This is the Coaching materials in Telephony, Cellular and Facsimile Part 2 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 2
71.When subscriber initiates a long distance call, the local exchange connects the caller to the toll office through a facility called _____,
Ans. Toll-connecting trunk or Inter-office toll trunk
72.The telephone switching plan that allows a certain degree of route selection when establishing a phone call
Ans. Switching hierarchy
73.It is simply a path between two subscribers and is comprised of one or more switches, two local loops or possibly one or more trunk circuits.
74. A call that cannot be completed because the necessary trunk circuits or switching paths are not available.
75.Class of switching office which is the local exchange where the subscriber loops terminated and received dial tone.
Ans. Class 5 End office
76.The class of switching office that provides service to small groups of class 4 offices within a small area of state
Ans. Class 3 Primary center
77.The highest ranking office in the DDD network in terms of size of the geographical area served and the trunk options available
Ans. Class 1 Regional center
78.It defines the procedures and protocols necessary to exchange information over the PSTN using a separate digital signaling network to provide wireless and wireline telephone call setup, routing and control.
Ans. Common Channel Signaling System no. 7 or SS7 or C7
79.A telephone service that uses a common 800 area code regardless of the location of the destination
Ans. Wide Area Telephone Service (WATS)
80.A mandate that requires all telephone companies to support the porting of telephone number.
Ans. Local Number Portability
81.It allows customers to change to a different service and still keep the same phone number
82.In SS7, signaling points, codes that are carried in signaling messages exchanged between signaling points to identify the source and destination of each message
Ans. Point codes
83._____ are local telephone switches equipped with SS7-compatible software and terminating signal links.
Ans. Service Switching Points (SSP)
84.It provides functionality of communicating with the voice switch by creating the packets or signal units necessary for transmission over the SS7 network.
Ans. Service Switching Points (SSP)
85.For a certain telephone, the DC loop voltage is 48 V on hook and 8 V off hook. If the loop current is 40 mA, what is the DC resistance of the local loop?
Ans. 1000 ohms
86.For a certain telephone, the DC loop voltage is 48 V on hook and 8 V off hook. If the loop current is 40 mA, what is the DC resistance of the telephone?
Ans. 200 ohms
87.Calculate the dB of VNL required for a channel with a 3 ms delay.
Ans. 1 dB
88.If a telephone voice signal has a level of 0 dBm, what is its level in dBrn?
Ans. 90 dBrn
89.A telephone test-tone has a level of 80 dBrn at a point where the level is +5dB TLP. If C-weighting produces a 10-dB loss, what would the signal level be in dBrnc0?
Ans. 65 dBrnc TLP
90.AMPS uses the _____-MHz band.
91.The number of ERP classes in AMPS is _____.
92.A cell phone permanently installed in a car would be ERP class _______.
Ans. I (one)
93.The maximum ERP of class III cell phones is _______.
Ans. 600 mW
94.A portable, handheld cell phone would be ERP class _____.
Ans. III (three)
95.A MAC is a mobile ________ code.
96.A mobile switching center is also call an _________.
97.Telephone call traffic is measured in _______.
98.Traffic model used in telephone system that is based on the assumption, that calls not immediately satisfied at the first attempt are held in the system until it is satisfied?
Ans. Erlang C *
99.The reduction in cell size to increase traffic is called cell _______.
100. A _____ site is a very small unit that can mount on a streetlight pole.
101. Very small cells called ______ are used for reliable indoor reception.
102. Compared with AMPS, digital cellular phones require _____ bandwidth.
103. What is the speed of Cellular Data Packet Data (CDPD)
Ans. 17.2 or 19.2
104. In analog CMTS, the interfering signal strength must remain approximately less than _____ percent of the desired signal strength.
105. SCM identifies the _______________.
Ans. maximum power level of a cellphone
106. The SID is used by a cell phone to
Ans. recognize that it is “roaming”
107. The CMAC is used to
Ans. set the transmit power of the cell phone
108. In an AMPS system, voice is sent using _____.
109. In an AMPS system, control-channel signals are sent using _____.
110. The ERP of typical handheld AMPS cell phone is
Ans. less than 600 mW
111. The combination of the mobile cell phone and the cell site radio are called the
Ans. air interface
112. Phone traffic is measured in
113. One way to increase the capacity of a cell phone is
Ans. increase the number of cells
114. Base stations transmitter output power of Improved Mobile Telephone Services (IMTS)
Ans. 100-W to 200-W range
115. An area divided into hexagonal shapes that fit together to form a pattern is called ______.
116. Macrocells have base stations transmit power between __________.
Ans. 1 W to 6 W
117. Microcells have base stations transmit power between __________.
Ans. 0.1W to 0.6W
118. A geographic cellular radio coverage area containing three of more group of cells
119. Determine the number of channels per cluster and the total number of channel capacity of a cellular telephone area comprised of 10 clusters with 7 cells in each cluster and 10 channels in each cell
Ans. 70 channels per cluster, 700 total channels
120. What is the typical cluster size?
Ans. 3, 7 and 12
121. It is when the area of a cell, or independent component coverage areas of a cellular system, is further divided, thus creating more cell areas.
Ans. Cell splitting
122. The point when the cell reaches maximum capacity occurs when the number of subscribers wishing to place a call at any given time equals the number of channels in the cell.
Ans. Maximum traffic load
123. Determine the channel capacity of a cellular telephone area comprised of seven macrocell with 10 channels per cell
Ans. 70 channels per area
124. Determine the channel capacity if 7 macrocells with 10 channels per cell is split into 4 minicells.
Ans. 280 channels per area
125. Decreasing co-channel interference while increasing capacity by using directional antenna is called _____.
126. A technique that divides the group of channels into smaller groupings or segments of mutually exclusive frequencies; cell sites, which are within the reuse distance is assigned their own segment of the channel group
127. It is a means of avoiding full-cell splitting where the entire area would otherwise need to be segmented into smaller cells.
128. Provides a centralized administration and maintenance point for the entire network and interfaces with the public telephone network through the telephone wireline voice trunks and data links.
Ans. Mobile Telephone Switching Office (MTSO)
129. It is when a mobile unit moves from one cell to another from one company’s service area to another company’s service area.
130. The transfer of a mobile unit from one base station’s control to another base station’s control
Ans. Handoff or Handover
131. An open standard that allows PCs, peripherals, cordless telephones, and other consumer electronic devices to communicate and interoperate with one another without the complexity and expense associated with installing new wires?
Ans. Shared Wireless Access Protocol (SWAP)
132. A connection is momentarily broken during the cell-to-cell transfer is called
Ans. Hard handoff
133. A flawless cell-to-cell transfer is called ______.
Ans. Soft handoff
134. Soft handoff normally takes _____ of time delay
Ans. 200 ms
135. In IS-41 standard, it is a process where the mobile unit notifies a serving MTSO of its presence and location through a base station controller
Ans. Autonomous registration
136. It is a digital telephone exchange located in the MTSO that is the heart of a telephone system
Ans. Electronic switching center
137. Component of a cellular telephone network that manages each of the radio channels at each site
Ans. Cell-site controllers or Base station controllers
138. The actual voice channel where mobile users communicate directly with other mobile or wireline subscriber through the base station
Ans. User channel
139. A channel used for transferring control and diagnostic information between mobile users and a central cellular telephone switch through the base stations.
Ans. Control channel
140. What modulation technique is used by Advanced Mobile Phone System (AMPS)
Ans. Narrow band FM (NBFM)