Overview of Extended Cell Range The cell radius of an ordinary cell is 35 kilometres. In some cases, for example, in large rural areas, a cell of that size may be too small compared to the capacity required in the area. Extended ell !ange increases the cell radius up to about "# km $hich means that this kind of cell co%ers an area that is four times bigger than an ordinary cell. &ence Extended ell !ange sa%es the site costs of the operator. The implementation is based on a one'(& )broadcast control channel* and t$o'T!+ )transcei%er* solution. The normal co%erage area is ser%ed $ith different T!+s than the extended co%erage area. Timing of the T!+s, $hich ser%e the extended co%erage area, is delayed so that they can ser%e the area beyond 35 kilometres. This solution is possible $ith E3-/3- )Talk'family*. )Talk'family*. The purpose of Extended ell !ange is also to increase the cell radius. The implementation is based on a t$o'cell t$o'(& solution. This solution is possible $ith E01 )0nd generation*. Extended ell !ange is a licence'based soft$are. Its use is controlled by a capacity licence based on the number of T!+s. /or more information on 2icensing, see 2icensing in (. (4#3" Impro%ed olution for Extended ell is optional $ith (-#15 Extended ell.
!elated topics •
/unctionality of Extended ell !ange
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ser interface in Extended ell !ange
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63 interface in Extended ell !ange
Functionality of Extended Cell Range Extended ell !ange allo$s you to increase the cell radius to up to "# kilometres )the cell radius of a normal cell is 35 kilometres*. The implementation implementation is based on a one'(& one' (& and and t$o'T!+ t$o'T!+ solution. solution. This means that the $hole cell uses the same (& on the do$nlink direction. &o$e%er, different T!+s ser%e the normal co%erage area and the extended co%erage area. The follo$ing tables illustrate the radio arrangements of an extended cell.
N-TRX RX f1 f1 f1 f1 f1 f1 f1 f1 ------------------------------------------------I 0 I 1 I 2 I 3 I 4 I 5 I 6 I 7 I ------------------------------------------------BCCH/ NOT SDCCH TCH TCH TCH TCH TCH SDCCH IN USE
E-TRX RX (Delayed
f1 f2 f2 f2 f2 f2 f2 f2 ------------------------------------------------I 0 I 1 I 2 I 3 I 4 I 5 I 6 I 7 I ------------------------------------------------E-R!CH SDCCH TCH TCH TCH T CH TCH TC H TCH TCH
The 7'T!+ is configured $ith a (&& and T&s to ser%e the normal co%erage area at frequency 8f18. The E'T!+ is configured $ith the E' !9&, & and T&s to ser%e the extended area at frequency 8f08. Timing of the recei%er of the E'T!+ is delayed so that it can ser%e the area beyond 35 kilometres. Timing of transmitters of both the 7'T!+ and E'T!+ is the same. The time slot # of the E'T!+ is tuned to the (& frequency )8f18* to get random access messages from the extended area. The time slot 1 of the 7'T!+ cannot be used at all because the E'!9& is interfering $ith it.
:obile'originated call In case of a mobile'originated call, the : sends a random access message to the (T to initate the call. The (T recei%es that access burst either %ia the 7'T!+ or E'T!+ or %ia both the 7'T!+ and E'T!+ depending on the : location. If the : is located in the normal co%erage area, the ( allocates a dedicated radio channel from the 7'T!+. The : is assigned to mo%e to the dedicated channel %ia the 7'T!+.
Figure: Random access message via N-TRX If the : is located in the extended co%erage area, the ( allocates a dedicated radio channel from the E'T!+. &o$e%er, also in this case the : is assigned to mo%e to the dedicated channel %ia the 7'T!+.
Figure: Random access message via E-TRX If the : is located in an o%erlap area, the ( allocates a dedicated radio channel either from the E'T!+ or the 7'T!+. In this case the (T recei%es t$o random access messages and the ( filters the later one out. 9lso in this case, the : is assigned to mo%e to the dedicated channel %ia the 7'T!+ because the E'T!+ does not ha%e a do$nlink 9;&.
