Communication Technology
(1) Network Interface. Different telemedicine needs and communication environments have a variety of choices for communication networks, so there are high and low network interface rates. (2) Network protocol. ATM (Asynchronous Transfer Mode) interconnection protocol is widely used in telemedicine systems. H.324 videoconferencing protocol can be used for transmitting medical images over the telephone network.TCP/IP protocol can be used for LAN and WAN interfaces, with which medical images and remote medical information sources are accessed. (3) Video transmission. According to different telemedicine needs, the video transmission rate is different, which can be roughly categorized into two types: low rate and high rate transmission; the former is used for videoconferencing, while the latter is used for transmission of diagnostic videos. (4) Audio transmission. In addition to video, there is also audio transmission within the telemedicine system, which can also be categorized into low-rate and high-speed transmission, with the former being used for consulting sessions and the latter for diagnosing conditions. (5) Still image (film) transmission. Usually, the transmission of static images (slices) is a unidirectional communication, the transmission rate is calculated in terms of a single frame, and the traffic is bursty. (6) Medical record file. It is also a unidirectional transmission and is mainly textual information, so the transmission bandwidth requirement is not high. (7) Backbone network. There are a number of options available as a backbone network for telemedicine, but as the network expands, it is necessary to interconnect individual LANs into a WAN via bridges or routers.