This topic describes the timeslot assignment on the Abis interface. •
This describes the BTS topologies. The BSC provides flexible BTS topologies on the Abis interface. These topologies are star topology, chain topology, tree topology, and ring topology. •
This topic describes the principles and algorithm of timeslot assignment on the Abis interface. •
This topic describes the timeslot arrangement on the Abis interface. The timeslots on the Abis interface are reassigned in the processes such as modifying BTS multiplexing modes, adding a BTS, a cell, a TR, an idle timeslot, and a monitoring timeslot, manually assigning timeslots on the Abis interface, deleting a secondary chain of a BTS, and moving a BTS on the !"T. If the timeslot assignment failed, the !"T re#uests you to determine $hether to arrange timeslots. The BSC arranges timeslots automatically. automatically. •
This topic describes the BTS multiplexing modes. The BTS multiplexing in the BSC refers to the multiplexing of the !A%& signaling on the '( timeslots of the Abis interface. The BSC offers six )* +bits statistic multiplexing multiplexing modes -n(, n /0 )1. They are ((, 2(, 3(, *(, 4(, and )(. The BSC also offers the physical () +bits multiplexing mode. •
This topic describes the manual timeslot assignment on the Abis interface. Timeslot assignment assignment on the Abis interface is re#uired $hen you add BTSs, cells, TRs, idle timeslots, and monitoring timeslots. By default, the timeslots are assigned automatically. automatically. 5ou can also manually assign timeslots on the Abis interface if re#uired. •
This topic describes the principles of semipermanent connection. Semipermanent connection is a transparent channel that can be used to transmit information specified by a subscriber. The BSC provides the semipermanent connection of four types 6 +bits, () +bits, 32 +bits, and )* +bits.
•
This topic describes the principles of idle timeslot assignment. Idle timeslots carry the 7%RS services in the BSS.
This topic describes the principles and algorithm of timeslot assignment on the Abis interface.
NOTE: •
Physical 16 kbit/s multiplexing refers to the permanent assignment of a 16 kbit/s timeslot to a channel. The channel exclusiely uses this 16 kbit/s timeslot.
•
!tatistic multiplexing means that n channels use one 6" kbit/s timeslot. Each channel uses the 6" kbit/s ban#$i#th in a #i%erent time slice& that is& Time 'iision (ultiplexing )T'(*. +n statistic multiplexing mo#e& more than one channel is multiplexe# onto one 6" kbit/s ban#$i#th.
Principles of Timeslot Assignment on the Abis
Interface The principles of timeslot assignment on the Abis interface are as follo$s •
On one link& n:1 statistic multiplexing an# physical 16 kbit/s multiplexing cannot coexist.
•
The O(,s& -!,s& i#le timeslots& monitoring timeslots& an# Ts are assigne# base# on sub0timeslots.
•
+n physical 16 kbit/s multiplexing mo#e& any of the O(,s& -!,s& i#le timeslots& monitoring timeslots& an# Ts can coexist on one 6" kbit/s timeslot.
•
+n n:1 statistic multiplexing mo#e& the timeslots of #i%erent T!s cannot be multiplexe#& the signaling timeslots an# tra2c timeslots of one T! cannot be multiplexe#& monitoring timeslots an# other timeslots cannot be multiplexe#& an# the timeslots )use# for both
speech an# signaling* of #i%erent cabinet groups in one T! cannot be multiplexe#. 1. The timeslots of #i%erent T!s cannot be multiplexe# onto one 6" kbit/s timeslot. 3. Tra2c channels an# signaling channels cannot be multiplexe# onto one 6" kbit/s timeslot. 4. One 6" kbit/s timeslot must be use# een if one signaling channel or tra2c channel is con5gure#. ". (onitoring timeslots cannot share the same 6" kbit/s timeslot $ith other timeslots& except for the semipermanent connection. . +n #i%erent E1s of casca#e# T!s& all the ob7ects multiplexe# onto one 6" kbit/s timeslot must stay in the same 6" kbit/s timeslot an# the relatie positions of their correspon#ing sub0 timeslot numbers must remain the same. 6. The timeslots of #i%erent e8uipment groups in one T! cannot be transmitte# on the 6" kbit/s ban#$i#th of the same E1. 9. +#le timeslots an# the timeslots on T-s cannot use the same 6" kbit/s ban#$i#th $ith the semipermanent connection. ;. The number of O(,s for the . The number of -!,s for the
?hen T!s& cells& T-s& i#le timeslots& or monitoring timeslots are a##e#& timeslots on the @bis interface must be assigne#. The resources on the @bis interface are assigne# to the follo$ing ob7ects: O(,s& -!,s& channels& i#le timeslots& an# monitoring timeslots.
