GSM And CDMA: Radio Networks Design! Trivia Knowledge Quiz

The correct answer is Call setup Success Rate (CSSR). CSSR is a key performance indicator that measures the percentage of successful call setups out of the total attempted call setups. It is used to identify issues in a cell during the call establishment procedure. A low CSSR indicates that there are problems with the cell, such as congestion or poor coverage, which can result in dropped calls or failed call setups. By monitoring CSSR, network operators can identify and address issues to improve the overall call setup success rate.

WCDMA (UMTS) technology uses the frequency bands of 900 MHz, 1900 MHz, and 2100 MHz. These frequency bands are used for transmitting and receiving signals in order to provide wireless communication services. The frequency bands determine the range and capacity of the network and are essential for ensuring efficient and reliable communication.

The two duplex techniques used in LTE are FDD (Frequency Division Duplexing) and TDD (Time Division Duplexing). FDD allows for simultaneous transmission and reception on different frequencies, while TDD allows for alternating transmission and reception on the same frequency. Both techniques are used to optimize the use of available spectrum and improve network efficiency in LTE.

BSIC stands for Base Station Identity Code, and it is used in GSM networks to uniquely identify each base station. The BSIC is a combination of two parts: the Network Color Code (NCC) and the Base Station Color Code (BCC). The NCC represents the network operator, while the BCC represents the specific base station within that network. Therefore, the statement "BSIC is a combination of NCC & BCC" is correct.

A horizontal beam width of 65º would be the best choice to reduce interference between co-located cells in an LTE urban network environment with a 300-meter inter-site distance and tri-sector sites. A narrower beam width helps to focus the antenna's signal in a specific direction, reducing the chances of interference with neighboring cells. A wider beam width would allow the signal to spread out more, increasing the chances of interference. Therefore, a horizontal beam width of 65º strikes a balance between focusing the signal and minimizing interference.

The downlink footprint of GSM2 is defined by the Broadcast Control Channel (BCCH), the downlink footprint of WCDMA is defined by the Common Pilot Channel (CPICH), and the downlink footprint of LTE is defined by the Reference Signal (RS).

A splitter is used to distribute a signal with equal power distribution to multiple output ports. It takes an input signal and splits it into multiple output signals, ensuring that each output receives the same power level. This is commonly used in various applications such as telecommunications, audio/video distribution, and networking, where the signal needs to be shared among multiple devices or locations. By providing equal power distribution, a splitter allows for efficient and reliable signal transmission to multiple destinations.

Uu is the correct answer because it is the interface used in WCDMA by users equipment (UE) to communicate with a radio base station. The Uu interface is the air interface that allows for wireless communication between the UE and the base station. It is responsible for transmitting voice, data, and control signals between the two devices. The Uu interface operates in the frequency range allocated for UMTS/WCDMA and is essential for the functioning of the WCDMA network.

After re-tuning BCCH frequencies with a frequency planning tool, it is important to verify the Base Station Identity Code (BSIC). The BSIC is a unique identifier for each base station and is used to differentiate between neighboring cells. Verifying the BSIC ensures that there is no interference or confusion between neighboring cells, allowing for efficient and reliable communication within the network.

The correct answer is "eNB with MME". In an LTE network, the eNB (evolved NodeB) is responsible for managing the radio interface with the User Equipment (UE), while the MME (Mobility Management Entity) is responsible for managing the mobility and authentication of the UE. Therefore, the eNB and MME are interconnected by the interface S1 to facilitate communication and coordination between them.

Clutter type refers to the type of environment in radio network design process. It is important to consider the type of environment, such as urban, suburban, or rural, as it affects the propagation characteristics of radio waves. Different types of clutter, such as buildings, trees, or open spaces, can cause signal attenuation, reflection, or interference. Understanding the clutter type helps in determining the appropriate antenna placement, power levels, and frequency allocation for optimal radio network design.

The two output plots in LTE design when using a planning tool are a signal to interference-plus-noise ratio (SINR) plot and a receive signal reference power (RSRP) plot. The SINR plot helps to analyze the quality of the signal by comparing it with the interference and noise levels. The RSRP plot provides information about the power level of the received signal, which is crucial for determining the coverage and strength of the signal.

To reduce the negative effect of an overshooter within a cluster, two actions can be taken. First, increasing the electrical downtilt can help adjust the vertical coverage of the antenna, directing the signal downwards and reducing interference from the overshooter. Second, changing the antenna azimuth can alter the horizontal direction of the antenna's main lobe, further minimizing the impact of the overshooter by adjusting the coverage area. By implementing these two actions, the negative effects of the overshooter can be mitigated within the cluster.

