初级选择86题.doc

The _______ temporarily stores information about the MS currently visiting its Service Area? VLR HLR EIR Which of the following numbers is the directory number of a subscriber in a GSM/PCS network? IMSI MSISDN MSRN What is the interface between MSC and BSC known as? A-interface Abis-interface B-interface Xxx The interface between BSC and the BTS is known as? A-interface A-bis-interface B-interface Xxb The normal cell maximum radius for GSM is? 35 km 70 km 50 km xxx Which unit is used for the transcoding of speech information? TRAU（TC） TRH TRX The two different types of multiframes are? 13- and 26-frame 26- and 51-frame 51- and 102-frame xxb The Cell Identity is unique to? The Location Area The MSC/VLR Service Area The PLMN What type of interference is produced by other transmitters on the same requency? Double interference Co-channel interference Adjacent channel interference Reflected interference Timing interference Xxx What property of a cell is limited by timing advance? Number of simultaneous calls Frequency of call setups Radius Antenna length Color Xxb What is the idea of using a combiner? Up to four sites can share one PCM link Several TRXs can share one antenna system The mobile can listen to two base stations at the same time Only one base station is needed per site Sending and transmitting can be performed from the same antenna Xxx、xxb Which of the following is the nominal output power for a GSM 900 class 4 or GSM 1800/GSM 1900 class 1 mobile station? 27 dbm 29 dbm 31 dbm 33 dbm 35 dbm Why are base stations sometimes cascade/chain(级连) connected? To save antennas To be able to reuse frequencies To share RBS equipment To simplify the installation To share PCM links Xxx、xxb A transmitted signal is received at -50 dBm and there is -150 dBm interference at the same frequency. What is C/I? 12 dB 30 dB 50 dB 80 dB 100 dB Frequency Hopping ________________ . Improves the speech quality of slow moving vehicles. Reduces the effects of Co-Channel Interfere