Publication: Magyar Közlöny
Issue: MK-2007-70 (Year: 2007, Number: 70)
Era: 2004-2010
Section: Melléklet a 2007. évi XLVI. törvényhez
Paragraph Index: 4465

b) Demand assigned circuits: This shall provide voice circuit access which is arbitrated by the ground station in response to an access request received from the aircraft station. This type of operation shall allow dynamic sharing of the channel resource increasing trunking efficiency. 6.8.1.2 Priority access. The voice unit operation shall support a priority override access for authorized ground users. 6.8.1.3 Message source identification. The voice unit operation shall support notification to the user of the source of a received message (i.e. whether the message originated from an air or ground station). 6.8.1.4 Coded squelch. The voice unit shall support a coded squelch operation that offers some degree of rejection of undesired co-channel voice messages based on the burst time of arrival. 6.8.2 Speech encoding, parameters and procedures 6.8.2.1 The VDL Mode shall use the advanced multiband excitation (AMBE) 4.8 kbits/s encoding/decoding algorithm, version number AMBE-ATC-10, developed by Digital Voice Systems, Incorporated (DVSI) for voice communications. Note 1.— Information on technical characteristics of the 4.8 kbits/s AMBE algorithm is contained in AMBE-ATC-10 Low Level Description, obtainable from DVSI. Note 2.— The 4.8 kbits/s AMBE encoding/decoding technology described in the document is subject to DVSI patent rights and copyrights. Manufacturers must enter into a license agreement with DVSI prior to obtaining a detailed description of the algorithm before incorporation in equipment operating in the VDL Mode 3 service. By letter to ICAO dated 29 October 1999, DVSI confirmed its commitment to license the technology for the manufacture and sale of aeronautical equipment under reasonable terms and conditions, negotiated on a non-discriminatory basis. 6.8.2.2 Speech encoding definition, voice unit parameters, and procedure descriptions for VDL Mode 3 Voice Unit operation are contained in the Manual on VDL Mode 3 Technical Specifications. 6.9 VDL MODE 4 6.9.1 A Mode 4 station shall conform to the requirements defined in sections 6.1.2.3, 6.1.4.2, 6.2.1.1, 6.2.3.1, 6.2.4, 6.3.1, 6.3.3.1, 6.3.4, 6.3.5.1, 6.3.5.2, 6.3.5.3, 6.3.5.4.1 and 6.9. 6.9.2 VDL Mode 4 radio channels 6.9.2.1 VDL MODE 4 STATION FREQUENCY RANGE 6.9.2.1.1 Transmitter/receiver tuning range. A VDL Mode 4 transmitter/receiver shall be capable of tuning to any of the 25 kHz channels from 117.975 MHz through 137 MHz. The transmitter shall have a means for the tuning range to be restricted to a narrower range. Note.— Operational conditions or certain applications may require the equipment to be operated in a narrower frequency range. 6.9.2.1.2 Recommendation.— A VDL Mode 4 transmitter/receiver should be capable of tuning to any of the 25 kHz channels from 108 to 117.975 MHz. Note.— The band 108–117.975 MHz may be utilized in accordance with the relevant provisions of the ITU Radio Regulations. 282I 25/11/04 No. 79 2007/70/II. szám 2007/70/II. szám 2007/70/II. szám Annex 10 — Aeronautical Telecommunications Volume III 1/11/01 No. 76 1/11/01 No. 76 6.9.5.3.3.2 Measurement of channel power. Regardless of the ability of the demodulator to detect a valid training sequence, a VDL Mode 4 station shall consider the channel busy with at least a 95 per cent probability within 1 ms after on-channel power rises to the equivalent of at least four times the estimated noise floor for at least 0.5 milliseconds. 6.9.5.3.4 Channel busy to idle detection 6.9.5.3.4.1 A VDL Mode 4 station shall employ the following means to determine the channel busy to idle transition. 6.9.5.3.4.2 Measurement of transmission length. When the training sequence has been detected, the channel busy state shall be held for a period of time at least equal to 5 milliseconds, and subsequently allowed to transition to the idle state based on measurement of channel power. 6.9.5.3.4.3 Measurement of channel power. When not otherwise held in the channel busy state, a VDL Mode 4 station shall consider the channel idle with at least a 95 per cent probability if on-channel power falls below the equivalent of twice the estimated noise floor for at least 0.9 milliseconds. 6.9.5.4 RECEIVER/TRANSMITTER INTERACTION 6.9.5.4.1 Receiver to transmitter turnaround time. A VDL Mode 4 station shall be capable of beginning the transmission of the transmitter power stabilization sequence within 16 microseconds after terminating the receiver function. 6.9.5.4.2 Frequency change during transmission. The phase acceleration of the carrier from the start of the synchronization sequence to the data end flag shall be less than 300 Hz per second. 