What is Compressed Mode

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What is compressed mode? Higher layers can request a UE to monitor cells on other frequencies (FDD, TDD), or other systems (GSM). This implies that the UE has to perform measurements, on the other frequencies/systems and thus higher layers command the UE... See more 21) What is CCTrCH? A Coded Composite Transport Channel is the result of combining (multiplexing) severalTransport Channels of the same type; i.e.: we can have a CCTrCh made up of one orseveral DCHs, a CCTrCh made up of DSCHs. One exception is that we can have one orseveral FACHs multiplexed with a PCH on the same CCTrCh. A better notation would be for example:CCTrCh4DCH: A CCTrCh consisting of 4 DCHsCCTrCh3FACH: A CCTrCh consisting of 3 FACHsCCTrChPCH,2FACH: A CCTrCh consisting of the PCH and 2 FACHs22) What is compressed mode?Higher layers can request a UE to monitor cells on other frequencies (FDD, TDD), or othersystems (GSM). This implies that the UE has to perform measurements, on the otherfrequencies/systems and thus higher layers command the UE to enter Compressed Mode.The UTRAN need to send to the UE all the parameters for the Compressed Mode. Compression Methods: When in Compressed Mode the information normally transmitted during a 10 ms frame iscompressed in time sothat gaps of adequate length are created. To achieve this one ofthree mechanisms· Puncturing This method is NOT applicable to downlink.· Spread Factor Reduction Actually halving the Spread Factor. So with this method if SF is used in non- compressedframes then SF/2 is used in the compressed frames.· Higher Layer Scheduling Higher Layers set restrictions so that only a subset of allowed TFCs are used inCompressed Mode. Compressed Mode Parameter: TGSN (Transmission Gap Starting Slot Number): A transmission gap pattern begins in aradio frame, called firstradio frame of the transmission gap pattern, containing at least onetransmission gap slot. TGSN is the slot numberof the first transmission gap slot within thefirst radio frame of the transmission gap pattern; TGL1 (Transmission Gap Length 1): Duration of the first transmission gap within thetransmission gap pattern, expressed in number of slots; TGL2 (Transmission Gap Length 2): Duration of the second transmission gap within thetransmission gap pattern, expressed in number of slots. If this parameter is not explicitly setby higher layers, then TGL2 =TGL1; TGD

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Higher layers can request a UE to monitor cells on other frequencies (FDD, TDD), or other systems (GSM). This implies that the UE has to perform measurements, on the other frequencies/systems and thus higher layers command the UE...

Transcript of What is Compressed Mode

What is compressed mode?Higher layers can request a UE to monitor cells on other frequencies (FDD, TDD), or other systems (!")# This implies that the UE has to perform measurements, on the other frequencies$systems and thus higher layers command the UE###!ee more21) What is CCTrCH? A Coded Composite Transport Channel is the result of combining (multiplexing) severalTransport Channels of the same tpe! i"e"# $e can have a CCTrCh madeup of one orseveral %CHs& a CCTrCh made up of %'CHs" (ne exception is that $e can have one orseveral )ACHs multiplexed $ith a *CH on the same CCTrCh" A better notation $ould befor example#CCTrCh+%CH# A CCTrCh consisting of + %CHsCCTrCh,)ACH# A CCTrCh consisting of , )ACHsCCTrCh*CH&2)ACH# A CCTrCh consisting of the *CH and 2 )ACHs22) What is compressed mode?Higher laers can re-uest a ./ to monitor cells on other fre-uencies ()%%& T%%)& or othersstems (0'1)" This implies that the ./ has to perform measurements& on the otherfre-uencies2sstems and thus higher laers command the ./ to enter Compressed 1ode"The .T3A4 need to send to the ./ all the parameters for the Compressed1ode"Compression Methods:When in Compressed 1ode the information normall transmitted during a 15 ms frame iscompressed in time sothat gaps of ade-uate length are created" To achieve this one ofthree mechanisms6PuncturingThis method is 4(T applicable to do$nlin7"6Spread Factor ReductionActuall halving the 'pread )actor" 'o $ith this method if ') is used in non8compressedframes then ')22 is used in the compressed frames"6Higher Layer Scheduling Higher 9aers set restrictions so that onl a subset of allo$ed T)Cs are used inCompressed 1ode"Compressed Mode Parameter: TGSN(Transmission 0ap 'tarting 'lot 4umber)# A transmission gap pattern begins in aradio frame&called :rstradio frame of the transmission gap pattern& containing at least onetransmission gap slot" T0'4 is the slot numberof the :rst transmission gap slot $ithin the:rst radio frame of the transmission gap pattern!TGL1(Transmission 0ap 9ength 1)# %uration of the :rst transmission gap $ithin thetransmission gap pattern& expressed in number of slots! TGL(Transmission 0ap 9ength 2)# %uration of the second transmission gap $ithin thetransmission gap pattern& expressed in number of slots" ;f this parameter is not explicitl setb higher laers& then T092