1.
Which of the following codecs can be used for HD voice?
Correct Answer
B. 12. 65 AMR - WB
Explanation
The codec 12.65 AMR-WB can be used for HD voice.
2.
If QCI 1 is mapped to pbit 6, then what is the binary equivalent for the pbit?
Correct Answer
C. 101
Explanation
The binary equivalent for the pbit is 101. This can be determined by mapping QCI 1 to pbit 6 and converting the decimal number 6 to binary, which is 101.
3.
Which of the following can impact peformance of a VoLTE call
Correct Answer
D. All of the above
Explanation
Jitter, packet loss, and latency can all impact the performance of a VoLTE call. Jitter refers to the variation in the delay of packets, which can cause disruptions in the call quality. Packet loss occurs when packets of data are not successfully transmitted, resulting in missing or distorted audio during the call. Latency refers to the delay in the transmission of data, which can cause delays in the conversation and affect the real-time nature of the call. All of these factors can contribute to a degraded VoLTE call experience.
4.
Standards for VoLTE are defined in
Correct Answer
C. GSMA IR.92
Explanation
GSMA IR.92 is the correct answer because it is a technical specification developed by the GSM Association (GSMA) that specifically defines the standards for Voice over LTE (VoLTE). RFC3261 is a standard for the Session Initiation Protocol (SIP) used in VoIP, but it does not specifically define VoLTE standards. 3GPP - Release 8 is a set of standards for mobile communications, but it does not specifically focus on VoLTE. Therefore, the correct answer is GSMA IR.92.
5.
The LTE RAN network must support the following combination of radio bearers
Correct Answer
D. Both A. & C. possible
Explanation
Both A. & C. are possible because they both satisfy the requirement of supporting SRB1 and SRB2, along with a combination of AM DRB and UM DRB. In option A, there are 2 AM DRBs and 1 UM DRB, while in option C, there is 1 AM DRB and 1 UM DRB. Both combinations fulfill the given criteria, making both options A and C correct.
6.
From Figures 1 and 2, we can incur that _________________________
Correct Answer
A. Call drops & all bearers are setup in next call.
7.
S-TMSI is combination of which of the two IDs?
Correct Answer
A. MMEC & M-TMSI
Explanation
The correct answer is MMEC & M-TMSI. S-TMSI stands for "Serving Temporary Mobile Subscriber Identity" and it is a combination of MMEC (Mobile Management Entity Code) and M-TMSI (Mobile Temporary Subscriber Identity). MMEC is a unique identifier assigned to the MME (Mobility Management Entity) in the LTE network, while M-TMSI is a temporary identifier assigned to a mobile subscriber by the MME. Together, MMEC and M-TMSI form the S-TMSI, which is used for identification and tracking of mobile subscribers within the LTE network.
8.
What protocol stack is used over the S1-U interface?
Correct Answer
A. GTP/UDP/IP/L1,L2
Explanation
The S1-U interface uses the GTP/UDP/IP/L1,L2 protocol stack. This stack includes the GTP (GPRS Tunneling Protocol) for tunneling user data, UDP (User Datagram Protocol) for transport, IP (Internet Protocol) for addressing and routing, and L1,L2 (Layer 1, Layer 2) for the physical and data link layers of the network.
9.
The QoS for default bearer will be defined on which network component?
Correct Answer
B. MME
Explanation
The QoS for the default bearer is defined on the MME (Mobility Management Entity). The MME is responsible for the control and management of the bearer and session establishment for the user equipment. It handles the signaling between the user equipment and the core network, including the establishment, modification, and release of bearers. Therefore, the QoS parameters for the default bearer, which is the initial bearer established for a user, are defined on the MME.
10.
The interface between PCRF and IMS is __________. Refer to Figure below.
Correct Answer
B. Rx
Explanation
The interface between PCRF and IMS is Rx. Rx is a reference point defined by the 3GPP (Third Generation Partnership Project) for the control plane interaction between the PCRF (Policy and Charging Rules Function) and the IMS (IP Multimedia Subsystem). It is responsible for the exchange of policy and charging related information between these two network elements.
11.
The transport, application protocol, QCI value, and GBR for the message in the Figure below are _________,________,_________&_________.
