RSRP（Reference Singnal Received Power，參考信號接收功率）是終端接收到的Cell-specific Reference Signal（CRS）功率值，數值爲測量帶寬內單個RE功率的線性平均值，反映的是本小區有用信號的強度。
RSRP levels for usable signal typically range from about -75 dBm close in to an LTE cell site to -120 dBm at the edge of LTE coverage.
RSSI（Received Singnal Strengthen Indicator，接收信號強度指示）接收信號強度指示。是指導頻符號上(一個包含有CRS的OFDM符號)總的接收功率在測量週期內的平均值。反應的是整個包含有CRS的OFDM符號的總功率。包括了有用信號，循環前綴，小區內干擾，鄰小區干擾，噪聲等。在本小區有業務時會增高，因爲PDSCH和PDCCH上面有數據在跑。RSSI的正常範圍是[-90dBm,-25dBm]
RSRQ（Reference Singnal Received Quality，參考信號接收質量）是N倍的RSRP與RSSI的比值，RSRQ=N*RSRP/RSSI,其中N表示RSRP的測量帶寬內包含的RB數目，能反映出信號和干擾之間的相對大小。
The reporting range of RSRQ is defined from -3…-19.5dB
SINR（Signal to Interference&Noise Ratio，信煩躁比）是有用信號功率與干擾和噪聲功率之和的比值，直接反映接收信號的質量。
如果要看RS-SNR
Click View --> New --> LTE --> Lower Layer1 --> LTE LL1 SNR CQI/RI MCS Display.
隨機接入的debug如下
服務小區的信號強度和質量可以在下面這個包看
0xB193 LTE ML1 Serving Cell Meas Response
2016 Dec 24 03:32:57.587 [30] 0xB193 LTE ML1 Serving Cell Meas Response
Version = 1
Number of SubPackets = 1
SubPacket ID = 25
Serving Cell Measurement Result
Version = 18
SubPacket Size = 96 bytes
E-ARFCN = 1825
Physical Cell ID = 448
Serving Cell Index = PCell
Is Serving Cell = 1
Reserved = 0
Current SFN = 804
Current Subframe Number = 8
Is Restricted = false
Cell Timing[0] = 39000
Cell Timing[1] = 39000
Cell Timing SFN[0] = 804
Cell Timing SFN[1] = 804
Inst RSRP Rx[0] = -90.38 dBm
Inst RSRP Rx[1] = -84.69 dBm
Inst Measured RSRP = -84.69 dBm
Inst RSRQ Rx[0] = -3.88 dB
Inst RSRQ Rx[1] = -3.56 dB
Inst RSRQ = -3.56 dB
Inst RSSI Rx[0] = -67.75 dBm
Inst RSSI Rx[1] = -62.38 dBm
Inst RSSI = -62.38 dBm
Residual Frequency Error = 0
FTL SNR Rx[0] = 11.40 dB
FTL SNR Rx[1] = 15.40 dB
Projected Sir = 8 dB
Post Ic Rsrq = 4294967266 dB
MSG1 is transmitted by the UE in (SFN, SN)(906, 7) and the response (i.e. MSG2) is expected to be received from the network between (SFN, SN)(907, 0) and (SFN, SN)(908, 0):
1980 Jan 6 00:08:22.903 [58] 0xB167 LTE Random Access Request (MSG1) Report
Version = 5
Preamble Sequence = 27
Physical Root Index = 46
Cyclic Shift = 767
PRACH Tx Power = -28 dBm
Beta PRACH = 242
PRACH Frequency Offset = 0
Preamble Format = 0
Duplex Mode = TDD
f_ra = 0
t_0_ra = Resource reoccurring in all radio frames
t_1_ra = RA resource in second half frame
t_2_ra = 0
Density Per 10 ms = 4
PRACH Timing SFN = 906
PRACH Timing Sub-fn = 7
PRACH Window Start SFN = 907
RACH Window Start Sub-fn = 0
PRACH Window End SFN = 908
PRACH Window End Sub-fn = 0
RA RNTI = 8
PRACH Actual Tx Power = -28
如果基站有收到上行的包就會在PHICH上給一個HARQ的ACK，如下圖的格式，這個圖是隨便找的，並不是按照上面所描述順序對應
the RACH attempt fails:
1980 Jan 6 00:08:22.918 [F9] 0xB062 LTE MAC Rach Attempt
Version = 1
Number of SubPackets = 1
SubPacket ID = 6
SubPacket - ( RACH Attempt Subpacket )
Version = 2
Subpacket Size = 36 bytes
RACH Attempt V2:
Retx counter = 1
Rach result = Failure at MSG2
Contention procedure = Contention Based RACH procedure
Msg1 - RACH Access Preamble[0]
Preamble Index = 27
Preamble index mask = Invalid
Preamble power offset = -90 dB
Msg2 - Random Access Response
Backoff Value = 0 ms
Result = False
TCRNTI = 56048
TA value = Not applicable
Later, the UE ramps up the PRACH Tx power and sends the MSG1, but still there is no response received from the network resulting in contiuous RACH failures:
1980 Jan 6 00:08:23.219 [62] 0xB062 LTE MAC Rach Attempt
Version = 1
Number of SubPackets = 1
SubPacket ID = 6
SubPacket - ( RACH Attempt Subpacket )
Version = 2
Subpacket Size = 36 bytes
RACH Attempt V2:
Retx counter = 19
**Rach result = Failure at MSG2**
Contention procedure = Contention Based RACH procedure
Msg1 - RACH Access Preamble[0]
Preamble Index = 6
Preamble index mask = Invalid
Preamble power offset = -54 dB
Msg2 - Random Access Response
Backoff Value = 0 ms
**Result = False**
TCRNTI = 56048
TA value = Not applicable