Spectrum mgmt, plng, SACFA, GSM RF, Mobile traffic report Flashcards
SACFA stands for
Standing Advisory Committee on Frequency Allocation
Who requires SACFA Clearance Certificate or SACFA approval?
1) DTH broadcast services
2) Internet Service Providers
3) Cellular Services
4) Community Radio Services
5) all the above
all the above
Where to register for SACFA clearance certification
1) SACFA website
2) WPC website
3) DOT website
4) TRAI website
WPC website
_____ portal is Govt of India receipts portal where SACFA application processing fee is paid
1) Saral Sanchar Portal
2) Bharatkosh portal
Bharatkosh portal
after fee payment download the system-generated SACFA clearance from the ________ Portal.
1) Saral Sanchar Portal
2) Bharatkosh portal
Saral Sanchar Portal
Towers located more than __ km from the nearest Airport
and having height (including AMSL of site) <= ___ meters will be cleared automatically for all AAI and JCES airports
1) 5km, <= 20 meters
1) 7km, <= 20 meters
1) 7km, <= 40 meters
1) 10km, <= 40 meters
7km, <= 40 meters
ARP (Airport Reference Point) criteria for all Airports
Mast heights beyond __ kms up to the height of ___ m
1) 10 kms, 50m
2) 20 kms, 100m
3) 20 kms, 150m
4) 56 kms, 150m
20 kms, 100m
JCES stands for
Joint Communications & Electronic Staff
Who chairs a SACFA committee
Chairman of the Telecom Commission, Department of Telecommunications
AAI cleared category for IFR (Instrument Flight Rules) civil airports
Mast heights beyond __ kms up to the height of ___ m
1) 10 kms, 50m
2) 20 kms, 100m
3) 20 kms, 150m
4) 56 kms, 150m
56 kms, 150m
AAI cleared category for VFR (Visual Flight Rules) civil airports
Mast heights beyond __ kms up to the height of ___ m
1) 10 kms, 50m
2) 20 kms, 100m
3) 20 kms, 150m
4) 56 kms, 150m
20 kms, 150m
JCES cleared acategory
Mast heights beyond ___ kms up to the height of ___ m
1) 10 kms, 50m
2) 20 kms, 100m
3) 20 kms, 150m
4) 56 kms, 150m
20 kms, 100m
clearance for additional antenna category
1) Auto cleared on self-declaration basis
2) Manual cleared on self-declaration basis
Auto cleared on self-declaration basis
clearance for additional antenna category
Processing fee is Rs _____ per site
1) Free
2) 100/-
3) 1000/-
4) 10,000/-
Rs 100/- per site
5G Small Cells on Street Furniture
1) clearance from SACFA
2) clearance from DoT
3) clearance from TRAI
4) No clearance required
No clearance required
5G Small Cells on Street Furniture max power limit
1) 50W
2) 100W
3) 200W
4) 500W
100W
______ are unidirectional channels in GSM
1) common channels
2) dedicated channels
common channels
______ are bidirectional channels in GSM
1) common channels
2) dedicated channels
dedicated channels
logical channel frame number is transmitted in the _________ channel
1) SACCH
2) FACCH
3) SCH
4) SDCCH
SCH: Synchronization Channel
Information carried in one time slot is
1) frame
2) burst
burst
control channel multi frame ____ frames are there.
1) 26
2) 51
51
multiframe -> superframe->hyperframe
duration of superframe is same (6.12sec) for both control and traffic channels
traffic channel multi frame ____ frames are there.
1) 26
2) 51
26
multiframe -> superframe->hyperframe
Types of burst
1) Normal burst (NB)
2) Frequency correction burst (FB)
3) Synchronization burst (SB)
4) Access burst (AB)
5) dummy burst
all of them
Normal burst of count _______ is required for full info
1) 1
2) 2
3) 3
4) 4
4
Last frame in 26-frame is not allotted in
1) TCH full frame
2) TCH half frame
TCH full frame
26th frame is idle
TCH full rate speech is ______
1) 22.8 kbps
2) 11.4 kbps
22.8 kbps
common control channel 51-frame multiframe of uplink consists of only
1) BCCH
2) RACH
3) SDCCH
RACH
In GSM, using a FDMA scheme, into 124 carrier frequencies spaced one from each other by a frequency band
1) 200 MHz
2) 200 KHz
3) 25 KHz
4) 25 MHz
25 KHz
Which of the following is NOT
broadcast control channel?
1) BCCH
2) FCCH
3) RACH
4) SCH
RACH
In busy mode SMS sent on which
channel?
