Wireless & Mobile Communications Questions and Answers Part-9

1. Which of the following is not an open standard?
a) Bluetooth
b) WWW
d) VPN

Answer: d
Explanation: An open standard is a standard that is publicly available. It has various rights to use associated with it. Bluetooth is an open standard that has been embraced by over thousand manufacturers of electronic appliances. VPN (Virtual Private Network) is a private network.

2. What is the nominal range of Bluetooth?
a) 1 Km
b) 10 m
c) 1 m
d) 10 Km

Answer: b
Explanation: The power of the transmitter governs the range over which a Bluetooth device can operate. Generally, Bluetooth devices are said to fall into one of three classes. The most common kind is class 2, and it operates in 10 m range.

3. Bluetooth standard is named after ___________
a) King Ronaldo Bluetooth
b) Pope Vincent Bluetooth
c) King Herald Bluetooth
d) Pope Francis Bluetooth

Answer: c
Explanation: Bluetooth standard is named after King Harald Bluetooth. He was the 10th century Viking who united Denmark and Norway. The Bluetooth standard aims to unify the connectivity chores of appliances within the personal workspace of an individual.

4. Bluetooth operates in which band?
a) 2.4 GHz ISM Band
b) L Band
c) Ku Band
d) Ka Band

Answer: a
Explanation: Bluetooth is a radio technology operating in 2.4 GHz frequency band. Bluetooth is best suited for low-bandwidth applications like transferring sound data with telephones (i.e. with a Bluetooth headset) or byte data with hand-held computers (transferring files) or keyboard.

5. Which of the following scheme is used by Bluetooth?
a) Frequency hopping TDD scheme
b) Frequency hopping FDD scheme
c) DSSS TDD scheme
d) DSSS FDD scheme

Answer: a
Explanation: Frequency hopping TDD (Time Division Duplexing) scheme is used by Bluetooth. Frequency hopping provides a form of multiple access among co-located devices in different piconets.

6. What is the range of time slot in Bluetooth?
a) 120 milliseconds
b) 577 microseconds
c) 625 microseconds
d) 5.7 seconds

Answer: c
Explanation: Bluetooth uses a timeslot of 625 microseconds. A data channel hops randomly 1600 times per second between 79 RF channels. Thus, each channel is divided into time slots 625 microseconds.

7. Which of the following standard committee specifies Bluetooth and other Personal Area Networks (PAN)?
a) IEEE 802.11b
b) IEEE 802.15
c) IEEE 802.11g
d) IEEE 802.16

Answer: b
Explanation: IEEE 802.15 standards committee is formed to provide an international forum for developing Bluetooth and other PANs. PANs are used to interconnect pocket PCs, personal digital assistants (PDAs), cell phones, light projectors and other appliances.

8. Which modulation scheme is used by Bluetooth?
b) MSK

Answer: c
Explanation: Bluetooth uses GFSK (Gaussian Frequency Shift Keying). When GFSK is used for Bluetooth modulation, the frequency of the carrier is shifted to carry the modulation. By doing this the Bluetooth modulation achieves a bandwidth of 1 MHz with stringent filter requirements to prevent interference on other channels.

9. What is the name of the European WLAN standard that provides user data rate upto 54 Mbps?

Answer: d
Explanation: HIPERLAN/2 has emerged as the next generation European WLAN standard. It provides upto 54 Mbps of user data to a variety of networks. The networks includes the ATM backbone, IP based networks and the UMTS network.

10. What is WISP?
a) Wideband Internet Service Protocol
b) Wireless Instantaneous Source Provider
c) Wireless Internet Service Provider
d) Wideband Internet Source Protocol

Answer: c
Explanation: WISP is wireless Internet Service Provider used to explore public LANs (publican). It builds a nationwide infrastructure of WLAN access points in selected hotels, restaurants or airports. It then charges a monthly subscription fee to users who wish to have always on Internet access in those selected locations.