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Lte drive test parameters

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Lte drive test parameters

  1. 1. LTE DRIVE TEST PARAMETERS RSRP :- Reference signal receive power. • RSRP (dBm) = RSSI (dBm) -10*log (12*N) where RSSI = Received Signal Strength Indicator N: number of RBs across the RSSI is measured and depends on the BW Significance : RSRP is the most basic of the UE physical layer measurements and is the linear average power (in watts) of the downlink reference signals (RS) across the channel bandwidth for the Resource elements that carry cell specific Reference Signals. Knowledge of absolute RSRP provides the UE with essential information about the strength of cells from which path loss can be calculated and used in the algorithms for determining the optimum power settings for operating the network. Reference signal receive power is used both in idle and connected states Range :- -44 to -140 dBm • RSRP term is used for coverage same as RSCP in 3G RSRQ :Reference signal receive quality RSRQ = RSRP / (RSSI / N) N is the number of resource blocks over which the RSSI is measured RSSI is wide band power, including intra cell power, interference and noise. Significance :- It provides the Indication of Signal Quality . Measuring RSRQ becomes particularly important near the cell edge when decisions need to be made, regardless of absolute RSRP, to perform a handover to the next cell. Reference signal receive quality is used only during connected states Range :- -3 to -19.5 dB RSRQ term is used for Quality same as Ec/No in 3G. * SINR :-Signal to Noise Ratio. SINR = S / I + N S -- Average Received Signal Power I -- Average Interference power N -- Noise Power Significance : Is a way to measure the Quality of LTE Wireless Connections. As the energy of signal fades with distance i.e Path Loss due to environmental parameters ( e.g. background noise , interfering strength of other simultaneous transmission) RSSI :- Received Signal Strength Indicator. • RSSI = wideband power = noise + serving cell power + interference power • RSSI=12*N*RSRP • RSSI per resource block is measured over 12 resource elements. N: number of RBs across the RSSI is measured and depends on the BW
  2. 2. Based on the above: RSRP (dBm) = RSSI (dBm) -10*log (12*N) Significance :– RSRP Is the parameter represents the entire received power including the wanted power from the serving cell as well as all the co channel power & other sources of noise CQI :- Channel Quality Indicator Range :- 1 to 15 Significance: CQI is a measurement of the communication quality of wireless channels i.e. it indicates the downlink mobile radio channel quality as experienced by the UE .CQI can be a value representing a measure of channel quality for a given channel. Typically, a high value CQI is indicative of a channel with high quality and vice versa. CQI is measured in the Dedicated mode only. CQI depends on the RF conditions. Better the CQI better the throughput will get and vice versa. PCI :- Physical Cell Id Range :- 0 to 503 Significance - PCI used to identify the cell & is used to transmit the data PCI = PSS + 3*SSS PSS is Primary Synchronization Signal ( Identifies Cell Id ). PSS value can be 0, 1 & 2 SSS is Secondary Synchronization Signal ( identifies Cell Id group). SSS value can be 0 to 167. BLER :- Block Error Rate Block Error Ratio is defined as the ratio of the number of erroneous blocks received to the total number of blocks transmitted Significance: A simple method by which a UE can choose an appropriate CQI value could be based on a set of Block Error Rate (BLER) thresholds . The UE would report the CQI value corresponding to the Modulation Coding Schemes that ensures BLER ≤ 10% based on the measured received signal quality BLER is Calculated using Cyclic Redundancy error Checking method High BLER leads to loss of Peak rates & efficiency BLER threshold should be low i.e. ≤ 10% Downlink Throughput - n E-UTRAN may use a maximum of 2 Tx antennas at the ENodeB and 2 Rx antennas at the UE ( MIMO ).
  3. 3. Significance: Target for averaged user throughput per MHz, 3 to 4 times Release 6 HSDPA i.e Higher user throughput as compared to 3G ( Over 300 Mbps downlink as compared to 14 Mbps in UMTS) The supported user throughput should scale with the spectrum bandwidth. Uplink Throughput -I n E-UTRAN uses a maximum of a single Tx antenna at the UE and 2 Rx antennas at the E Node B. - Greater user throughput should be achievable using multiple Tx antennas at the UE ( MIMO ) Significance: Target for averaged user throughput per MHz, 2 to 3 times Release 6 Enhanced Uplink i.e Higher user throughput as compared to 3G (Over 50 Mbps Uplink as compared to 5.76 Mbps in UMTS).The user throughput should scale with the spectrum bandwidth provided that the maximum transmit power is also scaled. Phone-Based Drive Test for LTE Phone-based drive test systems are useful for evaluating basic network performance and are essential to characterizing the end-user experience while using the network. Phone-based systems address the need to verify network settings such as cell selection and re-selection boundaries and to measure the voice and data application performance in the live network. Most modern mobile phones chipsets have engineering measurement capabilities built into them, which were used during the mobile phone’s design process. These same parameters are exploited in drive test software to provide new value to the RF engineers rolling out the final network. With radio resource management taking place in the eNB, suitably instrumented phones can be used to monitor the performance of the physical layer including modulation schemes, access procedures, synchronization, and power control. The same types of parameters are measured for LTE as for other cellular technologies. Beyond the essential protocol log, which provides visibility of the fundamental interaction with the network, the initial focus is on RF coverage and quality. Figure 3 identifies the main measurements that are made. In LTE, these equate to reference signal received power (RSRP) and reference signal received quality (RSRQ), which are measures of the strength and quality of reference signals. These two results are the major components of network-based decisions to keep a UE on its current cell or hand it over to an adjacent cell. Additional measurements used to assess the link quality include call quality index (CQI) and block error rates (BLER). While RSRQ is the 3rd Generation Partnership Project (3GPP)-defined measure of signal-to-noise ratio (S/N), which all mobiles must make and report, many LTE UEs are also making custom carrier-to-noise ratio (C/N) measurements, which they use internally to assess channel quality. These additional carrier-to-interference (C/I) measurements are not reported back to the network, but they are available within the drive test logs and can be used by RF engineering teams to get extra insight as to how the mobiles perceive the RF environment.
  4. 4. Instrumented phones can also report the measured channel state information (CQI, pre-matrix indicator [PMI], and rank indicator [RI]) and hybrid automatic repeat request (HARQ) statistics. The number of resource blocks assigned to a device at a particular time, together with the modulation and coding scheme applied, can be used to evaluate the eNB scheduler performance. These types of tests are of particular interest during early stages of deployment of a new network but also must be monitored as network loading increases and true end-user traffic patterns establish One of the most interesting LTE network features to RF optimization engineers is the impact that multiple input multiple output (MIMO) with spatial multiplexing and antenna diversity brings to the end-user performance. Drive-test-enabled devices can log the current rank, number of transmit and receive paths in active use, together with the reported availability of antennas. They can also individually report the signal strength and quality from each of the device’s antennas. This information can be correlated with the measured data application performance to establish the impact MIMO has on network performance. Because full MIMO is a feedback system, an instrumented mobile that is part of the active channel is the only way to evaluate the true impact that this technology can make. As LTE networks are deployed alongside existing cellular networks, cellular operators are particularly interested in the efficient use of each network resource and the transition between the network technologies. Drive testing is used extensively to monitor the handover points between LTE and legacy technologies. The signal strength, quality, cell ID, and neighbor information both before and after a handover are analyzed and optimized. The length of time it takes to complete an initiated handover, success rates, and the end-user data-interruption time (during the actual transition between technologies) are key performance indicators that are closely monitored. End-user data throughput performance and latency are the two key measures of a network’s optimization. If the network is not achieving the expected data performance, it is important to be able to analyze the signaling performance and settings at each signaling layer, including the radio resource control (RRC), radio link control (RLC), and media access control (MAC). Monitoring the resources allocated to a UE together with the measured network conditions, available neighbor cells. and power levels will allow troubleshooting and optimization of network settings
  5. 5. Header (computing) From Wikipedia, the free encyclopedia In information technology, header refers to supplemental data placed at the beginning of a block of data being stored or transmitted. In data transmission, the data following the header are sometimes called the payload or body. It is vital that header composition follow a clear and unambiguous specification or format, to allow for parsing. Examples •E-mail header: The text (body) is preceded by header lines indicating sender, recipient, subject, sending time stamp, receiving time stamps of all intermediate and the final mail transfer agents, and much more. See RFC 5322 for details. Similar headers are used in Usenet (NNTP) messages, and HTTP headers. •In a data packet sent via the Internet, the data (payload) are preceded by header information such as the sender's and the recipient's IP addresses, the protocol governing the format of the payload and several other formats. The header's format is specified in the Internet Protocol. •In data packets sent by wireless communication, and in sectors of data stored on magnetic media, typically the header begins with a syncword to allow the receiver to adapt to analog amplitude and speed variations and for frame synchronization. •In graphics file formats, the header might give information about an image's size, resolution, number of colors, and the like. •In Archive file formats, the file header might serve as a fingerprint or signature to identify the specific file format and corresponding software utility. •In some programming languages (for example C and C++) the functions are declared in header files. GSM Interview Question -Answer 1. What is the function of SDCCH & SACCH?
