CHAPTER 19 CELLULAR TELEPHONE CONCEPTS # DEFINITION TERMS 1) The term for mobile telephone services which began in 1940s and are sometimes called Manual telephone systems. Mobile Telephone Manual System (MTSs) 2) The frequency used by MTSs. 35 MHz-45MHz 3) Switch that was used by MTS to activate the transceiver. Push-to-Talk (PTT) 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) 5) The term suggested any radio transmitter, receiver, or transceiver that could be moved while operation. Mobile 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 7) It is similar to two-way mobile radio in that most communications occurs between base stations and mobile units. Cellular Telephone 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 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 Prepared By : JENNIFER F. DOCOT 117
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 11) On June 17, 1946, they introduced the first American commercial mobile radio-telephone service to private customers. AT&T and Southwestern Bell 12) A radio telephone service introduced by AT&T in 1947. Highway Service. 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 14) The year when FCC granted AT&T the first license to operate a developmental cellular telephone service in Chicago. 1975 15) A satellite-based wireless personal communications satellite (PCSS) Iridium 16) Another term for cellular telephone. Cellular Radio 17) A large geographic market area. Coverage zone 18) It is employed to increase the capacity of a mobile telephone channel. Frequency Reuse 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 Prepared By : JENNIFER F. DOCOT 118
20 Large cells that typically has 1 mile and 15 miles radius with base station transmit power 1W and 6 W. The smallest cells that typically has radius of 1500 feet or less with base station transmit powers between 0.1 21 W and 1 W. Macrocells Microcells 22) The process in which the same set of frequencies can be allocated to more than one one cell, provided the cells are separa ted by sufficient distance. Frequency Reuse 23) A geographic cellular radio coverage area containing three groups of cells. cluster 24) Typically equal to 3,7, or 12. Cluster size 25) The process of finding the tier with the nearest co-channel cells First Tier 26) Two cells using the same set of frequencies. Co-channel cells The interference between the co-channels cells. 27) 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 Prepared By : JENNIFER F. DOCOT 119
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 29) Channel next to one another in the frequency domain. Adjacent Channel 30) It results from imperfect filters in receivers that allow nearby frequencies to enter the receiver. Adjacent-Channel Interference 31) Most prevalent when a mobile unit is receiving a weak signal from the base station. Near-Far Effect 32) The area of a cell, or independent component coverage areas of cellular system is further subdivided thus creating more areas. Cell Spliting 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 34) A condition occurs when a new call is initiated in an area where all the channels are in use. Blocking 35) Smaller areas when a single omnidirectional antenna is replaced by several directional antennas, each radiating within smaller area. Sectors 36) Using directional antennas. Sectoring 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 Prepared By : JENNIFER F. DOCOT 120
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 41) It handles all cell-site control and switching functions. Cell-Site Controller 42) Occurs when a mobile unit moves from one cell to another company s service. Roaming 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 netwroks Mobile Telephone Switching Office (MTSO) 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) 45) 46) A connection that is momentarily broken during the cell-to-cell transfer. It is a break before-make process. A flawless hand off with no perceivable interruption ofservice. Hard Handoff Soft Handoff Prepared By : JENNIFER F. DOCOT 121
47) It is used by computers that is based on variations in signal strength and signal quality. Handoff Decision 48) Either the mobile unit or the network determines the need for a handoff and initiates the necessary network procedures. Initiation 49) Appropriate network procedures reserve the resources needed to support the handoff. Resources Reservation 50) The actual transfer of control from one base station to another base station takes place. Execution 51) Execution Unnecessary network resources are relinquish and made available to other mobile units. Completion 52) Roaming from one company s calling area into another company s calling area. Interoperator Roaming 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 55) Stands for Cellular Telecommunication Industry Association. CITA Prepared By : JENNIFER F. DOCOT 122
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 58) A datalink protocol at a transmission rate of 9.6 kbps. X.25 59) Another name for cell-site controller. Base Station Controller 60) It manages each of the radio channels at each site supervises calls, turns the radio transmitter and eceiver on and off, injects data onto the control and voice channels, and performs diagnostic tests in the cell-site equipment. Cell-site Controller 61) Stands for Base transceiver station. BTS 62) A part of base station subsystem that can be either narrowband FM analog system or either PSK or QAM fro digital systems with effective audio frequency. Radio Transceiver 63) The radio receiver that detects the strongest signal. Receiver Diversity 64) It governs the way telephone calls are established and disconnected. Examples of Protocol: IS-54 IS-136.2 IS-95 Communications Protocol Prepared By : JENNIFER F. DOCOT 123
65) The actual voice channel where mobile users communicate directly with either mobile and wireline subscribers through a base station. User Channel It is used for transferring control and diagnostic nformation between mobile users and a central cellular telephone switch through a base station. Transmit on base station: forward control channel forward voice channel 66) Receive on base stations: Control Channel reverse control channel reverse voice channel types of calls: Mobile to wireline mobile to mobile wireline to mobile Prepared By : JENNIFER F. DOCOT 124