Study and learn these Interview MCQ Questions and Answers on VoWi-Fi (VoWiFi - Voice Over Wi-Fi) or GAN (Generic Access Network) Architecture and Interfaces. GAN is another name for VoWi-Fi. There are Trusted and Non-Trusted VoWiFi networks that connect to Mobile Services Core Servers. Voice Over WiFi allows cellular network operators to offer good quality calls even if the coverage is poor. These cover Frequently Asked Questions (FAQ) also. Attend Job interview and College exams easily after going through these Multiple Choice Questions (MCQs). You can download PDF of these questions by using Print to PDF option in any of the modern browsers.
1) Which organization provides standards for VoWi-Fi technology?
A) ANSI (American National Standards Institute)
B) 3GPP (Third Generation Partnership Projects)
C) 3GPP2 (Third Generation Partnership Projects 2)
D) None
B
2) Voice Over Wi-Fi uses ____ spectrum. (Unlicensed/Licensed)
A) Unlicensed
B) Licensed
C) -
D) -
A
3) What is the problem with Licensed spectrum for Mobile Network Operator (MNO)?
A) It is provided in limited quantity (Mhz or Ghz) to each network operator of the respective country.
B) It is provided after action from Regulatory authorities.
C) Spectrum fee is either one time or recurring.
D) All the above
D
4) State TRUE or FALSE. To use the Unlicensed spectrum, either the Operator or the Customer has to apply for permission from the government.
A) FALSE
B) TRUE
C) -
D) -
A
5) What does WiFi (Wi-Fi) stand for?
A) Wireless Feature
B) Wide Area Network Feature
C) Wireless Fidelity
D) Wide Area Network Fidelity
C
6) What is the IEEE standard for a Wi-Fi technology?
A) 802.1
B) 802.11
C) 802.3
D) None
B
7) State TRUE or FALSE. All modern Wi-Fi modems or routers support VoWiFi feature?
A) FALSE
B) TRUE
C) -
D) -
A
Explanation:
A Wi-FI enabled product has to specifically implement VoWiFi feature either through software or hardware changes. It involves an additional cost.
8) Voice over WiFi works on ____ network.
A) Same operator WiFi hotspot
B) Different operator WiFi hotspot
C) Any Operator Internet Service like Broadband with a WiFi router
D) All
D
9) Voice Over Wi-Fi or VoWi-FI is also called ___.
A) Wi-Fi Calling
B) Hotspot Calling
C) Home Free Calling
D) All
D
10) Which is a 3GPP based network below?
A) 2G (GSM)
B) 3G (UMTS)
C) 4G LTE-A, 4G LTE-A Pro
D) All
D
11) Which is a Non-3GPP network below?
A) Wi-Fi
B) WiMax
C) 4G LTE-A
D) 3G UMTS
A
12) VoWi-Fi calling usually allows seamless handover of calls from and to the Cellular network. State TRUE or FALSE.
A) FALSE
B) TRUE
C) -
D) -
B
13) A Generic Access Network (GAN) is a 3GPP network. State TRUE or FALSE.
A) FALSE
B) TRUE
C) -
D) -
A
14) What does VoLTE stand for?
A) Voice over LTE
B) Voice Offload LTE
C) Voice Outgoing LTE
D) None
A
15) Over VoLTE or VoWi-Fi, a customer is authenticated through ____.
A) Username, Password
B) SIM
C) Fingerprint
D) None
B
16) What is the other name for GAN network?
A) Virtual Network Access (VMA)
B) Licensed Mobile Access (LMA)
C) Unlicensed Mobile Access (UMA)
D) All
C
17) What is the operating frequency of a Wi-Fi access point?
A) 2.4 GHz
B) 5 GHz
C) Both 2.4 GHz and 5 GHz
D) None
C
18) What is the advantage for a Mobile Network Operator of implementing VoWi-Fi on its network?
A) Good call quality as Home Wi-Fi offers superior data speed.
B) Network operator saves its precious spectrum or radio resources as calls are routed through an External-IP or Public IP network.
C) Network operator need not upgrade its Tower or Base Station hardware to support too many users. Coverage issues are solved by customers themselves by using WiFi.
D) All
D
19) How many UMA or GAN based handset modes are available?
A) 2
B) 4
C) 8
D) 16
B
20) What does GERAN stand for?
A) General Radio Access Network
B) Generic Edge Radio Access Network
C) GSM EDGE Radio Access Network
D) None
C
21) A GERAN-Only network mode supports ___ network.
