Location Area Update in DEDICATED mode

[rajmeena06]

Dear All Members of Finetopix,

I have a doubt in my mind pl help me 2 clarify it.

Is location update is possible in dedicated mode, if not then how call waiting procedure can work b/c when you are in dedicatd mode & some 1 is calling you so incoming call needs current LAC.

[danikd]

Dear All Members of Finetopix,

I have a doubt in my mind pl help me 2 clarify it.

Is location update is possible in dedicated mode, if not then how call waiting procedure can work b/c when you are in dedicatd mode & some 1 is calling you so incoming call needs current LAC.

Everything is pretty simple

The location area used for paging once mobile is in Idle Mode.
Location area is a VLR related property. Just to remind you Idle Mode Mobility Management performed by mobile itself (cell selection/reselection) and by VLR (routing of incoming calls - paging).
In Idle Mode the mobile's position is known per Location Area resolution (this is right for GSM and UMTS).
Once mobile engaged in connection (GSM active mode or UMTS RRC mode), then mobile's position known with per cell resolution and controlled by BSC or RNC (GSM and UMTS respectively).
The core network also handling this connection and fully aware which cell under which BSC/RNC handling specific connection. There is no paging send from core network once mobile in connected mode and just supplementary service (call waiting is activated and DTAP signalling sent from MSC/VLR to mobile).This how MTC (Mobile terminated calls handled in Active (Connected) mode. If during the call mobile crossed the LA's border, then the LA update will be performed only after finishing the call once mobile will be again in Idle Mode.

[rajmeena06]

Thanks Sir.

[rajmeena06]

Dear All,

well this forum help us in understanding Telecom and give us new things to Learn.i Would like to all Memebers of Finetopix.
Sir There is One More Question:-
As we Know we use speech coding H/R,F/R,EFR.
why we not use 1/3,1/4....Plz Suggest.

[gilver123]

It is not critical to have a location update when mobile is busy, since the network now knows the mobile location to a finer granularity. Location update is done once the MS goes to idle mode.

[rajmeena06]

Dear All,

well this forum help us in understanding Telecom and give us new things to Learn.i Would like to all Memebers of Finetopix.
Sir There is One More Question:-
As we Know we use speech coding H/R,F/R,EFR.
why we not use 1/3,1/4....Plz Suggest.

Dear Location Area Probleum is Resolved,I want Know the Answer of above question.

[gilver123]

Yes, we do have AMR which supports rates from 4.75 kbps to 12.2 kbps. This should account for all the different fractions you seem to suggest.

[danikd]

Dear Location Area Probleum is Resolved,I want Know the Answer of above question.

I'm not fully understand what do you mean by 1/3 and 1.4 codec.

Do you mean AMR FR/HR?

Please, clarify

[rajmeena06]

I mean to say ,is this possible to run 3-4 calls on same time slot.If yes then how it is possible.

[rajmeena06]

In same duration.

[danikd]

I mean to say ,is this possible to run 3-4 calls on same time slot.If yes then how it is possible.

Gotcha!!!!

The answer will be NOT!!!

Now some explanation and motivation:
1. There are 3 vocoder types were standardized by 3GPP (ETSI before):
SV1 - Full Rate and Half Rate
SV2 - Enhanced Full Rate
SV3 - Adaptive Multi Rate Full and Half

2. The vocoder rate and their efficiency significantly affects the actual voice quality i.e. lower vocoder rate produce lower quality voice. (just for your imagination - MP3 (codec) can generate bit rate 320kbps as well 32kbps, but 32kbps bit rate coded music.....could not be called music)

3. Current full rate codecs generating bit rate of ~12kbps with MOS close to 4, while half rate codecs (even AMR HR) generating ~4.5-7kbps bit rate with voice quality below MOS 3.5 which is rather bad, especially for languages where sounds tones are significant (Vietnamese, Chinese and come other eastern languages).

4. Why not to put more voice connections on the same physical timeslot? The maximal payload throughput of single physical timeslot is 13kbps and this structure is fixed and can not be changed.
Now you can count that only up to 2 voice connections can share single physical timeslot. As I mentioned in 3 - making more voice compression is useless due to significant losses in voice quality.

Conclusions - Single physical timeslot in GSM can handle single voice connection with FR or EFR or AMR FR vocoders. Or it can be 2 voice connections with HR or AMR HR vocoders per single physical timeslot.

Hope this was clear.

[nayeemuddinkhadri]

Dear All Members of Finetopix,

I have a doubt in my mind pl help me 2 clarify it.

Is location update is possible in dedicated mode, if not then how call waiting procedure can work b/c when you are in dedicatd mode & some 1 is calling you so incoming call needs current LAC.

Hi dear,
As the mobile is in dedicated mode, your mobile is not at all paged and the call waiting come through sacch. Yes location updated is possible in dedicated mode also( For every 120ms sacch comes for one user & after every 3 sacch, in the fourth turn Location update happens) and to sum up location update happens in dedicated mode for every 480ms.

[plannerguy]

Hi

4 calls supported in OSC Technology of NSN


Regards
Plannerguy