1) SDCCH
2) FACCH
3) RACH
4) SAACH
SAACH
The most important RF signalling
channel which carries Call Set-up
message is-
1) RACH
2) SDCCH
3) AGCH
4) SAACH
SDCCH
SMS to called party mobile, in
dedicated mode, is delivered by-
1) SACCH
2) SDCCH
3) FACCH
4) PCH
SACCH
Carrier aggregation advantages
1) Improve the data rate per user
2) Mitigate inter-cell interference
3) Enhance the network deployment
- Improve the data rate per user (higher peak user throughput)
- Mitigate inter-cell interference (efficient use of spectrum)
- Enhance the network deployment (intra-band contiguous, intra-band non contiguous, inter-band non contiguous)
Carrier aggregation can be used to aggregate downlink carriers in unlicensed frequency bands, primarily in the 5 GHz range, with carriers in licensed frequency bands. This process is known as
1) Carrier Assisted Access
2) License Assisted Access
License Assisted Access
LTE release 10 allows carrier aggregation of up to __ DL CCs and __ UL CCs
1) 3
2) 4
3) 5
4) 6
5 DL CCs and 5 UL CCs
CC: Component Carrier
LTE release 10: Two or more CCs are aggregated in order to support wider transmission bandwidths up to ___MHz
1) 50MHz
2) 75MHz
3) 100MHz
4) 200MHz
100MHz
- up to 5 component carriers of 20MHz each
It is not possible to configure a UE with more UL CCs than DL CCs
LTE release 10 CA: It is _____ to configure a UE with more UL CCs than DL CCs
1) possible
2) not possible
not possible
CA: Carrier Aggregation
CC: Component Carrier
LTE release 10 CA can be used for both FDD and TDD modes
1) FDD DL (intra-band & inter-band)
2) FDD UL (intra-band only)
3) TDD (intra-band only)
T
All component carriers need to have the same duplex scheme and in the case of TDD, same uplink downlink configuration.
release 13: LTE advanced Pro: Two or more CCs are aggregated in order to support wider transmission bandwidths up to ___MHz
1) 160MHz
2) 320MHz
3) 640MHz
4) 760MHz
640MHz
up to 32 component carriers of 20MHz each
release 15: 5GNR allows carrier aggregation of up to __ DL CCs and __ UL CCs
1) 4
2) 8
3) 16
4) 32
16 DL CCs and 16 UL CCs
CC: Component Carrier
NR does not support carrier aggregation with LTE
T
Thus dual connectivity is needed to support aggregation of the LTE and NR throughput.
Multiple BWPs with different numerologies can be multiplexed within a single
NR carrier to support different types of services.
T
BWP: Bandwidth Part
For dual connectivity (DC)
1) The base stations do not need to be synchronized
2) The base stations must be co-located
The base stations do not need to be synchronized (and therefore may not be co-located)
Primary cell (PCell) in which the device initially performs the initial connection establishment procedure.
Once the device is in connected mode, one or more secondary cells (SCells) can be configured to provide additional radio resources.
____________ is introduced as part of the Rel-15, to support simultaneous transmissions across LTE and NR
EN-DC operation
release 15: 5GNR radio enhancements, several configurations of CA have been introduced
T
- inter-band CA/Dual Connectivity for 2 bands DL with up to 2 bands UL
- inter-band Carrier Aggregation for 3 bands DL with 1 band UL
Which type of transmission technique is employed by paging system?
a) Multicasting
b) Unicasting
c) Hybrid
d) Simulcasting
Simulcasting
Simulcast is a reliable technique used by paging system by transmitting the same paging signal from multiple paging transmitters at approximately equal times
Which of the following is not a TDMA standard of 2.5G network?
a) GPRS
b) GSM
c) HSCSD
d) EDGE
GSM
GSM (Global System for Mobile) is a TDMA standard for 2G network. HSCSD (High Speed Circuit Switched Data), GPRS (General Packet Radio Service) and EDGE (Enhanced Data rates for GSM Evolution) are TDMA standards of 2.5G technology
Which of the most widely used model for signal prediction in urban areas?
a) Okumura model
b) Attenuation factor model
c) Ericsson Multiple Breakpoint Model
d) Log distance path loss model
Okumura model
Okumura’s model is one of the most widely used models for signal prediction in urban areas. This model is applicable for frequencies in the range 150 MHz to 1920 MHz (Extrapolated upto 3000 MHz).
Which of the following is not a practical path loss estimation technique?
a) Determination of percentage of coverage area
b) Hata model
c) Log distance path loss model
d) Log normal shadowing
Hata model
Hata model is only valid for exterior environment.
