This paper investigates Collaborative Radio Resource Management (CRRM) for femto-cell network deployments. The aim of the approach is to exploit the advantages of rapid and un-planned deployment of femto-cells, supporting more than one Radio Access Technology (RAT). The proposed approach overcomes deficiencies in existing methods that rely either on accurate determination geographic location, proximity or simultaneous support for multiple RATs. The aim of the proposed approach is to exploit the opportunities for femto-cells to use different RAT and RAT modes (such as frequency bands or bandwidths) and determine how best to share radio resources. The first problem in achieving this goal is RAT selection, followed by determining when to trigger handover of RAT and finally when to reconfigure RAT mode (such as change frequency band or bandwidth of the RAT). In this paper we address these problems and assess the advantages of a novel lightweight method of supporting CRRM functions.