• 热门标签

当前位置: 主页 > 航空资料 > 国外资料 > ICAO >

时间:2010-07-20 23:38来源:蓝天飞行翻译 作者:admin
曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者

release" CM-LIDU (indicating that the aircraft user has
terminated the call) the GES will forward a "clear back BITE
to the ground network and terminate the call. Similarly, jf the
GES receives a "clear forward FITE from the ground network
(indicating that the ground user has terminated the call) the
GES will send six "call progress - channel release"
CM-LIDUs over the C channel sub-band and then monitor the
AES to ensure that it has terminated its from-aircraft C
channel carrier.
Attachment A to Part I Annex I0 - Aeronautical TsEseommunicaabns
8.1.5.1.4 Events such as unsuccessful continuity checks
and call clearing will result in the eventual termination of
C channel transmissions from the AES. While these various
termination events are progressing, the GES will monitor the
from-aircraft carrier to ensure that the AES is performing
similar call termination activities. If the from-aircraft carrier
has not terminated within tG17 seconds after the transmission
of an initial series of "call progress - channel release"
CM-LIDUs, the GES will send twelve additional of these
CM-LIDUs via the C channel sub-band and a thirteenth via
the P channel. If these transmissions are not successful in
causing the AES to terminate its C channel transmission
within tG18 seconds after the last transmission, the GES will
terminate all call activities unilaterally.
8.1.5.2 Airrrsft earth station (AES) procedure
8.1.5.2.1 An incoming call to ad AES is announced by
the receipt of "call announcement" and "C channel assignment"
CM-LIDUs. Since these are sent on the direct link
service, circuit-mode services implements an error recovery
procedure whereby the AES can infer that one of these
CM-LIDUs is missing (e-g, due to bit errors on the P channel)
and request that it be repeated by the GES. The AES initiates
the request by transmitting an appropriately encoded "telephony
acknowledge" CM-LIDU via the R channel. When an
AES has received a "call announcement" CM-LIDU and its
associated "C channel assignment" CM-LIDU it will initially
verify that the called terminal is available and that adequate
C channel resources (i.e. channel unit and AES EIRP) are
either available or pre-emptable. If the foregoing requirements
are not all met the AES will send an appropriately encoded
"call progress - call attempt result" CM-LIDU via the
R channel and then terminate all activities for the call.
Otherwise, it will activate a C channel unit on the assigned
C channel frequency pair and begin the C .channel continuity
check procedure by sending a "call progress - test"
CM-LIDU via the C channel sub-band.
8.1.5.2.2 The AES will send an additional "call progress
- test" CM-LIDU every tA26 seconds for tA41 seconds until
an identical CM-LIDU is received from the GES. This constitutes
a successful continuity check and will immediately cause
the AES to: (1) enable the voice circuit between the aircraft
voice channel and the C channel unit, (2) forward a "call
origination" FITE to the aircraft destination, and (3) send a
"'telephony acknowledge" CM-LIDU via the C channel
sub-band to the GES. The AES will then await tA42 seconds
for the aircraft destination to answer the call. If the call is not
answered within this time period the AES will clear the call
toward the aircraft destination, send six "call progress -
channel release" CM-LIDUs to the GES, and then terminate
the call. Otherwise, if the aircraft destination answers within
this time limit the AES will send a "call progress - connect"
CM-LlDU to the GES and maintain the C channel during the
talk phase of the call.
8.1.5.2.3 When the "call progress - connect"
CM-LIDU is sent, the AES will initiate an error recovery
procedure to ensure its receipt at the GES. (The talk phase
progresses in the interim.) Timer tA26 is used to implement a
transmission repeat cycle for this CM-LIDU which must result
in receipt at the AES of a "telephony acknowledge" CM-LIDU
within tA30 seconds of the original transmission. Failure to
receive the acknowledgement within tA30 seconds will cause
the AES to terminate the call.
8.2 Interworkiig of circuit-mode
se~kews ith other
voice networks
8.2.1 AMS(R)S circuit-mode procedures. A standardized
set of circuit-mode procedures within the AES and GES
implement the AMS(R)S circuit-mode protocols and provide
specific interfaces with non-MS(R)S telephony interworking
procedures. The AMS(R)S circuit-mode procedures correspond
 
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址:附件10--航空电信an10_v3_1ed(140)