6.9.5.4.3 Transmitter to receiver turnaround time. A VDL Mode 4 station shall be capable of receiving and demodulating with nominal performance an incoming signal within 1 ms after completing a transmission. Note.— Nominal performance is defined as a bit error rate (BER) of 10–4. 6.9.5.5 PHYSICAL LAYER SYSTEM PARAMETERS 6.9.5.5.1 Parameter P1 (minimum transmission length) 6.9.5.5.1.1 A receiver shall be capable of demodulating a transmission of minimum length P1 without degradation of BER. 6.9.5.5.1.2 The value of P1 shall be 19 200 bits. 6.9.5.5.2 Parameter P2 (nominal co-channel interference performance) 6.9.5.5.2.1 The parameter P2 shall be the nominal co-channel interference at which a receiver shall be capable of demodulating without degradation in BER. 6.9.5.5.2.2 The value of P2 shall be 12 dB. 6.9.5.6 FM BROADCAST INTERFERENCE IMMUNITY PERFORMANCE FOR VDL MODE 4 RECEIVING SYSTEMS 6.9.5.6.1 A VDL Mode 4 station shall conform to the requirements defined in section 6.3.5.4 when operating in the band 117.975–137 MHz. 6.9.5.6.2 A VDL Mode 4 station shall conform to the requirements defined below when operating in the band 108–117.975 MHz. 6.9.5.6.2.1 The VDL Mode 4 receiving system shall meet the requirements specified in 6.3.5.1 in the presence of two-signal, third-order intermodulation products caused by VHF FM broadcast signals having levels in accordance with the following: 2N1 + N2 + 72 < 0 for VHF FM sound broadcasting signals in the range 107.7–108.0 MHz and for VHF FM sound broadcasting signals below 107.7 MHz, where the frequencies of the two VHF FM sound broadcasting signals produce, within the receiver, a two-signal, third-order intermodulation product on the desired VDL Mode frequency. N1 and N2 are the levels (dBm) of the two VHF FM sound broadcasting signals at the VDL Mode 4 receiver input. Neither level shall exceed the desensitization criteria set forth in 6.9.5.6.2.2. ∆f = 108.1 – f1, where f1 is the frequency of N1, the VHF FM sound broadcasting signal closer to 108.1 MHz. Note.— The FM intermodulation immunity requirements are not applied to a VDL Mode 4 channel operating below 108.1 MHz, and hence frequencies below 108.1 MHz are not intended for general assignments. 6.9.5.6.2.2 The VDL Mode 4 receiving system shall not be desensitized in the presence of VHF FM broadcast signals having levels in accordance with Tables 6-5 and 6-6. 2N1 N2 3 24 ∆f 0.4 ------ log –       ≤ + + 282L 25/11/04 No. 79 2007/70/II. szám Part I Annex 10 — Aeronautical Telecommunications 1/11/01 No. 76 6.9.6 Link layer Note.— Details on link layer functions are contained in the Manual on VDL Mode 4 Technical Specifications. 6.9.7 Subnetwork layer and SNDCF Note.— Details on subnetwork layer functions and SNDCF are contained in the Manual on VDL Mode Technical Specifications. 6.9.8 ADS-B applications Note.— Details on ADS-B application functions are contained in the Manual on VDL Mode 4 Technical Specifications. 282M 25/11/04 No. 79 2007/70/II. szám Annex 10 — Aeronautical Telecommunications Volume III 1/11/01 No. 76 1/11/01 No. 76 TABLES FOR CHAPTER 6 Table 6-1. Modes 2 and 3 data encoding Table 6-2. Modes 2 and 3 modulation stability Table 6-3. Scrambler functions Table 6-4. Physical services system parameters Xk Yk Zk ∆φk 0 π / 4 1 π / 4 2 π / 4 3 π / 4 4 π / 4 5 π / 4 6 π / 4 7 π / 4 VDL Mode Aircraft Modulation Stability Ground Modulation Stability Mode 2 ± 0.0050 per cent ± 0.0050 per cent Mode 3 ± 0.0005 per cent ± 0.0002 per cent Function Data in Data out scrambling clean data scrambled data descrambling scrambled data clean data Symbol Parameter name Mode 2 value P1 Minimum transmission length 131071 bits 282N 25/11/04 No. 79 2007/70/II. szám Part I Annex 10 — Aeronautical Telecommunications 1/11/01 No. 76 Table 6-5. VDL Mode 4 operating on frequencies between 108.0–111.975 MHz Table 6-6. VDL Mode 4 operating on frequencies between 112.0–117.975 MHz Frequency (MHz) Maximum level of unwanted signal at receiver input (dBm) 88–102 +15 +10 +5 107.9 –10 Frequency (MHz) Maximum level of unwanted signal at receiver input (dBm) 88–104 +15 +10 +5 107.9 Note.— The relationship is linear between adjacent points designated by the above frequencies. 282O 25/11/04 No. 79 2007/70/II. szám Annex 10 — Aeronautical Telecommunications Volume III 1/11/01 No. 76 1/11/01 No. 76 FIGURES FOR CHAPTER 6 Figure 6-1. Transmitter Power Stabilization Figure 6-2. PN-generator for bit scrambling sequence Centre of first symbol of unique word Major divisions are symbol periods Power at 90 per cent by t =  1 2 3 4 5 5.5 Data in Data out T

Source: https://magyarkozlony.hu/hivatalos-lapok/7e70cec03f34e3c2efd8610b865b65591eafd701/dokumentumok/a55dc160549d57fa4db0035e37c6a6a98dd1a0b9/letoltes