At the same time that Nokia is enabling multimedia mobile applications like VOIP (voice over Internet Protocol), it's helping operators limit such services.

On one hand Nokia is rolling out services that let phone users make free calls. Separately, however, it has been offering technology that can let operators decide to make the services low priority.

For example on Wednesday, Nokia introduced a new offering that allows Nokia N80 phone users to make VOIP over Wi-Fi calls via SIPphone's Gizmo service. Nokia is offering a feature on the phone that lets users download a file that configures the VOIP settings to easily enable the use of Gizmo.

Gizmo customers can call each other for free although N80 Gizmo users could incur costs for accessing Wi-Fi networks. SIPphone also offers free calling to landline phones in some countries.

Nokia also recently introduced support for Skype VOIP calls on its N73 phones for customers who subscribe to an upcoming offering from 3 Group, the operator owned by Hutchison Whampoa. That offering uses the 3G (third-generation) network, rather than Wi-Fi.

While end users might be pleased with such offerings, which can allow them to save on their mobile phone bills because they enable free or low-cost calling, operators have typically been reluctant to enable the services. VOIP on cell phones competes with the voice services that operators offer and also uses up network bandwidth that the operators might prefer to dedicate to more revenue-intensive offerings.

So while Nokia is introducing applications that help end users take advantage of VOIP and other multimedia services, it is also trying to help operators ensure that customers don't use them extensively.

Last week, Nokia introduced Peer-to-peer Traffic Control, software that allows mobile operators to identify data traffic on their networks according to the type of service and then prioritize that traffic based on preferred services. That means operators can decide to make certain services, like VOIP, low priority so that if the network is full of traffic from more important services, the VOIP users won't get network access.

The traffic control product likely won't help operators hoping to control use of the Gizmo VOIP offering because that operates over Wi-Fi networks, which are typically owned by third parties or end users.

The seemingly opposing offerings from Nokia indicate a general hedging of bets in the mobile world, said Darren Siddall, an analyst at Gartner. On one hand, operators don't want their networks to be used mainly by services they aren't making money on. But they also want to discover which applications are popular with users and figure out how to earn revenue from such services, Siddall said. "There's a lot of uncertainty about which applications users will find valuable," he said.