•
The timeslots for a T! are assigne# in the follo$ing or#er: O(,s& -!,s& Ts& i#le timeslots& an# monitoring timeslots.
Algorithm of Timeslot Assignment on the Abis
Interface The algorithm of timeslot assignment on the Abis interface is as follo$s •
Each E1 port of the T! manages sub0timeslots AB3. !ub0timeslots AB9 are use# for synchroniCation. They cannot be assigne# to any ob7ects.
•
The O(, of a T! is assigne# on timeslot 41. +n n:1 statistic multiplexing mo#e& the O(, is assigne# on sub0timeslot A of timeslot 41. +n physical 16 kbit/s multiplexing mo#e& the O(, is assigne# on sub0timeslot 4 of timeslot 41.
•
Except for the incoming E1 timeslot& the E1 port #irectly connecte# to the ! is selecte# preferentially #uring the timeslot assignment of the upper0leel T!.
•
(onitoring timeslots an# i#le timeslots can be assigne# only on the ports of the main cabinets in the main cabinet groups.
•
,o$er0leel T!s can be establishe# only on the ports of the main cabinets in the main cabinet groups.
•
efore the O(, bet$een the T! an# the ! is establishe#& the T! #oes not kno$ its position on the O(,. The T! scans #i%erent timeslots an# tries to establish the O(, to the !. To re#uce the link setup time& the number of T! casca#es is limite#.
This topic describes the timeslot arrangement on the Abis interface. The timeslots on the Abis interface are reassigned in the processes such as modifying BTS multiplexing modes, adding a BTS, a cell, a TR, an idle timeslot, and a monitoring timeslot, manually assigning timeslots on the Abis interface, deleting a secondary chain of a BTS, and moving a BTS on the !"T. If the timeslot assignment failed, the !"T re#uests you to determine $hether to arrange timeslots. The BSC arranges timeslots automatically. In the follo$ing example, there are t$o cascaded BTSs. !evel ( BTS uses timeslots * through 48 and level 2 BTS uses timeslots )6 through (29. :our idle timeslots of level ( BTS are deleted and timeslots ), 9, 6, and 8 are released. A ne$ TR is added to level 2 BTS. The TR carries six TC;s.
•
If the existing timeslot distribution meets the re#uirements for BSC automatic arrangement, the BSC starts to arrange timeslots. If the existing timeslot distribution does not meet the re#uirements for BSC automatic arrangement, you need to add
physical '( lin+s and add the corresponding site chains on the !"T. 5ou can use the follo$ing methods to arrange timeslots to meet the re#uirement of the ne$ly added TR for timeslots. •
•
Arrange the timeslots of level ( BTS. "ove the services on timeslots * and 4 to timeslots 6 and 8. Therefore, an '( contains three complete )* +bits timeslots. There are sufficient timeslot resources to add a TR. The RS! of the added TR can use timeslots *, 4, ), and 9. The remaining t$o complete )* +bits timeslots can be assigned to six TC;s.