Correct Answer
C. UDP, GTPV2, 1 & 38
Explanation
The transport protocol used for the message in the figure is UDP, as indicated by the second option. The application protocol used is GTPV2, as stated in the same option. The QCI value is 1 and the GBR is 38, as also mentioned in the second option. Therefore, the correct answer is UDP, GTPV2, 1 & 38.
12.
The UE ip address is __________ and the command code is _________. Refer to Figures 1 and 2 below.
Correct Answer
C. 10.0.8.174, No command codes for GTPV protocol
13.
Which IMS node is responsible for identifying the S-CSCF of the UE?
Correct Answer
A. I-CSCF
Explanation
The I-CSCF (Interrogating-Call Session Control Function) is responsible for identifying the S-CSCF (Serving-Call Session Control Function) of the UE (User Equipment) in an IMS (IP Multimedia Subsystem) network. The I-CSCF acts as a front-end for the S-CSCF, receiving requests from the UE and forwarding them to the appropriate S-CSCF based on the user's profile and location. It plays a crucial role in the call setup and routing process within the IMS network.
14.
Which of the following protocols is used in an IMS network for media handling?
Correct Answer
A. RTP
Explanation
RTP (Real-time Transport Protocol) is the correct answer for this question. RTP is a protocol used for the delivery of real-time audio and video over IP networks. In an IMS (IP Multimedia Subsystem) network, RTP is used for media handling, ensuring the timely and synchronized delivery of media streams between different devices and applications. SIP (Session Initiation Protocol) is also used in an IMS network for session establishment and signaling, but RTP specifically handles the media transport aspect. SCTP (Stream Control Transmission Protocol) and HTTP (Hypertext Transfer Protocol) are not directly related to media handling in an IMS network.
15.
What is the correct explanation of the error message – “408 Request Time out”? (Hint: Refer to RFC3261)
Correct Answer
B. The server could not produce a response within a suitable amount of time
Explanation
The error message "408 Request Time out" indicates that the server was unable to generate a response within a reasonable timeframe. This could be due to various reasons such as network congestion, server overload, or issues with the server's processing capabilities. The server may retry the request by creating a new request with appropriate modifications, but in this specific case, the error message simply signifies a timeout in receiving a response from the server.
16.
What is the reason for MO call setup failure? Refer to call flow in Figure below.
Correct Answer
A. User disconnects the call.
Explanation
The reason for MO call setup failure is that the user disconnects the call. This means that the user intentionally ends the call before it can be successfully set up.
17.
How many possible transactions take place in the following dialogue? Refer to call messages in Figure below.Note: Logs collected at MO UE.”
Correct Answer
B. 4
Explanation
Based on the given information, the correct answer is 4. This means that there are 4 possible transactions taking place in the dialogue. The figure mentioned in the question likely provides additional context or details about these transactions. However, since the figure is not provided, it is not possible to provide a more detailed explanation.
18.
QCI 1 needs to be configured in eNB with…
Correct Answer
B. RLC UM
Explanation
The correct answer is RLC UM. QCI 1 is a Quality of Service Class Identifier used in LTE networks to prioritize traffic. RLC UM stands for Radio Link Control Unacknowledged Mode, which is a type of RLC mode used for data transfer in the LTE network. It provides an unreliable and unacknowledged mode of transmission, suitable for non-delay sensitive traffic. Configuring QCI 1 with RLC UM in the eNB ensures that the traffic with QCI 1 receives the appropriate level of service and priority in the LTE network.
19.
Uplink Scheduling Stratey for VOLTE is decided based on ……
Correct Answer
B. LCG
Explanation
The correct answer is LCG. LCG stands for Logical Channel Group and it is used as a scheduling strategy for VOLTE (Voice over LTE) services. LCG allows for the prioritization of different types of traffic based on their QCI (Quality of Service Class Identifier). By using LCG, the network can allocate resources more efficiently and ensure that VOLTE traffic is given higher priority to maintain the required level of service quality and minimize delays or missed targets.
20.
What is in LCG 3?
Correct Answer
A. QCI 9/best effort traffic
Explanation
The correct answer is QCI 9/best effort traffic. This means that in LCG 3, the quality of service for the traffic is set to QCI 9, which is the lowest priority level and provides best effort service. This suggests that the traffic in LCG 3 is given the least priority and may experience delays or lower quality compared to other traffic with higher QCI levels.