  6. 6. Ans. (a) SDCCH---- Slow Dedicated Control Channel. Function: a) Location updates b) SMS c) Ciphering Initiation d) Equipment Validation e) Subscriber authentation f) Call set up signaling (b) SACCH---Slow Associated Control Channel. Function: (a) Timing advance data (b) Transmit power control (c) transmission of signaling data (d) radio link supervision measurements 2. What are the reasons for Hand Overs? (Ans) . (a) Signal Strength (RX LEVEL) (b) Signal Quality (RX Qual) (c) Power Budget (d) Timing Advance. (e) Interference 3. What are the shortcomings in handovers? a) Call Dropping. b) Ping- Pong handover c) Far- Away cell effect 4. What is intelligent hand over? Ans a) Fuzzy logic b) Neutral networks 5. What are internal & external hand over? Ans 1) INTERNAL HANDOVER a) ( INTER BTS): Transfer between two channels (time slot) in same cell. b) ( INTRA BSC ( BTS –BTS): 1 . transfer between BTS under control of same Bsc 2 . Measuring the quality of radio connection 3 . Power levels 2). EXTERNAL HANDOVER. a) INTER BSC (BSC_ BSC):
  7. 7. 1. Transfer between BTS under the control of diff BSC 2. BSC TO BSC 3 . NSS to attends the hand over 4. MSC controls. b) INTER MSC ( MSC- MSC) ----1. transfer between cell under the control of diff MSC 6.What is the frequency Hopping? • It is defined as sequential change of carrier frequency on the radio link between mobile & base station. • Two types of freq hopping: 1. Base band freq hopping. 2. synthesized frequency hopping. 7. Explain the major difference between BBH & SFH? Ans • In BBH the number of hopping freq is same as number of TRX. • In SFH the number of Hoping freq can be in the range of 1 to 63. 8. what are the advantages of Frequency Hopping? 1. Frequency Diversity 2. Interference Averaging 3. increase the network capacity 9. How in frequency hopping there is enhancement of network capacity? • Freq hopping implement will enable more aggressive freq reuse pattern, that leads to better spectrum efficiency. • It can add more transceiver in the existing sites , while maintaing the net work quality/ • Freq hopping compressing the available spectrum to make room for extra capacity . 10. Define the freq. hopping parameters? Frequency Hopping Parameters GSM defines the following set of parameters: - Mobile Allocation (MA): Set of frequencies the mobile is allowed to hop over. Maximum of 63 frequencies can be defined in the MA list. - Hopping Sequence Number (HSN): Determines the hopping order used in the cell. It is possible to assign 64 different HSNs. Setting HSN = 0 provides cyclic hopping sequence and HSN = 1 to 63 provide various pseudo-random hopping sequences. - Mobile Allocation Index Offset (MAIO): Determines inside the hopping sequence, which frequency the mobile starts do transmit on. The value of MAIO ranges between 0 to (N-1) where N is the number of frequencies defined in the MA list. Presently MAIO is set on per carrier basis.
  8. 8. Motorola has defined an additional parameter, FHI. Hopping Indicator (FHI): Defines a hopping system, made up by an associated set of frequencies (MA) to hop over and sequence of hopping (HSN). The value of FHI varies between 0 to 3. It is possible to define all 4 FHIs in a single cell. Motorola systemallows to define the hopping systemon a per timeslot basis. So different hopping configurations are allowed for different timeslots. This is very useful for interference averaging and to randomize the distribution of errors. 11. What are the effects of freq hopping? (Ans) 1 Handovers: 2 Call setup: 3 Frame Erasure Rate (FER): 12 .Explain in brief what is FER. FER= Number of erased blocks total no of blocks *100 It is the right measure of voice quality. FER is performed on speech& signaling frames FER: 0 to 4%, GOOD. 4 to 15% , slightly degraded > than 15%, useless 13. What happens when speech frames discarded in FER? System will interpolate. 14. What happens when signaling frames discarded in FER? MS is instructed to resend. 15. What is TCH_ TCH Interference? How it is measured. • When TCH carries are reused that leads to co-channel interference. • When TCH carrier have call activity. • This is measured by delta measurement: 1. BCCH carries are diff 2. TCH carriers of both cell 1& cell2 are same AFRCN TCH 16. Define the terms? • BER:The number of erroneous bits received Total no of bits received. • RBER: 1. Residual bit error rate 2. It is performed on demodulated speech frames that are not mark corrupt *BFI : Bad frame indication. 17. Explain the parameters in TEMS POCKET mobile.
  9. 9. L BC BS RXLEV L TC TS TX C/I RQ FE TA DSC CHM RH CiMd MCC MNC LAC RA CI 1. 2. Llcell BCCH ARFCN 3. 4. 5. Logical channel.----- BCCH Logical channel ----- TCH -- serving cell BCCH AFRCN. -- base station identity code. - recieved signal strength -- traffic channel - time slot number. - transmit power -- Carrier to interference ratio in db -- Receive bit error rate –frame erasure rate. -- Timing advance
  10. 10. --C hannel Mode -- cell reselction Hystresis —Ciphering mode – Routing area code. —Location area code. 18. Explain the analysis behind RX Qual.? RX Qual is the basic measure. It reflects the average BER over the certain period of time (0.5s) RX QUAL done over 104 TDMA frames. Limitation of RXQUAL: 1. The distributions of bit error over time. 2. Frame erasure 3. Hand over. 19. What are type of interference occur? 1. Co- channel interference. 2. Adj-channel interference. 3. Near end- Far end interference. 20. What is ERLANG? One ERLANG is one channel occupied continuously for one hour. 1E = 64Kbps. 21. what do you mean by GOS? It is the probabity of having a call blocked during busiest hour. Ex GOS=0.05 means one call in 20 will be blocked call during busiest hour because of insufficient capacity. 22. What are the technique GSM offers which combat Multipath fading? Channel coding 23. What are control &traffic channels? CONTROL CHANNEL.:1. BCH 2. CCCH 3. DCCH.
  11. 11. TRAFFIC CHANNEL: Half rate Full rate EFR == Enhanced full rate. 24. What are BCH, CCH, DCCH channels? BCH-- 1. BCCH 2 .FCCH 3. SCH CCCH. --- 1.PCH 2. AGCH 3. RACH DCCH---- 1.SDCCH. 2. SACCH 3. FACCH 25. What are types of bursts? Normal Burst Frequency Correction Burst Synchronization Burst. Dummy Burst Access Burst. 26. What is adjacent channel separation in GSM? Urban Environment-------- 200khz Sub Urban Environment ---- 400khz Open environment ----- 800khz 27. What is the watt to dBm conversions? Power in dBm = 10 log( watts *100) 0 dBm= 1mili watt 1watt = 30dbm 28. What are the optimizations you have done during Drive Test? What are samples in gsm? Which modulation take place in GSM In one TRU how many frames are there? What is the value RXLEV of neighboring cell? What do you mean by VAD?
