Local Switch Measurement per Cell

Description

The measurement unit provides several measurement counters in the local switch state. The measurement counters involve the number of call detect messages originated during local switching, the number of loopback start attempts, the number of loopback handovers, the number of successful handover attempts, the loopback success rate, the loopback handover success rate.

The BSS local switch consists of BSC local switch and BTS local switch.

In BSC local switch, the calling and called MSs are served by the same BSC. On the Abis interface, the BSC directly routes the speech signals to the addressed MS without routing them to the NSS, as shown in Figure 1. The BSC local switch aims to save the transmission resources on the Ater interface and the DSP resources on the DPU when the GTCS is remotely located.

Figure 1 BSC local switch

The call setup in BSC local switch must meet the general policy of BSS local switch, start conditions of BSC local switch, the related conditions for selecting speech versions of the calling and called MSs. In addition, the calling and called MSs must be served by the same BSC.

In BTS local switch, the calling and called MSs are served by the same BTS or by the same BTS group. The BTS or BTS group processes the Abis speech signals associated with the call and transmits the speech signals to the called MS without routing them to the BSC or MSC, as shown in Figure 2. Based on the different positions of the calling and called MSs, the BTS local switch can save the transmission resources on segment B and C or on segments A, B, and C. The BTS local switch aims to save the transmission resources on the Abis interface and on the Ater interface.

Figure 2 BTS local switch

The call setup in BTS local switch must meet the general policy of BSS local switch, start conditions of BTS local switch, the related conditions for selecting speech versions of the calling and called MSs. In addition, the calling and called MSs must be served by the same BTS.

NOTE:

At present, the BSS local switch supports speech services instead of data services. The general policy of BSS local switch and the start conditions of BSC/BTS local switch are set in Configure BSS Local Switch on the LMT.

The general policy of BSS local switch is as follows:

• BTS Priority
• BSC Priority
• BTS Only
• BSC Only
• Neither Start

The start conditions of BSC/BTS local switch are as follows:

• Unconditional Start
• Start upon Transmission Congestion
• Prefix Number
• Close Based on Number

Measurement Object

Cells

Measurement Counter

The following table lists the measurement counters related to Local Switch Measurement per Cell.