21.
What PmServiceTimeUE does?
Correct Answer
A. Count Service Time
Explanation
PmServiceTimeUE refers to the counting of service time. It is a metric used to measure the amount of time a service is active or in use. This could be the duration of a call, the time a user spends using a particular application, or any other type of service. By counting the service time, it allows for the analysis of usage patterns and the identification of any potential issues or improvements that need to be made.
22.
VOLTE enabler features includes….
Correct Answer
C. TTI Bundling, DRX, RoHC
Explanation
The correct answer is TTI Bundling, DRX, RoHC. These features are part of the VOLTE enabler. TTI Bundling stands for Transmission Time Interval Bundling, which combines multiple radio frames into one transmission to improve efficiency. DRX stands for Discontinuous Reception, which allows the device to periodically turn off the receiver to save power. RoHC stands for Robust Header Compression, which reduces the size of IP headers to optimize bandwidth usage. These features are essential for providing a reliable and efficient VOLTE service.
23.
What is the maximum PDB limit for GBR?
Correct Answer
A. 300 ms
Explanation
The maximum PDB limit for GBR is 300 ms. This means that the Guaranteed Bit Rate (GBR) for a connection cannot exceed 300 milliseconds. The GBR is a measure of the minimum rate at which a network connection can transmit data. In this case, the maximum limit is set at 300 ms, indicating that the connection cannot transmit data at a rate higher than this value.
24.
GBR stands for...
Correct Answer
A. Gurrantee bit rate
Explanation
GBR stands for "Guarantee Bit Rate". This term is commonly used in telecommunications to refer to a guaranteed minimum rate of data transfer or transmission. It ensures that a certain amount of bandwidth is allocated or reserved for a specific service or application, guaranteeing a minimum level of performance.
25.
Delay based scheduling bundle ____ packets for scheduling efficiency.
Correct Answer
C. 2
Explanation
Delay based scheduling bundles 2 packets for scheduling efficiency.
26.
DBS main benefit?
Correct Answer
A. Schedule volte packets without compromising VOLTE quality & Weight VOLTE package for scheduling
Explanation
This answer is correct because it states that the main benefit of DBS is to schedule VOLTE packets without compromising VOLTE quality. Additionally, it mentions that the VOLTE package is weighted for scheduling, indicating that it is given priority in the scheduling process. This combination of scheduling VOLTE packets without compromising quality and prioritizing them through weight is the main benefit of DBS.
27.
DBS saves _____ .
Correct Answer
C. PDCCH, SE/TTI, increase VOLTE capacity at cell edge
Explanation
The correct answer is "PDCCH, SE/TTI, increase VOLTE capacity at cell edge." This answer suggests that DBS (Dynamic Bandwidth Sharing) saves PDCCH (Physical Downlink Control Channel) resources, SE/TTI (Spatial Efficiency/Transmission Time Interval) resources, and increases VOLTE (Voice over LTE) capacity at the cell edge. This implies that DBS optimizes the allocation of resources in order to improve the capacity and efficiency of the network for VOLTE services at the cell edge.
28.
DBS viop package are bundled at scheduling interval
Correct Answer
A. 40 ms
Explanation
The correct answer is 40 ms. The DBS viop package is bundled at a scheduling interval of 40 ms.
29.
To send VOLTE packet UE will send ___ and ___ ___ until scheduled
Correct Answer
B. SR and stay awake
Explanation
To send VOLTE packet, the UE will send Status Report (SR) and stay awake until scheduled. This means that the UE will send a report on its status and will remain active until the scheduled time for sending the VOLTE packet.
30.
RoHC function as
Correct Answer
A. Compressor
Explanation
RoHC stands for Robust Header Compression. It is a protocol used in IP networks to compress the IP, UDP, and RTP/UDP headers in order to reduce the overhead of the packet size. This compression is done at the source and decompressed at the destination. Therefore, the correct answer is "compressor" as RoHC functions as a compressor.
31.
