TelecomStudy18

Cell Selection Procedure • First MS powers-on • MS starts measuring received power level from all cells in range • MS calculates average power level received from each cell: • Stored in RXLEV(n) parameter • MS calculates C1 parameter for each cell based on RXLEV(n) • Mobile compares cells which give a positive value of C1 and ‘camps-on’ to the cell with the highest C1 value. On switch-on, an MS periodically measures the received power level on each of the BCCH frequencies of all cells within range. From these periodic measurements the MS calculates the mean received level value from each cell, stored in the parameter RXLEV (n) where n=neighboring cell number. Cell Re-selection – GSM Phase 1 Mobiles For GSM Phase 1 mobiles, cell reselection is achieved by comparing current cell C1 with neighboring C1 cell measurements: • Between cells within a Location Area: C1 (new) > C1 (old)         (for more than 5 seconds) • Bet...

Command Description RLDHP:CELL=ALL; CELL DYNAMIC HR ALLOCATION DATA DBTSP:TAB=AXEPARS; DATABASE TABLE FILE PRINTOUT STATUS PLLDP; PROCESSOR LOAD DATA RAEPP:ID=ALL; BSC EXCHANGE PROPERTY DATA RLCAP; BSC CIPHERING ALGORITHM DATA RLDCP; BSC DIFFERENTIAL CHANNEL ALLOCATION DATA RLLBP; BSC LOCATING DATA RLLSP; BSC LOAD SHARING STATUS RLOMP; BSC BAND OPERATION MODE DATA RLTYP; BSC SYSTEM TYPE DATA RLVAP; CELL SEIZURE SUPERVISION OF LOGICAL CHANNELS ALARMED OBJECTS DATA RRGBP; RADIO TRANSMISSION GB INTERFACE CONFIGURATION DATA RLHBP; BSC LOCATING HIERARCHICAL CELL STRUCTURE BAND DATA ALLIP; ALARM LIST SAAEP:SAE=ALL; SIZE ALTERATION OF DATA FILES INFORMATION SAACP:SAE=ALL; SIZE ALTERATION OF DATA FILES CROSS-REFERENCE RLCPP:CELL=ALL; CELL CONFIGURAT...

• Asynchronous transmission • Plesiochronous transmission • Synchronous transmission Asynchronous transmission Asynchronous transmission is transmission of data in which time intervals between transmitted characters may be of unequal length. Transmission is controlled by start and stop bits at the beginning and end of each character. Transition of signals do not occur at the same nominal rate Generally free running quartz oscillators derive the clock, there is no timing pulses sent from transmitter to receiver Plesiochronous transmission Plesiochronous is a Greek word meaning Almost Synchronous , but not fully synchronous. The digital transitions in the signals occur at almost the same rate. There may be a phase difference between the transitions of the two signals, and this would lie on specified limits. Synchronous transmission The digital transitions in the signals occur at exactly the same rate. There will be no phase difference between the transitions of...

It is the process of combining a number of individual channels into a common frequency band or into a common bit stream for transmission. Different multiplexing techniques are: • Frequency Division Multiplexing (FDM) • Time Division Multiplexing (TDM) • Wavelength Division Multiplexing (WDM) Frequency Division Multiplexing FDM is a process in which the bandwidth is divided in frequency domain, or in other words each of the input signals is transmitted at a different frequency (Carrier) but simultaneously (or in the same time slot).  FDM is a multiplexing technique used for analog signals. Time division multiplexing TDM is a type of multiplexing in which different signals are multiplexed in different time slots. In TDM each time slots is fixed for different signals sequentially. TDM uses full bandwidth for every channel, but not at the same time so that every channel gets its time slot in the shared line. Wavelength division multiplexing It is a type ...

The Network Management Subsystem (NMS) is the third subsystem of the GSM network in addition to the Network Switching Subsystem (NSS) and Base Station Subsystem (BSS), which we have already discussed. The purpose of the NMS is to monitor various functions and elements of the network. The functions of the NMS can be divided into three categories: ·                 Fault management ·                 Configuration management ·                 Performance management These functions cover the whole of the GSM network elements from the level of individual BTSs, up to MSCs and HLRs. Fault management The purpose of fault management is to ensure the smooth operation of the network and rapid correction of any kind of problems that are detected. Fault manag...