Coaching Materials in Telephony, Cellular and Facsimile Part 3

(Last Updated On: February 10, 2020)

This is the Coaching materials in Telephony, Cellular and Facsimile Part 3 as one topic in ECE Board Exam taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies (EST), Communications Books, Journals and other Communications References. This particular Coaching Notes in Communications Engineering has random Questions and Answers in random topics. Make sure to familiarize this review notes to increase the chance of passing the ECE Board Exam.

Telephony, Cellular and Facsimile Coaching Materials Part 3

141. What is the frequency deviation of AMPS?

Ans. 12 kHz

142. Transmission from mobile stations to the base stations is called _____.

Ans. Reverse link or Uplink

143. Determine the transmit and receive carrier frequencies for AMPS channel 3 and channel 991.

Ans. 870.09 MHz and 869.04 MHz

144. It is a 34-bit binary code that represents the 10-digit telephone number.

Ans. Mobile Identification Number (MIN)

145. A 32-bit binary code permanently assigned to each of the mobile unit.

Ans. Electronic Serial Number (ESN)

146. Supervisory Audio Tones (SAT) have frequencies

Ans. 5970 Hz, 6000 Hz, and 6030 Hz

147. The bit length of System Identification (SID)

Ans. 15

148. The bit length of Station Class Mark (SCM)

Ans. 4

149. The bit length of Digital Color Code (DCC)

Ans. 2

150. It is a database in the PCS network that stores information about the user, including home subscription information and what supplementary services the user is subscribed to.

Ans. Home Location Register (HLR)

151. A database in the PCS network that stores information about subscribers in a particular MISO serving area.

Ans. Visitor Location Register (VLR)

152. Determine the transmit power for a CDMA mobile unit that is receiving a signal from the base station at 100 dBm.

Ans. Pt = -76 dB – Pr; Pt =-76 dB – 100; Pt = 24 dBm

153. The North American PCS band is

Ans. 1.9 GHz

154. PCS cells are typically _______ than AMPS cells.

Ans. Smaller

155. IS-136 PCS is usually just called _______.

Ans. TDMA PCS

156. GSM is a _____ system.

Ans. TDMA

157. IS-95 PCS uses ______ technology.

Ans. CDMA

158. Current PCS systems are called ____-generation systems.

Ans. Second

159. Types of Class 4 toll center which provides human operators for both outward and inward calling service.

Ans. Class 4C

160. The ERP of class II mobile phone used in GSM system.

Ans. 1.6

161. The ESS assigned at the factory of cellular mobile phone, consists of how many bits?

Ans. 32

162. The speech coding rate for GSM cellular mobile is _______.

Ans. 13 kbps

163. What modulation technique is used by the European Cordless Telephone?

Ans. GFSK

164. Compared to AMPS, PCS cells are _______ in size.

Ans. Smaller

165. The spread-spectrum technique used in IS-95 is ________.

Ans. CDMA (direct sequence)

166. The spread-spectrum technique used in GSM is ________.

Ans. frequency hopping

167. Unlike AMPS, CDMA such as IS-95 allows for a _______ handoff.

Ans. Soft

168. The orthogonal PN sequences used in CDMA are called a ______ code.

Ans. Walsh

169. ______ diversity is inherent in any spread-spectrum system.

Ans. Frequency

170. RF channels S/N ratios _____ than zero is typical in CDMA systems.

Ans. Less

171. CDMA uses a ______-rate vocoder.

Ans. Variable

172. A phone user typically talks less than ________ of the time during a conversation.

Ans. 50%

173. How does GSM achieve frequency diversity?

Ans. It uses limited frequency hopping.

174. Why was PCS assigned to 1.9 GHz instead of the 800-MHz band used for AMPS?

Ans. The 800 MHz band was already overcrowded.

175. The “forward” PCS channel is

Ans. from base to the mobile

176. CDMA technology was invented by

Ans. Qualcomm

177. In GSM, voice channels are called

Ans. traffic channels

178. In CDMA

Ans. all frequencies are used in all cells

179. CDMA uses a set of PN sequences that are _______.

Ans. Orthogonal

180. If a 28.8 kbps modem is being used over a cell phone, how many words of text would be lost during a 100-msec handoff interruption assuming 10 bits per letter and 5 letters per word?

Ans. 57.6

181. A certain cell site contains 200 cell phones. The probability that cell phone is being used is 15%. What is the traffic in erlangs?

Ans. 30

182. WISPs offer access to the internet at speed up to _____ Mbps.

Ans. 11 *

183. The data signaling channel in a cellular system that handles the administrative overhead is known as

Ans. Paging channel

184. The data rate of information transfer of mobile devices using “Bluetooth”

Ans. 1 Mbps

185. The access method used in 3G mobile telephony.

Ans. WCDMA

186. A 3G wireless system promise to increase its network capacity by how much percent as compared to lower generation wireless system.

Ans. 70

187. In CMTS, the frequency separation between forward and reverse channel is

Ans. 45 MHz

188. The period for a single time slot in the GSM-TDMA slot is ______ µsec.

Ans. 577 *

189. The ratio of the separation distance between two co-channel cells and the cell radius is known as

Ans. co-channel interference reduction

190. Bluetooth Standard

Ans. IEEE 802.15

191. Bluetooth maximum distance

Ans. 10 m

192. Bluetooth is operating at the ISM frequency range of

Ans. 2.402 – 2.480 GHz *

193. Bluetooth uses

Ans. frequency hopping

194. What is the other name of the IEEE 802.16 standard for broadband wireless

Ans. WiMAX

AMPS	Advanced Mobile Phone Service	MSC	Mobile Switching Center
BSC	Base Station Controller	MTSO	Mobile Telephone Switching Office
CDPD	Cellular Digital Packet Data	NAM	Number Assignment Module
CMAC	Control Mobile Attenuation Code	PCS	Personal Communication Systems
DCC	Digital Color Code	PN	Pseudo random Noise
EDGE	Enhanced Data Rates for Global Evolution	RCC	Radio Common Carrier
ERP	Effective Radiated Power	SAT	Supervisory Audio Tone
ESN	Electronic Serial Number	SCM	Station Class Mark
ESN	Electronic Serial Number	SID	System Identification Number
GPRS	General Packet Radio Service	SIM	Subscriber ID
IMSI	International Mobile Subscriber Identification	UPT	Universal Personal Telecommunications
IMT	International Mobile Telecommunications	UWT	Universal Wireless Telecommunications
MIN	Mobile Identification Number	WCDMA	Wide CDMA
MSC	Mobile Switching Center	WISP	Wireless Internet Service Provider

Complete List of Communications Engineering Coaching Materials

Important List of Communications Engineering Materials