Intermodulation interference occurs when two or more transmitted signals combine and produce interference on another frequency. This phenomenon is caused by non-linearities in the transmission system, such as amplifiers or mixers, which create additional frequencies that were not originally present. These additional frequencies can interfere with other signals and cause degradation in the overall signal quality. Therefore, intermodulation interference is the correct term to describe this type of interference.

The correct answer is "make before break handover". This refers to a process used by CDMA2000 and WCDMA technologies where the new connection is established before the old connection is terminated. This ensures a smooth handover without any interruption in the communication.

The radiated power of the base station is given as 100 W. To convert this power to dB units, we can use the formulas: dBm = 10log10(P/1mW) and dBW = 10log10(P/1W).

Using the first formula, we can calculate the power in dBm: dBm = 10log10(100/1) = 20 dBm.

Using the second formula, we can calculate the power in dBW: dBW = 10log10(100/1) = 20 dBW.

Therefore, the two equivalent powers expressed in dB units are 50 dBm and 20 dBW.

During the initial tuning process of a new radio network, three commonly used KPIs to evaluate the packet switched (PS) performance for the acceptance cluster are drop call rate, uplink and downlink throughput, and call setup success rate. Drop call rate measures the percentage of calls that are prematurely terminated, indicating the network's ability to maintain stable connections. Uplink and downlink throughput assess the data transfer rates in both directions, ensuring efficient transmission. Call setup success rate indicates the network's ability to successfully establish connections, reflecting its overall performance in handling call setups.

The image shows multiple antennas placed at different locations or orientations, which is known as space diversity. This technique is used to improve the reliability and performance of wireless communication systems by reducing the effects of fading and interference. Additionally, the image also shows different polarization orientations of the antennas, which is known as polarization diversity. This technique helps to mitigate the effects of signal polarization mismatch and improve the overall signal quality.

The correct answer is a theoretical capacity at which the base station receiver noise rise is infinite. This statement describes pole capacity in WCDMA or CDMA200 systems. It refers to the maximum capacity of the system where the receiver noise rise becomes infinite, indicating that the system cannot accommodate any more users beyond this point. This theoretical capacity is determined by the limitations of the base station receiver and represents the maximum number of users that can be connected to the system.

The hybrid ring combiner and filter combiner are the two RF devices that would be used to combine signals to and from two different base stations onto a single antenna. The hybrid ring combiner combines the signals from the two base stations using a hybrid ring circuit, while the filter combiner combines the signals using a filtering circuit. Both devices are designed to ensure that the signals from the two base stations do not interfere with each other and are properly combined onto the single antenna.

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Noise figure (NF) is a measure of the degradation in the signal-to-noise ratio (SNR) caused by active or passive RF system components. It quantifies how much the noise introduced by these components affects the overall quality of the signal. A lower noise figure indicates better performance and less degradation of the SNR.

Larger diameter cables have lower transmission loss per meter because they have lower resistance and higher capacitance, which results in less attenuation of the signal as it travels through the cable. This means that a larger diameter cable would be more effective in reducing transmission loss between a base station and an antenna.

Performing a drive test using a scanner is the action that should be taken to improve the accuracy of the propagation model. By conducting a drive test, data can be collected on the actual signal strength and quality at different locations, allowing for a more accurate model to be developed. This test helps in identifying any issues or discrepancies in the model and allows for adjustments to be made accordingly.

The statement "SHO can only be performed between cells using the same carrier frequency" is correct because in WCDMA soft handover, the handover is only possible between cells that are using the same carrier frequency.

The statement "Cell in active set are always in SHO" is also correct because in WCDMA soft handover, the cells in the active set are always involved in the handover process.

The three components used for propagation model tuning are GPS, CW transmitter, and radio receiver. GPS is used to accurately determine the location of the transmitter and receiver, which is essential for studying the propagation of signals. The CW transmitter is used to transmit continuous wave signals, which can be used to measure the signal strength and quality at different distances. The radio receiver is used to receive and analyze the signals transmitted by the CW transmitter, helping to understand how the signals propagate and interact with the environment.

