The present disclosure relates to virtualizing a network function in an ad-hoc group. The ad-hoc group comprises a plurality of mobile terminals (302, 304) that are configured for device-to-device communication, e.g., Proximity-Based Services (ProSe). The Pro Se-enabled mobile terminals (302, 304) subscribe to a Network Functions Virtualization (NFV) service with an NFV management server (322). The NFV management server (322) discovers the ad-hoc group that is suitable for NFV and informs an NFV application server (324) of the ad-hoc group. The NFV application server (324) then downloads data and configuration parameters to the ad-hoc group to offload a network function to the ad-hoc group for execution.