2. What is the difference between NOC & NMS?

Network operation center (NOC). NOCs are responsible for
monitoring the network for alarms like as power fail,
Service affected alarm (site down,LAPD OML fault, TRX close
HPA alarm etc)& communicate its field engineer to solved the
problem. if need any support for software base they provide
to recover the problem.

A Network Management System (NMS) is a combination of
hardware and software used to monitor and administer a
network. Communicate with NOC recover the Alarm.

NMS-->NOC-->Field Engineers=Solved the problem

3. Explain BTS configuration 4+2+2?

as per the utilization of sector,we can configure the
sectors a,b,c like below combination...
if 1st sector utilization is high 4+2+2
if 2nd sector utilization is high 2+4+2
if 3rd sector utilization is high 2+2+4

4. What is the total output power of an complete BTS, in dbm and watts?

43dbm/20 Wattb but this the output pwr of TRX So Total o/p
pwr of BTS depends on no. of TRX and also no. of combiner used

5. What is the difference between FER and BER?

Error ratios used in conjunction with GSM speech channels:
· Frame Erasure Rate, FER, is defined as the amount of swept speech frames (260 bits each)
divided by the amount of transmitted speech frames. The speech frame is swept if even one of
its most important 50 bits is observed not to be correct. The three parity bits following the 50
class Ia bits are used for error detection.
· Bit Error Rate, BER, is the ratio of erroneously received bits to all received bits. It is
important to notice that BER is evaluated before channel decoding, i.e. after equaliser. BER is
used for defining the RXQUAL value

6. What is snmp protocol? How is snmp work with NMS and EMS?

SNMP is based on the manager/agent model consisting of an
SNMP manager, an SNMP agent, a database of management
information, managed SNMP devices and the network protocol.
The SNMP manager provides the interface between the human
network manager and the management system. The SNMP agent
provides the interface between the manager and the physical
device(s) being managed.
The SNMP manager and agent use an SNMP Management
Information Base (MIB) and a relatively small set of
commands to exchange information. The SNMP MIB is organized
in a tree structure with individual variables, such as
point status or description, being represented as leaves on
the branches. A long numeric tag or object identifier (OID)
is used to distinguish each variable uniquely in the MIB
and in SNMP messages.

SNMP uses five basic messages (GET, GET-NEXT, GET-RESPONSE,
SET, and TRAP) to communicate between the SNMP manager and
the SNMP agent. The GET and GET-NEXT messages allow the
manager to request information for a specific variable.

The agent, upon receiving a GET or GET-NEXT message, will
issue a GET-RESPONSE message to the SNMP manager with
either the information requested or an error indication as
to why the request cannot be processed. A SET message
allows the SNMP manager to request a change be made to the
value of a specific variable in the case of an alarm remote
that will operate a relay. The SNMP agent will then respond
with a GET-RESPONSE message indicating the change has been
made or an error indication as to why the change cannot be
made. The SNMP TRAP message allows the agent to
spontaneously inform the SNMP manager of an "important"
event.

7. What is RRC States in Umts?

There are four RRC states present in UMTS .
1.CELL_DCH STATE
2.CELL_FACH STATE
3.CELL_PCH STSTE
4.URA_PCH STATE

WHEN MOBILE IS MOVING FROM IDLE MODE TO DEDICATED MODE AND
DATA TRANMISSION IS OF LARGE AMOUNT OF DATA THEN CELL_DCH
STATE COMES IN TO PICTURE .

IF DATA TRANSMISSION IS OF SMALL AMOUT OF DATA THEN
CELL_FACH STATE WILL COME IN TO PICTURE

WHEN MOBILE IS MOVING FROM ONE CELL TO ANOTHER CELL IT
SHOULD PERFORM HANDOVER THEN MOBILE RRC STATE WILL BE IN
CELL_PCH STATE.

URA MEANS UTRAN REGISTRATION AREA

THE AREA COVERED BY ONE RNC IS KNOWN AS URA

SO WHEN MOBILE IS MOVING FROM URA AREA TO ANOTHER URA AREA
THEN LOCATION UPDATION SHOULD PERFORM THEN MOBLIE RRC STATE
COMES TO URA_PCH STATE .


THESE ARE THE FOUR RRC STATES PRESENT IN UMTS NETWORK

8. What is Crankback?

Crankback is a mechanism used by ATM networks when a
connection setup request is blocked because a node along a
selected path cannot accept the request. In this case, the
path is rolled back to an intermediate node, which attempts
to discover another path to the final destination

9. In GSM we use MSRN for routing but what parameter is used in CDMA for routing?

In Gsm We use routing number towards the calling subscriber
and tldn towards the calling subscriber , but in cdma the
subcriber will not be allocated any routing number for the
internal routing, i..e.. for the itra cell or intra msc
routing there will be no token issued, but for the inter
msc there will be token only towards called party.

10. What is FREQUENCY BAND for 3G?

In india its 1920-1980
and 2110-2170 MHZ

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