Placing the amplifier just after the antenna (location A) maximizes the sensitivity of the overall receive system. By placing the amplifier at this location, any noise introduced by the feeder cable or base station receiver is minimized, allowing for a stronger and cleaner signal to be amplified. This ensures that the system can effectively pick up and process weak signals, improving the overall sensitivity of the receive system.

The purpose of a tower mounted amplifier is to improve the sensitivity of a base station receiver system, particularly in cases where there are high feeder losses. This means that the amplifier helps to enhance the ability of the receiver system to detect and receive signals, compensating for any signal loss that may occur due to the feeder. By improving sensitivity, the tower mounted amplifier ensures that the base station can effectively receive and process incoming signals, leading to improved overall performance.

Shadowing, also known as log-normal fading, occurs when the signal is obstructed by obstacles near the terminal. This obstruction causes variations in the received signal strength, leading to fading. The presence of physical objects such as buildings, trees, or mountains can block or attenuate the signal, resulting in shadowing. This phenomenon is commonly observed in urban environments where there are many obstacles that can interfere with the propagation of wireless signals.

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Eb/No, also known as the Energy per bit to Noise power Spectral Density ratio, is a measure of the signal quality in a communication system. It represents the ratio of the energy per bit to the noise power spectral density. In the context of WCDMA Link Budgets, Eb/No is used to define the base station or mobile station receiver noise figures. This means that it helps determine the level of noise in the receiver, which is an important factor in assessing the overall performance and quality of the communication system.

Increasing the power amplifier (PA) output power would be the best solution to resolve the problem of an overloaded cell with low DL interference. By increasing the PA output power, the signal strength of the cell will be enhanced, allowing it to handle the high DL load more efficiently. This will help in improving the overall performance and capacity of the cell, ensuring a better user experience. Increasing the number of scrambling codes or the bandwidth may not directly address the issue of overload, while disabling soft handover (SHO) may result in degraded network performance.

Changing antenna tilts can improve dominance by adjusting the angle and direction of the antenna to optimize signal coverage and reduce interference. Adding a new site in the area can also improve dominance by increasing the number of available cell sites and improving overall coverage and capacity.

Generally, remote radio units reduce feeder losses. This means that by using remote radio units, the signal loss in the feeder cables is minimized, resulting in better signal quality and coverage.

Cross polar antennas provide sufficient diversity. Cross polar antennas are designed to transmit and receive signals in different polarizations, which helps to mitigate the effects of signal fading and interference. This diversity improves the reliability and performance of the wireless network.

Link budget analysis is a method used to calculate the power budget for a wireless communication system. It takes into account factors such as transmit power, antenna gain, path loss, and receiver sensitivity to determine the maximum distance between sites. By using link budget analysis, an estimation can be provided for the number of sites needed to cover a large city based on the available power and signal strength. This method is commonly used in the telecommunications industry to plan and optimize network coverage.

The correct answer is that the idle mode cell reselection behavior of an LTE UE selects the serving cell based on a ranking using RSRP measurements, offset, and hysteresis parameters. This means that the UE will prioritize the cell with the strongest received signal strength (RSRP) while also taking into account certain parameters such as offset and hysteresis to ensure a smooth handover between cells.

The 10 K value of VSWR is 1.1. VSWR stands for Voltage Standing Wave Ratio, which is a measure of how well a transmission line is matched to the impedance of the connected device. A VSWR of 1.1 indicates a very good match between the transmission line and the device, with minimal reflections and maximum power transfer.

The symbol rate is determined by the modulation scheme and the coding rate. In this case, the modulation scheme is 64-QAM, which means that each symbol represents 6 bits of data. The coding rate is 1/2, which means that for every 2 input bits, 1 coded bit is produced.

Since the input data rate is 10 kbps, the output data rate after convolutional coding is 10 kbps * (1/2) = 5 kbps.

To find the symbol rate, we divide the output data rate by the number of bits represented by each symbol: 5 kbps / 6 bits/symbol = 0.833 ksps.

However, the question asks for the symbol rate in kilo symbols per second, so we round up to the nearest whole number: 1 ksps.

Therefore, the correct answer is 120 ksps.

HARQ with soft combining in WCDMA is a technique where one or more transmissions of a packet are used until the packet can be successfully decoded. This means that if a transmission is unsuccessful, the receiver can request retransmission of the packet until it can be decoded correctly. This helps to improve the reliability and efficiency of the communication by allowing for error correction and minimizing the impact of noise or interference.