TTI bundling is only benefitial for UE in ____
Correct Answer
B. Bad radio condition
Explanation
TTI bundling, or Transmission Time Interval bundling, is a technique used in wireless communication systems to improve the reliability and efficiency of data transmission. It involves combining multiple TTI intervals into a single transmission, which can be beneficial in bad radio conditions. In bad radio conditions, the signal quality may be poor, leading to a higher chance of errors and packet loss. By bundling multiple TTIs together, the chances of successfully receiving the data increase, as it allows for retransmissions and error correction mechanisms to be applied more effectively. Therefore, TTI bundling is particularly beneficial in bad radio conditions to improve the overall performance and reliability of the user equipment (UE).
32.
TTI bundling will benefit in less overhead for
Correct Answer
D. MAC and RLC
Explanation
TTI bundling refers to the bundling of multiple Transmission Time Intervals (TTIs) together, which reduces the overhead in the MAC (Medium Access Control) and RLC (Radio Link Control) layers. By bundling TTIs, the amount of control signaling needed for MAC and RLC is reduced, resulting in less overhead. This allows for more efficient use of resources and improved overall system performance. Therefore, TTI bundling benefits MAC and RLC specifically.
33.
RRC Re-establishement benefit are
Correct Answer
D. VOLTE call can survive a RLF
Explanation
RRC re-establishment is a procedure in LTE where the connection between the UE (User Equipment) and the network is re-established after a temporary interruption. RLF (Radio Link Failure) refers to the loss of communication between the UE and the eNodeB (base station). The given answer suggests that a VOLTE (Voice over LTE) call can survive a RLF, meaning that even if there is a failure in the radio link, the VOLTE call will not be interrupted and will continue to function.
34.
DRX stands for...
Correct Answer
B. Discontinous reception
Explanation
DRX stands for Discontinuous Reception. It is a power-saving feature in mobile networks where the device periodically switches off its receiver to conserve battery life. This allows the device to conserve power when there is no data to receive, and it periodically wakes up to check for any incoming data. Discontinuous reception helps to optimize battery usage in mobile devices while still maintaining connectivity to the network.
35.
___ QCI is associated to __ DRX profile
Correct Answer
B. Each, 1
Explanation
QCI stands for Quality of Service Class Identifier and is used in LTE networks to prioritize different types of data traffic. DRX stands for Discontinuous Reception and is a power-saving feature in LTE networks. The QCI is associated with the DRX profile to determine the level of power saving and resource allocation for a specific type of data traffic. In this case, the correct answer is "Each, 1" which means that each QCI is associated with a DRX profile of 1, indicating a moderate level of power saving and resource allocation.
36.
How many DRX profile can be configured?
Correct Answer
A. 19
Explanation
There are 19 DRX profiles that can be configured.
37.
SID stands for...
Correct Answer
C. Silent injection descriptor
Explanation
The correct answer is "Silent injection descriptor." This term refers to a descriptor used in telecommunication systems to describe the process of silently injecting signals into a communication channel. It is commonly used in the context of Voice over LTE (VOLTE) technology, where it allows for the seamless integration of voice calls over LTE networks without interrupting ongoing data sessions.
38.
How many QCI profile configured in eNB?
Correct Answer
B. 9
Explanation
The correct answer is 9. This suggests that there are 9 QCI profiles configured in the eNB.
39.
Offset for the start of the OnDuration period
Correct Answer
A. DRX start offset
Explanation
The correct answer is DRX start offset. The DRX start offset refers to the time interval between the start of the OnDuration period and the start of the DRX (Discontinuous Reception) cycle. This offset determines when the device should start monitoring for incoming signals after a period of inactivity. It helps in optimizing power consumption by allowing the device to sleep during idle periods and wake up only when necessary to receive data.
40.
RLC UM is for
Correct Answer
B. QCI1
Explanation
The correct answer is QCI1 because QCI1 is the highest priority QoS class for RLC UM (Unacknowledged Mode). RLC UM is a mode of the Radio Link Control (RLC) protocol in LTE networks, which is used for transmitting data without requiring acknowledgment from the receiver. QCI1 is typically used for delay-sensitive applications such as voice over IP (VoIP) and real-time video streaming, where low latency and high reliability are crucial. Therefore, QCI1 is the most appropriate QoS class for RLC UM in this scenario.
