Electronics Communications interview questions and answers - part 3


Electronics Communications interview questions and answers - part 3

Part 1   Part 2   Part 3   Part 4   Part 5   Part 6

12. What are the drawbacks of walsh codes?

Walsh codes have the following drawbacks :

1. The codes do not have a single, narrow autocorrelation peak.
2. The spreading is not over the whole bandwidth; instead the energy is spread over a number of discrete frequency components.
3. Although the full sequence cross correlation is identically zero, this does not hold for a partial sequence cross correlation function. Thus advantage of using orthogonal codes is lost.
4. Orthogonality is also affected by channel properties like multi path.

13. Explain radio environment in building.

Building penetration : Building penetration depends on the material used for construction and architecture used. This varies building to building and is based on building construction.
Building Height Effect : The signal strength is always higher at top floor and generally floor gain height is about 2.7dB/floor which is not dependent on building construction.
Building Floor Reception : The signal isolation between floors in a multi floor building is on the average about 20dB. Within a floor of 150 * 150 feet, the propagation loss due to interior walls, depending on the wall materials is about 20 dB between the strong and the weak areas.

14. List some advantages of GSM.

Here are some advantages of GSM :
1. GSM is mature, this maturity means a more stable network with robust features.
2. Less signal deterioration inside buildings.
3. Ability to use repeaters.
4. Talk time is generally higher in GSM phones due to pulse nature of transmission.
5. The availability of Subscriber Identity Modules allows users to switch networks and handset at will.
6. GSM covers virtually all parts of world so international roaming is not a problem.

15. What are the various types of numbers for network identity?

Various types of number for network identity are as follows :
1. MSISDN ( Mobile station ISDN) Number : It is international mobile subscriber number which is normally called mobile number. It is unique worldwide.
2. MSRN ( Mobile Subscriber Routing Number) : MSRN is used during mobile terminate trunk call to provide location of mobile subscriber.
3. HON ( Hand Over Number ) : HON is used for providing information required to transfer call from one B?SC to another BSC or to another MSC.
4. ISMI ( International Mobile Subscriber Identity Number) : Purpose of ISMI is for location update and authentication.
5. TMSI ( Temporary Mobile Subscriber Identity ) : TMSI is used instead of IMSI to improve security efficiency of network.
6. IMEI : International Mobile Equipment Identity.

Part 1   Part 2   Part 3   Part 4   Part 5   Part 6

Write your comment - Share Knowledge and Experience

Discussion Board
What is frequency?

Frequency is the rate at which something occurs at particular periode of time.

Ankit Atara 07-13-2018 04:50 AM


Sir , I am fresher plz help me gidence for future . Plz help me company interview

anil kumar 04-4-2015 02:07 AM


what is frequency

o.jeevesh 11-11-2014 10:45 PM


Latest MCQs
» General awareness - Banking » ASP.NET » PL/SQL » Mechanical Engineering
» IAS Prelims GS » Java » Programming Language » Electrical Engineering
» English » C++ » Software Engineering » Electronic Engineering
» Quantitative Aptitude » Oracle » English » Finance
Home | About us | Sitemap | Contact us | We are hiring