  12. 12. What is BFI, where it is use? 2929. Define the hopping parameters in detail? The MA is a list of hopping frequencies transmitted to a mobile every time it is assigned to a hopping physical channel. The MA-list is a subset of the CA list. The MA-list is automatically generated if the baseband hopping is used. If the network utilises the RF hopping, the MA-lists have to be generated for each cell by the network planner. The MA-list is able to point to 64 of the frequencies defined in the CA list. However, the BCCH frequency is also included in the CA list, so the practical maximum number of frequencies in the MA-list is 63. The frequencies in the MA-list are required to be in increasing order because of the type of signaling used to transfer the MA-list. 1.1 Hopping Sequence Number The Hopping Sequence Number (HSN) indicates which hopping sequence of the 64 available is selected. The hopping sequence determines the order in which the frequencies in the MA-list are to be used. The HSNs 1 - 63 are pseudo random sequences used in the random hopping while the HSN 0 is reserved for a sequential sequence used in the cyclic hopping. The hopping sequence algorithm takes HSN and FN as an input and the output of the hopping sequence generation is a Mobile Allocation Index (MAI) which is a number ranging from 0 to the number of frequencies in the MA-list subtracted by one. The HSN is a cell specific parameter. For the baseband hopping two HSNs exists. The zero time slots in a BB hopping cell use the HSN1 and the rest of the time slots follow the HSN2 as presented in Error! Reference source not found.. All the time slots in RF hopping cell follow the HSN1 as presented in Error! Reference source not found.. 1.2 Mobile Allocation Index Offset When there is more than one TRX in the BTS using the same MA-list the Mobile Allocation Index Offset (MAIO) is used to ensure that each TRX uses always an unique frequency. Each hopping TRX is allocated a different MAIO. MAIO is added to MAI when the frequency to be used is determined from the MA-list. Example of the hopping sequence generation is presented in Error! Reference source not found.. MAIO and HSN are transmitted to a mobile together with the MA-list. In Nokia solution the MAIOoffset is a cell specific parameter defining the MAIOTRX for the first hopping TRX in a cell. The MAIOs for the other hopping TRXs are automatically allocated according to the MAIOstep -parameter introduced in the following section. 30. What is the effect of frequency hopping in RXQual? Frequency hopping causes some changes in the RXQUAL distribution. Also, there are some differences in a way the RXQUAL distribution should be interpreted. The Frame Erasure Ratio (FER) is a ratio of discarded speech frames compared to all the received speech frames. A speech frame is generally discarded if after the decoding and error correction process any of the category 1a bits is found to be changed based on the three parity bits following them in a speech frame. FER is a measure of how successfully the speech frame was received after the error correction process and it is thus a better indication of the subjective speech quality compared to the RXQUAL which gives an estimate of the link quality in terms of BER. The RXQUAL doesn’t
  13. 13. indicate how the bit errors were distributed in a speech frame. The bit error distribution affects the ability of the channel decoding to correct the errors. The following table gives an idea of the correlation between RXQUAL and FER and between subjective speech quality and different FER classes. 31. What is the relation link between RXQUAL& FER? Table 1. RXQUAL vs. FER comparison according to the laboratory tests. The relation of downlink FER and RXQUAL was measured during a FH trial. The relation is clearly different in the hopping case compared to the non-hopping case. The distributions of FER in each RXQUAL class are presented in Error! Reference source not found. and Error! Reference source not found.. One clear observation can be made; in the non-hopping case there are significant amount of samples indicating deteriorated quality (FER>10%) in RXQUAL class 5 while in the hopping case the significant quality deterioration (FER>10%) happens in RXQUAL class 6. Thus, it may be concluded that in the frequency hopping networks significant quality deterioration starts at RXQUAL class 6 while in non-hopping network this happens at RXQUAL class 5. This improvement of FER means that the higher RXQUAL values may be allowed in a frequency hopping network. RXQUAL thresholds are used in the handover and power control decisions. Because of the improvement in the relative reception performance on the RXQUAL classes 4-6, the RXQUAL thresholds affecting handover and power control decisions should be set higher in a network using frequency hopping network. In a frequency hopping network RXQUAL classes 0-5 are indicating good quality.
  14. 14. Typically, the share of the RXQUAL classes 6 and 7 may increase after FH is switched on, even if no other changes have been made. This may seem to be surprising since it is expected that frequency hopping improves the network quality. However, in most cases the quality is actually improved, but the improvement is more visible in the call success ratio. The improved tolerance against interference and low field strength in FH network means that it is less likely that the decoding of SACCH frames fails causing increment in the radio link timeout counter. Thus, it is less likely that a call is dropped because of the radio link timeout. Instead, the calls generating high RXQUAL samples tend to stay on. This may lead to increase in the share of RXQUAL 6-7. However, at the same time the call success rate is significantly improved. In the Error! Reference source not found., there are presented some trial results of a DL RXQUAL distribution with different frequency allocation reuse patterns. As can be seen from the figures, the tighter the reuse becomes, the less samples fall in quality class 0 and more samples fall in quality classes 1-6. There’s bigger difference in downlink than in uplink direction. This difference is a consequence of interference and frequency diversities that affect the frequency hopping network. Because of these effects, the interference or low signal strength tend to occur randomly, while in a non-hopping network it is probable that interference or low field strength will affect several consecutive bursts making it harder for the error correction to actually correct errors. The successful error correction leads to less erased frames and thus improves the FER. 32. What do you understand by idle channel measurement? When a new call is established or a handover is performed, the BSC selects the TRX and the time slot for the traffic channel based on the idle channel interference measurements. The frequency hopping has a significant effect on the idle channel interference measurement results. When the frequency hopping is used, the frequency of a hopping logical channel is changed about 217 times in a second. The frequency of the idle time slots changes according to the same sequence. In a case of the random hopping, this means that the measured idle channel interference is likely to be the same for all the TRXs that use the same MA-list. If the interference is averaged over more than one SACCH frame, the averaging effect is even stronger. However, normally the interferers are mobiles located in interfering cells. In this case, there are probably differences in the measured idle channel interferences between different time slots in the cell. This happens, because the interfering mobiles are only transmitting during the time slot that has been allocated to them. This is illustrated in Figure Error! No text of specified style in document.-1. If the cyclic hopping sequence is used, there might occur differences on the measured idle channel interference levels between the TRXs on the same time slot as explained in the following section.
  15. 15. Figure Error! No text of specified style in document.-1. Idle channel interference in a case of the random RF hopping 33 .what are types of handover? There are four different types of handover in the GSM system, which involve transferring a call between: Channels (time slots) in the same cell Cells (Base Transceiver Stations) under the control of the same Base Station Controller (BSC), Cells under the control of different BSCs, but belonging to the same Mobile services Switching Center (MSC), and Cells under the control of different MSCs. 34. what are important parameter of power saving in GSM Discontinuous transmission Minimizing co-channel interference is a goal in any cellular system, since it allows better service for a given cell size, or the use of smaller cells, thus increasing the overall capacity of the system. Discontinuous transmission (DTX) is a method that takes advantage of the fact that a person speaks less that 40 percent of the time in normal conversation [22], by turning the transmitter off during silence periods. An added benefit of DTX is that power is conserved at the mobile unit. The most important component of DTX is, of course, Voice Activity Detection. It must distinguish between voice and noise inputs, a task that is not as trivial as it appears, considering background noise. If a voice signal is misinterpreted as noise, the transmitter is turned off and a very annoying effect called clipping is heard at the receiving end. If, on the other hand, noise is misinterpreted as a voice signal too often, the efficiency of DTX is dramatically decreased. Another factor to consider is that when the transmitter is turned off, there is total silence heard at the receiving end, due to the digital nature of GSM. To assure the receiver that the connection is not dead, comfort noise is created at the receiving end by trying to match the characteristics of the transmitting end's background noise. Discontinuous reception Another method used to conserve power at the mobile station is discontinuous reception. The paging channel, used by the base station to signal an incoming call, is structured into sub- channels. Each mobile station needs to listen only to its own sub-channel. In the time between successive paging sub-channels, the mobile can go into sleep mode, when almost no power is used. All of this increases battery life considerably when compared to analog : What is Tri-band and Dual-band? A: A tri-band phone operates at three supported frequencies, such as 900/1800/1900 MHz or 850/1800/1900 MHz. A dual-band phone operates at two frequencies, such as 850/1900 MHz or 900/1800
