3-neighbor cell planning neighbor cell planning guidelines-revisedguidelines-revised.pdf

Neighbor Cell Planning Guidelines


ZTE Confidential Proprietary /5


Principles of neighbor cell planning are mainly concerned with limited neighbor cell

number, geographic topological structure, coverage interference, etc.

1. Common Neighbor Cell Planning Principles for 2G and 3G

1） In the initial network deployment, Neighbor cell planning is to configure the neighbors

as much as possible, which means that it would rather increase neighbor cells than

deleting.

2） ZTE self-developed software CNO can generate a list of neighbor cells automatically.

As the system is put into operation officially, the neighbor cell list can be optimized

further according to the statistics of handover and drive test data.

3） Neighbor cell relationship must be bidirectional, unless it is in a special scene

4） Neighbor cell planning is determined by geographic topological structure and

coverage interference,

a) Cells of the same site have to be set as each other’s neighbor cell;

b) The first layer and the second layer cells can be chosen as the present cell’s

neighbor cell according to present cell’s coverage;

c) The first layer cells on the opposite direction of the present sector are set as its

neighbor cells.

The following figure shows an example of neighbor cell setting.

The red one is the present cell whose scrambling codes are set as 4, 8 and 12; those

cells formed in boldfaced broken lines are present sector’s neighbor cells. Pink ones are

the first layer cells; blue ones are the second layer cells.



196

200

204

4

8

12

100

104

108

124

128

132

16

20

24

88

92

96

220

224

228

76

80

84

112

116

120

208

212

216

64

68

72160

164

168

148

152

156

52

56

60

172

176180

40

44

48

28

32

36

136

140

144

184

188

192

Figure 1 Illustration of Neighbor Cell Configuration

The present cell’s neighbor cell can be set as follows:

Table 1 Demonstration of Neighbor Cell List Configuration

Sector

number

Scrambling

code

number

Neighbor cell list

1-1 4 8(1-2)、12(1-3)、32(3-2)、48(4-3)、88(8-1)、92(8-2)、

100(9-1)、108(9-3)、112(10-1)、128(11-2)、140(12-

2)、144(12-3)、156(13-3)、196(17-1)、200(17-2)、

204(17-3)、208(18-1)、220(19-1)

2. Specific Neighbor Cell Planning Principles for 2G

1) The BCCH frequency of main cell and neighbor cell should not be the same . The

BCCH frequencies of the two cells adjacent to the same main cell should not be the

same, either.

2) There cannot be too many neighbor cells, the number of which should not exceed 32

3) According to the actual situation, set the neighbor cell to handover cell, re-selection



cell, or handover and re-selection cell.

3. Specific Neighbor Cell Planning Principles for 3G

1) The maximum number of neighbor cells within a system of intra-frequency is regulated

as 31 and inter-frequency as 32 in protocol.

Figure 2 Neighbor cell number limitation

2) Principles of Inter-Frequency Neighbor Cell Planning:

Configure co-site and adjacent site as inter-frequency neighbors

3) The Neighbor Cell Interoperability Planning of 2G and 3G

a) The neighbor cell configurations should abide by 2/3G different strategies for

interoperability;

b) Both coverage and capacity should be considered while choosing 2G neighbor

cells for 3G network. The 2G network with good coverage will be chosen as the 3G

neighbor cells preferentially, so GSM900 is the priority choice. However, the traffic

balance between GSM900/1800 should be considered, too.

c) In the internal 3G continuous coverage areas, adopt the following principles to

configure the inter-system neighbor cell:

i. Apart from configuring the co-located 2G cells as the neighbor cells, 2G cells

(The first layer) need to be configured as neighbors of surrounding 3G cells (In

order to keep 3G users in 3G network as much as possible, set re-selection

and handover parameters to increase the difficulty of re-selection and

handover form 3G to 2G);

ii. Apart from configuring the co-located 3G cells as the neighbor cells, 3G cells

also need to be configured as neighbors of 2G cells, to absorb users from 2G

to the 3G network as much as possible.

d) In the coverage edge or hole of the 3G network, adopt the following principles to

configure the neighbor cell:

i. In addition to configuring the co-located 2G cells as neighbor cells, 3G cells

also need to configure the 2G cells in the first layer as neighbors(parameters

are configured for the easier re-selection and handover from 3G to 2G, to

make the handover quicker accordingly in the border area);

ii. Only configure the co-located 3G cells as the neighbor cell of 2G cell, to



avoid re-selection to the 3G network at the 3G coverage edge;

4. Principles of neighbor cell planning between outdoor and IBS cells

1) Configure bidirectional neighbors between outdoor cells and IBS cells in all the

entrances of the building. The choice of outdoor cells configured has to be based on

the testing result, but not from the topology on the map.

2) In high building case, neighbor cell configuration between outdoor cells and IBS cells

is closed at the initial phase. After the network is launched, neighbor cell optimization

between outdoor cells and IBS cells will be performed by NCOS based on OMM KPI

data and also CQT.

From the above analysis, outdoor cells and IBS cells' neighbor configuration would

be considered if it is necessary to solve the strong interference on indoor users by

outdoor cell's signal. But the principle is to keep indoor users stay in IBS cells as

much as possible, so such configuration has to be careful, and checked by testing

result from outdoor cell's signal.

3-neighbor cell planning neighbor cell planning guidelines-revisedguidelines-revised.pdf

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