Figure: Random access message via bot N-TRX and E-TRX
:obile'terminated call 9 mobile'terminated call is handled $ith the same $ay as the mobile originated'call except that paging messages are sent to the : %ia the 7'T!+.
&ando%ers &ando%ers to the extended cell and from the extended cell are performed according to the existing hando%er criteria )for more information, see !/
ou should take this into account in the net$ork planning phase so that, for example, the : is not handed o%er to the extended co%erage area $hen it is located in the normal co%erage area. This kind of planning error causes interference for other calls. &ando%ers bet$een different areas of the extended cell are performed according to the timing ad%ance information. &ando%ers bet$een 7'T!+s and E'T!+s in the extended cell )similar to hando%ers tofrom E'T!+ bet$een different cells* are performed as asynchronous hando%ers.
/requency hopping It is not possible to use base band hopping in an extended cell. Instead of that, !/ hopping can be used but only 7'T!+s can hop. :obile allocation ):9* cannot contain any non'hopping frequencies of the cell. :9I? management $orks as in a normal cell but only $ith 7'T!+s.
/loating transcei%er /loating transcei%er can normally be used to ser%e an extended area. If the (& 7'T!+ is breaking up in some other sector, the floating E'T!+ can be configured to ser%e the normal area of that sector. ?f course, the extended co%erage area is lost in that case.
hannel configurations The table belo$ presents an example of channel configuration.
----------------------------------------------------RTS&(' BCCH N-TRX N-TRX E-R!CH E-TRX E-TRX ----------------------------------------------------0 BCCHSDCCH/4 TCH E-R!CH TCH 1 NOT IN USE TCH SDCCH/) TCH 2-7 TCH' TCH' TCH' TCH' ----------------------------------------------------/ollo$ing restrictions apply for channel configurations@ • •
9n E'!9& must be configured to only one E'T!+ !T2 # The !T2 1 of a (& 7'T!+ must be configured to the 7?T I7 E state
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9n E'!9& cannot be defined for 7'T!+s
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9 (& cannot be defined for an E'T!+.
(& and E'!9& !eco%ery (& and E'!9& reco%ery depends on the number of 7'T!+s ser%ing the normal co%erage area and the number of E'T!+s ser%ing the extended co%erage area. The reco%ery procedure $orks as follo$s@ One N-TRX! one E-TRX If the 7'T!+ breaks up, the E'T!+ is configured $ith the (& and other control channels to ser%e the normal co%erage area. This means that the extended co%erage area is lost and an alarm is gi%en. 9fter the 7'T!+ is repaired, it is configured $ith the E'!9& and other control channels to ser%e the extended co%erage area. If the E'T!+ breaks up, the extended co%erage area is lost and an alarm is gi%en. "everal N-TRXs! one E-TRX If a (& 7'T!+ breaks up, another 7'T!+ is configured $ith the (& and other control channels. 9fter the 7'T!+ is repaired, it is configured to ser%e the normal co%erage area. If the E'T!+ breaks up, a non'(& 7'T!+ is configured $ith the E'!9& and other control channels to ser%e the extended co%erage area. 9fter the E'T!+ is repaired, it is configured to ser%e the normal co%erage area. One N-TRX! several E-TRXs If an 7'T!+ breaks up, a non'E'!9& E'T!+ is configured $ith the (& and other control channels to ser%e the normal co%erage area. 9fter the 7'T!+ is repaired, it is configured to ser%e the extended co%erage area.
If the E'!9& E'T!+ breaks up, an E'T!+ is configured $ith the E'!9& and other control channels to ser%e the extended co%erage area. 9fter the E'T!+ is repaired, it is configured to ser%e the extended co%erage area. "everal N-TRXs! several E-TRXs If a (& 7'T!+ breaks up, an 7'T!+ is configured $ith the (& and other control channels to ser%e the normal co%erage area. 9fter the 7'T!+ is repaired, it is configured to ser%e the normal co%erage area. If the E'!9& E'T!+ breaks up, an E'T!+ is configured $ith the E'!9& and other control channels to ser%e the normal co%erage area. 9fter the E'T!+ is repaired, it is configured to ser%e the extended co%erage area. apacity !estrictions
apacity •
9 (& 7'T!+ pro%ides a maximum of 4 T&s/ or 10 T&s&.