  16. 16. RF Optimization and Log File Analysis in GSM Optimization and Log File Analysis in GSM 1. INTRODUCTION Every 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. 1.1. 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. 1.2. Optimization Process Optimization process can be explained by below step by step description: 1.2.1. Problem Analysis Analyzing performance retrieve tool reports and statistics for the worst performing BSCs and/or Sites Viewing ARQ Reports for BSC/Site performance trends Examining Planning tool Coverage predictions Analyzing previous drive test data Discussions with local engineers to prioritize problems Checking Customer Complaints reported to local engineers 1.2.2. Checks Prior to Action
  17. 17. Cluster definitions by investigating BSC borders, main cities, freeways, major roads Investigating customer distribution, customer habits (voice/data usage) Running specific traces on Network to categorize problems Checking trouble ticket history for previous problems Checking any fault reports to limit possible hardware problems prior to test 1.2.3. Drive Testing Preparing Action Plan Defining drive test routes 6 Collecting RSSI Log files Scanning frequency spectrum for possible interference sources Re–driving questionable data 1.2.4. Subjects to Investigate Non–working sites/sectors or TRXs In–active Radio network features like frequency hopping Disabled GPRS Overshooting sites – coverage overlaps Coverage holes C/I, C/A analysis High Interference Spots Drop Calls Capacity Problems Other Interference Sources Missing Neighbors One–way neighbors Ping–Pong Handovers Not happening handovers Accessibility and Retainability of the Network Equipment Performance Faulty Installations 7 1.2.5. After the Test Post processing of data Plotting RX Level and Quality Information for overall picture of the driven area Initial Discussions on drive test with Local engineers Reporting urgent problems for immediate action Analyzing Network feature performance after new implementations Transferring comments on parameter implementations after new changes 1.2.6. Recommendations Defining missing neighbor relations Proposing new sites or sector additions with Before & After coverage plots
  18. 18. Proposing antenna azimuth changes Proposing antenna tilt changes Proposing antenna type changes BTS Equipment/Filter change Re–tuning of interfered frequencies BSIC changes Adjusting Handover margins (Power Budget, Level, Quality, Umbrella HOs) Adjusting accessibility parameters (RX Lev Acc Min, etc..) Changing power parameters Attenuation Adds/Removals MHA/TMA adds 8 1.2.7. Tracking Re–driving areas after implementing recommendations Create a tracking file to follow–up implementation of recommendations 1.2.8. Other Optimization Topics Verifying performance of new sites Verifying handovers Verifying data after Re–Homes Investigating GPRS performance Verifying Sectorizations Collecting DTI Scan files Verifying coverage Verifying propagation model by importing DTI scan files to Planet Periodic Consistency Checks Frequency Planning Check Analyzing cell access parameters Analyzing Handover parameters Analyzing Power control parameters Analyzing Frequency Hopping parameters (HSN, MAIO) Implementing/analyzing optional features Keep helping local engineers with emergency cases Benchmarking 9 1.3. Before Starting This document was prepared with TEMS screen shots from live examples of previous experiences to guide RF Engineers on how to define/analyze problems or cases and optimize network. After each case/problem demonstration, specific step to be taken will be defined and appropriate recommendation will be given. The document will be focusing on Drive Testing part of the Optimization Process and give definitions on basic GSM principals, features and parameters when needed. The readers of this document are considered to have basic knowledge of cell planning and TEMS
  19. 19. Investigation usage. Only little information will be given just to remember TEMS interface. 10 2. DRIVE TESTING Drive testing is the most common and maybe the best way to analyze Network performance by means of coverage evaluation, systemavailability, network capacity, network retainibility and call quality. Although it gives idea only on downlink side of the process, it provides huge perspective to the service provider about what’s happening with a subscriber point of view. The drive testing is basically collecting measurement data with a TEMS phone, but the main concern is the analysis and evaluation part that is done after completition of the test. Remember that you are always asked to perform a drive test for not only showing the problems, but also explaining them and providing useful recommendations to correct them. Please note that a successful analysis should be supported by handling of network statistics from a statistics tool (Metrica/NetDoc–NMS/SRP–OSS, etc..) and careful evaluation of coverage predictions from a cell planning tool (Planet, DB–Planner, TEMs Cell Planner, etc..). Please see Figure 1 for a usual view from TEMS. Dharmendra Kumar Singh Email id:hidharmendrasingh@gmail.com Mobile No: ************* Passport No: ******** 0BJECTIVES To work in high engineering & skilled environment with positive attitude, seeking assignments in Project management / Networking / Telecom with an organization of repute in the Telecom sector, to hold a position of responsibility in an organization with an opportunity of growth of the organization along with having a long-term relationship and to conduct myself in such a manner so as to uphold the dignity of profession. PR0FESSI0NAL SYN0PSIS Presently 2G / 3G / RF/Telecom Consultant/Corporate Telecom Trainer in United Telecom Limited (UTL Technologies Limited) since July 2012 to Till Date. Ability to perform quality work within deadlines with or without direct supervision and always work with confidence and hard work. Excellent written and oral communications, interpersonal, analytical, abstract reasoning and organizational skills. Extensive knowledge of 2G,3G & Strong knowledge on RF Engineering EMPL0YMENT RECITAL United telecom Ltd Associate Telecom Consultant July 2012 to Till Date
  20. 20. Teleysia Network Pvt. Ltd. RF PR0JECT C0- 0RDINAT0R Jan 2012- June 2012 Metrotel Works (Akrosh) Pvt Ltd SR.RF ENGINEER DEC 2010-Dec-2011 Metrotel (Akrosh Consultants Pvt Ltd) RF ENGINEER OCT 2009- NOV 2010 CURRENT J0B RESP0NSIBILITIES Prepare, schedule and perform training of new hires. Keep knowledge of branch products Offer on-going training to existing Telecom/RF employees including Practical Training on RF Engineering. Coordinate and implement all activities related to several training courses offered including course and sending out invitations to participants, instructor scheduling, maintaining sign-in records, ensuring correct room set-up and equipment, creating or ordering materials and maintaining inventory. Recommends research and develops training courses for Telecom Engineers & Provide support for mentoring program for new employees and Foreign Current Company Job Profile: At UTL Group, our expertise across multiple domains along with stable partnerships has been our driving force. We are continuously looking to extend our business horizons beyond Indian shores. Today, our footprint extends over 60-plus nations across South Asia, Africa, America and Europe. Our international business presence in strategic locations has enabled us to deliver highly reliable solutions, quickly and cost-effectively. Our credibility is established by our ability to work effectively with some of the biggest players across various industries. Some of the business conglomerates and technology partners we work with include Cisco, ZTE, Duratel, UT- Starcom, Polycom and Emerson. While we are rapidly expanding as one of India's leading business houses, our overriding vision remains unchanged – to offer the best-in-class solutions and services that significantly improve the lifestyles of our customers. PREVIOUS J0B RESP0NSIBILITIES 3G-3.5G / UMTS DT (RF Drive Test), DATA ANALYSER, C0-0rdination & FIELD OPTIMIZATION Optimization of UMTS sites based on Coverage_RSCP, Quality_Ec/Io, Pilot pollution,
  21. 21. Missing neighbors, Soft Handover using drive test data’s. Optimize to improve Ec/Io (Reduce Pilot Pollution) by improving RSCP of dominant cells and reducing coverage (Interference) of less dominant sectors through antenna Tilt changes and power changes, thus rectify the overshooting sectors issues. Checking Co scrambling code issues. Adding missing 3G-3G neighbors and deleting the long neighbors using scanner measurements.2G GSM 900/1800 DRIVE TEST, DATA ANALYSER & FIELD OPTIMIZATION: Physical optimization of existing sites. Finding out the Interference problem & rectify the same. Identify the reasons for TCH Blocking, TCH Drop & Handover failures. Primary verification of drive data and taking necessary corrective measures, like Neighbour addition and deletion and interference analyasis.Providing appropriate Tilts (Electrical /Mechanical) to reduce the interference or improve the coverage.3.5G DRIVE TEST - HSDPA & HSUPA drive testing for checking throughput in Network.HSDPA parameters like CQI, Modulation etc. 2G-GSM,RF DATA ANALYSER, C0-0rdinati0n & FIELD OPTIMIZATION Optimization of GSM sites based on Coverage_Rx Level, Quality_Ec/Io, Pilot pollution Proposing new sit after analysis of coverage issue. Coverage by skewing sectors, down tilt/Up tilt, power increase/decrease by using better antenna gain Site Auditing and Verifying Hardware, Tilt, Antenna height and Orientation, According to the site database Analyzed the Drive test log files using TEMS Investigation. Find the swap, Interference in the sites during the optimization & resolve the swap .Missing neighbors, Soft Handover using drive test data’s. C0MPLETED PR0JECT PR0JECT: 1) UNINOR-2G:- ALCATEL LUCENT, ORISSA, INDIA Duration: Oct 2009 to JAN 2010 2) VIDEOCON-2G NSN, TAMILNADU, INDIA Duration: FEB2010 to DEC 2010 3) AIRCEL 3G – HUWEAI, KERALA, INDIA Duration: 4) TATA 3G HUWEAI, KERALA, INDIA Duration: 5) IDEA 3G – NSN, KERALA, INDIA Duration:
