Wireless & Mobile Communications Multiple Choice Questions on “Wireless and Fixed Telephone Networks”.
1. In a wireless communication, base station is connected to central hub called _______
a) PSTN
b) MSC
c) CO
d) PBX
Answer: b
Clarification: To provide wireless communication within a particular geographic region, an integrated network of base stations must be deployed to provide sufficient radio coverage to all mobile users. The base station, in turn must be connected to a central hub called MSC (mobile switching center).
2. PSTN stands for ________
a) Public switched telephone network
b) Personal switched telephone network
c) Personal switched telephone node
d) Public switched telephone node
Answer: a
Clarification: PSTN stands for public switched telephone network. The PSTN forms the global telecommunication grid which connects conventional telephone centers with MSCs throughout the world.
3. MSCs provide connectivity between PSTN and the base stations.
a) True
b) False
Answer: a
Clarification: The MSC provide connectivity between the public switched telephone network (PSTN) and the numerous base stations. It ultimately provides connectivity between all of the wireless subscribers in the system.
4. Communication protocol, CAI stands for ___________
a) Common air interchange
b) Control air interchange
c) Common air interface
d) Control air interchange
Answer: c
Clarification: To connect mobile subscribers to the base stations, radio links are established using a carefully defined communication protocol called common air interface (CAI) which in essence is a precisely defined handshake communication protocol.
5. At the base station, the air interface portion of mobile transmission is passed to MSC.
a) True
b) False
Answer: b
Clarification: At the base station, the air interface portion (i.e., signalling and synchronization data) of the mobile transmission is discarded, and the remaining voice traffic is paased along to the MSC on fixed networks.
6. PSTN is ___________ and wireless networks are ________
a) Highly dynamic, virtually static
b) Static, virtually static
c) Highly dynamic, virtually dynamic
d) Virtually static, highly dynamic
Answer: d
Clarification: The network configurations in the PSTN are virtually static, since the network connections may only be changed when a subscriber changes residence. Wireless networks are highly dynamic with the network configuration being rearranged everytime a new subscriber moves into the coverage region of a different base station.
7. In public switched telephone network, LATA stands for ______
a) Local access and transport area
b) Land area and transport area
c) Local access and telephone access
d) Local area and telephone access
Answer: a
Clarification: In public switched telephone network, LATA stands for Local access and transport area. LATA is a city or a geographic grouping of towns in PSTN.
8. LATAs are connected by a company called _________
a) Land exchange carrier
b) Local exchange carrier
c) Local control exchange
d) Land area exchange
Answer: b
Clarification: Surrounding LATAs are connected by a company called a local exchange carrier (LEC). A LEC is a company that provides telephone services and may be a local telephone company.
9. A long distance telephone company that collects toll is called _________
a) LATA
b) LEC
c) PSTN
d) IXC
Answer: d
Clarification: A long distance telephone company collects toll fees to provide connections between different LATAs over its long distance network. These companies are referred to as interexchange carriers (IXCs).
10. Wireless networks are extremely hostile and random nature of radio channel.
a) True
b) False
Answer: a
Clarification: A problem unique to wireless networks is the extremely hostile and random nature of the radio channel, and since users may request service from any physical location while traveling over a wide range of velocities.
11. The technique for separate but parallel signalling channel is called ________
a) Common channel signalling
b) Forward channel signalling
c) Reverse channel signalling
d) Separate channel signalling
Answer: a
Clarification: During the mid 1980s, the PSTN was transformed into two parallel networks- one dedicated to user traffic, and one dedicated to call signalling traffic. This technique is called common channel signalling.
12. In North America, the cellular telephone signalling network uses _______
a) SS7
b) IXC
c) IS-41
d) PSTN
Answer: a
Clarification: In North America, the cellular telephone signalling network uses No. 7 Signalling System (SS7), and each MSC uses the IS-41 protocol to communicate with other MSCs on the continent.
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