41.
Best effort Traffic is on
Correct Answer
A. LCG3
Explanation
The correct answer is LCG3 because the given options are related to different aspects of traffic. "Traffic is on" is a general statement indicating that there is traffic present. "SRB" stands for Signaling Radio Bearer, which is a logical channel used for transmitting control signaling messages. "VOLTE" refers to Voice over LTE, which is a technology that allows voice calls to be transmitted over a 4G LTE network. "QCI1 and QCI5" are Quality of Service Class Identifiers, which are used to prioritize different types of traffic. LCG3, on the other hand, is a specific term that could be related to a particular type or category of traffic.
42.
What PmServiceTimeUE counts?
Correct Answer
A. Count Service Time
Explanation
PmServiceTimeUE counts the service time for all UE (User Equipment). It keeps track of the duration for which the UE is connected to the network and actively using services. This metric is used to measure the efficiency and performance of the network in terms of providing uninterrupted service to the users.
43.
IMS stands for
Correct Answer
C. IP multimedia subsystem
Explanation
IMS stands for IP multimedia subsystem. This is a framework that enables the delivery of multimedia services over IP networks. It provides a standardized architecture for integrating various communication services such as voice, video, messaging, and data. The IP multimedia subsystem allows for the seamless integration of different networks, devices, and applications, providing users with a consistent and unified experience across multiple platforms.
44.
ENB decodes the codec...
Correct Answer
A. No
Explanation
ENB (Evolved Node B) does not decode the codec. The decoding of the codec is done by the UE (User Equipment) or the mobile device. The ENB is responsible for receiving and transmitting the radio signals between the UE and the core network. It handles tasks such as modulation, demodulation, and channel coding, but it does not directly decode the codec used for audio or video data.
45.
RTP stands for
Correct Answer
B. Real-Time transport protocol
Explanation
RTP stands for Real-Time Transport Protocol. This protocol is used for delivering audio and video over IP networks. It provides mechanisms for the timely and synchronized delivery of data packets, ensuring that real-time applications such as video conferencing and streaming media can be transmitted in a smooth and efficient manner. RTP works in conjunction with other protocols such as UDP (User Datagram Protocol) for transport and RTCP (Real-Time Control Protocol) for monitoring and control.
46.
SIP stands for
Correct Answer
A. Session initiation protocol
Explanation
SIP stands for Session Initiation Protocol. It is a communication protocol used for initiating, modifying, and terminating sessions between participants over an IP network. It is commonly used for voice and video calls, instant messaging, and other multimedia communications. The other options, silent insertion protocol, session insertion portion, and season initiation protocol, are not valid definitions for SIP.
47.
QoS
Correct Answer
A. Quality of Service
Explanation
Quality of Service (QoS) refers to the ability of a network or system to prioritize and deliver different types of data or services based on their importance and requirements. It ensures that critical services, such as voice and video, are given higher priority and are delivered with minimal delay and packet loss. QoS helps to maintain a consistent and reliable performance for applications and services, even during periods of high network traffic or congestion.
48.
QCI
Correct Answer
C. Quality of Service Class Indicators
Explanation
The correct answer is "Quality of Service Class Indicators." QCI stands for Quality of Service Class Indicators, which are used in telecommunications to measure and classify the quality of service provided by a network. QCI values are assigned to different types of traffic to prioritize and ensure the appropriate level of service quality for each type. This helps in managing network resources efficiently and providing a better user experience.
49.
VIOP packages arrives to eNB at
Correct Answer
A. 20ms interval
Explanation
The correct answer is "20ms interval" because it indicates that the VIOP packages arrive at the eNB (evolved Node B) every 20 milliseconds. This interval is important for maintaining a smooth and continuous flow of data in real-time communication, such as voice over IP (VIOP) calls.
50.
SRVCC
Correct Answer
B. Single radio voice call continuity
Explanation
SRVCC stands for Single Radio Voice Call Continuity. This term refers to a feature in telecommunications that allows for seamless handover of a voice call from an LTE (Long-Term Evolution) network to a 2G or 3G network. This ensures that the call remains uninterrupted as the user moves between different network technologies. Therefore, the correct answer is "single radio voice call continuity".