  22. 22. Tools worked Upon: TEMS Investigation 8,9,10 & 11 ACTIX NEMO Outdoor 4 & 5. ZENEX Probe 2.x & 3.x Rhodes & Schwartz TSMQ scanner PCTEL Scanner MapInfo Professional 8.0, 8.5 MCOM Technical Skills Computer Proficiency: Have a good command over MS Office Operating Systems: WINDOWS 98, XP, WINDOW 7 Skills, Knowledge and Abilities: Proven ability to motivate others to study and excel Ability to work with all levels of bank employees and maintain credibility, trust, and cooperation Resolve conflict and handle sensitive employee situations Strong oral communication and presentation skills with ability to teach adults Strong professional image Excellent at PC applications to develop training materials and manuals Demonstrated organizational skills and implementing multiple priorities and plans Professional & Scholastic Qualifications Standard University/School Year Percentage B.E. (Electronics & Communication Engineering) (R.G.P.V.) Shri RamCollege of Engineering & Management Gwalior M.P. India. 2009 70.5% XII (Bihar. Board) Maharaja College, Ara. Bihar India. 2003 58.0% X (Bihar. Board) R.N.P.High School, Ara, Bihar India. 2001 69.0% PERS0NAL PR0FILE: Brief Profile: I am a Committed, gracious and enthusiastic person. Strengths: Flexibility, Competitiveness, Cooperativeness Date of Birth: ***********
  23. 23. Father’s name: ************* Gender: Male Marital Status: Single Language Known: Hindi, English Nationality: Indian Declaration: I hereby declare that all the information furnished above is true to the best of my knowledge and belief. I shall be responsible for any action if any of the above statements are incorrect at any stage in future. Place: Bangalore Date-08/01/2013 (Dharmendra Kumar Singh) GSM,WCDMA,RF ,RF Optimization Interview Objective Question Level 2-3 NPO Questions (RF Planning & Optimisation Engg) In the following questions, please select one alternative which you think is the best answer for the particular question. Q1. SMS broadcast is done over which channel 1. SDCCH 2. BCCH 3. TCH 4. A & C Q2. The parameter number of Slot Spread Trans (SLO)(BTS) is used to allocate a number of CCCH blocks for . a) Paging Channel (PCH) b) Random Access Channel (RACH) c) Access Grant Channel (AGCH)
  24. 24. d) Traffic Channel Q3. Which of the following comment is true? a) MAIO step is used to avoid intra-cell interference where as HSN is used to avoid inter-cell interference b) HSN is used to avoid intra-cell interference where as MAIO step is used to avoid inter-cell interference c) Both MAIO step and HSN are used to avoid intra-cell interference. d) Both MAIO step and HSN are used to avoid inter-cell interference Q4. Timer T200 is related with which KPI a) SDCCH Completion rate b) Paging success rate c) TCH assignment success rate d) All of the above Q5. Which parameter defines how often paging messages are sent to MS? a) No of Multi-frames between Paging (MFR) b) Max No of Retransmission (RET) c) No of Slots Spread Transmission (SLO) d) No of Blocks for Access Grant (AG) Q6. Which parameter is used as a margin to prevent ping-pong location updates? a) PLMN-Permitted (PLMN) b) Rx Level Access Minimum (RXP) c) Cell Reselect Hysteresys (HYS) d) Handover Margin Level (LMRG) Q7. Which Parameter describes the minimum received field strength required by an MS to get any service from the network in that cell in Idle mode? a) PLMN-Permitted (PLMN) b) Rx Level Access Minimum (RXP) c) Cell Reselect Hysteresis (HYS) d) Direct Access Level (DAL)
  25. 25. Q8. When is location updates carried out? a) Every time an MS changes its location area under one MSC. b) Every time an MS changes between two different MSCs c) On a periodic basis set by a timer d) All of the above Q9. Increasing Radio Link Time Out (RLT) from 16 to 24 will improve following KPI a) SDCCH Completion rate b) TCH Completion rate c) Paging Success rate d) All of the above Q10. If a cell is having TCH congestion, which of the following is true? a) It is having TCH blocking b) It may have TCH blocking. c) It is having TCH Drop. d) All of the above Q11. Which of the parameter is set to zero for cyclic hopping? a) BTS Hopping (HOP) b) Hopping sequence number (HSN) c) MAIO Offset (MAIO) d) All of the above Q12. What is directed retry? a) A feature that allows a recovery system to restore a BCCH to its original TRX after fault has been eliminated. b) It is designed to control the traffic load of a frequency hopping radio network in which frequencies are reused tightly. c) It is used in call set up to assign a TCH to an MS from a cell outside the serving cell due to TCH congestion d) None of the above
  26. 26. Q13. Which of the following is measured as BER? a) Received Signal Quality (RX QUAL) b) Speech Quality Index (SQI) c) Voice Quality d) All of above Q14. Polarization is characterized by 1. Direction of Magnetic Field 2. Direction of Electric Field 3. Direction of Electromagnetic Field 4. None of Above. Q15 Which one is correct for TMA, TMB and Repeater? 1. Amplifies U/L, Amplifies D/L, and Amplifies both. 2. Amplifies D/L, Amplifies U/L, and Amplifies both. 3. Amplifies U/L, Amplifies D/L, and Amplifies U/L. 4. Amplifies U/L, Amplifies D/L, and Amplifies D/L. Q16 Define Beam width of Antenna? 1. Angular distance between the points on two opposite sides of the peak direction where the radiation intensity drops to the 1/2 of the peak intensity. 2. Angular distance between the points on two opposite sides of the peak direction where the radiation intensity drops to the 1/3 of the peak intensity. 3. Angular distance between the points on two opposite sides of the peak direction where the radiation intensity drops to the 1/4 of the peak intensity. 4. Angular distance between the points on two opposite sides of the peak direction where the radiation intensity drops to the 1/8 of the peak intensity. Q17 From which technique we cancel the effect of Rayleigh Fading?
  27. 27. 1. Antenna Hoping. 2. Frequency Hoping. 3. Antenna Diversity. 4. MAIO. Q18 If HLR=5 Million subs, VLR/HLR=0.7,mErl/Sub=30.Then how much Capacity is required to cater the subscriber in RF for 70% utilized Network. 1. 150 K Erl 2. 300 K Erl 3. 135 K Erl 4. 165 K Erl Q19 Electrical Tilt antenna limits coverage through? 1. Tilting of Dipoles. 2. Inserting Phase Shift. 3. Inserting attenuation. 4. None of the above. Q20 Which Antenna has the highest front to back Ratio? 1. Loop 2. Yagi 3. Dipole 4. Parabolic Q21 Select relation between forward power and Reflected Power if load is not connected? 1. VSWR=1 2. VSWR=∞ 3. VSWR=0 4. VSWR=1/2 Q22 What is the difference between splitter and coupler? 1. Even Distribution of Power in coupler and uneven distribution in splitter. 2. Uneven Distribution of Power in coupler and even distribution in splitter. 3. Even Distribution of Power in both. 4. Uneven Distribution of Power in both.
  28. 28. Q23. What are mobility management states in GPRS? 1. Idle,Standby,Ready 2. Dedicated,Standby,Ready 3. Idle,Dedicated,Standby 4. None of above Q24. Which modulation is used for EDGE above MCS-4 1. QPSK 2. GMSK 3. 8PSK 4. PSK Q25. What does SGSN stands for? 1. Serving Gateway Support node 2. Serving GPRS Support node 3. Serving GMSC Support node 4. None of the above Q26 In dedicated mode, SMS comes on which channel? a) SDCCH. b) SACCH. c) FACCH. d) None of the above. Q27 In Dedicated Mode, MS receives which system info. Messages? 1. System Info 1, 2, 3. 2. System Info 1, 2, 3,4,13. 3. System Info 5, 6. 4. None of the above. Q28 Freq used in Uplink of Satellite communication is higher while in GSM it is lower. Why? 1. Loss α freq. 2. Loss α 1/freq. 3. Loss α sqr(freq)
  29. 29. 4. None of the above. Q29 AMR is used to improve? 1. SQI 2. Downlink quality. 3. Uplink Quality 4. None of the Above. Q30 In Idle Mode, MS receives which systeminfo. Messages? a) System Info 1, 2,3. b) System Info 1, 2, 3,4,13. 3. System Info 5, 6. d) None of the above Q31 The Common Control channel multiframe consists of? 1. 51 time slots. 2. 50 timeslots 3. 4 Time slots 4. 9 Time slots Q32 Which of the following are true? 1. Type 1 Paging: can address up to 2 mobiles using either IMSI or TMSI. 2. Type 2 Paging: can address up to 3 mobiles, one by IMSI and the other 2 by TMSI. 3. Type 3 Paging: can address up to 4 mobiles using the TMSI only. 4. All of the above. Q33 In GSM while performing handover 1. The MS breaks connection from source cell and then tunes on the target cell. 2. The MS continues connection from the source, tunes on the target and then releases the source cell. 3. MS gets paging message from the target and replies it on its RACH and gets TCH allocated. 4. MS gets paging message from the target and replies it on its RACH and gets SDCCH allocated. Q34 If E-RACH is used then which of the following is true?
  30. 30. 1. GSM range will increase beyond 35Km 2. It will increase no of RACH channels and release congestion on RACH. 3. SDCCH assignment will improve. 4. All above are false. Q35 In dedicated mode the BTS receives handover command on? 1. TCH 2. SDCCH 3. SACCH 4. FACCH Q36 The duration of a single timeslot is? 1. 4.615 ms 2. 1250 ms 3. 0.577 ms 4. 156.25 ms Q37 Modulation used in GSM radio interface is? 1. Phase shift keying (PSK) 2. Gaussian Minimum shift Keying (GMSK) 3. Frequency modulation. 4. 8PSK. Q38 TIE stands for? 1. Terminal Equipment identifier 2. Transcoder Input Erlang 3. TRX identifier for Edge TRX 4. None of the above Q39 As per GSM Standard in case of frequency hopping the C/I value should be at least? 1. 3 dB 2. 6 dB 3. 9 dB 4. 12 dB Q40 In inter BSC handover the handover is controlled by?
