Publication: Magyar Közlöny
Issue: MK-2007-70 (Year: 2007, Number: 70)
Era: 2004-2010
Section: Melléklet a 2007. évi XLVI. törvényhez
Paragraph Index: 4480

c) HFDL protocol implementation and frequency selection. 11.2.2 Operational coverage Frequency assignments for HFDL shall be protected throughout their designated operational coverage (DOC) area. Note 1.— Designated operational coverage (DOC) areas may be different from current MWARAs or RDARAs as defined in Appendix 27 to the ITU Radio Regulations. 25/11/04 No. 79 2007/70/II. szám Part I Annex 10 — Aeronautical Telecommunications 5/11/95 4/11/99 No. 74 Note 2.— Additional co-ordination with ITU is required in cases where DOC areas are not in conformity with the allotment areas specified in the ITU Radio Regulations. 11.2.3 Requirements for carriage of HFDL equipment Requirements for mandatory carriage of HFDL equipment shall be made on the basis of regional air navigation agreements that specify the airspace of operation and the implementation time-scale. 11.2.3.1 NOTICE The agreement above shall provide advance notice of at least two years for the mandatory carriage of airborne systems. 11.2.4 Ground station networking 11.2.4.1 Recommendation.— HFDL ground station sub-systems should interconnect through a common ground management sub-system. Note.— This provides a distributed subnetwork, with a subnetwork point of attachment (SNPA), depending on the method of implementation, which allows for the maintenance of virtual circuit connections as aircraft stations transition between designated operational coverage areas. The distribution may be multi-regional or world-wide. 11.2.5 Ground station synchronization Synchronization of HFDL ground station sub-systems shall be to within ±25 ms of UTC. For any station not operating within ±25 ms of UTC, appropriate notification shall be made to all aircraft and ground station sub-systems to allow for continued system operation. 11.2.6 Quality of service 11.2.6.1 RESIDUAL PACKET ERROR RATE The undetected error rate for a network user packet which contains between 1 and 128 octets of user data shall be equal to or less than 1 in 106. 11.2.6.2 SPEED OF SERVICE Transit and transfer delays for network user packets (128 octets) with priorities defined in Part I, Chapter 4, Table 4-26 for message priorities 7 through 14, shall not exceed the values of Table 11-1. Table 11-1. Transfer delays 11.3 HF DATA LINK PROTOCOL The HFDL protocol shall consist of a physical layer, a link layer, and a subnetwork layer, as specified below. Note.— The HFDL protocol is a layered protocol and is compatible with the open systems interconnection (OSI) reference model. It permits the HFDL to function as an aeronautical telecommunication network (ATN)-compatible subnetwork. The details of the protocol are described in the Manual on HF Data Link (Doc 9741). 11.3.1 Physical layer RF characteristics The aircraft and ground stations shall access the physical medium operating in simplex mode. 11.3.1.1 FREQUENCY BANDS HFDL installations shall be capable of operating at any single sideband (SSB) carrier (reference) frequency available to the aeronautical mobile (R) service in the band 2.8 to 22 MHz, and in compliance with the relevant provisions of the Radio Regulations. 11.3.1.2 CHANNELS Channel utilization shall be in conformity with the table of carrier (reference) frequencies of Appendix 27 to the ITU Radio Regulations. 11.3.1.3 TUNING The equipment shall be capable of operating on integral multiples of 1 kHz. Direction Priority Delay Transit delay To-aircraft 7 through 14 45 s From-aircraft 7 through 14 60 s Transfer delay (95 percentile) To-aircraft 11 through 14 7 through 10 90 s 120 s From-aircraft 11 through 14 7 through 10 150 s 250 s 338A 25/11/04 No. 79 2007/70/II. szám Annex 10 — Aeronautical Telecommunications Volume III 5/11/95 4/11/99 No. 74 11.3.1.4 SIDEBAND The sideband used for transmission shall be on the higher side of its carrier (reference) frequency. 11.3.1.5 MODULATION HFDL shall employ M-ary phase shift keying (M-PSK) to modulate the radio frequency carrier at the assigned frequency. The symbol rate shall be 1 800 symbols per second ±10 parts per million (i.e. 0.018 symbols per second). The value of M and the information data rate shall be as specified in Table 11-2. Table 11-2. Value of M and information data rate Note.— When M equals the value 2, the data rate may be 300 or 600 bits per second as determined by the channel coding rate. The value of M may change from one data transmission to another depending on the data rate selected. The channel coding rate is described in the Manual on HF Data Link (Doc 9741). 11.3.1.5.1 M-PSK CARRIER The M-PSK carrier expressed mathematically shall be defined as: s(t) = AΣ(p(t-kT)cos[2πf0t + ϕ(k)]), k = 0, 1 , N-1 where: N = number of M-PSK symbols in transmitted physical layer protocol data unit (PPDU) s(t) = analog waveform or signal at time t A = peak amplitude f0 = SSB carrier (reference) + 1 440 Hz T = M-PSK symbol period (1/1 800 s) ϕ(k) = phase of kth M-PSK symbol p(t-kT) = pulse shape of kth M-PSK symbol at time t. Note.— The number of M-PSK symbols sent, N, defines the length (duration = NT seconds) of the PPDU. These parameters are defined in the Manual on HF Data Link (Doc 9741). 11.3.1.5.2 PULSE SHAPE The pulse shape, p(t), shall determine the spectral distribution of the transmitted signal. The Fourier transform of the pulse shape, P(f), shall be defined by: P(f) = 1, if 0 < |f| < (1 – b)/2T P(f) = cos {π(2|f|T – 1 + b)/4b}, if (1 – b)/2T < |f| < (1 + b)/2T P(f) = 0, if |f| > (1 + b)/2T where the spectral roll-off parameter, b = 0.31, has been chosen so that the –20 dB points of the signal are at SSB carrier (reference) + 290 Hz and SSB carrier (reference) + 2 590 Hz and the peak-to-average power ratio of the waveform is less than 5 dB. 11.3.1.6 TRANSMITTER STABILITY The basic frequency stability of the transmitting function shall be better than:

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