Samsung SGH-2488 Service Manual

Also see for SGH-2488: Owner's manual

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Samsung SGH-2488 Service Manual Manual pdf 3 page image

Samsung Electronics 1-11. General Description1-1 Dualband System1-1-1 CallsDual band handsets supports the E-GSM and DCS system, DCS is an acronym for Digital Cellular system, andGSM ® is an acronym for Global System for Mobile communications© , using TDMA for wide-area cellularoperation. The GSM and DCS system consists of the sub-systems shown;The Mobile Station (MS) talks to the Base Station System (BSS) via an RF air interface. The Base Station System(BSS) consists of Base Transceiver Station (BTS) and a Base Station Controller (BSC). The interface between BTSand BSC is called an Abis interface. Generally one BSC controls 20 to 30 BTSs, and a Mobile Switching Center(MSC) controlling the traffic among different cells would be reported back from a number of BSSs. A VisitorLocation Register (VLR) will be allocated to one MSC to find the mobiles out of their home cell by listing themto VLR. The MSC would also be connected to the Home Location Register (HLR), the Authentication Center(AC) and the Equipment Identity Register (EIR) So the system verify that the users and equipment are legalsubscriber.1-1-2 ChannelsChannels used in the E-GSM and DCS system can be divided into two classes - Logical and Physical channel.Physical channels can be described in terms of their frequency and time domain characteristics. They are theactual frequencies and timeslots the MS and BS transmits or receives on. The logical channels are mapped ontothese physical channels logically. Any particular and instant, physical channels may be control or trafficchannels, which determines the function of a physical channel at a particular point in time.1-1-3 Airinterface of ARFCN (Absolute Radio Frequency Channel Number)975 1023 0 1 2 3 123 124... ... ... ...880.2 MHz 890.2 MHz 914.8 MHzDCS Rx: Fdl(n) = Ful(n) + 95MHz< Fig. 1 ARFCN Diagram >E-GSM: TX: Ful(n) = 890MHz + (0.2MHz) • n, 0≤n≤124 andFul(n) = 890MHz + (0.2MHz) • (n-1024), 975≤n≤1023512 8851710.2 MHz 1784.8 MHzDCS Tx: Ful(n) = 1710MHz + (0.2MHz) • (n-511)n = ARFCN, 512≤n≤885512 8851805.2 MHz 1879.8 MHz975 1023 0 1 2 3 123 124... ... ... ...925.2 MHz 935.2 MHz 959.8 MHzE-GSM: RX: Fdl(n) = Ful(n) + 45MHz