  31. 31. 1. GMSC 2. MSC 3. Source BSC 4. Target BSC Q41 The maximum no of neighbors that can be defined with a cell is? 1. 8 2. 16 3. 32 4. 64 Q42 The permissible value of VSWR for feeder cable is? 1. < 1.3 2. >1.3 3. > 1 4. <2 Q43 The function of Transcoder is 1. To convert 64 kbps speech channel on A interface to 16 kbps speech channel on A-ter Interface and vice versa. 2. To convert 16 kbps speech channel on A interface to 64 kbps speech channel on A-ter Interface and vice versa. 3. To convert analogue speech signal from MSC to Digital signal for use of BSC 4. To convert analogue speech signal from BSC to Digital signal for use of MSC Q44 TSC stands for 1. Time Synchronized Channel 2. Temporary subscriber code 3. Transcoder Signaling Controller 4. Training Sequence Code Q45 If Cell bar is set to “yes” on a cell then
  32. 32. 1. It will reject new calls as well as handover calls 2. It will reject new call assignment but will receive calls by Handover 3. It will reject Handover but allow new call to come 4. The BTS will go into locked state. Q46 DAP stands for 1. Dual Abis pool 2. Dynamic Allocation protocol 3. Dynamic Abis Pool 4. None of the above Q47 Who can initiate the GPRS detach 1. The MS only 2. The SGSN only 3. Both the MS and the SGSN 4. None of the above Q48 The mapping of logical name/Host name to IP addresses in the GPRS network is done by 1. Border Gateway 2. SGSN 3. GGSN 4. DNS Q49 Where is the mobility management context established in GPRS 1. In the MSC 2. In the SGSN 3. In the GGSN 4. All of the above Q50 Which layer uses the functionality of Uplink State Flag (USF)? 1. RLC Layer 2. Physical Layer 3. MAC Layer 4. All of the above
  33. 33. Q51 How many TDMA frames are there in a PDCH multiframe? 1. 51 2. 52 3. 26 4. 8 Q52 Which coding scheme does not use Forward Error Correction (FEC)? 1. CS-1 2. CS-2 3. CS-3 4. CS-4 Q53 Which new area is defined in GPRS compared to GSM? 1. Location Area 2. Routing Area 3. Both a and b 4. None of the above Q54 Which layer is responsible for segmentation and reassembly of LLC PDUs and backward error correction (BEC) procedures? 1. Physical Layer 2. Application Layer 3. RLC Layer 4. MAC Layer Q55 Which coding scheme has adopted the same coding as used for SDCCH? 1. CS-1 2. CS-2 3. CS-3 4. CS-4 Q56 What is the single timeslot data rate for coding scheme CS-2
  34. 34. 1. 7.8 Kbit/s 2. 10.4 Kbit/s 3. 13.4 Kbit/s 4. 21.4 Kbit/s Q57. Combiner works in a) Downlink direction b) Uplink direction c) In both direction d) As a Amplifier Q58 Number of AMR codec modes used only in FR? 1. 6 2. 4 3. 2 4. 8 Q59 During conference call which channel is used to establish another call- 1. SACCH 2. SDCCH 3. FACCH 4. TCH Q60 What is Duplex spacing. 1. Difference between first frequency of Uplink and last frequency of Downlink. 2. Difference between first frequency of Downlink and first frequency of Uplink. 3. Difference between last frequency of Downlink and first frequency of Uplink. 4. None of the above. Q61 What does MSRN stands for …. 1. Mobile Station Registration Number 2. Mobile System Registration Number 3. Mobile Station Roaming Number
  35. 35. 4. Mobile Station Register Number. Q62. If my MCC=404, MNC=05, LAC=100, CI = 14011, then what will be CGI for same?? 1. 4040510014011 2. 404056436BB 3. 4040514433273 4. 4040510033273 Q63. Which information is there in Handover Access Command in Layer 3 Message? 1. BCCH & BSIC of Source 2. BCCH & BSIC of Target 3. Handover Reference Value 4. All of above. Q64 What is the use of Immediate Assignment Extended Command? 1. Allocate AGCH for 2 Mobiles 2. Allocate SDCCH for 3 Mobiles 3. Allocate SDCCH for Call and SMS simultaneously. 4. None of Above. Q65. What is the cause value for normal call release? 1. 16 2. 3 3. 14 4. 45 Q66. Location Update Request falls under which management system? 1. RRM 2. CM 3. CRM 4. MM Q67. Which systeminformation message contains NCC Permitted Values? 1. SI 6 2. SI 2 3. All of Above. 4. None of Above.
  36. 36. Q68. When timer T3212 expires which process is initiated? 1. Cell Update 2. RAC Update 3. LAC Update 4. Handover Q69. If AMR FR & AMR HR is enabled in network, then what will be the formula for counting GSM FR Traffic with help of EOSFLX KPI Reports ? 1. Total Traffic – AMR FR Traffic 2. Total Traffic – AMR FR Traffic - AMR HR Traffic 3. Total Traffic – GSM HR Traffic – AMR FR Traffic – AMR HR Traffic 4. None of Above. Q70. By reducing value of RET parameter it will help to improve which KPI? 1. TCH Drop 2. SDCCH Drop 3. HO Success 4. None of above. Q71. What is the range of AMH TRHO PBGT Margin parameter? 1. -6 to +6, 255 2. -24 to +24, 255 3. -6 to +24, 255 4. +6 to +24, 255 Q72. What is the relation between HO Load Factor and HO Priority Level? 1. Load Factor > Priority Level 2. Load Factor >= Priority Level 3. Load factor < Priority Level 4. Load Factor <=Priority Level Q73. Which are the basic features helps to distribute traffic in nearby cells? 1. DR 2. IDR 3. AMH 4. All of above
  37. 37. Q74. Using Multi BCF Common BCCH feature operator can expand how many numbers of TRX in one segment without using another BCCH? 1. 16 2. 24 3. 30 4. 36 Q75. While Using Path loss Criterion C2 which parameter should be made “0” so that this particular cell have higher C2 Value even though having poor C1? 1. CRO 2. TEO 3. Penalty Time 4. None of above. Q76. Common BCCH feature is implemented in network, then which feature will help to access the secondary freq. spectrum directly? 1. DR 2. DADB 3. DADL 4. All of above Q77. Which types of GSM Reports are generated by Nemo Analyzer? 1. GSM Performance Report 2. GSM Benchmark Report 3. All of above 4. None of above Q78. What is the range of parameter PMRG? 1. -24to +63 2. -24 to +24 3. -63 to +63 4. 0 to +63
  38. 38. Q79. How many maximum uplink TBF can be there per RTSL? 1. 6 2. 7 3. 8 4. 9 Q80. What should be minimum value of CDED (%) to have 1 RTSL as dedicated GPRS Timeslot considering 2 TRX as GPRS TRX? 1. 0 2. 1 3. 8 4. 10 Q81. What does TRP Value = 3 means? 1. TCH allocation from BCCH TRX for non-amr user and from beyond BCCH TRX for amr USER 2. TCH allocation from beyond BCCH TRX for non-amr user and from BCCH TRX for amr USER 3. All of above 4. None of Above Q82. How many basic EGPRS MCS Families are there? 1. 1 2. 2 3. 3 4. 4 Q83. Which is / are the main factors affecting the Radio Accessibility for TBF in UL/ DL? 1. Coverage 2. Capacity 3. Interference 4. All of above. Q84. Which parameter setting can help to increase the TBF Retainability? 1. UL Power Control 2. DL Power Control 3. All of above. 4. None of above.
