Ans:

 Probable reasons for poor Uplink Quality
1. Poor Frequency plan (TCH)
2. Interference in UL
3. Overshoot of neighboring cells.
4. Poor Level on the UL.
5. Fault in TCH TRX
6. Codec issues.
7. Transmission related issues.
8. Boosters/Repeater related issues.
9. External interferences – Restricted area/Electronics equipment Factory/Jammers.


Uplink Quality Checkpoints
1. Poor Frequency Plan
a. Always resolve DL quality issues before attempting to correct the UL.
2. Interference in UL
a. Avoid using Co & adjacent TCH frequencies in the same cell or site.
b. Avoid using co TCH on neighboring cells.
c. Wrong values of the HSN or MAIO/MAIO Offset.
i. Do not reuse HSN in nearby sites.
ii. Review MAIO & MAIO Offsets as per the TCH plan(1x1, 1x3, adhoc etc).
d. In cases where intra-cell handovers are allowed, interference will cause a lot of intra-cell handovers thus degrading the UL & DL quality
3. Overshooting of neighboring cells.
a. TCH reuse becomes tight is there’s a lot of overshooting of nearby cells. Allow only 1 or up to 3 dominant servers only.
b. Reduce the overshooting of neighboring cells.
4. Poor level on the uplink
a. Possible coverage problem.
b. Rx Level Versus Rx Quality distribution per TRX on a cell.
c. TMA’s can be used judiciously used to enhance UL level.
5. Fault in TCH TRX
a. Check the alarm printouts.
b. (BTS UL Quality history at 24 Hour/10 day resolution). Check if the BTS is within defined interference boundary limits & for how long it has been out of limits of acceptable interference.
c. BTS Analyzer. Check if the BTS is within defined interference boundary limits.
d. Path balance for TCH TRXs

6. Codec Issues
a. AMR related quality issues.
b. AMR related parameter settings. Check if the Codec (AMR/Non-AMR) settings are OK.
c. Check if the BTS s/w version is OK & supports the codec.
d. If the problem is with many sites in a BSC then that BSC’s parameter file needs to be checked/updated.
7. Transmission related issues.
a. Check the BSC ET availability & Quality profile .
b. Check the TCSM ET availability and quality,.
c. Check the QOS
8. Boosters/Repeater related issues.
a. Check for repeaters and/or booster installations. Check for spillage of the repeater signals in areas not intended to be covered.
b. If repeaters are a problem( you will know once you switch off the repeater for a short duration), adjust the gain of repeater
c. Adjust the repeater antenna & orient it to closest serving cell. DO NOT latch a repeater with a DISTANT dominant cell.
9. External Interferences
a. If you suspect external interference on single TRX, lock the TRX & see if the problem persists. If the problem is resolved then the TRX or its implementation is at fault.
b. If you suspect external interference on the entire site, Lock the site & scan the area served by the site for potential interferers. Somebody may be transmitting the same frequencies in the serving area of affected site.
c. Workaround: If you indeed found an interferer over which you have no control, try allocating a different frequency (beyond 2 MHz). There’s a high probability that the frequency which is being severely interfered now will no longer be interfered after frequency change.

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Vacancy: Senior 3G RNO Engineer, Location: Sub Saharan Africa

Please click on the link below to apply for this position or email your CV to amckeirnan@firstpointgroup.com 

Start date: ASAP 
End date: 12 months 

Job description: 

• Monitor & analyze the WCDMA/HSPA Radio Network Statistics on daily basis 
• Achieve & maintain the Radio Network Performance as per the contracted KPIs (Accessibility, Retainability, and Mobility & Service Integrity) 
• Responsible for reducing congestion and drops, improving the IRAT Handover, Soft Handover, Location Update, Paging, CSSR, RRC Connection & RAB Establishment Success rate in the 3G RAN network for all Voice, Video Packet & High Speed 
• Issuing capacity upgrade requests whenever needed • Responsible for the drive test analysis and taking the necessary action to improve the performance of his geographical area 

Requirements: 

• Strong knowledge with (UETR, UEH, and GPEH) traces, parsing and analysis and comfortable to work with it on daily basis 
• Evaluate and adapt new methods and technologies regarding Radio Network Optimization, Features, and Trials & Tuning 
• Good knowledge with the use of MS office,Mapinfo, TCPU (Tems cell planner universal), Drive test analysis and TEMS investigation drive test analysis 
• Must have good knowledge with SecureCRT, MOSHELL, Comand Prompts, OSS, Nexplorer
http://www.firstpointgroup.com/job/senior-3g-rno-engineer-jobid-fpg4099

 

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Ans:

 For telecom engineers, it is very help full to know about MAIO. Basically there is a set of frequencies where the channels are hop to avoid interference that set of frequencies is called MA-LIST. suppose MALIST contained frequencies [A,B,C,D,E,F,G,H,I,J,K,L].
Then MAIO corresponds the starting point of hopping sequence. suppose there are four TRx in one sector. then MAIO will be, for example, 0,2,4.
for first TRx for traffic, the MAIO is 0. means that hopping sequence starts from first frequency in the MALIST, that is frequency A. and for MAIO 2 it starts from frequency C and for MAIO 4 it starts from frequency E.

Also HSN (hopping sequence number), ranges from 0 to 63 . if we use HSN as, for example 4 it means that for MAIO 0, the sequence starts from frequency A and repeats frequencies in following manner.

For MAIO 0 and HSN 4
A,F,K,D,I,B,G,L,E,J,C,H,A,F

For MAIO 2 and HSN 4
C,H,A,F,K,D,I,B,G,L,E,J,C,H

For MAIO 4 and HSN 4
E,J,C,H,A,F,K,D,I,B,G,L,E,J

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