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9n E'!9& E'T!+ pro%ides a maximum of 4 T&/ or 10 T&&.
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?ther 7'T!+s or E'T!+s pro%ide a maximum of A T&/ or 14 T&&.
!estrictions TRXs 9ll T!+s of an extended cell ha%e to be E'T!+ capable.
#"" $icensing 2icence for Extended ell for ltraite (T T!+ count sets a limit for existing E'T!+ count in ltraite. /or more information on licensing, see 2icensing in (.
#T" software /0.1 supports an extended cell $ith f ixed a cell radius extension of 3# kilometers regardless of Rad*+' E,"e'*. parameter. /3.# includes support for dynamic radius extension.
Cannel configurations •
9n E'!9& must be configured to only one E'T!+ !T2 #.
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The !T2 1 of the (& 7'T!+ has to be configured to the 7?T I7 E state.
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>ou cannot define an E'!9& for the T!+ of a 0nd generation (T or 7'T!+.
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>ou cannot define an (& for an E'T!+.
Fre%uency o&&ing •
(ase band hopping cannot be used
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!adio frequency )!/* hopping cannot be used in E'T!+s.
'andovers In case of : controlled hando%er to an extended cell, the ne$ channel is al$ays allocated from the E'T!+.
(ntra-cell andover
Tests /ollo$ing tests are not possible $ith E'T!+s@ •
T!+ test
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!+ antenna test
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T!+ loop test
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9ntenna loop test
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!+ sensiti%ity test
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?riginating test call )if the T: is located at the same site as the E'T!+*
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Terminating test call )if the T: is located at the same site as the E'T!+*.
(ntelligent )nderlay-Overlay >ou cannot use intelligent underlay'o%erlay in an extended cell.
*istance verifying >ou can only use distance %erifying for random access messages recei%ed from the E'T!+.
Circuit &ool switcing In case of hando%er to a normal area of an extended cell, circuit pool s$itching is not possible.
CCC' $oad indication & load indication is recei%ed from both (& 7'T!+ and E'!9& E'T!+ bet$een a defined period. In case of an E'!9& E'T!+, only the !9& load is %alid.
*ouble #CC' +llocation $ist The ouble (& 9llocation 2ist )ouble (9 2ist* is needed in the extended cell range solution because of : compatibility issues. The intra'cell hando%er bet$een an 7'T!+ and an E'T!+ is performed by using a &ando%er ommand message. sing the &ando%er ommand requires that the (& frequency of the ser%ing cell is included in the (& allocation list. This can be achie%ed by using the ouble (9 2ist. /or more information, see ouble (& 9llocation 2ist.
,R" ell resources in the extended area of a cell are not used for ;
*ouble #CC' +llocation $ist Bith ouble (& 9llocation 2ist you can define a list of (& carriers to be used in cell selection and reselection by the : )mobile station* $hen in Idle tate. The list is sent to the : )mobile station* in ystem Information :essage type 0 on the (& and the : may store it $hen po$ering do$n. 7o$ the : does not need to search through the $hole band $hen po$ering up. If the list contains all the (& carriers of a certain geographical area of a <2:7, the : can use it to search the suitable !/ channels quickly in order to camp on a cell. >ou can add, remo%e, and output carrier frequency numbers on the Idle tate (& 9llocation lists $ith ::2 commands. /or a particular cell it is possible to define $hether it uses one of the Idle tate 2ists or the 7eighbour ell 2ist of its o$n at ystem Information :essage 0 on (&. If the cell is not attached to any of the Idle tate 2ists, the 7eighbour ell 2ist is used as a default list. The frequency of the (& carrier of the cell itself is al$ays added to the (& allocation in ystem Information :essage 0. 9nother selection can be made concerning the list in ystem Information :essage 5 on 9& . The default is the 7eighbour ell 2ist, but if an Idle tate 2ist is attached to the cell to be used in ystem Information :essage 0, the same list can also be used in ystem Information :essage 5 on 9&. If the frequency band of the (T in question is the same as the frequency band of the (& (T, the (& frequency is remo%ed from the Idle tate list of the ystem Information :essage 5. If one of the Idle tate 2ists is selected to be used on 9&, it is possible that the list contains carrier frequencies that are not the (& frequencies of the actual hando%er neighbours. In this case, the : measures signals on these frequencies but no hando%ers are attempted to$ards those undefined cells. Bith the commands of the /requency 2ist and ;ou can attach any of these lists to certain (Ts $ith the commands of the command group (ase Transcei%er tation &andling in ( )E *. ouble (& 9llocation 2ist is an application soft$are in the (.
