GSM Query

[aosan]

Dear all,

I have these questions regarding GSM Technology and need your help

1- is it possible to operate 1900MHZ band as GSM operatpr?
2- How many Erl can one BTS with three sector and 2 channel support?
3- if Ihave 1,000,000 million Sub and 5MHZ of 1900MHZ band then how many BTS do I need to provide a good voice service assuming using two channel with three sector BTS?
4- what is the minimum required Spectrum BW in GSM? is it 5M or 10M....

why I am asking these questions because our CDMA company with 1900MHZ band want now to enter GSM filed and really need these information and any other help/deument on how to calculate GSM budget

Thanks alot for your help

[kaizzer545]

we are at the same... and I can tell u this:

1)yes it is possible, I mean at least in our company

2)I try to understand this question like capability, and it depends of hoy many channels you assign like TCH for CS services (does your services are Half-rate or full rate?), including Signaling Channels

3)It depends.. i think mainlly on the config of each sector how many TCH you have..

4)I have understand that is 5M, please somebody confirm to me

3)

[telwind]

to have answer all these you need to prepare many input in practice. some sample answer:

1- is it possible to operate 1900MHZ band as GSM operatpr?

in term of technical, it should be. question is not sure easy to find the handset support this band like other bands.

2- How many Erl can one BTS with three sector and 2 channel support?

there are several requirement you need to answer this question like BTS configuration (# of TRXs, half rate %, AMR), QoS (normal 2% blocking rate)

two TRX you may config with 14 TCH, give 14.9 Erl at 2% blocking.

3- if Ihave 1,000,000 million Sub and 5MHZ of 1900MHZ band then how many BTS do I need to provide a good voice service assuming using two channel with three sector BTS?

how many erl/sub is required? QoS exactly blocking rate? in the practical industry, the coverage requirement should be addressed too.

4- what is the minimum required Spectrum BW in GSM? is it 5M or 10M....

no idea about this, gsm channel requires 200k, more spectrum band more capacity you get. you also need some guardband to adjacent operators' band.

why I am asking these questions because our CDMA company with 1900MHZ band want now to enter GSM filed and really need these information and any other help/deument on how to calculate GSM budget

Thanks alot for your help[/QUOTE]

[aosan]

to have answer all these you need to prepare many input in practice. some sample answer:

1- is it possible to operate 1900MHZ band as GSM operatpr?

in term of technical, it should be. question is not sure easy to find the handset support this band like other bands.

2- How many Erl can one BTS with three sector and 2 channel support?

there are several requirement you need to answer this question like BTS configuration (# of TRXs, half rate %, AMR), QoS (normal 2% blocking rate)

two TRX you may config with 14 TCH, give 14.9 Erl at 2% blocking.

3- if Ihave 1,000,000 million Sub and 5MHZ of 1900MHZ band then how many BTS do I need to provide a good voice service assuming using two channel with three sector BTS?

how many erl/sub is required? QoS exactly blocking rate? in the practical industry, the coverage requirement should be addressed too.

4- what is the minimum required Spectrum BW in GSM? is it 5M or 10M....

no idea about this, gsm channel requires 200k, more spectrum band more capacity you get. you also need some guardband to adjacent operators' band.

why I am asking these questions because our CDMA company with 1900MHZ band want now to enter GSM filed and really need these information and any other help/deument on how to calculate GSM budget

Thanks alot for your help


- Suppose to have 2TRX +50% half rate+amr+QoS 2% with BTS three sectors what will be the total Erl that the BTS can support with 25mErl for sub? and what will be if using all the time Full rate.

- 50% half rate +GPRS/EDG serves dose this will effect the voice capacity?

[telwind]

- Suppose to have 2TRX +50% half rate+amr+QoS 2% with BTS three sectors what will be the total Erl that the BTS can support with 25mErl for sub? and what will be if using all the time Full rate.

2TRXs give 14 TCHs (1 for BCCH, 1 SDCCH), with 50% HR then you have 19 TCHs (HR) -> 12.33Erl/sector at 2% -> 37Erl/Site

1Msubs of 25mErl -> 25,000Erl

=> required 676 sites

for all FR, Erl/sector decreasing equals to increasing site (50%), total 1,017 sites

- 50% half rate +GPRS/EDG serves dose this will effect the voice capacity?

yes, the effect depends on how you design the PDCH to carry GPRS/EGDE traffic by dedicated or on-demand.

[kaizzer545]

sorry, telwind but i misunderstand how you get the total Erlan, please explain me

BR

[telwind]

sorry, telwind but i misunderstand how you get the total Erlan, please explain me

BR

Sample guy, 1,000,000 sub x 0.025Erl/sub = 25,000 Erl

[kaizzer545]

Hi Master, this is me again, could you explain me detailed how you get 19TCH (i'm not so engaged with Half rate) and why 12.33 Erl, aditional to tjis how you get 0.023Erl, thanks
2TRXs give 14 TCHs (1 for BCCH, 1 SDCCH), with 50% HR then you have 19 TCHs (HR) -> 12.33Erl/sector at 2% -> 37Erl/Site
1,000,000 sub x 0.025Erl/sub = 25,000 Erl

[telwind]

Hi Master, this is me again, could you explain me detailed how you get 19TCH (i'm not so engaged with Half rate) and why 12.33 Erl, aditional to tjis how you get 0.023Erl, thanks
2TRXs give 14 TCHs (1 for BCCH, 1 SDCCH), with 50% HR then you have 19 TCHs (HR) -> 12.33Erl/sector at 2% -> 37Erl/Site
1,000,000 sub x 0.025Erl/sub = 25,000 Erl

As you plan 50% HF then from 14 TCH so the best choice is 9 TCH FR + 5 TCH for HR, or 8 TCH FR + 6 TCH HR. First choice gives you 9+5*2 = 19 TCH. HR/FR in GSM is GSM standard, you need to read GSM standard if you want to understand fully.

19 TCH give 12.33 Erl, simply lookup on erlang table or here http://www.finetopix.com/mapping-tools/11038-traffic-calculator-excel-tool.html I've posted the excel tools for traffic calculation. traffic engineering will help understand fully.