agement public telephone network, for communication with police and emergency service vehicles, for use by major public utilities, Governments, as members of the ITU, do not bind themselves to for cordless telephones, for wide area pagers, for citizens' band implement in all respects the worldwide or Region-wide provisions and SO on. of the international table of frequency allocations. For example, many countries, claiming special needs, have obtained international Thus, the national frequency allocation table becomes an import- agreement to the implementation of non-standard allocations within ant and complex national planning document. their territory; these agreements are recorded as footnotes to the The uses of radio change with time, often because desirable new international table. An administration is free to refrain from imple- facilities have become technically and economically feasible and menting within its jurisdiction any internationally agreed allocation. other, long established facilities have been superseded. It may be Also, an administration may assign frequencies for transmission in possible to provide for growth by assigning frequencies from fre- almost any frequency band to any kind of station, provided that the quency bands which are already in use, although it may first be emission is not capable of causing interference abroad. Finally the necessary to re-organise the existing use SO as to increase spectrum Constitution of the ITU allows governments complete freedom of utilisation efficiency. Failing this, the usual alternative is to develop action with regard to military radio installations. the use of vacant frequency bands, already appropriately allocated, However, if use of an assignment contrary to the international high in the currently used spectrum. table does cause harmful interference at a foreign receiving station However, in some countries most bands below 20GHz are already which is operating in accordance with the table, then the interfering filling up and much higher bands are c