HUAWEI TECHNOLOGIES CO., LTD.
www.huawei.com
Huawei Confidential
Security Level:2008-11-3
How to Analyze Crossed Feeder
Is...
Outline
• What is crossed feeder issue
• The problems raised by crossed feeder issue
• How to detect crossed feeder issue ...
HUAWEI TECHNOLOGIES CO., LTD. Page 3Huawei Confidential
What is crossed feeder issue (1)
The term crossed feeder is used t...
HUAWEI TECHNOLOGIES CO., LTD. Page 4Huawei Confidential
What is crossed feeder issue (2)
The crossed feeder problem would ...
HUAWEI TECHNOLOGIES CO., LTD. Page 5Huawei Confidential
What is crossed feeder issue (3)
There are server types of crossed...
HUAWEI TECHNOLOGIES CO., LTD. Page 6Huawei Confidential
The problems raised by crossed feeder issue
Crossed Feeder Situati...
HUAWEI TECHNOLOGIES CO., LTD. Page 7Huawei Confidential
The problems raised by crossed feeder
issue
Crossed feeder will ra...
HUAWEI TECHNOLOGIES CO., LTD. Page 8Huawei Confidential
How to detect crossed feeder issue by DT
Crossed transmit feeders
...
HUAWEI TECHNOLOGIES CO., LTD. Page 9Huawei Confidential
How to detect crossed feeder issue by DT
In the example shown abov...
HUAWEI TECHNOLOGIES CO., LTD. Page 10Huawei Confidential
How to detect crossed feeder issue by DT
Crossed receive feeders
...
HUAWEI TECHNOLOGIES CO., LTD. Page 11Huawei Confidential
How to detect crossed feeder issue by DT
Crossed receive feeders
...
HUAWEI TECHNOLOGIES CO., LTD. Page 12Huawei Confidential
How to detect crossed feeder issue by DT
Crossed transmit and rec...
Thank you
www.huawei.com
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Presnetatipn rf

LTE
Published on: Mar 4, 2016
Published in: Engineering      
Source: www.slideshare.net


Transcripts - Presnetatipn rf

  • 1. HUAWEI TECHNOLOGIES CO., LTD. www.huawei.com Huawei Confidential Security Level:2008-11-3 How to Analyze Crossed Feeder Issue by DT
  • 2. Outline • What is crossed feeder issue • The problems raised by crossed feeder issue • How to detect crossed feeder issue by DT
  • 3. HUAWEI TECHNOLOGIES CO., LTD. Page 3Huawei Confidential What is crossed feeder issue (1) The term crossed feeder is used to describe the problem that arises when the feeders for two or more sectors in a site are inadvertently connected incorrectly. For Example, consider a new cell site that has three sectors, A, B, and C:
  • 4. HUAWEI TECHNOLOGIES CO., LTD. Page 4Huawei Confidential What is crossed feeder issue (2) The crossed feeder problem would arise if the feeder for sector A is connected to sector C and vice versa. When this happens, the sectors typically continue to provide good coverage. However, the network parameters for the two sectors are also reversed. For example, the parameters storing the sectors' BCCH and lists of adjacent sectors would be swapped. For example, suppose we run a drive test through the area served by the cell whose feeders are crossed display the ServBCCH attribute on the Map while the cell sectors are colored by BCCH. This is what we might see:
  • 5. HUAWEI TECHNOLOGIES CO., LTD. Page 5Huawei Confidential What is crossed feeder issue (3) There are server types of crossed feeder: Crossed transmit feeders Crossed receive feeders Crossed transmit and receive feeders
  • 6. HUAWEI TECHNOLOGIES CO., LTD. Page 6Huawei Confidential The problems raised by crossed feeder issue Crossed Feeder SituationNormal Situation
  • 7. HUAWEI TECHNOLOGIES CO., LTD. Page 7Huawei Confidential The problems raised by crossed feeder issue Crossed feeder will raise many problems, such as: A greater degree of interference A poor uplink signal strength A poor performance of handover
  • 8. HUAWEI TECHNOLOGIES CO., LTD. Page 8Huawei Confidential How to detect crossed feeder issue by DT Crossed transmit feeders Crossed transmit feeders will result in the swap of 2 or more sectors BCCH frequency and TCH’s. As the sectors are pointing in the incorrect direction, performance will suffer as the frequency plan has been changed and a greater degree of interference will be present. In DT, we will find that the handset receives the single which shouldn't have been received in the current cell.
  • 9. HUAWEI TECHNOLOGIES CO., LTD. Page 9Huawei Confidential How to detect crossed feeder issue by DT In the example shown above, point A is in the area of coverage of Cell D3, but the handset at point A receives the stronger signal of Cell D2. It indicates that TX feeders were crossed between Cell D3 and Cell D2. Crossed transmit feeders
  • 10. HUAWEI TECHNOLOGIES CO., LTD. Page 10Huawei Confidential How to detect crossed feeder issue by DT Crossed receive feeders It is not easy to detect this fault by DT, because the BCCH frequencies will appear exactly as they were designed. However, the statistics for the cell would help us to detect the fault: Uplink signal strength would be very poor Link balance would be larger than expected Handover success rate would be very low
  • 11. HUAWEI TECHNOLOGIES CO., LTD. Page 11Huawei Confidential How to detect crossed feeder issue by DT Crossed receive feeders The MR measurement is very useful in detecting this type of feeder cross. Uplink-and-Downlink Balance Measurement per TRX and TCH Receive Level Measurement per TRX maybe are the most useful statistics . For example, if the uplink-and-downlink balance is always in level 10 or level 11, we can consider that there is something wrong in the receive path of the site, crossed receive feeder is a possible problem.
  • 12. HUAWEI TECHNOLOGIES CO., LTD. Page 12Huawei Confidential How to detect crossed feeder issue by DT Crossed transmit and receive feeder The symptom is similar with the fault “crossed transmit feeder”, and we can detect the fault by DT easily .
  • 13. Thank you www.huawei.com

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