6.1b BTS conditions

3GPP45.005GSM/EDGE Radio transmission and receptionTS

In the case of base transceiver stations the values apply for measurement at the connection with the antenna of the BTS, including any external multicoupler.

The Rx performance requirements of BTS for modulation schemes using higher symbol rate are based on input signals using wide pulse shaping filter unless otherwise stated. When the wanted input signal is such a signal, it is called Wanted signal Wide.

When the wanted input signal for BTS is using the higher symbol rate with narrow pulse shaping filter, it is called Wanted signal Narrow.

For channels with higher symbol rate the requirements for BTS for non-static propagation conditions are specified with RX diversity with two antennas applied and without RX diversity in the cases where the BTS has only one antenna port. The RX diversity requirements are specified for no correlation or gain imbalance between the two receive branches.

The requirements for the receiver performance in non-static channels with 16QAM, 32QAM and QPSK modulations are specified for training sequence 6 (TSC-6, as defined in 3GPP TS 45.002).

For speech and control channels in VAMOS mode, the requirements for BTS are specified only for non-static propagation conditions. These requirements are with RX diversity with two antennas with no correlation or gain imbalance between the two receive branches.

Unless explicitly stated, the requirements specified for GMSK modulated channels are applicable only for channels that are not in VAMOS mode.

In case of VAMOS mode, one of the VAMOS subchannels shall use training sequence 5 from TSC set 1 (and is referred to as VAMOS subchannel 1) and the other VAMOS subchannel shall use training sequence 5 from TSC set 2 (and is referred to as VAMOS subchannel 2). For the cases where SCPIR is not equal to 0 dB, the VAMOS subchannel 2 shall have lower power than VAMOS subchannel 1.The requirements for the receiver performance for speech and control channels in VAMOS mode in tables 1v and 2ac are applicable for both VAMOS subchannels (see 3GPP TS 45.001).

A BTS supporting EC-GSM-IoT shall, in addition to fulfilling EGPRS requirements, unless otherwise stated, fulfil the requirements for EC-channels in at least coverage classes CC1 and CC4 (using 4 consecutive PDCHs per TDMA frame without Overlaid CDMA). The BTS shall support 1 TS EC-RACH in CC1 and at least one of 1 TS EC-RACH and 2 TS EC-RACH in Coverage Classes CC4. The BTS may support at least one of 1 TS EC-RACH and 2 TS EC-RACH in Coverage Classes CC2 and CC3, as well as 2 TS EC-RACH in CC5.
The BTS requirements for EC-GSM-IoT are defined with RX diversity with two antennas with uncorrelated fading on fading channels and with equal gain between the two receive branches in case of sensitivity and interference performance. For performance of Overlaid CDMA the requirements are defined for single RX antenna configuration. The other receiver performance requirements for EC-GSM-IoT, i.e. erroneous frame indication performance (clause 6.4) and random access performance at high input levels (clause 6.5) are defined for single RX antenna configuration.

The set of coverage classes supported, whether the BTS supports Overlaid CDMA and in this case the number of subchannels supported, shall be included in the manufacturer’s declaration. The BTS shall support at least MCS-1 and MCS-1/16 for EC-PDTCH. The manufacturer shall also declare whether higher coverage classes (CC2, CC3, CC4, CC5) using MCS-1 when mapped to 2 consecutive PDCHs per TDMA frame are supported.

If Overlaid CDMA (see 3GPP TS 45.002 and 3GPP TS 45.004) is supported by the BTS for EC-PDTCH and EC-PACCH, using 4 consecutive PDCHs per TDMA frame, and two or more subchannels are assigned, the BTS shall be able to distinguish between signals from up to 4 different assigned MSs on the same timeslot. Performance is defined for two configurations of subchannel power imbalance ratio on uplink (SCPIR_UL, see definition in subclause 1.3):

– 0 dB, i.e. all Overlaid CDMA subchannels are received with the same power.

– 9 dB in case of two users per timeslot, or, 3, 6, 9 dB in case of four users per timeslot, each SCPIR_UL applying to one of the subchannels 2 to 4.

If Overlaid CDMA is supported by the BTS for EC-PDTCH/2TS and EC-PACCH/2TS, using 2 consecutive PDCHs per TDMA frame, and two subchannels are assigned, the BTS shall be able to distinguish between signals from 2 different assigned MSs on the same timeslot. Performance is defined for two configurations of SCPIR_UL: 0 dB and 9 dB.

The requirements for the receiver performance for packet data and control channels in table 1ad are applicable when in specified and supported coverage class and the other subchannel(s) always is/are in CC2. Further, in the case of two users per timeslot, the requirements are applicable when the two subchannels are assigned Overlaid CDMA codes 0 and 1, respectively, and in the case of four users per timeslot and SCPIR_UL setting equal to 3, 6, 9 dB, the requirements are applicable when the weakest subchannel is assigned Overlaid CDMA code 0, the second weakest subchannel is assigned Overlaid CDMA code 1, the second strongest subchannel is assigned Overlaid CDMA code 2 and the strongest subchannel is assigned Overlaid CDMA code 3.

NOTE: For information, to facilitate the comparison of performance with and without Overlaid CDMA applied, a diversity gain of 5 dB may be subtracted from the input signal level requirements for Overlaid CDMA which are defined for single RX antenna configuration.

In case of multicarrier BTS equipped with multicarrier receiver, the stated performance at each receiver antenna port connected to a multicarrier receiver shall be achieved for any of the wanted input signals at the specified power level when receiving up to the maximum supported number of wanted signals at equal power within the declared maximum Base Station RF bandwidth at the receiver antenna connector. The stated performance shall be achieved for requirements specifying an input level of each wanted signal up to and including ‑40 dBm. For requirements specifying a higher input level of each wanted signal, the stated performance applies for the total peak input level to the multicarrier BTS equipped with multicarrier receiver being not greater than the peak level when receiving a single wanted carrier for the same requirement. The stated performance shall be achieved provided that the frequency spacing between each wanted signal and each other signal that is not a dedicated interferer for that wanted signal is at least 600 kHz.

NOTE: Minimum receiver performance requirements for multicarrier base station declared as multistandard radio base station are defined in Annex P.