RLF and OOS

Radio Link Failure (RLF)

RLF is declared only in connected mode when the link goes bad;
> QXDM events are best way to pin-point RLF occurrences and their cause;
> RLF can happen for multiple reasons. Examples are: 
    >> Physical Layer Failure if hypothetical out-of-sync BLER>10% for T310 s (B129, B18A);
        >>> Hypothetical BLER is computed from SNR estimate from RLM;
        >>> RLF is only related to SNR of RS tones and is unrelated to Serving RSRP level;
    >> RACH failure after RRC connection request (B167, B168, B169, B16A, B061);
    >> RLC max re-transmissions limit reached ;
    >> Demapper recovery (Event ‘Internal’);

Out of Service (OOS)

> OOS is declared only in idle mode ;
> OOS is declared if Serving RSRP < 2 * Qrxlevmin dB;
> Qrxlevmin is signaled in SIB1, and is typically around -65;
> After the UE enters OOS, the UE goes through acquisition attempts, LFS and FFS until a new cell can be found.