Bugzilla – Full Text Bug Listing |
Summary: | A UE should not synchronize with an eNB if its RSRP is lower than -140 dBm | ||
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Product: | ns-3 | Reporter: | Zoraze Ali <zorazeali> |
Component: | lte | Assignee: | Biljana Bojović <bbojovic> |
Status: | NEW --- | ||
Severity: | enhancement | CC: | mmiozzo, ns-bugs |
Priority: | P5 | ||
Version: | ns-3-dev | ||
Hardware: | PC | ||
OS: | Linux | ||
Attachments: |
Example script
RSRP table Patch |
Created attachment 3236 [details]
RSRP table
Created attachment 3237 [details]
Patch
Attached is the patch inline with my proposal.
After applying the patch the UE RRC state will stay in IDLE_CELL_SEARCH until the RSRP of the cell is greater than -140 dBm. |
Created attachment 3235 [details] Example script Hi, I noticed that a UE synchronizes with the eNB, i.e., read MIB and SIB1 messages even if its RSRP is below the minimum RSRP level (-140 dBm). I think it is unnecessary to synchronize with a cell whose RSRP is below -140dBm. This is also in line with the S-criterion (qRxLevMeas - qRxLevMin > 0) condition in LteUeRrc::EvaluateCellForSelection (), where qRxLevMeas is the RSRP of the cell and qRxLevMin is the minimum RSRP required to camp on a cell. As per table 9.1.4-1 in 3GPP TS36133 the minimum RSRP level which a UE can report is -140 dBm. I am attaching a sample script to support my point. The scenario consists of one eNB and one UE, which is placed at 20000 m away from the eNB. One could see that the UE RRC state transitions from: IDLE_CELL_SEARCH to IDLE_WAIT_MIB_SIB1, and then to IDLE_WAIT_SIB1 and then from: IDLE_WAIT_SIB1 to IDLE_CELL_SEARCH because of the cell RSRP level, which fails to fulfill the S-criterion (qRxLevMeas - qRxLevMin > 0) in LteUeRrc::EvaluateCellForSelection (). I propose that a UE should only synchronize with a cell if its RSRP is greater than -140 dBm. Kind regards, Zoraze