This is the summary notes of the important terms and concepts in Chapter 19 of the book "Electronic Communications System" by Wayne Tomasi. The notes are properly synchronized and concise for much better understanding of the book. Make sure to familiarize this review notes to increase the chance of passing the ECE Board Exam.
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CHAPTER 19 |
CELLULAR TELEPHONE CONCEPTS |
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Items |
Definitions |
Terms |
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1 |
The term for mobile telephone services which began in 1940s and are sometimes called Manual telephone systems. |
Mobile Telephone Manual System (MTSs) |
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2 |
The frequency used by MTSs. |
35 MHz-45MHz |
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3 |
Switch that was used by MTS to activate the transceiver. |
Push-to-Talk (PTT) |
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4 |
It was introduced in 1964 which used several carrier frequencies and could, therefore, handle several simultaneous mobile conversations at the same time. |
Improved Mobile Telephone System (IMTS) |
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5 |
The term suggested any radio transmitter, receiver, or transceiver that could be moved while operation. |
Mobile |
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6 |
The term that described a relatively small radio unit that was handled, battery powered, and easily carried by a person moving at walking speed. |
Portable |
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7 |
It is similar to two-way mobile radio in that most communications occurs between base stations and mobile units. |
Cellular Telephone |
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8 |
It operates on half duplex and use PTT transceivers. Examples of two-way radio: · Citizens Band (CB) · Public land mobile radio |
Two-Way Radio |
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9 |
A one to one system that permits two-way simultaneous transmissions and operates the same way as the standard wire line telephone service. |
Mobile Telephone |
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10 |
Hinted of a cellular telephone scheme that he referred to as simply a small-zone radio telephone system in the July 28, 1945. |
E.K. Jett |
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11 |
On June 17, 1946, they introduced the first American commercial mobile radio-telephone service to private customers. |
AT&T and Southwestern Bell |
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12 |
A radio telephone service introduced by AT&T in 1947. |
Highway Service. |
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13 |
Unveiled the most famous mobile telephone to date: the fully mobile shoe phone in 1966 in a television show called Get Smart. |
Don Adams |
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14 |
The year when FCC granted AT&T the first license to operate a developmental cellular telephone service in Chicago. |
1975 |
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15 |
A satellite-based wireless personal communications satellite (PCSS) |
Iridium |
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16 |
Another term for cellular telephone. |
Cellular Radio |
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17 |
A large geographic market area. |
Coverage zone |
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18 |
It is employed to increase the capacity of a mobile telephone channel. |
Frequency Reuse |
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19 |
The shape that was used because it provides the most effective transmission by approximating a circular pattern while eliminating the gaps present between adjacent circles. |
Honeycomb |
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20 |
Large cells that typically has 1 mile and 15 miles radius with base station transmit power 1W and 6 W. |
Macrocells |
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21 |
The smallest cells that typically has radius of 1500 feet or less with base station transmit powers between 0.1 W and 1 W. |
Microcells |
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22 |
The process in which the same set of frequencies can be allocated to more than one cell, provided the cells are separated by sufficient distance. |
Frequency Reuse |
|
23 |
A geographic cellular radio coverage area containing three groups of cells. |
cluster |
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24 |
Typically equal to 3,7, or 12. |
Cluster size |
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25 |
The process of finding the tier with the nearest co-channel cells. |
First Tier |
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26 |
Two cells using the same set of frequencies. |
Co-channel cells |
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27 |
The interference between the co-channels cells. Adding radio channels to a system: · Decreasing the transmit power per cell · making cells smaller · filling vacated coverage areas with new cells |
Co-channel Interference |
|
28 |
The ratio of the cell radius and distance from the nearest co-channel cell |
The ratio of the cell radius and distance from the nearest co-channel cell |
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29 |
Channel next to one another in the frequency domain. |
Adjacent Channel |
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30 |
It results from imperfect filters in receivers that allow nearby frequencies to enter the receiver. |
Adjacent-Channel Interference |
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31 |
Most prevalent when a mobile unit is receiving a weak signal from the base station. |
Near-Far Effect |
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32 |
The area of a cell, or independent component coverage areas of cellular system is further subdivided thus creating more areas. |
Cell Spliting |
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33 |
Occurs when number of the number of subscriber wishing to place a call at any given time equals the number of channels in the cell. |