Table ( sho$s the timeslot distribution on the Abis interface before timeslot arrangement by the BSC. Table ( Timeslot distribution on the Abis interface before timeslot arrangement by the BSC Timeslo t
Sub=Timeslot
>
Synchroni?atio Synchroni?atio Synchroni?atio Synchroni?atio n n n n
(
@sed by level ( site
@sed by level ( site
Idle
Idle
2
Idle
Idle
@sed by level ( site
@sed by level ( site
3
@sed by level ( site
@sed by level ( site
@sed by level ( site
@sed by level ( site
...
...
...
...
...
(2
@sed by level ( site
@sed by level ( site
@sed by level ( site
@sed by level ( site
(3
@sed by level ( site
@sed by level ( site
@sed by level ( site
@sed by level ( site
(*
Idle
Idle
Idle
Idle
(4
Idle
Idle
Idle
Idle
> and (
2 and 3
* and 4
) and 9
()
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
(9
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
...
...
...
...
...
3>
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
3(
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
Table 2 sho$s the timeslot distribution on the Abis interface after timeslot arrangement by the BSC. Table 2 Timeslot distribution on the Abis interface after timeslot arrangement by the BSC Timeslo t
Sub=Timeslot
>
Synchroni?atio Synchroni?atio Synchroni?atio Synchroni?atio n n n n
(
Idle
Idle
Idle
Idle
2
@sed by level ( site
@sed by level ( site
@sed by level ( site
@sed by level ( site
3
@sed by level ( site
@sed by level ( site
@sed by level ( site
@sed by level ( site
...
...
...
...
...
(2
@sed by level ( site
@sed by level ( site
@sed by level ( site
@sed by level ( site
(3
@sed by level ( site
@sed by level ( site
@sed by level ( site
@sed by level ( site
(*
Idle
Idle
Idle
Idle
(4
Idle
Idle
Idle
Idle
()
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
> and (
2 and 3
* and 4
) and 9
(9
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
...
...
...
...
...
3>
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
3(
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
@sed by level 2 site
The process of timeslot arrangement by the BSC is as follo$s •
• •
• •
The BSC releases all the timeslots that are used by the cascaded BTSs except for the timeslots assigned manually. The BSC reassigns timeslots for each obect. If the reassignment of timeslots failed, a timeslot arrangement failure message is displayed. The BSC does not change the timeslots assigned manually. If the timeslot arrangement fails, the timeslot distribution before the timeslot arrangement is restored.
This topic describes the BTS multiplexing modes. The BTS multiplexing in the BSC refers to the multiplexing of the !A%& signaling on the '( timeslots of the Abis interface. The BSC offers six )* +bits statistic multiplexing modes -n(, n /0 )1. They are ((, 2(, 3(, *(, 4(, and )(. The BSC also offers the physical () +bits multiplexing mode. In all the n( multiplexing modes, the speech rate is () +bits or 6 +bits -half rate1. :our speech channels -eight channels for half rate1 occupy one )* +bits timeslot on the Abis interface. The rate of all the signaling lin+s is )* +bits. In different multiplexing modes -n(1, n signaling timeslots occupy one '( timeslot -)* +bits1 on the Abis interface. The )* +bits exchange of all the timeslots is performed on the 7'I@B of the BSC. In () +bits multiplexing mode, the data rate of all the multiplexed signaling lin+s must be () +bits. The BTS2>, BTS22, BTS3>>(C, and BTS3>>(C do not support the physical () +bits multiplexing mode.
As sho$n in :igure (, the four '(s are A>, A(, A2, and A3. If the multiplexing modes of BTS >, BTS (, BTS 2, and BTS 3 are ((, 2(, 3(, and *(, then four multiplexing modes exist on the 7'I@B. The multiplexing mode of each '( on the lin+ $here the BTS is located depends on the multiplexing mode of the BTS itself. •
• • •
:our multiplexing modes exist on A>. They are ((, 2(, 3(, and *(. T$o multiplexing modes exist on A(. They are 2( and *(.
•
This topic describes the '( timeslot assignment in ((, 2(, 3(, and *( multiplexing modes. •
This topic describes the timeslot assignment on the Abis interface in the tree topology.
