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
and receives a V/D message in the same slot.
Note.- The Reed-Solomon (72, 62) code is capable of 6.4.4.7 Fringe coverage indication.
correcting up to five 28-ury (code word) symbol errors in the
received word. 6.4.4.7.1 Recommendation,- Indication of near
edge-of-coverage should be provided to the VDL Made 3
6.4.4.3.4 Trunsmitter r~mzp-downT. his shall be as defined aircmft.
in Section 6.4.4.1.3.
6.4.4.4 I~zte~leavingT. here shall be no interleaving in
Mode 3 operation. 6.5 LLNK LAYER PROTOCOLS
AND SERVICES
6.4.4.5 Bit scmmbling. Under Mode 3 operation, bit
scrambling, as specified in Section 6.4.3.1.4 shall be
performed on each burst, starting after the training sequence. 6.5.1 General information
The scrambling sequence shall be reinitialized on each burst
efkctivcly providing a constant overlay for each of the Mode 6.5.1.1 Functionaliiy. The VDL link layer shall provide
3 fixed length bursts. the following sublayer finctions:
6.4.4.6 Rewiver/tmnsmitter interuction. The switching a) media access control (MAC) sublayer, which requires
times in this subsection will be defined as the time between the the use of the carrier sense multiple access (CSMA)
middle of the last information symbol of one burst and the algorithm for Mode 2 or TDMA for Mode 3;
middle of the first symbol of the synchronization sequence of
the subsequent burst. b) a data link service (DLS) sublayer:
Note.- This nominal time will be shortened by 1) for Mode 2, the DLS sublayer provides
considerations such us the finite width of each symbol due to connection-oriented point-to-point links using data
Nyquist fEltering and the ramp up and power stabilizution link entities (DLE) and connectionless broadcast link
sequence. Such alternative definitions could yield switching over the MAC sublayer; and
times up to 8 symbol periods shorte~
6.4.4.6.1 Receiver to transmitter switching time. An
aircraft radio shall be capable of switching from reception to
transmission within 17 symbol periods. This time can be
relaxed to 33 symbol periods for aircraft radios which do not
implement functions requiring discrete addressing.
Note 1.- The shortest RfT switching time for un uircraft
radio occurs when the reception of an uplink M channel
beacon is followed by a V/D transmission in the same slot. In
certain instances where aircraft radios do not implement
functions requiring discrete addressing, the R/T switching tzme
ca~z be increased since the last two Colay wards of the uplink
M channel beacon need not be read.
Note 2.- The minimum turnaround time assumes that in
conflgurutions 3VlD, 2VI0, und 3T (as contained in Section
5.5.2.4 of the Munual on VDL Mode 3 Technical
Specifications), the uircraft radios will be provided with
sofhuare that will prevent them from transmitting a downlink
M chan~,neml essage in u slot followin,g the reception of a voice
message from another aircraft with a long rime delay.
6.4.4.6.2 Transmitter to r~ceiver switching time. An
aircraft radio shall be capable of switching from transmission
to reception within 32 symbol periods.
2)for Mode 3, the DLS sublayer provides
acknowledged connectionless point-to-point and
point-to-multipoint links over a MAC sublayer that
guarantees sequencing; and
c) a VDL management entity (VME), which establishes
and maintains DLEs between the aircraft and the
ground-based systems using link management entities
(LME).
6.5.1.2.1 Connection-oriented. The VDL Mode 2 link
layer shall provide a reliable paint-to-point service using a
connection-oriented DLS sublayer.
6.5.1.2.2 Connectionless. The VDL Mode 2 and 3 link
layers shall provide an unacknowledged broadcast service
using a conncctionless DLS sublayer.
6.5.1.2.3 Acknowledged connectionless. The VDL Mode
3 link layer shall provide an acknowledged point-to-point
service wing a connectionless DLS sublayer that relies upon
tht MAC sublayet to guarantee sequencing.
l/lUOl
No. 76
Annex 10 - Aeronautical Telecommunicatiorzs VoZu~ne1 11
6.5.2 MAC sublayer
6.5.2.1 The MAC sublayer shall provide for the
transparenl acquisition of the shared communications path. It
makes invisible to the DLS sublayer the way in which
supporting communications resources are utilized lo achieve
this.
Note.- Specific MAC services and procedures for VDL
Modes 2 and 3 are contained in the Manuuls on VDL Mode 2
and VDL Mode 3 Technicul Specifications.
6.5.3 Data link service sublayer
6.5.3.1 For Mode 2, the DLS shall support bir-oriented
simplex air-ground communications using the aviation VHF
link control (AVLC) protocol.
Note.- Specifto data link services, parameters and protocol
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_76(32)