A) Cellular Only
B) Wi-Fi only
C) Both Cellular and WiFi
D) None
A
22) A GERAN-Preferred network mode supports ___ network.
A) Cellular only
B) WiFi only
C) Cellular if available, otherwise WiFi or 802.11 network
D) None
C
23) A GAN-Preferred network mode supports ___ network.
A) Cellular only
B) WiFi only
C) Cellular only if available, otherwise 802.11 network
D) WiFi or 802.11 network if available, otherwise a cellular network
D
24) A GAN-Only network mode supports ___ network.
A) Cellular only
B) WiFi or 802.11 only
C) Cellular and WiFi
D) None
B
25) What is the problem of using VoWi-Fi network for a customer?
A) Switching ON Wi-Fi and Mobile Data at the same time drains more battery
B) The customer has to waste his Home Wifi or Broadband data for calls
C) The customer has to purchase a Compatible Phone and Wi-Fi Router and spend extra money
D) All
D
26) Which 3GPP standard defined accessing Mobile Core IP network from the WLAN network?
A) 3GPP R4
B) 3GPP R5
C) 3GPP R6
D) 3GPP R7
C
27) A GAN (Generic Access Network) is based on ____.
A) IP Multimedia Subsystem (IMS)
B) Session Initiation Protocol (SIP)
C) Both IMS and SIP
D) None
C
28) To support VoWi-Fi, mobile phones have to confirm to which 3GPP standards?
A) 3GPP R8
B) 3GPP R9
C) 3GPP R10
D) All
C
29) Voice quality of VoWi-Fi compared to VoLTE network?
A) More
B) Less
C) Same
D) None
C
Explanation:
Both use the same core network.
30) What is the difference between VoWiFi and VoLTE?
A) VoLTE calls work on the same core network as the data is served from the core network itself.
B) VoWiFi calls may be originated from either the Same network data or Different network data
C) VoLTE calls require good network coverage whereas VoWiFi calls require any WiFi internet signal.
D) All
D
31) What is the core cellular technology generation supporting VoWiFi technology?
A) 2G
B) 3G
C) 4G and above
D) All
D
32) For untrusted VoWiFi (calling from any network wifi), the technologies to be supported by the Phone or WiFi router are?
A) IMS (IP Multimedia Subsystem)
B) IPsec (IP Security)
C) ePDG
D) All
D
33) VoWiFi allows calling from a Mobile even without a mobile signal. State TRUE or FALSE.
A) FALSE
B) TRUE
C) -
D) -
B
34) What is the main element of VoWiFi architecture?
A) PDG (Packet Data Gateway)
B) ePDG (Evolved PDG)
C) PDG or ePDG
D) None
C
35) What is the interface between a UE (User Equipment) and ePDG (Evolved Packet Data Gateway) in the GAN architecture?
A) SWm
B) SWn
C) SWu
D) SWa
C
36) What is the interface between ePDG (Evolved Packet Data Gateway) PDN -G (Packet Data Network Gateway) in the GAN architecture?
A) S2a
B) S2b
C) SWu
D) SWm
B
37) A Trusted Non-3GPP network element can directly communicate with PDN Gateway using ___ interface.
A) S2a
B) S2b
C) S2c
D) SWu
A
38) A Trusted Non-3GPP network element can directly communicate with a PCRF (Policy and Charging Rules Function) using ___ interface.
A) Gxa
B) Gxb
C) Gxc
D) None
A
39) A Trusted Non-3GPP network element can directly communicate with AAA authentication server using ___ interface.
A) STa
B) STb
C) STc
D) None
A
40) An Untrusted Non-3GPP network element can communicate with ePDG (Evolved Packet Data Gateway) using ___ interface in a GAN architecture.
A) SWm
B) SWn
C) SWa
D) SWb
B
41) An Untrusted Non-3GPP network element can communicate with the 3GPP AAA authentication server using ___ interface.
A) SWa
B) SWb
C) SWc
D) STa
A
42) What is the interface between an ePDG and 3GPP AAA server in a GAN or VoWiFi architecture?
A) SWa
B) SWb
C) SWm
D) SWn
C
43) What is the interface between a 3GPP AAA server and a PDN Gateway element in a VoWi-Fi network architecture?
A) S2a
B) S2b
C) S6a
D) S6b
D
44) What is the interface between ePDG and PCRF elements in a VoWiFi architecture?
A) Gxa
B) Gxb
C) S6a
D) S6b
B
45) What is the interface between a PDN Gateway and PCRF element in GAN (Generic Access Network) architecture?