This topic describes the '( timeslot assignment in ((, 2(, 3(, and *( multiplexing modes.
NOTE:
The timeslot assignment of each multiplexing mode is based on the follo$ing conditions •
The speech rate is 16 kbit/s. Dour channels of speech occupy one 6" kbit/s timeslot on the @bis interface.
•
Dor the 5rst T-& channel A )TAAA* is the an# channel 1 )TAA1* is the !'.
•
The an# the !' use the -!,& that is& the timeslots on the -!, contain the timeslots on the TAAA an# TAA1. Therefore& TAAA an# TAA1 are not liste# in the follo$ing tables.
1:1 Multiplexing Mode In the follo$ing example, BTS > is configured $ith a cell, the cell is configured $ith four TRs, the channels in the cell use default settings, and the multiplexing mode is ((. Table ( lists the timeslot assignment on the Abis interface. Table 1 Timeslot assignment in 1:1 multiplexing mo#e
Timeslo t o.
Sub=Timeslot o.
> and (
2 and 3
* and 4
) and 9
>
Synchroni?atio Synchroni?atio Synchroni?atio Synchroni?atio n n n n
(
RS!>>
2
T>>C2
T>>C3
T>>C*
T>>C4
3
T>>C)
T>>C9
T>(C>
T>(C(
*
RS!>(
4
T>(C2
T>(C3
T>(C*
T>(C4
)
T>(C)
T>(C9
T>2C>
T>2C(
9
RS!>2
6
T>2C2
T>2C3
T>2C*
T>2C4
8
T>2C)
T>2C9
T>3C>
T>3C(
(>
RS!>3
((
T>3C2
T>3C3
T>3C*
T>3C4
(2
T>3C)
T>3C9
...
3(
<"!>
2:1 Multiplexing Mode In the follo$ing example, BTS > is configured $ith a cell, the cell is configured $ith four TRs, the channels in the cell use default settings, and the multiplexing mode is (2. Table 2 lists the timeslot assignment on the Abis interface. Table 3 Timeslot assignment in 3:1 multiplexing mo#e
Timeslo t o.
Sub=Timeslot o.
> and (
2 and 3
* and 4
) and 9
>
Synchroni?atio Synchroni?atio Synchroni?atio Synchroni?atio n n n n
(
T>>C2
T>>C3
T>>C*
T>>C4
2
T>>C)
T>>C9
T>(C>
T>(C(
3
RS!>(RS!>2
*
T>(C2
T>(C3
T>(C*
T>(C4
4
T>(C)
T>(C9
T>2C>
T>2C(
)
T>2C2
T>2C3
T>2C*
T>2C4
9
T>2C)
T>2C9
T>3C>
T>3C(
6
RS!>3
8
T>3C2
T>3C3
T>3C*
T>3C4
(>
T>3C)
T>3C9
(( ...
3(
<"!>RS!>>
3:1 Multiplexing Mode In the follo$ing example, BTS > is configured $ith a cell, the cell is configured $ith four TRs, the channels in the cell use default settings, and the multiplexing mode is (3. Table 3 lists the timeslot assignment on the Abis interface. Table 4 Timeslot assignment in 4:1 multiplexing mo#e
Timeslo t o.
Sub=Timeslot o.
> and (
2 and 3
* and 4
) and 9
>
Synchroni?atio Synchroni?atio Synchroni?atio Synchroni?atio n n n n
(
T>>C2
T>>C3
T>>C*
T>>C4
2
T>>C)
T>>C9
T>(C>
T>(C(
3
T>(C2
T>(C3
T>(C*
T>(C4
*
T>(C)
T>(C9
T>2C>
T>2C(
4
RS!>2RS!>3
9
T>2C2
T>2C3
T>2C*
T>2C4
8
T>2C)
T>2C9
T>3C>
T>3C(
((
T>3C2
T>3C3
T>3C*
T>3C4
(2
T>3C)
T>3C9
(3 ...
