EGSM with Multiband Cell deployment

[icebreaker05]

Dear E// Experts,

Please could you tell me the possiblity of deploying EGSM(P + G1 Band) and 1800 with MBC. I would appreciate if you have actually deployed it in your own network.

Proposed Frequency Strategy
CHGR0 - P GSM BCCH Frequency
CHGR1 - Mixed P GSM/G1 GSM Band
CHGR2 - GSM 1800



Thanks and hope to hear from all of you.

[scumbie]

Dear E// Experts,

Please could you tell me the possiblity of deploying EGSM(P + G1 Band) and 1800 with MBC. I would appreciate if you have actually deployed it in your own network.

Proposed Frequency Strategy
CHGR0 - P GSM BCCH Frequency
CHGR1 - Mixed P GSM/G1 GSM Band
CHGR2 - GSM 1800



Thanks and hope to hear from all of you.

Hello ice,

Yes it can be done. However there are a few factors you need to consider:



What frequencies exactly you are using
The number of frequencies that you are assigning to each channel group
Are all the channels groups to be used at call setup(immediate assignment)


The maximum number of frequencies per cell is 128, but the number of frequencies per channel group is however limited to 32.

Now considering your scenario:

CHGR0 - P GSM BCCH Frequency- This is OK.

CHGR1 - Mixed P GSM/G1 GSM Band
if you are using more than 22 frequencies you have a range limit of 122 positions. Take a look at the attachment. Do not assign both ARFCN 975 and ARFCN 124 in CHGRs allowed for immediate assignment. Another thing which happened to me is on BSS 07B if you mix P GSM/G1 GSM Band in a CHGR you will need a patch from E******* for BlackBerry phones to use this CHGR. When the BSC attempts to assign this channel group to the BlackBerry the call will immediately fail, other phone works fine.

CHGR2 - GSM 1800 - this channel group cannot be considered at call setup set BCCD = No due to the range limit.

The Alex was a great help when I implemented this in my network. Do a search on hopping frequency.

Scumbie

[srilasitha]

Dear E// Experts,

Please could you tell me the possiblity of deploying EGSM(P + G1 Band) and 1800 with MBC. I would appreciate if you have actually deployed it in your own network.

Proposed Frequency Strategy
CHGR0 - P GSM BCCH Frequency
CHGR1 - Mixed P GSM/G1 GSM Band
CHGR2 - GSM 1800



Thanks and hope to hear from all of you.


1 if you plan to use EGSM band in TCH it is mandatory to use EGSM for BCCH

So you have to use EGSM for CHGR0

2 Mixing EGSM and PGSM frequencies would be OK if you don't use frequency hopping.
if you use frequency hopping with mixed MA list it will affect the handover performance and not advisable

3 for MBC site you can use CHGR 2 for GSM1800.

But when EGSM used as the BCCH , phone/equipment which doesn't support EGSM band (old phone models/ PABX modems) will loose the coverage

Be mindful of that

[icebreaker05]

Hello ice,

Yes it can be done. However there are a few factors you need to consider:



What frequencies exactly you are using
The number of frequencies that you are assigning to each channel group
Are all the channels groups to be used at call setup(immediate assignment)

The maximum number of frequencies per cell is 128, but the number of frequencies per channel group is however limited to 32.

Now considering your scenario:

CHGR0 - P GSM BCCH Frequency- This is OK.

CHGR1 - Mixed P GSM/G1 GSM Band
if you are using more than 22 frequencies you have a range limit of 122 positions. Take a look at the attachment. Do not assign both ARFCN 975 and ARFCN 124 in CHGRs allowed for immediate assignment. Another thing which happened to me is on BSS 07B if you mix P GSM/G1 GSM Band in a CHGR you will need a patch from E******* for BlackBerry phones to use this CHGR. When the BSC attempts to assign this channel group to the BlackBerry the call will immediately fail, other phone works fine.

CHGR2 - GSM 1800 - this channel group cannot be considered at call setup set BCCD = No due to the range limit.

The Alex was a great help when I implemented this in my network. Do a search on hopping frequency.

Scumbie


Hi Scumbie,
Have you tried this scenario. Yes, I'm aware of the BCCD and modulo 1024 requirements. Actually we are still about to deploy, just waiting for some features to be activated.
If you have tried this scenario, could you at least give me the problems that you have encountered, either KPI wise or subscriber perceived.

Thanks.

[icebreaker05]

1 if you plan to use EGSM band in TCH it is mandatory to use EGSM for BCCH

So you have to use EGSM for CHGR0

2 Mixing EGSM and PGSM frequencies would be OK if you don't use frequency hopping.
if you use frequency hopping with mixed MA list it will affect the handover performance and not advisable

3 for MBC site you can use CHGR 2 for GSM1800.

But when EGSM used as the BCCH , phone/equipment which doesn't support EGSM band (old phone models/ PABX modems) will loose the coverage

Be mindful of that

Hi srilasitha,

Could give some more details on your reply. Why is it mandatory to deploy EGSM on both TCH and BCCH. What if I'm planning for a 4 TRX,
CHGR0 - TRX 0 - BCCH @ P
CHGR1 - TRX 1 - TCH hopping@ P
CHGR2 - TRX 2 & 3 - TCH hopping @ G1 band
CHGR3 - GSM1800 TCH hopping


BR,

[scumbie]

Hi Scumbie,
Have you tried this scenario. Yes, I'm aware of the BCCD and modulo 1024 requirements. Actually we are still about to deploy, just waiting for some features to be activated.
If you have tried this scenario, could you at least give me the problems that you have encountered, either KPI wise or subscriber perceived.

Thanks.
Hello Ice,

Yes we have this implemented in our network. The only problem which we encountered was the issue with Blackberry phone outlined above. We were able to see improvements in call drop rate due to the fact we were able to use more hopping frequencies.


scumbie

[icebreaker05]

Hello Ice,

Yes we have this implemented in our network. The only problem which we encountered was the issue with Blackberry phone outlined above. We were able to see improvements in call drop rate due to the fact we were able to use more hopping frequencies.


scumbie


Good to hear that scumbie..i believe that your the expert i'm looking for to ask help. :). in any case, will it be possible for you to give me a printout of the frequency plan that you made. And some parameters that i should look out. It would be great if I can get a sample copy of your bsc dump if u will allow. Just for me to have familiarization on the common parameters. thanks to you in advance. i'll PM yuo with my email address. tnx.

BR,
ice

[srilasitha]

Hi srilasitha,

Could give some more details on your reply. Why is it mandatory to deploy EGSM on both TCH and BCCH. What if I'm planning for a 4 TRX,
CHGR0 - TRX 0 - BCCH @ P
CHGR1 - TRX 1 - TCH hopping@ P
CHGR2 - TRX 2 & 3 - TCH hopping @ G1 band
CHGR3 - GSM1800 TCH hopping


BR,

Cell frequency type is identified by MS from the BCCH. if the BCCH is PGSM then MS considers as cell is PGSM

EGSM is the larger set, it includes PGSM band as well. therefore identifying cell as EGSM would be OK. ( EGSM frequency specification in 3GPP came after PGSM specification)


Possible KPI degradations

1. TCH assignment success rate
2. incoming HO success rate

This issue is visible only in certain phone types.

if you dig throughly you will find more MS types with this issue

[chumav]

Hello,

On E******* BSS, The proposed configuration works fine as long as you don't mix PGSM and EGSM on the same Channel Group.

Cheers,

Chuma V.