A video-phone call with a portable video-phone terminal is enabled for a cellular phone which has not video-phone service provided, by making use of cameras and display devices placed on the street. For a video-phone call to a portable video-phone terminal, a media converter in a service center distributes data so as to send video data to a public communication terminal on the street, and voice data to a cellular phone without video recording/reproducing capability. A call agent in a service center issues an ID in response to a request from the cellular phone without video recording/reproducing capability on voice call. This ID may be received by a service center via a detector such as a sensor deployed on the street, to provide a video-phone service by using a public communication terminal on the street in the vicinity of the detector.