The government has identified 3300 MHz to 3600 MHz spectrum for 5G and there seem to be no chances of interference with the radio altimeters-essential component of the aeronautical safety-of-life system.
This was confirmed by the top officials Pakistan Telecommunication Authority (PTA) while talking to ProPakistani.
Radio Altimeters are an essential component of aeronautical safety-of-life systems. Some recent issues raised after the launch of 5G in C Band (ITU Region 2: US) had created the impression that Wireless Broadband (WBB) services in nearby frequency ranges can potentially cause interference in radio altimeter receivers operating in the 4200 to 4400 MHz band via three different technical mechanisms (overload, de-sensitization, and false altitude reports).
Radio altimeter measures altitude above the terrain presently beneath an aircraft or spacecraft by timing (essentially how long it takes a beam of radio waves to travel to the ground, reflect, and return to the craft). This type of altimeter provides the distance between the antenna and the ground directly below it in contrast to a barometric altimeter that provides the distance above a defined vertical datum, which is usually mean sea level, a PTA official added.
Radar altimeters are frequently used by commercial aircraft for approach and landing, especially in low-visibility conditions and automatic landings. Sources said that the 4200-4400 MHz band is a shared band that is internationally reserved for radio altimeters installed on aircraft. The Frequency Allocation Board (FAB) in Pakistan has also allocated the same band for ‘Aeronautical Radio navigation.’
Radio altimeters operate in the 4200 to 4400 MHz band, and the US has set aside a portion of the spectrum right up to the lower band of that for 5G. It had also auctioned 3.7-3.98 GHz 5G bandwidth to mobile phone companies in early 2021. America’s Federal Aviation Administration (FAA) had warned that the new 5G technology could interfere with instruments like altimeters. As a short-term solution, mobile operators had agreed to temporarily defer turning on some wireless towers near key airports to avert significant disruption to American flights.
As a longer-term solution, the FAA needs to clear and allow most American commercial airplane fleets to perform low-visibility landings at many airports where the 5G C-band will be deployed. This means certifying altimeters to operate near 5G base stations.
PTA officials said that Pakistan is using 3700-4200 MHz for satellite projects. As per the 5G Policy Guidelines issued by the Government of Pakistan, the 3300 MHz to 3600 MHz spectrum is identified for 5G, and interference with radio altimeters is unlikely.
However, this study of C Band and Altimeter usage has been included in 5G consultant Terms of Reference (TORs) for detailed analysis, findings, and future recommendations. Additionally, another ITU Region 3 Regulator, ACMA (Australia) study on the subject shows detailed subsets of planning for usage of this band and coexistence.
Additionally, possible 5G interference issues in altimeters have only been identified in the USA and have not been reported in Europe, South East Asia, China, the Gulf Cooperation Council (GCC), and other countries that have launched 5G.
Moreover, the government is planning to auction the 5G spectrum in the first quarter of 2023.
Now Pakistani Telcos will have another excuse for poor services