  39. 39. Q85. What should be SDCCH GOS when compared to TCH GOS? 1. SD GOS = TCH GOSDTX 2. SD GOS = 1/2(TCH GOS) 3. SD GOS = 1/4(TCH GOS) 4. SD GOS = 2(TCH GOS) Q86. Which feature/technique is not used to reduce blocking / congestion? 1. Directed Retry 2. Traffic Reason Handover 3. Dynamic SDCCH 4. Intra Cell Handover Q87. Rx Quality = 3 means BER =? 1. 0.2 - 0.4 2. 6.4 - 12.8 3. 1.6 - 3.2 4. 0.8 - 1.6 Q88. Following is false when using Dynamic SDCCH. 1. SDCCH Handover cannot be used. 2. Free TCH is used when SDCCH is required. 3. SDCCH carrying CBCH cannot be used. 4. Every SDCCH request can be fulfilled by Dynamic SDCCH. Q89. In Link Budget; what has the least importance? 1. GSM Antenna Gain 2. Path Loss 3. Feeder Loss 4. MS Antenna Gain Q90. When 2 calls are made from different TRXs of same cell having 1*1 RF hopping; what plays important role to neglect C/I? 1. MAL ID 2. HSN 3. MAIO Step 4. MAIO Offset Q91. Frame loss can be reduced by: 1. Speech Coding 2. Channel Coding 3. Interleaving
  40. 40. 4. Burst Formatting Q92. What can be done to overcome combiner loss when cell is upgraded from 2 TRX to 3 TRX? 1. Remove Combiner 2. Air-Combining 3. HOP = OFF 4. TMA Implementation Q93. What is the Basic feature amongst below: 1. SAIC 2. STIRC 3. AMR Progressive Power Control 4. Freq. Hopping Q94. Out of following channels which one is common channel? 1. AGCH 2. SACCH 3. TCH-FR 4. FACCH Q95. Out of following channels which one is the answer to RACH? 1. SDCCH 2. AGCH 3. FACCH 4. SACCH Q96. In Air-interface TDMA time-slot means how many Seconds? 1. 576.9us 2. 4.615ms 3. 6.12sec 4. 480ms Q97. Which type of antenna is used in MS? 1. Dipole 2. Omni 3. Loop 4. Cross-polar Q98. Choose the correct Erlang Formula? 1. x Erlang= (calls per hour) * (average call duration)/3600 Sec 2. x Erlang= (no. of user)*(3600 sec)/ (calls per hour) 3. x Erlang= (no. of calls)*(no. of user)/ (average call duration) 4. x Erlang= (calls per hour)*(no. of users)/3600 sec
  41. 41. Q99. If GOS of an N/W is 3%, what does it mean? 1. 3 out of 100 calls may fails 2. average call duration is 3min 3. at a time 3% of total users can make a call 4. 3% blocking in the N/W is permitted Q100. Which type of message is "Identity Request”? 1. Mobility Management 2. Radio Resource Management 3. Call Control 4. Call related SS message Q101. Paging message type 2 contains. 1. Paging message for 3 mobiles 2. Paging message for 2 mobiles 3. Paging message for 4 mobiles 4. Paging message for >4 mobiles Q102. Out of following which one is not a part of NSS? 1. Mobility Management 2. Connection Management 3. Radio Resource Management 4. Charging Q103. In L3 messages, out of following Info messages which one carries Dedicated Mode Information? 1. System Info 2 2. System Info 4 3. System Info 5 4. System Info 13 Q104. Which one out of following is not a part of AMR Codec Modes? 1. 4.6 2. 5.9 3. 7.4 4. 12.2 Q105. Frequency Hopping… 1. Eliminates the problem of fading dips 2. Eliminates the problem of ISI 3. is part of channel coding 4. spreads the problem of fading dips to many mobile stations
  42. 42. Q106. ISI is caused by: 1. fading dips 2. the Viterbi equalizer 3. reflection 4. interleaving Q107. Maximum data throughput / tsl possible incase of GPRS is: X` 1. 18.8kbps 2. 27.2kbps 3. 29.2kbps 4. 21.4kbps Q108. Out of following which element/s in the GSM N/W can not initiate HO? 1. BSC 2. BTS 3. MSC 4. None of Above Q109. Out of following, which type of antenna has highest directivity? 1. Dipole 2. Helical 3. Log-Periodic 4. Yaagi-Uda Q110. When we say the output power of a Transmitter is 30dBm, how many watts does it mean? 1. 3W 2. 1W 3. 1mW 4. 30mW Q111. Out of following which one is a passive device? 1. Repeater 2. Cross Polar Antenna 3. TMA (Tower Mount Amplifier) 4. TRX Q112. Out of following which can not be observed during Drive-test? 1. Rx Quality 2. Location Update 3. Paging Load
  43. 43. 4. GPRS Attach Q113. If a cell is EDGE capable, how much Downlink Throughput can we guarantee to customer? 1. 59.2kbps 2. 473.6kbps 3. 236.8kbps 4. can't guarantee Q114. How many blocks of AGCH are reserved in non combined mode? 1. 1-7 2. 0-2 3. 0-7 4. None of Above. Q115. What are the contents of authentication triplets? 1. A3,A5,A8 2. SRES,RAND,Kc 3. RAND,A3,A8 4. SRES,Kc,A8 Q116 Frequency hopping in a network: 1. May or may not be implemented 2. Does not provide optimal gain if the hopping frequencies are less than 4 3. Both above are correct. 4. None of the above. Q117 .Which of the following functions is not done by SDCCH CHANNEL: 1. Authentication 2. Transmission of short messages 3. Adaptive power control information from BTS to MS only 4. Assignment of traffic channel to MS. Q118 How many TS can be used at the most with HSCSD? 1. 2 2. 4 3. 6
  44. 44. 4. 8 Q119 What should be the value of C/I when you are in hopping mode? 1. Above 9 2. Above 12 3. Less than 9 4. All of the above are correct Q120 Which value of level and quality should be considered for analysis in a DT log 1. Full 2. Sub 3. Both 4. None of the above is correct. Q121 What are the coding schemes observerd in UL/ DL after implementing EDGE in your Network: 1. CS1-CS4 2. MCS1-MCS6 3. MCS5-MCS9 4. MCS1-MCS9 Q122 What does DAP stand for? 1. Dynamic Abis Pool 2. Dynamic Access Pool 3. Dynamic Access Protocol 4. None of the above Q123 How many codec’s can be defined for AMR HR 1. 5 2. 2 3. 6 4. 4 Q124 How many TRX’s can be accommodated max on a single E1 where DAP pool is assigned for 4 TS in a Ultra site
  45. 45. 1. 12 2. 16 3. 18 4. 24 Q125 How much traffic will be offered by a sector having 4 TRX with GOS of 2% 1. 24Erlangs 2. 21.03Erlangs 3. 23.56Erlangs 4. 22.12 Erlangs Q126 Which ND report would you refer in order to find the discrepancy for Handovers? 1. Report 163 2. Report 166 3. Report 153 4. Report 208 Q127 On what basis would an optimizer decide whether the site serving is overshooting: 1. On the basis of TA 2. From ND report 232 3. Physically verifying whether the cell is having up tilt 4. All of the above Q128 BBH is generally implemented where: 1. For dense network 2. For small capacity network 3. For cells where tight frequency reuse is required 4. None of the above Q129 In case of Directed retry HO: 1. HO is performed from TCH of serving to TCH of Adjacent cell 2. HO is performed from SDCCH of serving to TCH of adjacent cell
  46. 46. 3. HO is performed from TCH of Serving to SDCCH of adjacent cell 4. HO is performed from SDCCH of serving to SDCCH of adjacent cell Q130 Which alarm indicates the TRX faulty operation in the system: 1. 7601 2. 7602 3. 7725 4. 7745 Q131 C/I estimation during a DT can be done in: 1. U/L 2. D/L 3. Both A&B 4. Cannot be estimated. Q132 Which is the unique feature in TEMS for analsing speech quality: 1. Rx qual Full 2. Rx Qual Sub 3. SQI 4. Rx Qual. Q133 Drop calls due to Handovers can be caused basically due to: 1. Neighbors with Co-BSIC 2. Neighbor with Co-BCCH 3. Neighbors with Co-BCCH and Co-BSIC 4. All of the above. Q134 Consider a cell where the no calls are happening, the probable causes would be 1. Wrong definition of LAC,CI 2. DMAX=0 3. Only A is correct 4. Both A&B are correct. Q135 What should be the value of Rxlev Access min set:
  47. 47. 1. -47dbm 2. -110dm 3. -65dbm 4. -85dbm Q136 What would be the output of a cell with parameter setting as MstxPwrmax=0db,BsTxPWrMax =30db 1. Cell will carry max.no of calls 2. Cell will carry very few calls 3. Cell will not be latched 4. Cell with a correct parameter setting. Q137 What would be the power loss after using a combiner in a sector: 1. -2db 2. -1db 3. -3db 4. -4db Q138 What will happen in case where GTRX=Y(Non Edge TRX),EDGE=Y: 1. TRX will be unlocked 2. System will not allow the TRX to be unlock 3. TRX will go in Block state 4. Both B&C are correct. Q139 Which report would give you the total payload for GPRS: 1. 232 2. 208 3. 228 4. 226. Q140 In a Flexi BTS 1 physical TRX would logically represent how many Trx: 1. 1 2. 2
