Abis Interface

401 - 380 - 349Issue 2.0

November 1999

Lucent Technologies - ProprietaryThis document contains proprietary information

of Lucent Technologies and is not to be disclosed or usedexcept in accordance with applicable agreements

Copyright 1999 Lucent TechnologiesUnpublished and Not for Publication

All Rights Reserved

EG19: Abis Interface

Engineering Guidelinefor NR 8.6 and NR 8.5.1

Copyright ©1999 by Lucent Tec hnologies. All Rights R eserved .

This material is protected by the copyright laws of the United States and other countries. It may not bereproduced, distributed, or altered in any fashion by any entity (either internal or external to LucentTechnologies), except in accordance with applicable agreements, contracts, or licensing, without theexpress written consent of the Customer Training and Information Products organization and thebusiness management owner of the material.

Notice

Every effort was made to ensure that the information in this information product (IP) was complete andaccurate at the time of printing. However, information is subject to change.

Issue 2.0- November 1999 Lucent Technologies –ProprietarySee Notice on first page

iii

Contents

1 INTRODUCTION 1-1

About this Guideline 1-1

Overview 1-1

2 DIMENSIONING THE ABIS INTERFACE FOR E1 2-1

Dimensioning the Abis Interface 2-1

Abis Interface timeslot allocation 2-1

Releases prior to NR8.0 2-1


From release NR 8.0 2-3

Abis Timeslot Usage - Configuration Rules 2-4

Example 1 2-7

Example 2 2-8

Example 3 2-9

Example 4 2-10

Example 5 2-11

Example 6 2-12

Example 7 2-13

3 DIMENSIONING THE ABIS INTERFACE FOR T1 3-1

Dimensioning the Abis Interface 3-1

Abis Interface timeslot allocation 3-23-2

3-1

3-1

2-13

2-12

2-11

2-10

2-9

2-8

2-7

2-4

2-3

2-3

2-1

2-1

2-1

2-1

1-1

1-1

1-1

Contents Abis Interface Engineering Guideline

iv Lucent Technologies –ProprietarySee Notice on first page

Issue 2.0 - November 1999

Releases prior to NR8.0 3-2


Abis Timeslot Usage - Configuration Rules 3-4

Example 1 3-7

Example 2 3-8

Example 3 3-9

Example 4 3-10

Example 5 3-11

Example 6 3-12

Example 7 3-13

Summary 3-14

4 REFERENCES 4-1

References 4-1

5 ACRONYMS 5-1

Acronyms 5-1

COMMENTS FORM 5-35-3

5-1

5-1

4-1

4-1

3-14

3-13

3-12

3-11

3-10

3-9

3-8

3-7

3-4

3-3

3-2


1-1

1 Introduction

About this Guideline

This Engineering Guideline provides a description of the physical characteristics of the Abis Interface anddefines how it is dimensioned within the “Lucent GSM Network”.

Overview

The Abis Interface supports signaling and traffic circuits between the Base Transceiver Station (BTS-2000) and the Base station Controller Frame (BCF-2000). The E1 Abis Interface is based on a data rateof 2.048 Mbit/s, the T1 Abis interface is based on a data rate of 1.544 Mbit/s. E1 carries 32 x 64 Kbit/schannels, while T1 carries 24 x 64 Kbit/s channels.

Functions implemented at the Abis Interface are:

• Voice/Data traffic exchange• Signaling exchange between the BCF-2000 and BTS-2000• Transport of O&M information between the BTS-2000 and the BCF-2000

The bandwidth of each Abis Interface is shared by 31 timeslots1 for E1 and 24 timeslots for T1. Sometimeslots are allocated to carry traffic and others to carry signaling information.

When the Abis Interface is used in a Type 6 architecture, “Traffic” timeslots are subdivided into 4 x 16Kbit/s subrate GSM1800/GSM900GSM1900 traffic channels.2 The situation is shown schematically inFigure 1 (E1) and Figure 2 (T1).

Dual Band operation

Traffic channels from differing frequency bands may be freely mixed onto a single Abis link following thenormal configuration rules for single band use.

1 E1 has 32 timeslots but timeslot 0 is utilised for frame synchronisation.2 These are termed “full-rate” 16 Kbit/s traffic channels. “Half-rate” 8kbit/s traffic channels will beavailable in the future.

