The channels grouped according to their aim (simplex, semi-duplex) are meant for stations of different network title-holders, sharing in time the respective frequencies; the table below indicates the occupation densities of such channels:
Density of channels in shared occupation regime and grouping of networks by mobile station categories
| Mobile station category | Maximum number of sharing entities per channel | Number of mobile stations in each network | |
|---|---|---|---|
| Cellular channels | 1 | 10 | Up to 5 |
| 2 | 7 | From 6 to 10 | |
| 3 | 3 | From 11 to 20 | |
| 4 | 2 | From 21 to 35 | |
| 5 | 1 | More than 35 | |
| General channels[1https://www.anacom.pt/render.jsp?contentId=55129] (national level) | 1 | 30 | Up to 5 |
| 2 | 15 | From 6 to 10 | |
| 3 | 10 | From 11 to 20 | |
| 4 | 5 | From 21 to 35 | |
| 5 | 2 | More than 35 |
Private mobile radio networks are grouped in shared channels according to indications of the above table and charged according to the corresponding price table in effect.
If changes in the number of network mobile stations imply a change of category, then ANACOM may determine alteration of the network frequency in question in order to maintain balanced channel use. In such circumstances, there is no ANACOM compensation for any cost to the title-holder resulting from a change of frequencies.
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[1] The shared ?general channels? operating in semi-duplex are meant to be used by local (ambulatory) networks.
