3G to 2G Handover and Compressed Mode

[scorpion]

When a subscriber is moving out of 3G to 2G , after getting the target cell details The UE moves in to dedicated mode for re tuning in to GSM frequency. During that time what is the minimum bandwidth allotted in 3G network ?

When the phone tunes in to 2G lets assume that the target cell is configured with 2 DATA TCHs and can support GPRS & EDGE Coding then what will be the bw and what will be the coding scheme ?

[white_Noise]

there will be no data transmission over 2G in the compressed mode, it's called compressed cause the SF will turn to SF/2 when event 2D is triggered, which means you can
can transfer double the data rate so you can give the UE some time to tune to the GSM freq without any data transmission.

[esoestemp]

Another way of proceeding with Compressed mode is not scheduling data for this period.

After the HO to 2G, UE will gets resources according to his capability: multy slot capability(for example - 4/2; 5/1 for DL/UL); EDGE capability and depending of available resources/capability(EDGE supported or not) in the 2G cell.
MCS - The codding scheme(if all schemes are enabled) depends on radio conditions - better conditions means choosing of higher scheme.
MCS9(EDGE) is a higher and ideally with it can be carried 59.2 kbps per TS.
For pure GPRS - CS4 can carry max. about 20kbps.

P.S The throughput that the UE will reach of course depends also on how much UEs/MS are sharring the cell resources. If to UE are alocated 4 TS in DL, but if they are also alocated to 4 others UEs the throughput will be for example 5 times less .

[scorpion]

Thanks...

Then why they call it as compressed mode..instead something like No User Data mode..etc...

A pre topic query,,,When UE Sets a connection in 3G network how the RAB size is determines and what are all the metrics involved there ..SF/Spreadng code etc.. ?
What is the role os MSC/SGSN during such setup and what RNC will do ?
Who is the actual owner of RAB and who takes the decision on the size ?

[white_Noise]

Thanks...

Then why they call it as compressed mode..instead something like No User Data mode..etc...

A pre topic query,,,When UE Sets a connection in 3G network how the RAB size is determines and what are all the metrics involved there ..SF/Spreadng code etc.. ?
What is the role os MSC/SGSN during such setup and what RNC will do ?
Who is the actual owner of RAB and who takes the decision on the size ?

You need to do some reading to catch the basics buddy :) Good luck..