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RED

Hi Martin,

Do you know in which areas T-Mobile has upgraded the networks to NOM I? I'd believe that the upgrade wasn't cheap... wouldn't make a lot of sense if they already have UMTS coverage in these areas...

Also, do you know if T-Mobile is the only operator that is interested in DTM? I think they offer the DTM in their US market too

Martin

Hello Red,

no, I don't know, I've just observed it where I live. I don't think that it has cost a lot since NOM I means installing a signaling connection in the core network between the MSCs and the SGSNs and to activate the functionality in the core and access networks. The functionality itself has been available in the software for some time so I don't think it has been a huge step.

I think it is useful to have GPRS NOM I in areas with UMTS coverage as UMTS to GSM cell reselection speed benefits.

Not sure if you are mixing up NOM I with DTM. DTM = Dual Transfer Mode, i.e. phone calls + GPRS simultaneously. DTM and NOM-I have nothing to do with each other. I haven't heard of any operator that has introduced DTM yet. Also, there aren't a lot of mobiles supporting DTM yet. Noteworthy exceptions seem to be the latest Nokia N-series mobiles such as the N73, N93i, N95, etc.

Cheers,
Martin

Srinu

Hello Martin,

Suppose i ve a mobile which support either PS or CS at a time(not DTM), i.e, if PS call is initiated and receive a CS call later, then PS gets paused and gives priority to CS. To send paging for CS call network should operate in NMO-1, am i correct? Will there be any difference if i use Vodafone (NM0-2) or T-mobile (NMO-1)in this particular scenario?

Martin

Hello Srinu,

In NMO-I, CS paging is performed via the SGSN and PCU for GPRS attached mobiles. In NMO-II, CS paging is done via the BSC. If a mobile is not GPRS attached, CS paging is done via the BSC in both operation modes.

Cheers,
Martin

Martin

Hello Srinu,

In NMO-I, CS paging is performed via the SGSN and PCU for GPRS attached mobiles. In NMO-II, CS paging is done via the BSC. If a mobile is not GPRS attached, CS paging is done via the BSC in both operation modes.

Cheers,
Martin

mrinmoy

Hi Martin,
Regarding paging for CS service( Voice) as you said it will be done via BSC in NMO-II if mobile is GPRS attached.
Can you please explain how will it page mobile for voice call in NMO-II,
case 1: mobile is idle
case 2: PDP is active but , but no data transer
case 2: mobile is busy doing packet transfer

Will apprecite your help in clarifying my doubts.
-Mrin

Srinu

Hi Mrinmoy,

As per my understanding, i answer u.

NMO - 2 (SGSN and MSC are not interconnected, so SGSN have no idea of incoming call info from MSC)
Case 1: Mobile is Idle
---It gets Paged for Incoming call

Case 2: PDP active, but idle
Case 3: Active Data transfer

For Case 2 n 3, Mobile is attached to PS services, so it wont get paged for incoming calls.

Please let me know i am not right

-Srinu

Martin

Hi,

In case 1 and 2 the mobile will see the paging and accepts the voice call. Only case 3 is critical since the paging is done but not noticed by the mobile. Hence the call is missed.

Cheers,
Martin

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