Concerns about interference between PS-LTE (Public Safety LTE), LTE-R (LTE for Railways), and LTE-M (LTE Maritime) have become a reality. As a result, safety measures have to be established right away as interference is directly connected to lives of the people in South Korea.
A consultative group that is formed by Ministry of Interior and Safety (MOIS), Ministry of Oceans and Fisheries (MOF), and Ministry of Land, Infrastructure, and Transport (MOLIT) to resolve interference between public networks is wandering between difference in viewpoints and different opinions from departments. The purpose of the consultative group is to come up with technologies in order to increase stability of operation of PS-LTE, LTE-M, and LTE-R that share 700MHz band and plans for network design.
PS-LTE was started by the police with central areas such as Sejong and Chungcheong region at the center. MOF is planning to run LTE-M by the end of this year. MOLIT is going to expand construction of LTE-R and replace every network with LTE-M by 2027. LTE-R is the issue as there has yet to be any measure to avoid interference between PS-LTE and LTE-R in advance. Safety standards are also missing between PS-LTE and LTE-R.
The cause of missing measures and safety standards is difference in viewpoints between departments. MOLIT wants to construct networks first. It wants to see if there is any interference while actually constructing LTE-R with Korea Rail Network Authority and set up necessary measures if needed. If a possibility of interference based on a region is brought up, it is going to work closely with other departments and construct network while avoiding base stations or apply technologies that will prevent interference.
Regarding this choice of decision, other departments and experts believe that there needs to be discussions and comprehensive simulations regarding specific safety standards before networks are actually constructed. While safety can be guaranteed by securing a “joint blueprint” that includes application of technologies for preventing interference and distance between base stations, other departments and experts have criticized MOLIT for not responding to preliminary discussions about safety sincerely.
Experts have warned that concerns about interference can become a reality and that lives of the people can be in danger and that national resources can be wasted if a department constructs a network without any preliminary discussion with other departments and simulations.
If interference is present, it is difficult for PS-LTE to operate properly in case of a serious railroad accident. This is also true for LTE-R as well. It is expected that LTE-R will be used by station employees to communicate each other at first and used to control trains starting from 2023. If there is an issue with controlling a train due to interference, there is a chance that a running train coming to a stop and causing a very dangerous situation. In 2019, a train that goes from Wonju to Gangneung and was applied with LTE-R was severed off due to interference between PS-LTE and LTE-R. National budget can be wasted ff such dangerous situation is checked at a future date and leads to relocation of base stations.
Experts in disaster and safety management order for measures that are applied with technologies such as “RAN (Radio Access Network) sharing” that are verified of safety to be established as soon as possible with the consultative group at the center. When RAN sharing is used, wireless base stations optimize wireless radio signal resources so that PS-LTE and LTE-R networks are shared and interferences can be avoided. “At this rate, there can be a serious situation around June.” said a representative for a research institute. “Ministry off Science and ICT that is in charge of radio signals needs to make careful actions.”
Staff Reporter Park, Jisung | jisung@etnews.com