• 热门标签

当前位置: 主页 > 航空资料 > 国外资料 > ICAO >

时间:2010-07-21 23:04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

their failed call attempt has been registered. This notification
to the aircrew would carry an implied intent on the part of the
MS specialist to originate a subsequent reciprocal call to the
originating aircraft at the first opporhmity,
means to serialize access to the ground user that is ide&cal to
that of VHF radio except for the satellite delay effects. Note,- hmgmph 8.3.5 describes the air-originatedcall
Additionally, the facility automation function should also infirmation elements that can be wed by the terrestrial
the 66fist,o, f in mc so Ulu Ur gmund facilities to accomplish c d registration. The GES a d
user can be constantly aware of the presence - or absence - ternstrial network facilities aam mquiad to comey this
of each aircraft in the group call. information to the gmund userfhcili@.
8.5.2.2 Dudng group call origination, the individual
aircraft speech channels in a group call cannot be expected to
begin operation simultaneously. This is because: (1) the call
announcement signalling atriving over the I) channel will not
reach all aircraft in the group call simultaneously, (2) C
channel establishment delay after receipt of this signalling will
vary, and (3) all aircrew in the p u p rnay not be able to
answer the incoming call sirnulcaneously due to primary
8.6.2 Signulling of the call mgistmtion event. The AMSS
SARPs require that a call attempt to a busy destination be
deemed unsuccessful and that a "call unsuccessful - called
pmy busy" event (BTTE 16) then be generated by the enduser's
network facilities. (Intervening telephony signalling
systems, including those of the AMS(R)S subnetwork, convey
this event to the aircrew.) The call regWation event is
considexed a variation of the B E 16 event and it is carried
A#aclunsnt A to Part I Annex 10 - Aenr~uHcalT e&communic&ns
over the AMS(R)S subnetwork by a unique code value in the
cause value parameter of the AMS(R)S "call pmgress -
channel release" LZDU (Annex 10. Volume III. Part I,
Appendix 5 to Chapter 4, Figures A5-7 and AS-34 refer). Both
terrestrial network facilities and network-specific telephony
interworking logic within the CiES must support the
conveyance of this backwatd signal to the GES's airorigination
logic procedure if the recommended call
registration facility is implemented.
8.7 Notes on the abbrwlated
aimdgiaation procedures
8.7.1 Geneml. The procedures defined in the AMSS
SARF% for usein air-originated 4 1 s provide for a general call
set-up .and an abbreviated call set-up. The abbreviated
procedures provi& comparatively shorter and more consistent
access delay performance.
8.7.2 ACCESS REQUEST PHASE
8.7.2.1 Abbreviated access mqwst SU. An "abbreviated
access requesf' SU is used in the AMS(R)S procedures as a
means to deliver all call information (i-e. ground address and
calling terminal-ID) to the GES cancurrent with the R channel
access request. This eliminates the need for the GES to await
receipt of this information on the C channel sub-band as is the
case for the general access request procedure.
8.7.2.2 Series transmission of redundant access mquests.
In order to mitigate the effects of R channel collisions on
circuit-mode access delay performance, the AES will send a
short series of identical abbreviated access request SUs upon
both the initial access attempt and each of the four subsequent
attempts (which are initiated by expiry of timer tA50) for a
total of five attempts. The quantity of identical SUs in the
series increases with increasing call priority, The probability of
receiving at least one abbreviated access request SU at the
GES upon each of the five attempts over an R channel loaded
to 15 per cent is depicted in Table A-12 of this guidance
material. (The table brackets the expected performance by
depicting two cases where all conflicting R channel traffic
from other AESs camprises either I -SU bursts or 3-SU bursts.)
8.7.3 Sirnul&ne~us set-up of citlluit segments by the GES.
In addition to the enhanced delivery reliability for the
abbreviated access request SU as described in 8.7.2.2, end-toend
access delay performance is further aided by the GES
beginning forward completion of the call across the terrestrial
network at the same instant at which the GES allocates C
channel resources and begins C channel establishment in the
backward direction. Immediate initiation of forward call
completion is possible because the abbreviated access q u e s t
SU contains all necessary call information as described in
8.7.2.1. By establishing both the satellite and ternstrial
segments of the end-twnd call concurrently, the limiting
 
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_amend_75(153)