Paging Group

 The GSM system supports a maximum of 9%9=81 paging groups. the MS can be divided into 81 sub-groups at most from the opinion of the paging group. No matter what combination mode is adopted, the number of blocks used for paging in every 51 multi-frame does not exceed 9. The system enables the 51 multi-frame to cycle again , with a quantity of “BS-PA-MFRAMS” (number of frames of the same paging) of 51 multi-frames as a period.

Suppose that the number of frames of the same paging is 7 and the number of paging blocks (9or3-BS_AG_BLKS_RES: number of access granted reserved blocks) of each 51 multi-frame is 4. Then the paging group number cycles between 0-27 (28 in total).

  

 In GSM terms, the paging block in any 51 multiframe is called a paging super-group. Therefore, the number of paging super-frames in the system is the “number of frames of the same paging”. The number of paging groups in each super-group is 9 or 3 – “number of access granted reserved blocks”.

The number of paging blocks in each 51 multiframe is calculated according to the following formula:

If the CCCH and SDCCH are combined in one physical channel:

Number of paging groups per super-group=3－number of access granted reserved blocks

in other cases, i.e. the CCCH is not combined with the SDCCH:

Number of paging groups per super-group =9－ number of access granted reserved blocks

Both the above two parameters: “BS_AG_BLKS_RES” and the “BS-PA-MFRAMS” are broadcasted in system information type 3