Land mobile systems with various channel spacing schemes have been deployed or are planned in 400 MHz bands. The frequency usage in border areas requires coordination of frequency channels because the coordination threshold is too restrictive for the provision of coverage in border areas. For systems with channel spacing up to 25 kHz there are well established bi- or multilateral agreements based on preferential use of frequencies. In the known agreements the threshold for preferential frequencies field strength is defined either at 40 km or 50 km distance inside the neighbouring country. For wide band systems with channel spacing greater than 1 MHz a preferential regime on preferential channels is not generally possible. However, in situations where on both sides of the border only wide band system are considered the coordination threshold can be increased in comparison to the restrictive value of the T/R 25-08 as given in ECC Report 97 [6] or ECC Recommendation (15)01 [4]. This is because wide band systems are generally more immune to interference. This Report considers the coordination thresholds for systems with channel spacing greater than 1 MHz in the 400 MHz band from both sides of the border. In addition, a case of narrow band systems on one side of the border overlapping with wide band systems on the other side of the border is considered as well, because those scenarios occur very often. The case of harmonised use of spectrum for wide band systems is not very likely to be achieved on short term, because wide band allocations differ from country to country in location in spectrum and size. Only in exceptional cases the wide band allocations are the same in border areas of neighbouring countries (e.g. Sweden and Norway). Even if in most cases wide band allocations vary among different countries, the resulting overlap between wide band and narrow band allocations across the border is typically as small as a few hundred kilohertz (below 500 kHz). This means that in such cases only a few narrow band channels have to be considered wide band allocation on the other side of the border. All path loss calculations in this study are performed by the modified Okumura-Hata model (ERC Report 68, [8]).This model is also applied for antenna height gain in the 400 MHz band. Administrations may agree in bi- or multilateral negotiations on other propagation models which could lead to slightly different results. However, for all calculations only one model shall be applied in order to avoid systematic errors.
Land mobile systems with various channel spacing schemes have been deployed or are planned in 400 MHz bands. The frequency usage in border areas requires coordination of frequency channels because the coordination threshold is too restrictive for the provision of coverage in border areas. For systems with channel spacing up to 25 kHz there are well established bi- or multilateral agreements based on preferential use of frequencies. In the known agreements the threshold for preferential frequencies field strength is defined either at 40 km or 50 km distance inside the neighbouring country. For wide band systems with channel spacing greater than 1 MHz a preferential regime on preferential channels is not generally possible. However, in situations where on both sides of the border only wide band system are considered the coordination threshold can be increased in comparison to the restrictive value of the T/R 25-08 as given in ECC Report 97 [6] or ECC Recommendation (15)01 [4]. This is because wide band systems are generally more immune to interference. This Report considers the coordination thresholds for systems with channel spacing greater than 1 MHz in the 400 MHz band from both sides of the border. In addition, a case of narrow band systems on one side of the border overlapping with wide band systems on the other side of the border is considered as well, because those scenarios occur very often. The case of harmonised use of spectrum for wide band systems is not very likely to be achieved on short term, because wide band allocations differ from country to country in location in spectrum and size. Only in exceptional cases the wide band allocations are the same in border areas of neighbouring countries (e.g. Sweden and Norway). Even if in most cases wide band allocations vary among different countries, the resulting overlap between wide band and narrow band allocations across the border is typically as small as a few hundred kilohertz (below 500 kHz). This means that in such cases only a few narrow band channels have to be considered wide band allocation on the other side of the border. All path loss calculations in this study are performed by the modified Okumura-Hata model (ERC Report 68, [8]).This model is also applied for antenna height gain in the 400 MHz band. Administrations may agree in bi- or multilateral negotiations on other propagation models which could lead to slightly different results. However, for all calculations only one model shall be applied in order to avoid systematic errors.
draft_ecc_report_276.docx