C1 and C2 value

[radio_network]

We are using Dual band with 900 as Pimary band (BCCH only at 900) and 1800 for traffi.c. Is it possible to use C2 value to change preference for call latching and to set the boundary:time:

[santosjj]

Please find attached a document showing a dual band strategy.
Enjoy.

[hassen]

We are using Dual band with 900 as Pimary band (BCCH only at 900) and 1800 for traffi.c. Is it possible to use C2 value to change preference for call latching and to set the boundary:time:
yes

C2=C1 + CRO for PT=/=31
C2=C1 - CRO for PT=31
and define cell 1800 layer 1

[ghassen]

We are using Dual band with 900 as Pimary band (BCCH only at 900) and 1800 for traffi.c. Is it possible to use C2 value to change preference for call latching and to set the boundary:time:


C1 is cell reselection creteria in a network without hierarchical cell structure but C2 is a cell reselection criterion in a network with hierarchical cell structure.

What does it mean ???

It means that :

The mobile will take 5 measurement and wil average them:

Av_rxlev = (Rxlev1+Rxlev2+Rxlev3+Rxlev4+Rxlev5)/5

C1 = Av_rxlev-Rx_lev_acess_min-MAX(MS_TX_PWR_MAX-P,0) this how to calculate the cel reselection creterion

Rx_lev_acess_min : is the minimum received level by the mobile to access the bts

MS_TX_PWR_MAX : maximum power trransmitted by the mobile station

p : mobile power class

And it must be C1(neibourg cell) > C1( serving cell) to allow the mobile reselect a cell

For the celle reselection creterion 2 :

During Penality time

C2 = C1 + CRO - TFO

After penality time

C2 = C1 + CRO

For penality time = 31

C2 = C1 - CRO
where :

TFO : Temporary offset
CRO : Cell reselectio offset

A negative CRO will reduce the priority of the cell a positif one will increase the priority of the cell it means that with a positif CRO we add more difficulty to the mobile station to access the BTS

When a mobile reach the coverage area of neighbour cell given by C1 this cell will be excluded during penality time

And then the BTS will calculate now the speed of the mobile but how ??

++ If the mobile leave the coverage area of the serving cell before penality time is reached then the mobile will camp on a macro cell ( Fast moving mobile)

++If the mobile don't leave the coverage area of the serving cell before penality time is reached then it will camp on a micro cell ( Slow moving mobile)

why this mechanism ?

let's assume that d is the distance between the 2 cells boundaries

speed = d / penality time and then the bts will know now the speed of the mobile

And then C2 is only used for speedy mobile and only when hierarchical cell structure is present

[ozcank]

thank you so much for your useful sharing .

best regards,

[ghassen]

thank you so much for your useful sharing .


best regards,

@ozcank


i have updated the post

[punto]

In idle mode behaviour of MS ... not dedicated when you do HO ... for not mix up things ... to make it clear ...

#cell selection is based on the C1 criterion and cell priority
#cell RE-selection is based on the C2 criterion taking into account the mobile speed

Cell Selection and Cell Reselection
# Performed by MS
# Controlled by parameters broadcast on the BCCH carrier of each cell

P:)
p.s. @santosjj ... this is taken from your doc, is good and clear ... so pls., credit goes to santosjj ...

[ghassen]

In idle mode behaviour of MS ... not dedicated when you do HO ... for not mix up things ... to make it clear ...

#cell selection is based on the C1 criterion and cell priority
#cell RE-selection is based on the C2 criterion taking into account the mobile speed

Cell Selection and Cell Reselection
# Performed by MS
# Controlled by parameters broadcast on the BCCH carrier of each cell

P:)

yes for sure punta assuming that every body know it already

[radio_network]

Thanks guys for your reply. Very nice and intresting

[Mr.David]

Please find attached a document showing a dual band strategy.
Enjoy.

Dear My Friend Santosjj,

Just Positive thinking
I don't know it, but i have ever Post this file in this Forum
http://www.finetopix.com/showthread.php?t=2985&highlight=siemens

[radio_network]

thanks for posting this in open.

[NILCTG]

And also for the sake of clarity, let me add the fact that C1 & C2, both have certain role in cell reselection. Out of 5 criteria that can trigger a cell reselection, two involved C1 & C2 :

1. if C1 for serving cell falls below zero for a period of five seconds, cell reselection will be triggered.

2. if value of C2 for a non serving cell exceeds the value of C2 for the serving cell for a period of five seconds, cell reselection will be triggered(as long as these cells are in the same LAC)

[radio_network]

one more clarification pl. The senario to use C2. i.e for fast moving mobile, or for shifting the priority to ineer band (1800). We are using Rxlevl_access_min: 6 and c2 not enabled. By enabling c2 what are the other things we have to take care.
(******** Systems)

[NILCTG]

Actually, C2 is used(enabled) generally in every network. No special scenario needed.

[NILCTG]

And I am talking about general scenerio, in C2 since CRO(this parameter defines a signal strength offset to encourage or discourage MSs to reselect the cell) is used, one can play with this parameter to shift Idle mode cell radius/boarder to deal with congestion(when every other mechanism is already deployed and increasing capacity is not an immediate option). But then again you also have to remember, you should modify some HO parameters as well if CRO is modified significantly(to reduce unnecessary HO). For your network you have to find out how it should be used.

[k4conk]

In idle mode behaviour of MS ... not dedicated when you do HO ... for not mix up things ... to make it clear ...

#cell selection is based on the C1 criterion and cell priority
#cell RE-selection is based on the C2 criterion taking into account the mobile speed

Cell Selection and Cell Reselection
# Performed by MS
# Controlled by parameters broadcast on the BCCH carrier of each cell

P:)
p.s. @santosjj ... this is taken from your doc, is good and clear ... so pls., credit goes to santosjj ...


whats different Cell Selection and Cell Reselection if we don't observe C1 and C2 ..???:p

[ghassen]

one more clarification pl. The senario to use C2. i.e for fast moving mobile, or for shifting the priority to ineer band (1800). We are using Rxlevl_access_min: 6 and c2 not enabled. By enabling c2 what are the other things we have to take care.
(******** Systems)

you are right the speed is calculated depending how much time is needded for the mobile to cross the cell border

[plannerguy]

hai

Thanks to santhosji for this nice doc on seimens 900/1800.This is very help full to me as i am working on seimens Network.But i have a doubt how ti change value of C1 and C2 in siemens BSC or were could i find the Parameter in DBs.

Thanks
Plannerguy

[dexterhaba]

How is cell reselection in 3G? I know its not only field strength but quality as well,, please some experts share,, thanks in advance!

[justdream]

hai

Thanks to santhosji for this nice doc on seimens 900/1800.This is very help full to me as i am working on seimens Network.But i have a doubt how ti change value of C1 and C2 in siemens BSC or were could i find the Parameter in DBs.

Thanks
Plannerguy

please, reply upon this question?