Wireless Fixed Telephone Networks — Test 1

Correct Answer: B. B. Msc
Explanation: 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).

Correct Answer: A. A. Public switched telephone network
Explanation: PSTN stands for public switched telephone network. The PSTN forms the global telecommunication grid which connects conventional telephone centers with MSCs throughout the world.

Correct Answer: A. A. True
Explanation: 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.

Correct Answer: C. C. Common air interface
Explanation: 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.

Correct Answer: B. B. False
Explanation: 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.

Correct Answer: D. D. Virtually static, highly dynamic
Explanation: 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.

Correct Answer: A. A. Local access and transport area
Explanation: 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.

Correct Answer: B. B. Local exchange carrier
Explanation: 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.

Correct Answer: D. D. Ixc
Explanation: 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).

Correct Answer: A. A. True
Explanation: 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.