A) Gxa
B) Gxb
C) Gxc
D) Gx
D
46) What is the interface between a PCRF and IP Services (IMS, PSS etc) element in a Non-Roaming GAN architecture?
A) Gx
B) Gxc
C) Rx
D) SGi
D
47) What is the interface between PCRF and Operator's IP Services element in a Non-Roaming GAN architecture?
A) S2a
B) S2b
C) Rx
D) SGi
C
48) What is the interface between PCRF and Serving-Gateway in a Non-Roaming VoWi-Fi architecture?
A) Gx
B) Gxa
C) Gxb
D) Gxc
D
49) What is the interface between a HSS (Home Suscriber Server) and an MME (Mobility Management Entitiy) of a 3GPP access network in a Non-Roaming VoWi-Fi (or GAN) architecture?
A) S2a
B) S2b
C) S6a
D) S6
C
50) What is the interface between HSS (Home Subscriber Server) and 3GPP AAA Server in a Non-Roaming GAN architecture?
A) SWu
B) SWx
C) SWm
D) SWn
B
51) State TRUE or FALSE. In a Roaming GAN architecture, PCRF element is divided as vPCRF (Visitor PCRF) and hPCRF (Home PCRF) elements.
A) FALSE
B) TRUE
C) -
D) -
B
52) In an Evolved Packet System (EPS), what is the interface between vPCRF and hPCRF in Roaming architecture?
A) S6
B) S9
C) S8
D) S6a
B
53) In a Roaming GAN architecture, ePDG uses vPCRF and PDN-Gateway uses hPCRF. State TRUE or FALSE.
A) FALSE
B) TRUE
C) -
D) -
B
54) Choose the correct statement about Roaming GAN architecture elements below.
A) vPCRF interfaces with Serving Gateway and ePDG through Gxc and Gxb interfaces respectively.
B) hPCRF communicates with PDN Gateway and IP-Services-Element through Gx and Rx interfaces respectively.
C) A Trusted Non-3GPP access element communicates directly with vPCRF using Gxa interface.
D) All
D
55) Choose the correct abbreviations below.
A) EPS = Evolved Packet System
B) PMIP = Proxy Mobile IP
C) GANC = Generic Access Network Controller
D) All
D
56) Choose the correct abbreviations below.
A) SON = Self Configuring and Self-Optimizing Network
B) WMM = WiFi Multimedia
C) NSWO = Non-Seamless WLAN Offload
D) All
D
57) Rove-In refers to hand-over of call to ___ network.
A) 3GPP network
B) 802.11 or Wi-Fi network or GAN network
C) Any to any network
D) None
B
58) Rove-out refers to handing of Call to ___ network.
A) 3GPP network
B) 802.11 or Wi-Fi or GAN network
C) Any to Any network
D) None
A
59) To provide roaming of calls between Wi-Fi and 3GPP networks, the user SIM contains ____.
A) FQDN (Fully Qualified Domain Name) or IP address of GANC (GAN Controller)
B) SEGW (Security Gateway) IP address
C) GANC information associated with Cell Index of 2G, 3G or 4G Base Station.
D) All
D
60) State TRUE or FALSE. In Non-Roaming scenario, the mobile can use any local IP of the WiFi network to make and receive calls. In a Roaming scenario, unique global IP is mandatory.
A) FALSE
B) TRUE
C) -
D) -
B
61) State TRUE or FALSE. The mobile periodically informs to GANC (Generic Access Network Controller) about the cellular network parameters so that the call may be handed over to the Cellular network if required.
A) FALSE
B) TRUE
C) -
D) -
B
62) The authentication of user SIM to the GANC is done using ___.
A) EAP-SIM
B) EAP-AKA
C) Both EAP-SIM and EAP-AKA
D) None
C
Explanation:
Authentication is started using IKEv2 exchange.
63) A GAN network supports __ type of SMS services.
A) GSM Circuit Switched
B) GPRS Packet-Switched
C) Both GSM-Circuit-Switched and GPRS-Packet-Switched
D) None
C
64) GAN network uses __ to deliver SMS securely.
A) IPsec Tunneling
B) TCP Sessions
C) Both IPsec Tunneling and TCP Sessions.
D) None
C
65) Choose the correct statement about GANC call setup.
A) GANC sends Channel Mode to the MS
B) GANC sends Multi-rate Codec Configuration to the MS
C) GAC sends information bout UDP port, IP address for Uplink RTP stream and Voice Sample size.
D) All
D
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