Descripción: istructe exam Geotechnic foundation CM
Mises discusses conceptualizing God.
istructe exam Geotechnic foundation CMFull description
The mobile phones is used in our everyday life, the demand on mobile phone networks has increased steadily. Today, among other things like desktop laptops, mobile phones are used to access the internet, watch TV, read emails and use social media. The
Conservation International Philippines, Department of Environment and Natural Resources-Protected Areas and Wildlife Burea and Haribon Foundation. 2006. Priority Sites for Conservation in…Full description
Survey conducted of a very small population at a college to understand the reasons for the population switching the operators in the telecom industry (the population acts as our sample for the coun...
Social Problems of the Philippines - politics etc.Full description
A really wonderful song by Enya. It was originally played on the uilleann pipes, but you can play either on the piano or on any instrument you think best. ~ updated version with chords! ~Descrição completa
2 المشاكل التي يواجهها مهندس االتصاالت في مواقع المحمولG Problems facing the telecom engineer in the mobile sites the problems faced the telecom engineer in the mobile sites : 2G problems : a- Cross sector and cross feeder
There are 3 types of Cross sector 1-GSM cross sector 2-DCS cross sector 3-Total cross sector (GSM & DCS) cross sector
1-CROSS SECTOR We must know the normal connection in first to understand the problems happened
Totally cross sector in this case S1 is totally changed with S2
DCS cross sector In this case DCS is changed between two sectors (S1,S2)
GSM cross sector:
GSM cross sector example Cross sector between sec 1 & sec 3 on TEMS PRODUCT
GSM Cross feeder
DCS cross feeder
DCS CROSS FEEDER EXAMPLE
GSM cross feederSector
Sector 2 & sector 3 appeared with equal levels beside sector 2 ======================================================================= Hardware problem The common HW problem is faulty DTRU DTRU: Dual Transceiver Unit, Generate two frequencies
To solve this problem you should replace this dtru with another one ======================================================================= BAD QUALITY Rx qual is proportional to BER (Bit Error Rate), that affected by interference Interference is appeared in hopping channel window (C/I) C/I: Carrier to interference ratio.
======================================================================== Over shooting It means that the cell serve at very long distance with good level This area that the cell overshoots in it most probably have cells with Co-channel or adjacent BCCH, so it will make interference that will result in bad quality
Reason: Overshooting cell has small downtilt, 0 degree! Overshooting cell has too high altitude Closer cells have overshooting as well BSIC of closer cells can’t be decoded
Standing wave ratio (SWR) is the ratio of the amplitude of a partial standing wave at an antinode (maximum) to the amplitude at an adjacent node (minimum), in an electrical transmission line. The SWR is usually defined as a voltage ratio called the VSWR,
======================================================================= Missing Neighbors This case may cause to dropped calls , bad coverage as the ms will not be able to HO on the target site as it’s not known for the serving site. ========================================================================
HAND OVER FAILURE In the case of HO failure the MS fails to reach the target cell and so it returns back to the source cell. The reason for this case may be due to channel interference or poor coverage. In the other case HO delay the BSIC of the neighbor is decoded but HO occurs in much later time. The reason for this case that all possible neighbors may suffer blocking or some of the HO parameters (HO watch time , HO valid time) need to be adjusted.
======================================================================== Blocked call The call may be blocked due to: Cell congestionBad quality due to interference.Faulty TRX.Bad coverage.Transmission problem.Long distance between MS and BTS (MAX TA = 63).-
Blocked call reasons. No available TCH-No available SDCCH -Bad Rxlev. -Bad Quality
======================================================================== DROPPED CALL The call may be dropped due to: - Bad quality due to interference. - Faulty TRX. - Bad coverage. - Transmission problem. reasons. -Delayed HO Congestion or wrong HO parameter definition. -HO Failure. -Bad Quality. -Missing neighbor (Bad Rx level). -Transmission problem (Not RF problem)
COMING SOON PROBLEMS IN 3G & ALARMS IN MOBILE SITES
