Wireless Oom » cell reselection

Cell reselection

wirelessoom — Mon, 15 Mar 2010 20:56:38 +0000

Here, for example, Squal <= Sintersearch in SIB3/4

Then, the UE starts to measure the signal strengths of neighboring cells.

Rs = Qmeas,s + Qhysts
Rn = Qmeas,n – Qoffset,n

Rs is for the serving cell and Rn is for neighbor cell.
Qhysts is for reduce ping-pong effects between serving and neighbor cells.
Qoffset,n is an offset parameter between the serving and the neighbor cells.

Pick the best cell with the largest R value.

Does cell reselection happen in CELL_DCH state?

wirelessoom — Tue, 09 Feb 2010 18:34:35 +0000

No.

In the CELL_DCH state, the UE does not make cell reselections as it does in all of the other states: instead, the UE moves from cell to cell using handover.

What for SIB 4?

wirelessoom — Sun, 26 Jul 2009 19:29:49 +0000

SIB 4

contains information on the cell selection and reselection parameters that the UE need to use in connected mode.

If SIB3 is not present it can be also be used for UEs in idle mode.

What for SIB 3?

wirelessoom — Sun, 26 Jul 2009 19:28:15 +0000

SIB 3

contains information on the cell selection and reselection parameters that the UE need to use in idle mode.

If SIB4 is not present it can be also be used for UEs in connected mode.

What is cell reselection?

wirelessoom — Wed, 24 Jun 2009 06:35:05 +0000

When camped on a cell, the UE regularly search for a better cell according to the cell reselection criteria. If a better cell is found, that cell is selected.