3(
<"!>RS!>>RS!>(
4:1 Multiplexing Mode In the follo$ing example, BTS > is configured $ith a cell, the cell is configured $ith four TRs, the channels in the cell use default settings, and the multiplexing mode is (*. Table * lists the timeslot assignment on the Abis interface. Table " Timeslot assignment in ":1 multiplexing mo#e
Timeslo t o.
Sub=Timeslot o.
> and (
2 and 3
* and 4
) and 9
>
Synchroni?atio Synchroni?atio Synchroni?atio Synchroni?atio n n n n
(
T>>C2
T>>C3
T>>C*
T>>C4
2
T>>C)
T>>C9
T>(C>
T>(C(
3
T>(C2
T>(C3
T>(C*
T>(C4
*
T>(C)
T>(C9
T>2C>
T>2C(
4
T>2C2
T>2C3
T>2C*
T>2C4
)
T>2C)
T>2C9
T>3C>
T>3C(
9
RS!>3
6
T>3C2
T>3C3
T>3C*
T>3C4
8
T>3C)
T>3C9
(> ...
3(
<"!>RS!>>RS!>(RS!>2
This topic describes the timeslot assignment on the Abis interface in the tree topology.
•
•
The speech rate is () +bits. :our channels of speech occupy one )* +bits timeslot on the Abis interface. :or the first TR, channel > -T>>C>1 is the BCC; and channel ( -T>>C(1 is the S&CC;. The BCC; and the S&CC; use the RS!, that is, the timeslots on the RS! contain the timeslots on the T>>C> and T>>C(. Therefore,T>>C> and T>>C( are not listed in the follo$ing tables.
:igure ( sho$s the tree topology. The multiplexing modes of BTS >, BTS (, BTS 2, and BTS 3 are ((, 2(, 3(, and *(. 'ach BTS is configured $ith a cell, the cell is configured $ith t$o TRs, and the channels in the cell use default settings. :igure ( BTSs in tree topology
BTS > is the root node. Table ( to Table * sho$ the timeslot assignment on '(s -A>DA31 of BTSs. Table ( Timeslot assignment on A> Timeslo t o.
Sub=Timeslot o.
>
Synchroni?atio Synchroni?atio Synchroni?atio Synchroni?atio n n n n
(
RS!>>
2
T>>C2
T>>C3
T>>C*
T>>C4
3
T>>C)
T>>C9
T>(C>
T>(C(
> and (
2 and 3
* and 4
) and 9
*
RS!>(
4
T>(C2
T>(C3
)
T>(C)
T>(C9
9
<"!(RS!(>
6
T(>C2
8
T(>C)
(>
RS!((
((
T>(C*
T>(C4
T(>C3
T(>C*
T(>C4
T(>C9
T((C>
T((C(
T((C2
T((C3
T((C*
T((C4
(2
T((C>)
T((C9
(3
<"!2RS!2>RS!2(
(*
T2>C2
T2>C3
T2>C*
T2>C4
(4
T2>C)
T2>C9
T2(C>
T2(C(
()
T2(C2
T2(C3
T2(C*
T2(C4
(9
T2(C)
T2(C9
(6
<"!3RS!3>RS!3(
(8
T3>C2
T3>C3
T3>C*
T3>C4
2>
T3>C)
T3>C9
T3(C>
T3(C(
2(
T3(C2
T3(C3
T3(C*
T3(C4
22
T3(C)
T3(C9
23 ... 3(
<"!> Table 2 Timeslot assignment on A(
Timeslo t o.
Sub=Timeslot o.
>
Synchroni?atio Synchroni?atio Synchroni?atio Synchroni?atio n n n n
(
T(>C2
> and (
2 and 3
T(>C3
* and 4
T(>C*
) and 9
T(>C4
2
T(>C)
T(>C9
T((C>
T((C(
3
RS!((
*
T((C2
T((C3
T((C*
T((C4
4
T((C)
T((C9
)
<"!3RS!3>RS!3(
9
T3>C2
T3>C3
T3>C*
T3>C4
6
T3>C)
T3>C9
T3(C>
T3(C(
8
T3(C2
T3(C3
T3(C*
T3(C4
(>
T3(C>)
T3(C9
(( ... 3(
<"!(RS!(> Table 3 Timeslot assignment on A2
Timeslo t o.
