BS-PA-MFRAMS

BS-PA-MFRAMS

This parameter specifies the number of multi-frames in a cycle on the paging channel, that is, the number of paging sub-channels on a specific paging channel.

In actual situation, an MS monitors only the associated paging sub-channel. For details, see GSM Rec. 05.02 and 05.08.

If the value of this parameter increases, the number of paging sub-channels in a cell increases, thus reducing the number of MSs served by each paging sub-channel and prolonging the average service time of the MS battery. For details about the calculation of the paging group, see GSM Rec. 05.02. But the delay of paging messages increases, and the system performance deteriorates as the value of this parameter increases.

This parameter should be set on the basis that the paging channel is not overloaded. In addition, the value of the parameter should be as small as possible. The load of the paging channels should be periodically measured on the running network. The value of this parameter should be adjusted on the basis of the load.

A paging message must be sent simultaneously in all the cells in an LAC. Thus, the capacity of the paging channel in a cell, that is, the number of paging sub-channels in a cell, must be the same as or similar to that in other cells of an LAC.

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2 Multiframe Period

Multiframe Period

-

None

The larger this parameter is set, the larger the number of paging sub-channels in a cell and the smaller the number of MSs on each paging sub-channel. Setting this parameter larger can prolong the average service life of MS batteries but increase the delay of paging messages and reduce the system performance.

For an area with ordinary or heavy load on the paging channel, or an area with medium or high traffic, this parameter can be set to 6 or 7, that is, 6 or 7 multi-frames in a paging group are reserved.

None

Channel Management

Parameters About Radio Resources

One paging block (consisting of four consecutive CCCH timeslots) can carry two IMSI paging messages, four TMSI paging message, or two AGCH immediate assignment messages.

The downlink signaling link is faulty in idle mode, and the counter DSC is used to determine whether the downlink signaling link is faulty.

When an MS camps on a cell, the DSC is initiated to the integer closest to 90/N, where N equals BS_PA_MFRMS ranging from 2 to 9. The DSC increases by 1 (without exceeding the initial value) if the MS successfully decodes a message on its paging sub-channel, and the DSC decreases by 4 if the decoding fails. If the DSC is equal to or less than 0, the downlink signaling link is faulty. Then, a cell reselection is performed.

The value of this parameter is site-specific. For example, when the BTS2X exists in an LA, the CCCH is over-loaded if the value of this parameter is too small. Thus, it is recommended that this parameter be set to 5 or 6. The BTS3X series and double-transceiver BTSs do not have such a problem.