O SlideShare utiliza cookies para otimizar a funcionalidade e o desempenho do site, assim como para apresentar publicidade mais relevante aos nossos usuários. Se você continuar a navegar o site, você aceita o uso de cookies. Leia nosso Contrato do Usuário e nossa Política de Privacidade.
O SlideShare utiliza cookies para otimizar a funcionalidade e o desempenho do site, assim como para apresentar publicidade mais relevante aos nossos usuários. Se você continuar a utilizar o site, você aceita o uso de cookies. Leia nossa Política de Privacidade e nosso Contrato do Usuário para obter mais detalhes.
After BSC sends ASSIGN CMD, BTS transmits it transparently to MS, and abnormalities occur: 1. MS fails to receive the assignment command (ASSIGN CMD) or the UA frame from BTS. 2. BTS fails to receive SABM frame or assignment completed message (ASSIGN COMP) from MS, this causes assignment failure. The signaling analyzer can be used to analyze the cause of assignment failure of Abis interface message.
When hardware installation causes the unbalanced uplink and downlink level and TCH congestion. 1. Uplink flow: antenna --&gt;tower amplifier--&gt;feeder--&gt;lightning arrester--&gt;rack-top connector--&gt; CDU--&gt;TRX board. The error with RF cable causes the uplink level difference. Maybe the connector is not tight. 2. Downlink flow: TRX --&gt; CDU--&gt;rack-top connector--&gt;lightning arrester--&gt;feeder--&gt;antenna VSWR alarm occurs to the transmitting tributary of antenna feeder . The RF cable is twisted or the connector is not tight The error of cell antenna connection leads to the differences in the coverage, thus causing TCH congestion.
Processing principles: 1. If the congestion rate are related to the blocked TRX, check whether there is interference, check the performance of uplink and downlink. 2. If the congestion rate is not related to TRX, interference may exist in the whole cell or the propagation environment.
After all assignment failures are found on a specific TRX board, take the following into consideration: 1. MS TA value in the measurement report. 2. Uplink/downlink signal level. 3. Uplink/downlink signal quality. Analyze the causes for a certain assignment failures , and dialing test should be performed on-site.
1. According to the TEI values shown in the diagram, the TRX containing this SDCCH can be identified. 2. With the ARFCN, the TRX containing this TCH can be identified.
The way for on-site dialing test: 1. Carry out dialing test at each carrier and each channel, to check whether any timeslot or board can not be assignable. 2. Check whether the downlink levels of all carriers are nearly the same. For TRX with significantly abnormal level, the cause can be located step by step through changing the board or uplink/downlink antenna & feeder system.
The number of uplink reports of the first three TRXs in cell 5 under module 1 differs greatly from that of the last three TRXs. It can be seen that the uplink signal level of the last three TRXs is obviously lower than that of the first three TRXs. The level values corresponding to the receiving level grades are as follows: Grade 0 : -110~ -100 dBm Grade 1 : -100~-95 dBm Grade 2 : -95~-90 dBm Grade 3 : -90~-80 dBm Grade 4 : -80~-70 dBm Grade 5 : ＞ -70 dBm
From the TCH congestion rate (including handover) formula (refer to Page 6), we can see that it’s necessary to register the “Incoming Inter Cell Handover Measurement Function” and to analyze which cells fail on TCH seizure during handover.
Note: SDCCH congestion related to attempted SDCCH seizures meeting a SDCCH blocked state, this is different from TCH congestion. Attempted SDCCH seizures meeting a SDCCH blocked state refer to no SDCCH available. It is different from SDCCH seizure failure which includes attempted SDCCH seizure meeting a SDCCH blocked state, unsuccessful channel activation (NACK) and channel activation timeout (timeout)
Attempt SDCCH seizures measurement point: after BSC receives Channel Required. Attempted SDCCH seizures meeting a SDCCH blocked state measurement point: BTS finds no SDCCH channel available and cannot activate channel.
Omf000405 alálise de casos congestionamento versão1.4