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R  Intermediate Gain Antenna - Top  
R  Figure 022 
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R  7. Operation/Control and Indicating________________________________  
R  A. System Applications  
R  
R  (1) Data communication services  
R  
R  Cockpit data through SATCOM is an extension of the ATSU  
R  functionality. Communications using SATCOM rather than VHF3 are  
R  automatically selected when VHF3 is not available.  
R  Previously formatted data for SATCOM is transmitted to the ATSU in a  
R  series of short bursts or packets.  
R  
R  (2) Voice communication services  
R  Two channels are dedicated to the cabin (phone or fax).  
R  The airborne telephone cabin system provides civil airline passengers  
R  with a direct dial call facility via the international public  
R  switched telephone network. The system provides voice services in  
R  digital form through the use of voice coding devices called codecs.  
R  The codec transmission rate currently used is 9.6 kilobits per  
R  second.  
R  As the cockpit has priority over the cabin services, the two channels  
R  can be switched from the cabin to the cockpit for flight crew cockpit  
R  voice use.  
R  The cockpit voice interface is controlled by the Audio Control Panels  
R  (ACP) for the call number selection and by the Flight Warning  
R  Computer (FWC) for the display of the associated SATCOM  
R  memo/cautions.  
R  B. General Operation  
R  (1) RF channel configuration  
R  
R  A set of four RF transmission channels is needed to accommodate the  
R  full range of voice and data services. Any given channel can pass  
R  information in one direction only. Therefore, for simultaneous  
R  two-way communications (Full-Duplex operation), a pair of channels is  
R  assigned. A basic description of the four basic channel types is  
R  given below:  
R  
R  - P-Channel (Packet-mode channel):  
R  A time-division multiplexed channel is used for ground-to-air  
R  signalling, control and data communications. There are two types of  
R  P-Channel: Psmc (system management and control) and Pd (data).  
R  A Psmc-Channel is continuously broadcast by each GES to inform  
R  users of system status and configuration. It also carries the time
1EFF : 401-499, 1 23-28-00Page 38 1 1 Aug 01/05 1 1 1CES 1 1EFF : 401-499, 1 23-28-00Page 39 1 1 Aug 01/05 1 1 1CES 1 1EFF : 401-499, 1 23-28-00Page 40 1 1 Aug 01/05 1 1 1CES 1 1EFF : 401-499, 1 23-28-00Page 41 1 1 Aug 01/05 1 1 1CES 1 1EFF : 401-499, 1 23-28-00Page 42 1 1 Aug 01/05 1 1 1CES 1 1EFF : 401-499, 1 23-28-00Page 43 1 1 Aug 01/05 1 1 1CES 1 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址:A320飞机维护手册 AMM Communications 通讯1(134)