Sub=Timeslot o.
>
Synchroni?atio Synchroni?atio Synchroni?atio Synchroni?atio n n n n
(
T2>C2
T2>C3
T2>C*
T2>C4
2
T2>C)
T2>C9
T2(C>
T2(C(
3
T2(C2
T2(C3
T2(C*
T2(C4
*
T2(C)
T2(C9
> and (
2 and 3
* and 4
) and 9
4 (( ... 3(
<"!2RS!2>RS!2( Table * Timeslot assignment on A3
Timeslo t o.
Sub=Timeslot o. > and (
2 and 3
* and 4
) and 9
>
Synchroni?atio Synchroni?atio Synchroni?atio Synchroni?atio n n n n
(
T3>C2
T3>C3
T3>C*
T3>C4
2
T3>C)
T3>C9
T3(C>
T3(C(
3
T3(C2
T3(C3
T3(C*
T3(C4
*
T3(C)
T3(C9
4 ... 3(
<"!3RS!3>RS!3(
This topic describes the manual timeslot assignment on the Abis interface. Timeslot assignment on the Abis interface is re#uired $hen you add BTSs, cells, TRs, idle timeslots, and monitoring timeslots. By default, the timeslots are assigned automatically. 5ou can also manually assign timeslots on the Abis interface if re#uired. Ehen manually assigning timeslots on the Abis interface, adhere to the follo$ing principles •
•
•
•
•
The obects that support manual timeslot assignment are <"!s, RS!s, channels, idle timeslots, and monitoring timeslots. 5ou can assign timeslots on the Abis interface for multiple obects at a time. If you manually assign timeslots on the Abis interface for the obect that is located in a cascaded lin+, you must also manually assign the incoming Abis timeslots for all the BTSs on the lin+. If a timeslot to be manually assigned for an obect is used by another obect, the timeslot cannot be manually assigned unless the obect that use the timeslot is deleted or moved to another timeslot. The multiplexing mode of assigned timeslots must be the same as the multiplexing mode of the BTS. If the BTS uses the 2(
•
•
•
•
•
multiplexing mode, do not multiplex four signaling lin+s together. In the incoming '( and outgoing '( lin+s of all the cascaded BTSs on a lin+, all the obects multiplexed onto one )* +bits timeslot must be located in the same )* +bits timeslot and all the relative positions of sub=timeslots must be remain unchanged. :or example, three obects of a BTS use timeslots 6, 8, and (> of level=( BTS and timeslots *, 4, and ) of level=2 BTS. Ehen assigning timeslots for another obect of the BTS, you should not assign timeslot (( of level=( BTS or timeslot 9 of level=2 BTS. 5ou can assign a timeslot of level=( BTS except for timeslot (( and a timeslot of level=2 BTS except for timeslot 9. Ehen adding BTSs, cells, TRs, idle timeslots, and monitoring timeslots, you can manually assign timeslots for only the ne$ly added obects. The timeslots of existing obects cannot be manually assigned. If you only manually assign timeslots on the Abis interface $ithout performing other operations, you can assign timeslots for all the obects on the entire lin+. Ehen you change the assignment mode of the timeslots of an obect from manual mode to auto mode, the assignment mode of the timeslots that are already assigned cannot be changed. Ehen you change the assignment mode of the timeslots of an obect from auto mode to manual mode, you also need to release the timeslots that are automatically assigned for the obect. If the Abis timeslot on a channel is assigned manually, you should manually release the Abis timeslot assigned to the channel $hen changing the channel to a channel that does not use the Abis timeslot. 5ou can assign the timeslots on the Abis interface for the BTSs on only one lin+ of a topology at a time.
