A.2 Scenario 1: PLMN and CTS-GFL have no common frequency in whole coverage area

3GPP43.052GSM Cordless Telephony System (CTS), Phase 1Lower Layers of the CTS Radio Interface, Stage 2Release 17TS

In this section, we consider that any GFL in the considered PLMN coverage and any BA list in this PLMN never have any common frequency.

This section corresponds mainly to the following cases:

– donor PLMN and CTS are operated in separate bands;

– the considered PLMN is not a CTS Donor PLMN.

A.2.1 Cell Selection

A.2.1.1 GSM-MS has no BA list stored on the SIM

In this case, the GSM-MS shall scan all frequencies allowed by its type (GSM 900Mhz, 1800Mhz, multi-band, …), the number of such frequencies being possibly reduced by network parameter such as BA RANGE.

The GSM-MS may see a CTS-FP frequency as the next most powerful frequency and try to find a FCH. If it is not a CTS beacon frequency, frequency burst detection will fail. If it is a CTS beacon frequency, the frequency burst may be detected, but the MS will fail to decode an SCH.

The impact on GSM-MS is an additional delay of maximum 0,5 s per CTS frequency on which synchronisation is attempted, i.e. CTS frequency seen with higher power than the BCCH on which the MS is finally camping (see GSM 05.08 subclause 6.2 for maximum delay allowed for synchronisation to a BCCH carrier).

A.2.1.2 GSM-MS has a stored BA list on the SIM (optional)

The GSM-MS attempts first to camp on a cell with frequency in that BA list.

If the GSM-MS achieves to camp on a cell with frequency from the BA list, no frequency used by any CTS-FP has been scanned. CTS deployment has no impact on GSM-MS behaviour.

If the GSM-MS fails to camp on any cell with frequency from the stored list, the GSM-MS behaviour is like in subclause 2.1.1. The impact on GSM-MS is an additional delay of maximum 0,5 s per CTS frequency on which synchronisation is attempted.

A.2.2 Cell reselection

When camped on a cell, the GSM-MS shall monitor frequencies from the BA list provided on the BCCH.

Since the BA list and GFL have no common frequency, the GSM-MS never monitors CTS-FP frequency. CTS deployment has no impact on GSM-MS behaviour.

A.2.3 Handover

When in connected mode, the GSM-MS shall monitor frequencies from the BA list provided on the SACCH.

Since the BA list and GFL have no common frequency, the GSM-MS never monitors CTS-FP frequency. CTS deployment has no impact on GSM-MS behaviour.