In home network environments, user comfort, and privacy are very important issues that need to be addressed. The reference monitor is the collection of access controls for devices, files, memory, and other kinds of objects and it is also able to provide advanced facilities for access control. In order to meet the user's requirements for comfortability and privacy, a reference monitor model is proposed for improving the home gateway in the OSGi service platform. The proposed model is based on the RBAC model, and the policy is classified into two types: User-role assignment policy and Permission-role assignment policy. The policies are in XML format. With the use of the proposed reference monitor model, more effective guidelines can be provided for user access control in home networks.