Mobile Communication Basics - Cell Reselection Parameters

C1 = RX level – RX Level Access Min + Power Offset – Max [(MS_TX_PWR_MAX_CCH - P), 0]

Following parameter settings for our network,

• Power Offset = 0
• MS_TX_PWR_MAX_CCH = 33 dBm
• RX Level Access Min = -102 dBm

For GSM900 mobile P = 33 dBm

Then,

C1_GSM = RX level _GSM – (-102) + 0 – Max [ (33 – 33),0]

C1_GSM = RX level _GSM + 102 + 0 – Max [0,0]

C1_GSM = RX level _GSM + 102

For GSM 1800 mobile P = 30 dBm

Then,

C1_DCS = RX level _DCS – (-102) + 0 – Max [33-30,0]

C1 _DCS = RX level _DCS + 102 – Max [3,0]

C1 _DCS = RX level _DCS + 102 – 3

C1 _DCS = RX level _DCS + 99

C2 = C1+ CRO – TO* H (PT-T)

According to Huawei default parameter settings,

· TO = 0

· PT = 0

Then,

C2 = C1 + CRO

C2 _GSM = RX level _GSM + 102 + CRO

C2 _DCS = RX level _DCS + 99 + CRO

According to our network settings,

CRO_DCS = 8 (16dB), CRO_GSM = 0 (0dB),

Then,

C2_GSM = RX level_GSM + 102 + 0

C2_DCS = RX level_DCS + 99 + 16

C2_GSM = RX level_GSM + 102

C2_DCS = RX level_DCS + 115

For reselection,

C2_target > C2_serving (for 5 seconds)

Some examples:

Example1:

If both cells are GSM cells (Cell A & Cell B)

Then,

C2_A > C2_B (for 5 seconds) to reselect to Cell A

RX level_A + 102 > RX level_B + 102

Which means,

RX level_A > RX level_B (for 5 seconds) is enough for a cell reselection

If both cells are DCS, then it is same as 2 GSM cells.

Example2:

If one cell is GSM & other is DCS, find the requirement to reselect to DCS cell.

Then,

C2_DCS > C2_GSM  (for 5 seconds) to reselect to Cell A

RX level_DCS + 115 >  RX level_GSM + 102

RX level_DCS >  RX level_GSM + 102 – 115

RX level_DCS >  RX level_GSM – 13

Which means RX level_DCS >  RX level_GSM – 13  (for 5 seconds) is enough for a cell reselection to DCS Cell

If RX level_GSM = -80 dBm, then RX level_DCS >  RX level_GSM – 13

RX level_DCS > -80  – 13

RX level_DCS > -93 dBm

Read more mobile communication fundamentals

Location Update

Why location updates? Network has to identify where is the mobile is located to page it when an incoming call is received. Why cannot page the entire network? Millions of calls receive every moment, the...

How to improve Hand Over Success Rate

It is very important to maintain correct neighbour plan and do the basics. If you do not follow the basics of neighbour planning, it is very limited to possibilities to improve HOSR by using parameters. Edge,..

External Cell Parameters

It is required to define correct data in external cells to have a proper inter-BSC handovers & inter-MSC handovers, especially values of Layer, Layer Threshold and Minimum DL Power of the candidate cell. This...

Cell Reselection Parameters

C1 = RX level RX Level Access Min + Power Offset Max [(MS_TX_PWR_MAX_CCH - P), 0] Following parameter settings for our network, Power Offset = 0 MS_TX_PWR_MAX_CCH = 33 dBm RX Level Access Min...

 

Please leave a comment before go-away...