Interview Questions.

Question 1. What Are The Bandwidths Used For Lte Deployment?

Answer :

This following Bandwidths being used for LTE,

1.4 MHz

three MHz

five MHz

10 MHz

15 MHz

20 MHz

Question 2. What Is Subcarrier Bandwidth In Lte?

Answer :

15 kHz

Networking Interview Questions
Question 3. What Maximum Lte Throughput Can Be Achieved In The Field?

Answer :

upto 70Mbps on TDD community with 20 MHz bandwidth channel.

Question four. How Many States A Ue Can Have?

Answer :

There are 2 UE stats i.E. UE Idle and UE Connect.

UE can either be on Connected or on Idle state at a time.

Networking Tutorial
Question 5. What Is Difference Between Ho , Redirection, Cell Selection And Re-selection?

Answer :

Handover (HO): UE movements from one eNB to target eNB while maintaining its connected nation. LTE Services can be uninterrupted.In handover method, goal cellular would be organized and UE will latch on the right track cellular based on the configuration sent by supply enodeb to UE.

Redirection: UE adjustments its nation from connected to Idle mode at some stage in Redirection. LTE Service could be interrupted. Meaning the Source ENB shall release the relationship of the UE and will ask the UE to redirect itself onto the target ENB through indicating the carrier frequency or the cellular id inside the RRC connection release message. For example, During CS Fallback, the UE is redirected from LTE RRC_CONNECTED mode to (2G/3G) idle mode).

Cell Selection: It permits a UE to go looking and camp on a suitable cellular. Cell selection occurs in the course of Initial cell choice (while UE switches ON),  Stored statistics mobile choice (makes use of saved mobile information to pick out suitable cell),  and Cell choice when leaving RRC connected mode (When UE move from RRC CONNECTED to RRC IDLE mode)

Cell Reselection: Its Idle mode technique and happens from idle mode to idle mode. Reselection can occue on mobile within identical RAT (Intra-RAT) or special RAT(Inter-RAT).

Telecommunication Project Management Interview Questions
Question 6. What Is Rrc Reconfiguration?

Answer :

RRC CONNECTION RECONFIGURATION message is the command to alter an RRC connection. Main purposes of RRC Connection Reconfiguration are to,

Establish/adjust/launch Radio Bearers
Perform Handover
Setup/modify/launch Measurements
Add/modify/release SCells
Dedicated NAS Information may additionally be transferred from eNodeB to UE
Question 7. What Are The Handover Types In Lte ?

Answer :

The Handover is the manner of shifting an ongoing records session/Call from

one (source) cellular connected to the middle network to another (goal) mobile. Handovers are wanted whilst UE moved out of its serving cellular’s coverage or for load balancing functions.

In cell communication, Handover can either be Network controlled (i.E. HO selection is with community) or Mobile Evaluated (i.E. Mobile terminal makes HO decision and tell Network to arrange sources on target cells)

LTE uses both the techniques in a way that, LTE succesful UE sends size file to community and based totally on this document; network directs UE to move to a goal cell.

Handover Types in LTE:

Intra-LTE Handover:  Source and target cells are a part of the equal LTE community.

Handover the usage of X2 Interface

Handover the usage of S1 Interface

Inter-LTE Handover:  Handover occurs closer to other LTE nodes. (Inter-MME and Inter-SGW

Inter-MME Handover

Inter-MME/SGW Handover

Inter-RAT Handover: Handover among one-of-a-kind radio technology. For instance handover from LTE to WCDMA.

Microwave Engineering Tutorial 4G Interview Questions
Question eight. Difference Between X2 And S1 Hand Over?

Answer :

X2 Hand Over:

HO occurs whilst source and target eNBs are served within the same MME pool. The techniques is predicated at the presence of X2 interface between Source and Target eNB,

that's summarized as follows:

Source eNB makes HO decision and setup an immediate tunnel i.E X2 delivery bearer between Source and target eNB.
Detach UE from Source eNB and Forward site visitors from source eNB to Target.
Path transfer process between Target eNB and MME
Releases S1 bearer of source eNB
Release X2 delivery bearer for direct packet forwarding.
S1 Hand Over:

S1 handover is while If  eNodeBs are not connected with equal MME or the X2 interfaces aren't described between eNB or when X2 method fails(because of unreachability/Error response and many others).

Summary of S1-HO is as follows:

Source eNB makes HO selection and setup a oblique tunnel i.E S1 bearer between Source eNB and SGW, and goal eNB and SGW.
S1 bearer for UL setup between goal and source eNB
Detach UE from Source eNB and oblique packet forwarding
No want for the Path switch manner among Target eNB and MME, as MME is privy to HO
Releases S1 bearer of source eNB
Release S1 delivery bearer for oblique packet forwarding.
If the 2 eNodeBs are linked with same MME, it's miles favored to perform X2 based handover but there may be no limit in the use of S1 based handover even in this case. If two eNodeBs aren't related with identical MME, you have to perform S1 based handover even in this case.
Question nine. What Is The Difference Between Erlang And Gos?

Answer :

Both Erlang and GoS are used in smartphone change for size of calls such as calls dropped, calls exceeded and so forth.

3G Interview Questions
Question 10. What Is Bit Error Rate And How It Is Calculated?

Answer :

Bit error rate (BER) is used to degree overall performance of the wi-fi or wired device in channel or impairment environment. BER is the ratio of received faulty bits to the entire quantity of bits transmitted.

5G Tutorial
Question 11. What Is The Difference Between Cas And Ccs?

Answer :

CAS stands for Channel Associated Signaling and CCS stands for Common Channel Signaling. Both are related to PCM utilized in telephony.

Telephone Etiquette Interview Questions
Question 12. Explain Multipath Fading.?

Answer :

The version is received sign energy over time is referred as fading. When the signal traverse from transmit cease to receive give up, it's going to have many reflections from homes and partitions till it reaches obtain quit. This effects into multipath fading.

Networking Interview Questions
Question thirteen. What Is Type Of Modulation Used In Gsm?

Answer :

GMSK stands for Gaussian Minimum Shift Keying.

LTE Tutorial
Question 14. What Is The Difference Between Lte And Lte Advanced?

Answer :

LTE is laid out in 3GPP launch eight and launch nine.
LTE superior is specified in 3GPP launch 10.
The fundamental difference between them is carrier aggregation is added in LTE superior.
Number of antennas supported by way of MIMO has been elevated to 8 in LTE advanced.
Question 15. What Is The Difference Between Lte Fdd And Lte Tdd?

Answer :

The distinction lies in the LTE body structure in both the FDD and TDD variations of the LTE.

In FDD there might be pair of frequencies assigned within the downlink and uplink instructions and as a result transmissions from more than one subscribes can manifest at the identical time however on exclusive frequencies as referred to.In TDD, one unmarried frequency could be used at one-of-a-kind time instants with the aid of multiple subscriber terminals (UEs).

Both frame variations of LTE may have 1 ms sub-body period and zero.Five ms slot period.

Microwave Engineering Interview Questions