Reason for TCH DROP in GSM Network

-

·         The parameters SACCH Multi-Frames and Radio Link Timeout are set to too small values.
·         The parameter RXLEV_ACCESS_MIN is set to a too small value.
·         The parameter RACH Min.Access Level is set to a too small value.
·         The parameters Min DL Power on HO Candidate Cell and Min Access Level Offset are inappropriately set.
·         The length of timer T3103 (this timer is set to wait for a Handover Complete message) is set to a too small value.
·         The length of timer T3109 (this timer is set to wait for a Release Indication message) is set to a too small value.
·         The length of timer T3111 (this timer specifies the connection release delay) is set to a too small value.
·         The length of timer T305/T308 is set to an invalid or too great value.
·         The parameter TCH Traffic Busy Threshold is set to a too small value.
·         The parameter Call Reestablishment Forbidden is set to Yes.
·         The parameters related to edge handover are inappropriately set.
·         The parameters related to BQ handover are inappropriately set.
·         The parameters related to interference handover are inappropriately set.
·         The parameters related to concentric cell handover are inappropriately set.
·         The parameters related to power control are inappropriately set.
·         T200 and N200 are set to too small values.
·         Some neighboring cell relations are not configured.
·         The parameter MAIO is inappropriately set.
·         The parameter Disconnect Handover Protect Timer is set to a too small value.
·         The parameter TR1N is set to a too small value.
·         The parameters Software Parameter 13 and MAX TA are set to too small values.
·         If a repeater is used, the parameter Directly Magnifier Site Flag is set GSM BSS Network KPI (TCH Call Drop Rate) Optimization Manual INTERNAL to No
·         Drop due to hardware issue (Faulty, VSWR, ICM, Mismatch combining & Alarm)
·         Drop due abis link error or high abis link UTL.
·         Drop due to Co-Channel interference or due to poor Qual UL & DL.
·         Drop due to poor level UL & DL or due to High TA.
·         Drop due to HO Delay.
·         Drop due to Poor Antenna installation.

·         Drop due to poor path Imbalance ( UL & DL)

Popular posts from this blog

SCFT - Single Cell Function test

-
Single Cell Function test SCFT is for verifying whether individual BTS works well or not, by making a single cell function test of BTS hardware and software. Essential items to be tested are as follows: 1) BTS Transmitter Output Measurement Test 2) Initial parameter establishment (Pilot PN/System ID/Site ID/Frequency, Neighbor List) 3) Call Origination and Termination Test 4) Softer Handoff Test/Antenna installation check (Direction, Tilt, Transmission Line) 5) Single Cell Coverage Test 6) Noise Floor Test 7) Parameter check.
Read more

Troubleshooting for GSM KPIs (SD Block & SD Drop)

-
KPIs to be monitored: ·             SD Blocking ·             SD Drop SDCCH Channel: ·    SDCCH channel is a dedicated channel which is using for LAC updation, Call Setup, SMS in Ideal mode. It works in UL & DL SD Blocking: ·    SD Blocking means that you are not getting SD resource for the call origination. When MS connects with Network then RACH and AGCH are provided. After AGCH, SDCCH is provided but if SDCCH is not provided at this time due to some problem or due to unavailable of SD by BSC. KPI Formula in Ericsson: ·             SDCCH CONGESTION = (CCONGS / CCALLS) * 100 ·             CCONGS - Congestion counter. ·  ...
Read more

PS core network

-
Image
The PS core network consists of two parts, the traditional General Packet Radio Service (GPRS) core network and the new Evolved Packet System (EPS) core network. The PS core network connects mobile subscribers to Packet Data Networks (PDNs) such as the Internet, corporate networks or operator services networks.  a functional overview of the PS core network. Logical entities and interfaces are shown in black and form a 2G/3G network, while the blue boxes and lines in Figure  show the LTE/EPC related parts. The LTE/EPC network can be regarded as an extension and evolution of existing 2G/3G networks. From a node implementation perspective, there is no strict border between the two networks. The corresponding logical entities of GPRS and EPS networks can be deployed concurrently in Ericsson PS core nodes, such as the SGSN-MME and EPG; these are marked in red. In addition, Ericsson GPRS nodes can be upgraded with EPC functionality by software only. Network evolution i...
Read more