# Coexistence of 5G/6G and Digital Terrestrial Television Networks
## 4 Discussion  
The paper examines the feasibility of re-purposing the sub-1 GHz UHF band in the range 470-694 MHz, at present designated for digital terrestrial television, for use by IMT 5G/6G and other future telecommunications systems. The analyses suggest that it is viable to split the 470-694 MHz spectrum, designating the 606-694 MHz segment for IMT systems, while preserving the 470-606 MHz for exclusive DTT use. Alternatively, the second method shows that the entire 470-694 MHz range could be intelligently shared on a supplementary downlink basis for 5G/6G IMT services. Both approaches to accessing the valuable sub-1 GHz UHF band offer a strategy to secure additional spectrum for IMT/5G/6G systems without compromising the integrity of prevailing and necessary DTT services. If the sub-1 GHz UHF band were divided to create dedicated portions for 5G/6G IMT and DTT services, a considerable replanning of all terrestrial television multiplex networks would be required. This scenario, exemplified by the case study presented, would necessitate collaboration with neighboring countries, a process currently under discussion at the European level and pending potential decisions at future ITU-R radiocommunication conferences. While reallocating the spectrum would involve significant frequency planning and co-ordinations issues, modifications, and expenses for network operators, redistribution would yield the considerable advantage of making the entire 600 MHz band (606-694 MHz) available for both uplink and downlink 5G/6G IMT operations. However, this option could impose stricter spectrum constraints on terrestrial television and is likely to present substantial challenges for international coordination, complicating the introduction of additional transmissions, such as local television programs. International coordination of such a solution can take 3-5 years and must include any neighboring administrations in the region that wish to adopt it. Because DTT usage is dropping in certain countries, their administrations may be not interested in coordinating efforts for a system that might be turned off in the next few years, despite their desire to implement IMT across the entire DTT spectrum. Taking into account the terms of reference of the ITU WRC31, where the UHF band discussion may resume and a discussion about DTT turn-off may occur, such a temporary solution of spectrum splitting may be unacceptable to the administration, leaving the solution as an interesting but unexplored idea. The option necessitates extensive administrative efforts as well as numerous DTT network operator tasks, resulting in additional costs and effort for network operators and broadcasters, and may be viewed as a costly solution for achieving duplex mode transmission in the low-UHF band. Depending on the specific location, as demonstrated by the results of the case study in Poland, the interleaved spectrum available for SDL IMT 5G/6G mode could range from 16 MHz (two 8 MHz TV channels) to as much as 160 MHz (twenty 8 MHz channels). These substantial bandwidths are particularly attractive as they can be introduced without interfering with current existing terrestrial network operations, thereby avoiding the costly and labor-intensive restructuring associated with DTT network replanning (as is the case with the first proposed method). Such an advanced scheme would not only dramatically increase the 5G/6G networks' downlink range and capacity but would also circumvent the extensive process of international channel coordination and the high expenses tied to the modification of DTT infrastructure. This aligns with the ITU-R WRC23's endorsement of assigning the 470-694 MHz frequency range to IMT as a secondary service. The only disadvantage of the solution is limiting the free spectrum for additional broadcasting services in the band: e.g., additional local TV stations or Service Ancillary to Broadcasting (radio-microphone, cameras, etc.).