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International Civil Aviation Organisation
Middle East Office
Seminar on Aeronautical Spectrum Management
Cairo 4-6 June 2006
Agenda Item 8: HF Planning issues in AFI
Presented by Mary Obeng
RO/CNS, ICAO Dakar
INTRODUCTION
• Due to increase in VHF coverage, there has been
considerable decrease in the use of HF in AFI.
However, IFALPA has been complaining of some HF
congestion in AFI, notably AFI-3 (11300 KHz) and
AFI-4 (8894 KHz).
• A COM survey was conducted by IFALPA and IATA
on VHF and HF coverage in the AFI Region to see
how best the congestion could be eased.
Objectives of the Survey
• Establish status of implementation of mobile
communications throughout the region
• Monitor progress in extension of VHF radio coverage
• Identify deficiencies in aeronautical mobile service
coverage
• Assess problems of congestion on mobile frequencies
and the extent to which they are used for ground/ground
coordination
• Provide information to the COM/SG which will be useful
in planning the improvement of air/ground
communications
The Survey Form
Call sign: Origin: Date:
Aircraft type: Destination: Signed:
Position: Time: z Flight Level:
Communications information
ATS Unit: Strength Clarity Congestion
Low – Medium -
VHF (SEE NOTE 3) 1–2–3–4-5 1–2–3–4-5
Fre- High
quency: Low – Medium -
HF 1–2–3–4-5 1–2–3–4-5
High
Was the frequency apparently in use for ground/ground co-ordination? Yes No
Comments:
IATA Mobile Communications Survey - 2000
Last Survey made in 1994
Responding to decision 4/16 of COM SG/4
Survey conducted in cooperation between IATA &
IFALPA
Dates – 20 April – 30 May 2000
More than 1140 pilot reports received
Analysis by IATA Regional Office using Access
database
Main Conclusions
• Higher proportion of calls are being made on VHF
compared to 1994
• HF still the only means available in significant portions of
the AFI Region en route
• Noticeable improvement in average quality of
communications, in line with increased availability of VHF
• Some reduction in congestion on AFI-4 family of
frequencies but severe congestion persists on AFI-3
(11300Khz)
• Congestion directly associated to lack of VHF cover and
non availability of ATS/DS
Use of VHF 1994 - 2000
• 1994 - 37% of reports – VHF
• 2000 – 54% of reports - VHF
1994 2000
HF VHF HF VHF
VHF EXTENTIONS IN SOUTHERN
AND EASTERN AFI ALSO ACCRA
LUANDA,N’DJAMENA,KANO,NIAMEY,TUNIS FIRS
Percentage Use of VHF by FIR - 2000
Quality of Communications
Strength 1994 vs 2000
40
35
30
Percentage
25
20
1994
15
2000
10
5
0
0 1 2 3 4 5
Strength
Quality of Communications
Clarity 1994 vs 2000
1994
2000
35
30
25
Percentage
20
15
10
5
0
0 1 2 3 4 5
Clarity
Quality 1994 vs 2000
• 1994 - 63% of reports 3x3 or better
• 2000 – 79% or reports 3x3 or better
1994 2000
3x3 or better 3x3 or better
Quality by FIR - 2000
Deficiencies in Mobile Coverage
The survey identifies those positions where
mobile communications deficiencies occur
Following slides show positions where repetitive
reports indicate difficulties in air/ground
communication in both HF and VHF
All reports used in these slides indicate quality of
communication less than 3x3
Deficiencies in Mobile coverage
Abidjan
• MISLA
Luanda
Alger
• ATAFA; Djanet; MOKAT; NSL; RAZEL; ROFER;
Khartoum
• ALVOR; ME; Malakal;
Deficiencies in Mobile coverage
Kinshasa
• Buta Zega; KIBRO; MERON; SOBTO; TALAC;
USDUP
N’djamena
• MERON
Tripoli
• Kufra; NALUT; SEB;
HF Frequencies – by number of reports
ALG; KAN; NIM; ACC; FIH; GBE; KAN;
AFI-2 LAD; NDJ; NIM
AFI-4
90
ADD; CAI; KRT; MGQ;
80 NBO; TIP
AFI-3
70
60
FIH DKR; ROB ACC; ABJ
50 AFI-4 AFI-1 AFI-4
40
30 DAR; MRU; SEZ; TNR
20 INO-1
10
0
8894
8903
11300
13294
8861
6586
8879
6535
11291
8898
5517
Congestion by FIR
•Percentage of Reports indicating HIGH congestion - Top
Five
•Percentage of Reports indicating HIGH and/or MEDIUM
congestion - Top Five
40.0 100%
35.0 90%
80%
30.0
70%
25.0
60%
20.0 50%
15.0 40%
30%
10.0
20%
5.0
10%
0.0 0%
KRT NBO TIP ADD KAN KRT TIP NDJ LAD NBO
Use of Mobile Frequencies for Coordination
AFI-3
AFI-4
Frequency used
for coordination
INADEQUATE ATS/DS IN AFI-3
IMPLEMENTATION OF VSAT
COM/SG/5 DECISION
Outcome of the survey
• By improving aeronautical fixed services,
implementation of the NAFISAT network will reduce the
use of air-ground frequencies for ATS coordination (e.g.
reduction of congestion on HF frequency 11300KHz.
• NAFISAT MOU has been signed by Djibouti, Egypt,
Eritrea, Libya, Kenya (Somalia), Civil Aviation Caretaker
Authority (CACAS) Seychelles, Sudan, Uganda,
Tanzania, Yemen, ATNS and IATA hopefully Ethiopia and
Saudi Arabia will join the network.
• NAFISAT contract already awarded. The network is
expected to be operational by 2007.
