Optimization
- 1. 1 DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING ACE Engineering College Ankushapur(V), Ghatkesar(M), R.R.Dist - 501 301 2013-14 Under the guidance of G.NARESH Submitted by B.Venkateswara 11AG5A0401 K.Vamsi 10AG1A0455 K.Saikrishna 10AG1A0460 S.K Sameer raja 11AG5A0402 K. Manjunath 11AG5A0424 3G UMTS HSPA RADIO NETWORK OPTIMIZATION IN BSNL SERVICE AREA
- 2. Every alive Network needs to be under continues control to maintain/improve the performance. Optimization is basically the only way to keep track of the network by looking deep into statistics and collecting/analyzing drive test data. It is keeping an eye on its growth and modifying it for the future capacity enhancements. It also helps operation and maintenance for troubleshooting purposes. Successful Optimization requires: • Recognition and understanding of common reasons for call failure • Capture of RF and digital parameters of the call prior to drop • Analysis of call flow, checking messages on both forward and reverse links to establish “what happened”, where, and why. • Optimization will be more effective and successful if you are aware of what you are doing. The point is that you should now where to start, what to do and how to do. Itroduction
- 3. Purpose and Scope of Optimization The optimization is to intend providing the best network quality using available spectrum as efficiently as possible. The scope will consist all below • Finding and correcting any existing problems after site implementation and integration. • Meeting the network quality criteria agreed in the contract. • Optimization will be continuous and iterative process of improving overall network quality. • Optimization can not reduce the performance of the rest of the network. • Area of interest is divided in smaller areas called clusters to make optimization and follow up processes easier to handle.
- 4. 4 • Every a live Network needs to be under continues control to maintain/improve the Performance • Recognition and understanding of common reasons for call failure • Capture of RF and digital parameters of the call prior to drop • Analysis of call flow, checking messages on both forward and reverse links to establish “what happened”, where, and why. Optimization process : • Optimization will be more effective and successful if you are aware of what you are doing. The point is that you should now where to start, what to do and how to do. Optimization is an important step in the life cycle of a wireless network.
- 5. 5 Dropped-call rate : • Due to technical reasons, were cut off before the speaking parties had finished their conversation and before one of them had hung up • The dropped-call rate in conventional (so-called land-line) networks is extremely low and is significantly less than 0.01%. Throughput: • Throughput is the average rate of successful message delivery over a communication channel • The throughput is usually measured in bits per secon(bit/s or bps), and sometimes in data packets per second or data packets per time slot. Handover : • Handover or handoff refers to the process of transferring an ongoing call or data session from one channel connected to the core network to another channel. • desensitization then handover failure occurs. Parameters used in optimization
- 6. 6 BSIC: This code used in GSM to uniquely identify a base station. The code is needed because it is possible that mobile stations receive the broadcast channel of more than one base station on the same frequency. LAI: Each location area of a public land mobile network (PLMN) has its own unique identifier which is known as its location area identity (LAI). It is composed of a three decimal digit mobile country code (MCC), a two to three digit mobile network code (MNC) that identifies the GSM PLMN in that country, and a location area code (LAC) which is a 16 bit number thereby allowing 65536 location areas within one GSM PLMN. Latency : Latency is a time interval between the stimulation and response, or, from a more general point of view, as a time delay between the cause and the effect of some physical change in the system being observed
- 8. 8 Drivetest : • The testing process starts with selection of the 'live' region of the network where the tests need to be performed, and the drive testing path. • Before starting the tests the engineer should have the appropriate kits that include mobile equipment (usually three mobiles), drive testing software (on a laptop), and a GPS (global positioning system) unit. • When the drive testing starts, two mobiles are used to generate calls with a gap of few seconds (usually 15-20 s). The third mobile is usually used for testing the coverage. It makes one continuous call, and if this call drops it will attempt another call.
- 9. 9 DRIVETEST PROCEDURE • After collecting the required information form the BTS and the OMC-R, the drive test is started. • The equipment is set up in a vehicle and long calls as well as short calls are generated. • A long call is a call which is generated as well as terminated by the user himself. • A short call is a pre programmed call generated by the system for a very small duration, say 10 seconds or more. • A long call is used to measure the handover success rate as well as the Rx quality. • while CSR and Rx level are measured on a short call. The drive test is done over a distance of 3 km or more from the starting point.
- 10. As Drive Test Tools MODE OF DRIVE TEST 1. Dedicated / Continuous / Long Call Mode Making continuous call along drive test activity. Before starting the route, call the drive test number, ex. 199 for Telkomsel, And only stop the call when the route (drive test) finish. To see the quality and coverage of the network
- 11. As Drive Test Tools MODE OF DRIVE TEST 2. Idle Mode Along the drive test activity, the MS is “ON” but no call occur To see the coverage of the network
- 12. As Drive Test Tools MODE OF DRIVE TEST 3. Sequential / Qos / Short Call Mode Creating the sequence of call along the drive test activity Before starting the route create call sequence, for example: Create call for 70 s and idle for 10 s. Along the drive test, play this sequence until the route is finished To see the real network performance run, when people call
- 13. 13 Actix post processing tool • Actix Analyser is a software application, that provides a series of analysis tools for post-processing cellular network data using Drive Test Call Details report. • This report provides a complete overview of the content of the drive test • These data sources could include field-test equipment and switch call traces, and could be from a one-off test, or part of a planned series of samples to build up an image of overall network performance. • Once the data is loaded, a variety of analysis tools and displays provide a clear view of network performance for engineers, technicians or operations management staff.
- 15. 15 Short Call: • Issues Observed: Problem occurred due to “abnormal case, Unspecified”. Problem Description: Here Handover failure causes due to the interference of same frequencies of two different BSICs. Same frequencies serving in same direction. • Here the problem can be seen clearly as follows. Table 3: Handover failure at two different BSICs • So ,here 21 and 36 BSICs serving same frequencies then the interference occurred and thereby Handover failure happened. • Action Steps : Re-orient the sectors ,Change the frequency planning. Problems analysing using post processing tool Cell ID BCCH BSIC 48132 67 21 47291 67 36
- 16. 16 Long Call: • Issues Observed: Problem occurred due to “abnormal case, Timer expired”. • Problem Description: MS is lost after Timer T3103 expired. MS didn‟t answer the Base station within 2 seconds. T3103, Handover timer is the time the network waits after transmitting a HANDOVER COMMAND message until receiving HANDOVER . Event Handover Failure 1 Handover Failure 2 Cell ID 48151 48131 Time 17:16:45 17:00:51 Latitude 17.41876 17.41969 Longitude 78.40263 78.35316 • Action steps: Tilt the antenna direction. Increase the signal Level. Place the new tower.
- 17. • Optimization is a process that never ends. • You can always try improving the quality of the Network by making site configuration changes or changing parameters or try to understand what is happening in the network by looking into stats. • Everybody knows that there is a lot that could be done by means of optimization but it is always hard to start. • People sometimes get lost in stats, sometimes struggle with parameters or log files. CONCLUSION
- 18. 18 Queries
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