Maximum Traffic Load |
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34 |
A condition occurs when a new call is initiated in an area where all the channels are in use. |
Blocking |
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35 |
Smaller areas when a single omnidirectional antenna is replaced by several directional antennas, each radiating within smaller area. |
Sectors |
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36 |
Using directional antennas. |
Sectoring |
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37 |
Placing two receive antennas one above the other. |
Space Diversity |
|
38 |
A means of avoiding full-cell splitting where the entire area would otherwise need to be segmented into smaller cells. |
Dualization |
|
39 |
A means of avoiding co-channel interference, although it lowers the capacity of a cell by enabling reuse inside the reuse distance which is normally prohibited. |
Segmentation |
|
40 |
The locations of radio-frequency transceivers. It serves are central control for all users within that cell. |
Base Stations |
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41 |
It handles all cell-site control and switching functions. |
Cell-Site Controller |
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42 |
Occurs when a mobile unit moves from one cell to another company’s service. |
Roaming |
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43 |
It controls channel assignment, call processing, call setup and call termination. Different Names: · Electric Mobile Exchange (EMX)- Bell Lab. · AEX- Ericcson · NEAX-NEC · Switching Mobile Center (SMC) · Master Mobile Center (MMC)-Novatel · Mobile Switching Center- PCS networks |
Mobile Telephone Switching Office (MTSO) |
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44 |
The transfer of a mobile unit from one base station’s control to another base station’s control. Four stages: · Initiation · Resource reservation · execution · completion |
Handoff (Handover) |
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45 |
A connection that is momentarily broken during the cell-to-cell transfer. It is a break before-make process. |
Hard Handoff |
|
46 |
A flawless hand off with no perceivable interruption of service. |
Soft Handoff |
|
47 |
It is used by computers that is based on variations in signal strength and signal quality. |
Handoff Decision |
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48 |
Either the mobile unit or the network determines the need for a handoff and initiates the necessary network procedures. |
Initiation |
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49 |
Appropriate network procedures reserve the resources needed to support the handoff. |
Resources Reservation |
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50 |
The actual transfer of control from one base station to another base station takes place. |
Execution |
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51 |
Execution Unnecessary network resources are relinquish and made available to other mobile units. |
Completion |
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52 |
Roaming from one company’s calling area into another company’s calling area. |
Interoperator Roaming |
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53 |
Stands for Electronics Industries Association/Telecommunications Industry Association, developed the IS-41 Protocol. |
EIA/TIA |
|
54 |
It aligns with a subprotocol of the SS7 protocol stack that facilitates communications among database other network entities. |
IS-41 |
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55 |
Stands for Cellular Telecommunication Industry Association. |
CITA |
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56 |
The process where a mobile unit notifies a serving MTSO of its presence and location through a base station controller. Components of Cellular Telephone System: · Electronic switching center · a Cell-site controller · radio transceiver · system interconnections · mobile telephone units · common communications protocol |
Autonomous Registration |
|
57 |
A digital telephone exchange located in the MTSO that is the heart of a cellular telephone system. |
Electronic Switching Center |
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58 |
A datalink protocol at a transmission rate of 9.6 kbps. |
X.25 |
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59 |
Another name for cell-site controller. |
Base Station Controller |
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60 |
It manages each of the radio channels at each site supervises calls, turns the radio transmitter and receiver on and off, injects data onto the control and voice channels, and performs diagnostic tests in the cell-site equipment. |
Cell-site Controller |
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61 |
Stands for Base transceiver station. |
BTS |
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62 |
A part of base station subsystem that can be either narrowband FM analog system or either PSK or QAM for digital systems with effective audio frequency. |
Radio Transceiver |
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63 |
The radio receiver that detects the strongest signal. |
Receiver Diversity |
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64 |
It governs the way telephone calls are established and disconnected. Examples of Protocol: · IS-54 · IS-136.2 · IS-95 |
Communications Protocol |
|
65 |
The actual voice channel where mobile users communicate directly with either mobile or wireline subscribers through a base station. |
User Channel |
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66 |
It is used for transferring control and diagnostic information between mobile users and a central cellular telephone switch through a base station. Transmit on base station: · forward control channel · forward voice channel Receive on base stations: · reverse control channel · reverse voice channel Types of calls: · Mobile to wireline · mobile to mobile · wireline to mobile |
Control Channel |
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