed approach to IMS equipment, going with who they perceive is the best vendor for a specific IMS-compliant component.

This doesn’t necessarily mean end-to-end vendor infrastructure approaches will suffer, said Rob Prudhomme, IMS/Convergence Practice Lead at inCode Wireless. “We have been seeing both approaches,” Prudhomme said. “In the early going with IMS, most end-to-end vendors may not have all components in their end-to-end approach at an equal quality level. That could take some time. As a result, partnering between major vendors and start-ups may happen to fill early needs.”

A global IMS deployment matrix assembled by inCode shows that there are about 12 major carriers in different regions around the world that have either announced or launched IMS projects. The list includes Sprint, which announced IMS implementation late last year as part of its ongoing CDMA 1X EV-DO network upgrade, as well as BT, which recently launched its Fusion fixed-mobile convergence service to early adopters.

Prudhomme said some carriers are guarding information for now about which vendors they are using to support specific aspects of their IMS deployments. In some cases, they still may be holding “bake-offs,” in which they call multiple vendors into their labs to evaluate their ability to launch certain IMS-based applications.