!elated topics •
9cti%ating and testing ouble (& 9llocation 2ist
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eacti%ating and testing ouble (& 9llocation 2ist
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?%er%ie$ of !adio 7et$ork onfiguration :anagement
Effect of ouble (& 9llocation 2ist on interfaces ser Interface of ouble (& 9llocation 2ist
Target cell e%aluation according to radio criteria Bhen the ( recognises the necessity to make a hando%er because of radio criteria, it forms a list of the preferred &? candidates on the basis of the radio link properties, priority le%els and load of the neighbouring cells. The basic e%aluation algorithm calculated according to radio link properties is based on the follo$ing strategy and order@
EU!TION 1% !RX&ENCE&&( RxLevMinCell(n) !X(08 9a :e#e 9a ; ( - 9 *f 9a ; ( - 9 *f
MsTxPwrMaxGSM(ADJ)(n)
ad00 .# =S )00 MsTxPwrMaxGSM1x00(ADJ)(n) ad00
EU!TION 2% 9B=T( HoMarginPBGT(n) The parameter RX le ?* ell( )set for each of the 30 ad=acent cells* is the le%el $hich the signal le%el 9CD!+2ECD7E22)n* of the ad=acent cell )n* must exceed before the hando%er is possible. The range is from '11# d(m to '-" d(m.
S ",@:# ?a, $'?(!DA( '< or S ",@:# ?a, $'?1,00(!DA( '< depending on a frequency band is the difference bet$een the maximum transmission po$er that an : is permitted to use on a traffic channel in the ad=acent cell )n* and the maximum transmission po$er of the : )<*. The range of the : transmission po$er in ;: ## and in ;: A## is from 5 to 3 d(m, in ;: 1A## from # to 34 d(m and in ;: 1## from # to 33 d(m. The parameter can be defined for each of the 30 ad=acent cells. The parameter HO ?a#$* @$"( )set for each of the 30 ad=acent cells* is the margin $hich the po$er budget <(;T)n* of the ad=acent cell )n* must exceed before the hando%er is possible. It is also used as a threshold to pre%ent repetiti%e hando%ers bet$een cells. The range is from '0- d( to 43 d( and the step size is 1d(. The po$er budget )<(;T* equation )0* is explained in more detail in
hando%er margins for signal le%el and quality is taken into account in target cell e%aluation. The %alue 8yes8 indicates that the margins is taken into account.
EU!TION 2% !RX&ENCE&&( !RX&ED&HO ( BsTxPwrMax - BSTX9R HoMarginLev/Qal(n) The parameter HO ?a#$* le( )set for each of the 30 ad=acent cells* is the margin by $hich the signal le%el 9CD!+2ECD7E22)n* of the ad=acent cell )n* must exceed the signal le%el 9CD!+2ECD2D&? of the ser%ing cell before the hando%er is possible. It is used as a threshold if the cause of the hando%er is signal le%el. The range is from '0- d( to 0- d( and the step size is 1 d(. The parameter HO ?a#$* +al( )set for each of the 30 ad=acent cells* is the margin by $hich the signal le%el 9CD!+2ECD7E22)n* of the ad=acent cell )n* must exceed the signal le%el 9CD!+2ECD2D&? of the ser%ing cell before the hando%er is possible. It is used as a threshold if the cause of the hando%er is signal quality. The range is from '0- d( to 0- d( and the step size is 1 d(.
BS TX @:# ?a, '(DT+
