10+ Pristine Title Services Interview Questions and Answers

I have worked on LTE & VoLTE features such as QoS, SRVCC, CSFB, TTI bundling, etc. and their related parameters.

• QoS parameters such as ARP, QCI, GBR, MBR, etc.

• SRVCC parameters such as HO margin, HO failure threshold, etc.

• CSFB parameters such as timer values, RAT priority, etc.

• TTI bundling parameters such as bundle size, bundle factor, etc.

• VoLTE parameters such as AMR codec modes, RTP packetization, etc.

• UE categories and their capabilities

• eNodeB configuration parameters such a...read more

HARQ & TTI Bundling are techniques used in wireless communication to improve data transmission efficiency.

• HARQ stands for Hybrid Automatic Repeat Request and is used to improve the reliability of data transmission by retransmitting erroneous packets.

• TTI Bundling stands for Transmission Time Interval Bundling and is used to reduce latency by transmitting multiple packets in a single transmission time interval.

• The value set for HARQ in the network depends on the specific implem...read more

CFRA and CBRA are different algorithms used in RACH. Success rates can be fetched separately.

• CFRA stands for Contention Free RACH Algorithm, while CBRA stands for Contention Based RACH Algorithm.

• CFRA is used for devices with higher priority, while CBRA is used for devices with lower priority.

• Success rates for CFRA and CBRA can be fetched separately by analyzing the RACH logs.

• CFRA success rate is usually higher than CBRA success rate due to its priority usage.

The maximum throughput in LTE network with 20MHz TDD bandwidth depends on various factors.

• Theoretical maximum throughput is 1.6 Gbps

• Practical maximum throughput is around 1 Gbps

• Actual throughput depends on factors like signal strength, interference, number of users, etc.

• Carrier aggregation and MIMO can increase throughput

• Real-world throughput can be measured using tools like speedtest.net

I analyze network data to identify areas with high PS drops and work on optimizing those areas.

• Analyze network data to identify areas with high PS drops

• Optimize network parameters such as RSRP, RSRQ, SINR, etc.

• Check for interference and adjust antenna tilt and azimuth

• Ensure proper handover parameters are set

• Perform drive tests to validate improvements

• Collaborate with other teams such as RF and Core to resolve issues

• Implement features such as Carrier Aggregation and MIMO to im...read more

We ensure accessibility improvement in LTE network through various measures.

• Conducting regular network audits to identify areas of improvement

• Deploying small cells and repeaters to improve coverage in remote areas

• Implementing carrier aggregation to increase network capacity

• Providing network optimization services to improve network performance

• Collaborating with device manufacturers to ensure compatibility with our network

• Offering accessibility features on our devices such as t...read more

I ensure proper parameter tuning, interference management, and capacity planning for LTE network throughput improvement.

• Regularly monitor network KPIs to identify areas of improvement

• Optimize network parameters such as handover parameters, antenna tilt, etc.

• Implement interference management techniques such as interference coordination, power control, etc.

• Perform capacity planning to ensure sufficient resources are available to handle traffic demand

• Upgrade network hardware and...read more

The mobile network operator has major involvement in SRVCC.

• SRVCC stands for Single Radio Voice Call Continuity

• It is a feature that allows a seamless handover of voice calls from LTE to 3G or 2G networks

• The mobile network operator is responsible for implementing and supporting SRVCC

VoLTE uses various speech codecs for efficient voice transmission.

• AMR-WB (Adaptive Multi-Rate Wideband) codec is widely used in VoLTE.

• Other codecs used include EVS (Enhanced Voice Services), Opus, and G.711.

• The choice of codec depends on factors such as network capacity, device compatibility, and call quality requirements.

FDD and TDD are two different duplexing techniques used in wireless communication networks.

• FDD stands for Frequency Division Duplexing while TDD stands for Time Division Duplexing.

• In FDD, separate frequency bands are used for uplink and downlink communication while in TDD, the same frequency band is used for both uplink and downlink communication.

• FDD is commonly used in 3G and 4G networks while TDD is commonly used in 5G networks.

• FDD provides better voice quality and is more ...read more

VoLTE e2e call flow is the process of establishing a voice call over LTE network.

• The call is initiated by the user and the device sends a SIP invite message to the IMS network.

• The IMS network authenticates the user and sends a SIP 180 ringing message to the device.

• Once the called party answers, the IMS network sends a SIP 200 OK message to the device.

• The device then sets up the media path and sends a SIP ACK message to the IMS network.

• The voice call is established and the med...read more

SIP call flow in VoLTE involves signaling between UE, IMS, and PSTN networks.

• UE sends INVITE message to IMS network

• IMS network authenticates and authorizes the user

• IMS network sends INVITE message to PSTN network

• PSTN network sends ringing message to IMS network

• IMS network sends ringing message to UE

• When call is answered, media flow is established between UE and PSTN network

• Call teardown involves exchange of BYE messages

There are 3 MCS (Modulation and Coding Schemes) in LTE.

• MCS 1: QPSK modulation with coding rate of 1/2

• MCS 2: 16QAM modulation with coding rate of 1/2

• MCS 3: 64QAM modulation with coding rate of 2/3

• Higher MCS values indicate higher modulation and coding rates

• The selection of MCS depends on the channel quality and available bandwidth