Examples of Timeslot Assignment in Tree Topology

This provides examples of timeslot assignment on the Abis interface in the tree topology.

NOTE:

The timeslot assignment in each multiplexing mode is based on the following conditions:

The speech rate is 16 kbit/s. Four channels of speech occupy one 64 kbit/s timeslot on the Abis interface.
For the first TRX, channel 0 (T00C0) is the BCCH and channel 1 (T00C1) is the SDCCH.
The BCCH and SDCCH use RSLs, that is, the timeslots occupied by T00C0 and T00C1 are included in the timeslots occupied by RSLs. Therefore, T00C0 and T00C1 are not listed in the following tables.

Figure 1 shows the tree topology.

The multiplexing modes of BTS 0, BTS 1, BTS 2, and BTS 3 are 1:1, 2:1, 3:1, and 4:1 respectively. Each BTS is configured with a cell, the cell is configured with two TRXs, and the channels in the cell use default settings.

Figure 1 BTSs in tree topology

BTS 0 is the parent node. Table 1-Table 4 shows the timeslot assignment on E1s (A0-A3) of BTSs.

**Table 1** Timeslot assignment on A0
Timeslot No.	Sub Timeslot No.
Timeslot No.	0, 1	2, 3	4, 5	6, 7
0	Synchronization	Synchronization	Synchronization	Synchronization
1	RSL00
2	T00C2	T00C3	T00C4	T00C5
3	T00C6	T00C7	T01C0	T01C1
4	RSL01
5	T01C2	T01C3	T01C4	T01C5
6	T01C6	T01C7
7	OML1 + RSL10
8	T10C2	T10C3	T10C4	T10C5
9	T10C6	T10C7	T11C0	T11C1
10	RSL11
11	T11C2	T11C3	T11C4	T11C5
12	T11C06	T11C7
13	OML2+RSL20+RSL21
14	T20C2	T20C3	T20C4	T20C5
15	T20C6	T20C7	T21C0	T21C1
16	T21C2	T21C3	T21C4	T21C5
17	T21C6	T21C7
18	OML3+ RSL30+RSL31
19	T30C2	T30C3	T30C4	T30C5
20	T30C6	T30C7	T31C0	T31C1
21	T31C2	T31C3	T31C4	T31C5
22	T31C6	T31C7
23
...
31	OML0

**Table 2** Timeslot assignment on A1
Timeslot No.	Sub Timeslot No.
Timeslot No.	0, 1	2, 3	4, 5	6, 7
0	Synchronization	Synchronization	Synchronization	Synchronization
1	T10C2	T10C3	T10C4	T10C5
2	T10C6	T10C7	T11C0	T11C1
3	RSL11
4	T11C2	T11C3	T11C4	T11C5
5	T11C6	T11C7
6	OML3 + RSL30 + RSL31
7	T30C2	T30C3	T30C4	T30C5
8	T30C6	T30C7	T31C0	T31C1
9	T31C2	T31C3	T31C4	T31C5
10	T31C06	T31C7
11
...
31	OML1+ RSL10

**Table 3** Timeslot assignment on A2
Timeslot No.	Sub Timeslot No.
Timeslot No.	0, 1	2, 3	4, 5	6, 7
0	Synchronization	Synchronization	Synchronization	Synchronization
1	T20C2	T20C3	T20C4	T20C5
2	T20C6	T20C7	T21C0	T21C1
3	T21C2	T21C3	T21C4	T21C5
4	T21C6	T21C7
5
11
...
31	OML2 + RSL20 + RSL21

**Table 4** Timeslot assignment on A3
Timeslot No.	Sub Timeslot No.
Timeslot No.	0, 1	2, 3	4, 5	6, 7
0	Synchronization	Synchronization	Synchronization	Synchronization
1	T30C2	T30C3	T30C4	T30C5
2	T30C6	T30C7	T31C0	T31C1
3	T31C2	T31C3	T31C4	T31C5
4	T31C6	T31C7
5
...
31	OML3 + RSL30 + RSL31