Which of the following explains the concept of diffraction loss?
a) Archimedes’ Principle
b) Fresnel zone
c) Principle of Simultaneity
d) Pascal’s Principle
Fresnel zone
The concept of diffraction loss is a function of the path difference around an obstruction. It can be explained by Fresnel zones. Fresnel zones represent successive regions where secondary waves have a path length from Tx to Rx which are nλ/2 greater than total path length.
Which of the following problem occur due to adjacent channel interference?
a) Cross talk
b) Missed calls
c) Blocked calls
d) Near-far effect
Near-far effect
It occurs when a mobile close to a base station transmits on a channel close to one being used by a weak mobile.
Which of the following is not an effect caused by multipath in radio channel?
a) Random frequency modulation
b) Time dispersion
c) Rapid changes in signal strength
d) Power of base station
Power of base station
KPIs in GSM
● TCH Congestion < 2%
● SDCCH Congestion
● Call Drop Rate <3%
● Handover Success Rate >95%
● Call Setup Success Rate
● Paging Success Rate
TCH congestion should be less than
1) 1%
2) 2%
3) 3%
4) 5%
2%
TCH congestion may reduced by
1) Fourth sector may be introduced at the same BTS
2) Dual band (1800) may be introduced i.e. upto 8 TRE in the sector
3) Increase TRE if traffic exceeds
4) Lowering of HR triggering thresholds
all of them
SDCCH congestion may reduced by
1) Defining Proper No of SDCCH Channels
2) Optimize LAC boundary
3) Dynamic SDCCH may be defined
4) Check Hardware/Transmission Alarms
all of them
Reasons for call drop
1) Improper RF planning
2) Wrong Hopping Parameters e.g. MAIO/HSN
3) VSWR/RF cable fault
4) Handover failure
5) fluctuation in Abis/Ater links
all of them
Reasons for handover failure
1) Congestion in target sector
2) Missing neighbor/Too many neighbors
3) Improper RF planning mainly same BCCH/BSIC
4) Frequent Inter MSC/Inter BSC handovers
5) cable swap
all of them
Reasons for low Call Setup Success Rate (CSSR)
1) TCH Congestion
2) SDCCH Congestion/Drop
3) cable swap/VSWR
4) BER in Abis/Ater links
all of them in addition to Improper RF planning
Call drop rate should be less than
1) 1%
2) 2%
3) 3%
4) 5%
3%
paging success rate can be improved by
1) Proper LAC dimension and distribution
2) Separate Broadcast channel in place of Combined broadcast channel
3) Removal of dummy Cell site database created in Network
4) Use of TMSI
5) Minimize SDCCH cong/Cong in Abis interface/ BTS downtime etc
all of them
Mobile CNMC stands for
Centralized Network Monitoring Center
https://www.cnmc.bsnl.co.in
Use of HSN and MAIO
The HSN is used to define the hopping sequence from one frequency list, and MAIO is used to set the initial frequency on this list
Which type of antenna is used for center excited cells?
a) Dipole antenna
b) Grid antenna
c) Sectored antenna
d) Omnidirectional antenna
Omnidirectional antenna
Which type of antenna is used for edge excited cells?
a) Omnidirectional antenna
b) Grid antenna
c) Sectored directional antenna
d) Dipole antenna
Sectored directional antenna
For a cellular system, if there are N cells and each cell is allocated k channel. What is the total number of available radio channels, S?
a) S=k*N
b) S=k/N
c) S=N/k
d) S=kN
S=k*N
What is a frequency reuse factor for N number of cells in a system?
a) N
b) N2
c) 2*N
d) 1/N
1/N
Capacity of a cellular system is directly proportional to __________
a) Number of cells
b) Number of times a cluster is replicated
c) Number of Base stations
d) Number of users
Number of times a cluster is replicated
A spectrum of 30 MHz is allocated to a cellular system which uses two 25 KHz simplex channels to provide full duplex voice channels. What is the number of channels available per cell for 4 cell reuse factor?
a) 150 channels
b) 600 channels
c) 50 channels
d) 85 channels
150 channels
Total bandwidth is 30 MHz. And the channel bandwidth is 50 KHz/duplex channel (25KHz*2). Therefore, total available channels are 600 channels (30,000/50). For 4 cell reuse factor, total number of channels available per cell will be 150 channels (600/4)
Which of the following measures spectrum efficiency of a wireless system?
a) Spectral capacity
b) Channel capacity
c) Carrier capacity
d) Radio capacity
Radio capacity