  48. 48. 3. 3 4. None of the above. Q141 ‘Booster ’ becomes a solution in case of : 1. Capacity 2. Coverage 3. A & B Both 4. None of the above Q142 Recommended value of ITCF is : 1. 2 2. 0 3. 1 4. 4 Q143. Which ND report gives the data for RACH rejection on cell level? 5. 134 6. 132 7. 188 8. 111. Q144. Which ND report would you refer in order to find the discrepancy for Handovers? 5. Report 163 6. Report 166 7. Report 153 8. Report 208 Q145.On what basis would an optimizer decide whether the site serving is overshooting: 5. On the basis of TA 6. From ND report 232 7. Drive test logs 8. All of the above Q146.Which ND report would give you the total payload for GPRS: 5. 232 6. 208 7. 228 8. 226. Q147 What is a Command to check active alarms on bts:
  49. 49. 1. ZERO 2. ZEQO 3. ZEOL 4. ZELO Q148 Value of BSC Timers can be checked by command: 1. ZEFO 2. ZEDO 3. ZEHO 4. ZEGO Q149 ND Report 71 Tells: 1. Adjacencies having highest success rate 2. Adjacencies having highest failure rate 3. All adjacencies 4. None of the above Q150.Which report gives value of dedicated data time slots: 1. 051 2. 053 3. 061 4. 063. Q151. Which is ND Report number for AMR Parameters? 1. 051 2. 111 3. 216 4. 053 Q152. Which report shows percentage of HO attempts happening due to GPRS? 1. 150 2. 151 3. 153 4. 154
  50. 50. Q153 Which ND report gives detailed analysis of a cell? 1. 204 2. 216 3. 186 4. 226 Q154 In which ND report we can see hourly Traffic Profile for a cell? 1. 180 2. 181 3. 182 4. 186 Q155. In which ND report we can see hourly call drops due to TCH_RF_NEW_HO counter? 1. 216 2. 213 3. 163 4. 166 Q156. In which ND report we can see adjacency discrepancy between neighbor definitions? 1. 061 2. 060 3. 067 4. 073 Q157. Which are the Coverage Enhancement Features of NSN System? 1. ICE 2. Reverse ICE 3. Smart Radio Concept(SRC) 4. All of Above Q158. Which ND Report shows Paging Success Rate per LA? 1. 213 2. 216 3. 186 4. 222 Q159. Which ND report shows EGPRS KPI? 1. 230 2. 226
  51. 51. 3. 229 4. 228 Q160 Which counter shows DL multislot assignment in percentage? 1. msl_13 2. msl_14 3. msl_15a 4. msl_16a Q161. How many 64 Kbps DAP TSLs are required if MS is using MCS 9 (consider: dedicated data timeslot = 4, single data user attached)? 1. 2 2. 4 3. 6 4. 8 Q162. How many maximum Abis timeslots can be handle by PCU ? 1. 64 2. 128 3. 256 4. 264 Q163. What is the Maximum output power of Metrosite BTS in terms of Watt? 1. 5 2. 10 3. 20 4. 40 Q164. What is the maximum number of TRX’s can created per BCSU in BSC 3i with version S12? 1. 110 2. 200 3. 100 4. 220 Q165. Which interface is required to implement combine paging (Voice + Data) 1. Gs 2. DPM ( Dual Paging Mode) 3. Gn 4. DPT ( Dual Paging Transmission)
  52. 52. Q166. In which ND report we can see TRHO Handovers attempt and success? 1. 153 2. 154 3. 155 4. 156 Q167. How many TRX’s can be handled by 1 BB2F Card in Ultra Site BTS? 1. 2 2. 3 3. 4 4. 6 Q168. Which of the following BTS Type do not have combiner in-built in them? 1. Ultra Site 2. Metro Site 3. Flexi BTS 4. None of above Q169. Which report will help to see EDAP Congestion? 1. 280 2. 281 3. 128 4. 082 Q170. In which ND report we can see paging deletion counts for cell level? 1. 180 2. 181 3. 182 4. 186 Q171 Out of following, which is true as per NSN Specification? 1. CDED<=CDEF 2. CDED>CDEF 3. CDED=CDEF+CMAX 4. CDEF=CDED+CMAX
  53. 53. Q172. What should be minimum value of CDED(%) to have 1 RTSL as dedicated GPRS Timeslot considering 2 TRX as GPRS TRX? 1. 0 2. 1 3. 8 4. 10 Q173 Which report shows Intra Cell Handover Statistics? 1. 150 2. 153 3. 154 4. 158 Q174 What is the maximum data throughput/timeslot can be achieved in case of MCS 9? 1. 64 Kbps 2. 59.2 Kbps 3. 118 Kbps 4. 230.4 Kbps Q175 Which BTS Type does not support Rx Diversity (RDIV) parameter? 1. Flexi Edge BTS 2. Ultra BTS 3. Metro BTS 4. Talk Family BTS Q176 In case of EDGE which of the following CS offers highest coverage? 1. MCS 1 2. MCS 9 3. MCS 5 4. CS 1 Q177 Which ND Report shows Trx vise quality distribution? 1. 180 2. 269 3. 196 4. 169 Q178 ND Report gives radio timeslot configuration? 1. 111 2. 222 3. 121
  54. 54. 4. 051 Q179 Noise separation feature can be implemented in? 1. TCSM 2. BSC 3i 3. Flexi BTS 4. TRX Q180 Which of the following is not a feature of GSM network alone, but also feature of analog mobile communication network? 1. Digital transmission of user data in air interface 2. Possibility of full international roaming in any country 3. Better speech quality 4. Fully digitized switching exchange Q181 which of the following is parameter affecting cell sites while planning the network 1. Antenna height 2. MS power 3. BTS Power 4. None Of Above Q182 What is E interface? 1. MSC-MSC 2. MSC-VLR 3. MSC-HLR 4. HLR-VLR Q183 In GSM which type of handover occurs? 1. Hard 2. Soft 3. Both of the above 4. Make before break Q184 Choose the correct bit pattern of a flag in LAP-D format ? 1. 01111110 2. 11111111 3. 10101010. 4. 01010101. Q185 Mobile identity is a part of?
  55. 55. 1. Physical layer Info 2. Lap-D Info 3. BSSMAP Info 4. GSM L3 Info Q186 Maximum PLMN Permitted can be ? a) 7 b) 8 c) 1 d) 2 Q187 how many BSIC possible if NCC=4, no of BCCH ARFCN =8 ? a) 32 b) 64 c) 256 d) 1024 Q188 DTX helps in a) Reducing TCH congestion b) Reducing SDCCH congestion c) Reducing interference d) Improving paging success Q189. BSSAP needs the services of SCCP to a) Analyze A subscriber data b) To perform Connectionless signaling with the MSC c) Send MAP messages to HLR via the MSC d) To make a virtual connection between the MS and the MSC Q190. Which of the following is true? a) MAP stands for Mobile Access Part b) LAP-D protocol is used to communicate between MSC and BSC c) MAP is used for communication between MSC and HLR d) BSSAP is used for communicating between BSC and MS
  56. 56. Q191. If an inter MSC handover occurs during a call, the decision to make a handover is done by a) BSC controlling the target cell b) MSC controlling the target cell c) BSC controlling the current cell d) MSC controlling the current cell Q192. Which of the following is not an advantage of the GSM network Compared to other networks which use the same frequency band? a) Lower Carrier to Interference Ratio for signal reception b) Use of MAP signaling c) Frequency reuse is more efficient than in other networks d) Lower bit rate for voice coding Q193. The basic principle of speech coding in a GSM Mobile Station is a) A-Law PCM with 8 bits per sample b) -Law PCM at 104Kbits/s c) A-Law PCM with special filtering at 13Kbits/s d) None of the above Q194. Authentication verification is carried out in a) HLR b) MSC c) VLR d) Authentication Centre Q195. No calls initiating in a cell, handover traffic is present 1. wrong neighbor defined 2. CGI creation problem 3. Same BCCH Allocated in neighbor 4. None of above Q196. Which of the following facility is not supported by Net monitor? 1. Neighbor Cell Id 2. DTX Status
  57. 57. 3. Ciphering status 4. HSN Q 197. In a cell configured with phase diversity, with air combining, what should be ideal distance between two antennas of same sector? 1. At least λ/4 separated 2. At least λ/10 separated 3. 0 distance 4. None of above Q198. Which of the following is supported by remote tune combiner? 1. BB Hopping 2. RF Hopping 3. Cyclic Hopping 4. All of above Q199. Which of the following is affecting SDCCH capacity on Abis Interface? 1. TRX Signaling Size 2. No of TCH in sector 3. EDAP Pool 4. OMU Signaling Q200. Alarm no. 2993 indicates 1. TCH Drop on Abis Interface 2. TCH Drop on Ater Interface 3. TCH Drop on Air Interface 4. TCH Drop on A Interface

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