6.8 BMC test method and architecture

34.123-33GPPPart 3: Abstract test suite (ATS)TSUser Equipment (UE) conformance specification

Figure 6.8: BMC testing architecture single party method

6.8.1 BMC test architecture

The single party test method is used for BMC testing, i.e. it does not exist an Upper Tester. BMC emulation is used as shown in Figure 6.8. The BMC emulation makes use of two PCOs. The CBMC PCO is defined, to pass configuration information for a BMC entity. The BMC PCO is defined for BMC message data transfer.

Separation of TTCN test cases from the configuration of the tester and initialization of the UE is achieved by using test steps. For BMC test cases, common test steps and newly defined test steps for BMC configuration will be used to perform the configuration of the tester and on UE side. These test steps make use of PCOs, CRLC, CMAC, and CPHY.

The UE shall be able to activate and deactivate a certain CB MessageID according CB data to be sent while testing.

BMC messages are sent in BMC message blocks on the CTCH. For sending BMC messages (BMC Scheduling Message (Level 2, DRX) and BMC CBS Message ) a configuration in downlink direction shall be performed to map the CTCH (RB#30) onto the FACH – S-CCPCH.

6.8.2 BMC test method

For BMC testing, only PS Cell Broadcast Service as distributed BMC service is applied. CBS Messages and BMC Schedule Messages are only sent in downlink direction. No uplink is used for BMC testing. The BMC test data with necessary CBS information shall be given by PIXIT parameter with a description of the indication on the display.

There are two level of BMC scheduling, Level 1 for CTCH configuration and Level 2 for DRX. The BMC scheduling information is conveyed to both BMC and MAC layer.

Level 1 scheduling is used to configure the CTCH on the S-CCPCH. For BMC testing (FDD), the Level 1 scheduling parameter MTTI contains one radio frame in the TTI of the FACH used for CTCH. Therefore, only Level 1 scheduling information N (period of CTCH allocation on S-CCPCH) and K (CBS frame offset to synchronize to the SFN cycle (0 to 4 095 frames per cycle)) are necessary to configure the CTCH onto the S-CCPCH.

The Level 1 scheduling is done in the SS MAC layer, therefore this information is given by using the primitive "CMAC_BMCscheduling_REQ" to inform the MAC on SS side about K and N. The Level 1 scheduling information, K and N, is broadcast as system information in SIB 5 and SIB 6. After having performed the CTCH configuration as Level 1 scheduling, the SS is configured to send BMC messages and the UE has to listen to each CTCH for a BMC message.

Segmentation of BMC messages is performed by RLC in UM according to the payload size on RB#30 (152 bits).

If only one CB data as BMC CBS message is sent and repeated for a BMC test case, Level 1 scheduling is adequate, i.e. no BMC Scheduling Message (Level 2) is needed. Then, no level 2 scheduling information are included in the "CMAC_BMCscheduling_REQ" primitive. If more then one BMC CBS message are transmitted and repeated or if BMC Scheduling Messages are transmitted, BMC scheduling Level 2 message shall be performed. Level 2 scheduling is used to predict the sent event of the next BMC message blocks and the BS index contents.

BMC scheduling Level 2 predicts exactly, which information is contained on a certain CTCH block set with an aligned Block Set index number and how many CTCH blocks are given as offset, before the next BMC message block will be sent. Figure 6.8.2.1 shows an example, how the messages flow shall be done for BMC scheduling Level 2.

Figure 6.8.2.1: BMC Scheduling

The BMC test method makes use of the primitive: "BMC_Data_REQ" to transmit the BMC Messages to RLC. If BMC Scheduling Level 2 is used, it includes BMC CBS PDUs or BMC Schedule PDUs, created by the BMC TTCN and forwarded to the BMC emulation. The transmission of BMC PDU is confirmed through the primitive BMC_Data_CNF.

According to the K and N value, the MAC layer at SS side determines the CTCH blocks for the BMC use. The CTCH blocks are indexed (i = 1 … 256).

If BMC DRX is needed, the BMC scheduling Level 2 information indicates the occupancy/spare of the available CTCH blocks by using a DRX_Selection_Bitmap and the list of CTCH BS index offsets. In the bitmap each bit, set to ‘1’, corresponds to an actually available CTCH block belonging to the DRX period for the SS transmission. The all consecutive occupied CTCH blocks constitutes a BMC DRX period, whilst the consecutive spared blocks indicate the DRX offset as spare CTCH slot. Following the DRX_Selection_Bitmap, the segmented BMC messages are transmitted. Each BMC PDU is transmitted in a BMC_Data_REQ primitive in the order of expected transmission. The list of CTCH BS index offset indicating the offset start of the relative to the previous message transmitted is included in the CMAC_BMC_Scheduling_REQ. If any, the retransmission is handled by the BMC TTCN.

The figure 6.8.2.2 shows an example of DRX level2 scheduling when sending 4 BMC messages (either BMC schedule or CBS BMC data messages) with the CTCH BS Index Offset List={0,6,2,11} and the Bitmap=‘107002’O.

Figure 6.8.2.2: Example of BMC DRX scheduling: CTCH BS index offset list and Bitmap handling