Sita Lowman is director of core network marketing for Nortel, handling carrier core products for both wireline and wireless networks. In the week before the 3GSM exhibition in Barcelona, she spoke with Editor-at-Large Carol Wilson about Nortel’s IP multimedia subsystem initiatives and its recent announcement that BEA Systems, IP Unity Glenayre, and Vantrix are new partners in its IP Multimedia Subsystem (IMS) Developer Program.

On the partnership announcement: On the carrier VoIP side, we have strong market leadership, and we have been working with our carrier customers to figure out how we migrate them to IMS as their needs occur. They need to be able to take the products we have in the market and enable them on the new IMS core. All new applications are being built so they can work in pre-IMS or IMS environment. A big part of our carrier strategy is to enable interoperability. So we have been working with partners, like BEA, to make sure their terminals, clients and software can work with Nortel’s equipment.

We have had a SIP-based developer program for some time. What this announcement is, is re-affirmation of that program and recognition that you need to have interoperability – that’s one of the key things to enable IMS adoption.

On the role of interoperability in IMS adoption: We are a huge proponent of interoperability testing. Network vendors are doing a lot around creating new equipment around IMS, but the ecosystem world has not yet as aggressively engaged. A lot of what Nortel is doing is working with companies like a BEA--take their products and make them IMS compliant. We can then bring those to our carrier customers so they can see there really are applications that are compliant. The industry players are trying to work with the independent software vendors. That is something we do a lot of--working with industry players to get them all to the next level.

On the IMS adoption curve: I think it is slow steady progress. Most of the carriers have a specific kind of application or a lead application that they want to launch within IMS. So, the lead application vendor is going to become very IMS compliant. Customers aren’t focused on 10 apps--they are focused on one or two. They have a dedicated focus on very specific applications and some very specific app providers. Then the rest of the market is going to say, “It’s my turn.”

On IMS applications: On the wireline side, it’s very much about taking their existing VoIP services and making sure they can be interoperable over IMS. Then you expand that to include FMC [fixed mobile convergence], the handoff between cellular and Wi-Fi, and use SIP environment to access 3G mobile [devices] plus some interest like gaming. Then they can move on to simple stuff like IM [instant messaging] to SMS [short message service], but they are starting out very voice centric. That’s certainly what they want to trial.

We have an FMC product we announced--it is what they really want to play with. It’s interesting, they want to enable VoIP access on a wireless network at home, on a PC or a dual mode [phone]. The wireless guys are more interested in the Wi-Fi-cellular handoff. To some extent, they are all kind of going after the same subscriber for a similar service. They are all interested in FMC. Two years ago, push to talk was the rage, going into 3GSM. The other application we are seeing is VoIP on the wireless side. We are in several trials with carrier customers on how they would do pure VoIP over CDMA DO Rev A.