A Remote Radio Unit (RRU) is a module that is installed close to the antenna in order to reduce feeder loss. This means that the RRU helps to minimize signal loss that can occur when transmitting and receiving signals over long distances. Additionally, an RRU is also a solution to increase coverage, meaning it helps to extend the range of a wireless network and improve the overall coverage area.

The pilot channel is set to a level equal to 10% of the total base station transmitter output power. Therefore, the transmitted power of the pilot channel can be calculated by multiplying the total output power by 10% (0.10). In this case, 40 W * 0.10 = 4 W. Converting this power value to dBm, we use the formula 10 * log10(power in watts) + 30. Thus, 10 * log10(4) + 30 = 36 dBm.

The three map types used as input to propagation prediction tools for RF & Monte Carlo Prediction are traffic distribution map, elevation map, and clutter type (environment) map. These maps provide important information for predicting the propagation of radio frequency signals and optimizing network coverage. The traffic distribution map helps in understanding the distribution of user traffic and identifying areas with high demand. The elevation map provides data on the terrain, which affects signal propagation. The clutter type map helps in identifying the type of environment, such as urban or rural, which also affects signal propagation.

The given antenna has a horizontal beamwidth of 65 degrees and a gain of 15 dBi. This means that the antenna provides maximum gain in a specific direction, and the gain decreases as the angle from the maximum direction increases. The statement that the gain is approximately 12 dBi at horizontal angles of 30 and -30 degrees from the direction of maximum gain is correct. At these angles, the gain is slightly lower than the maximum gain of 15 dBi, but still relatively high at 12 dBi.

Link adaptation is a method for adjusting CQI (Channel Quality Indicator) values to combat radio channel impairments such as multipath, fading, and interference. This technique allows for the optimization of transmission parameters, such as modulation and coding, based on the instantaneous conditions of the radio channel. By adapting to the changing channel conditions, link adaptation helps to maximize the quality and reliability of high rate data transmissions.

For a fixed physical sized antenna, the vertical beam width is smaller for higher frequency. This means that the antenna's coverage area in the vertical direction is narrower for higher frequency signals compared to lower frequency signals. Additionally, the antenna gain is higher for higher frequency. This means that the antenna is more efficient at radiating and receiving signals at higher frequencies, resulting in a stronger signal strength.

The total transmitted power in the transmitter bandwidth can be calculated by adding the power measured by the spectrum analyzer to the power that falls outside the measurement bandwidth. In this case, the spectrum analyzer measures 10 dBm in a measurement bandwidth of 50 KHz. Since the signal spectral density is constant over the transmitter bandwidth of 500 KHz, we can assume that the power outside the measurement bandwidth is the same as the power inside the measurement bandwidth. Therefore, the total transmitted power in the transmitter bandwidth is 20 dBm.

The out-of-band emission level for a base station transmitter is measured at -50 dBm per 100 kHz. To find the power of the out-of-band emission in a 1 MHz bandwidth, we need to calculate the power level for a 1 MHz bandwidth. Since the given measurement is for a 100 kHz bandwidth, we can divide the power level by 10 to get the power level for a 1 MHz bandwidth. -50 dBm divided by 10 is -5 dBm. Therefore, the power of the out-of-band emission in a 1 MHz bandwidth is -5 dBm. However, none of the given answer options match this calculation, so the correct answer is not available.

The first correct statement is that mobile phones can simultaneously connect to more than one radio link in the WCDMA or CDMA2000 network. This means that the phone can be connected to multiple base stations or cells at the same time, allowing for better coverage and improved signal quality.

The second correct statement is that mobile phones can combine multiple links using a RAKE receiver. A RAKE receiver is a type of receiver that can combine multiple signals from different paths or multipaths to improve the overall signal quality. This allows for better reception and reduces the effects of signal fading and interference.

Therefore, the correct statements are that mobile phones can simultaneously connect to more than one radio link and can combine multiple links using a RAKE receiver.

Multipath reflections in WCDMA and CDMA2000 systems have two characteristics. Firstly, they provide additional diversity, which means that the multiple reflected signals can be combined to improve the overall signal quality and reliability. Secondly, these reflections cause fast fading of the received signal, as the multiple paths can result in constructive or destructive interference, leading to rapid fluctuations in signal strength.

Based on the information provided, the RRU is installed next to the antenna and is required to match the Effective Radiated Power (EIRP) of the macro base station transmitter. Since the macro base station transmitter has an output power of 40 W, the RRU must also have an output power of 40 W in order to match the EIRP. Therefore, the correct answer is 20 W.