Introduction Abis Interface Engineering Guideline

1-2 Lucent Technologies –ProprietarySee Notice on first page


BTS-2000 BCF-2000

TS0 TS1 TS31

64Kbit/s

16Kbit

16Kbit

16Kbit

16Kbit

13Kbit

3Kbit

4 Sub-rateT ffichannels in

timeslot

Ove

r-he

ad

Voc

oded

Spe

ech

Bit transferRate

8 Bitframes

2.048 Mb/s

either or

64Kbit

Signallinglink

16Kbit

16Kbit

16Kbit

16Kbit

Lucent release 4method


LAPD signalling concentration

function

Abis PhysicalCharacteristics

Figure 1: Physical characteristics of the E1 Abis Interface.

BTS-2000 BCF-2000

TS0 TS1 TS24

64Kbit/s

16Kbit

16Kbit

16Kbit

16Kbit

13Kbit

3Kbit

4 Sub-rateT ffichannels in

timeslot

Ove

r-he

ad

Voc

oded

Spe

ech

Bit transferRate

8 Bitframes

1.544 Mb/s

either or

64Kbit

Signallinglink

16Kbit

16Kbit

16Kbit

16Kbit



LAPD signalling concentration

function

Abis PhysicalCharacteristics

Figure 2: Physical characteristics of the T1 Abis Interface.


2-1

2 Dimensioning the Abis

Interface for E1

Dimensioning the Abis Interface

Lucent BTS-2000 products can have up to 3 Abis interface connections (e.g. 3 x E1 2.048Mbit/s links).

• 2 Abis interfaces to a BCF-2000• 1 Abis link output to provide the multidrop capability

Alternatively:

• 1 Abis interface to a BCF-2000• 2 Abis interface outputs to provide the multidrop capability

One exception is the Lucent BTS-2000/2C which has a maximum of 2 Abis interfaces:

• 1 Abis interface to a BCF-2000• 1 Abis link output to provide the multi-drop capability.

Abis Interface timeslot allocation

Releases prior to NR8.0

Each TRX connected via the Abis interface requires three timeslots:

• 2 for voice traffic/data• 1 for signaling

Dimensioning the Abis Interface for E1 Abis Interface Engineering Guideline



Each Cell/Sector connected via the Abis interface requires 1 timeslot for O&M signaling.

Example: for a 3-sectored (3,3,3) site;

# Timeslots = 3 x # TRXs + # Cells

= 3 x 9 + 3 = 30 timeslots required

The Lucent BSS configuration allows a maximum of 7 multi-dropped BTS-2000s on a single Abis

Interface connection.3

The maximum number of TRXs which can be placed on a single Abis is 10.

i.e. 3 x # TRXs + # Cells

= 3 x 10 + 1

= 31 (Max. No. of timeslots available on a single Abis

A single cell cannot be split across different Abis links. An omni 11 or omni 12 cannot be supported withRelease 4 software release. A 3-sectored 4,4,4 or 4,4,3 can be supported by placing the 3rd cell on asecond Abis.

Number of Multidrops

1 2 3 4 5 6 7

Maximum TRXs 10 9 9 9 8 8 8

TimeslotsRequired

31 29 30 31 29 30 31

Table 1: E1 Timeslot allocation summary (without LAPD concentration)

3 Multidrop indicates that more that one BTS can utilise the same Abis interface connection



2-3

SYNC ST T T ST T T ST T T ST T T ST T T

ST T T ST T T ST T TT orS07

T orS05

T orS04

T orS03

T orS04

S01T orS06

TR

X1

TR

X2

TR

X3

TR

X4

TR

X5

TR

X6

TR

X7

TR

X8

TR

X9

TR

X10

Where T =Traffic Channel ST = TRX Signalling

S0n = Signalling for Cell n

Figure 3: Timeslot allocation with Release 4 software release.


From release NR 8.0 Network Release 8.0 provides the LAPD Link Concentrator Function. This allows the concentration of 4logical signaling links onto one physical timeslot on the Abis Interface (i.e. .4 x 16Kbit/s subrate slots).This allows a more economical use of the Abis transmission capacity. Both TRX related signaling andcell (O&M) related signaling can be combined into a single timeslot, but all signaling channels sharing atimeslot must be in the same cell.

Each TRX connected via the Abis interface requires:

• 2 timeslots for voice traffic/data• 1 timeslot for signaling. 1 timeslot can accommodate signaling for:

− up to 4 TRXs (all TRXs must be in the same cell)

or

− 3 TRXs + 1 O&M ( all TRXs must be in the same cell and O&M must relate tothat cell)

With these capacity increases, a single Abis interface can support up to 12 TRXs in multicell or singlecell configurations




Abis Timeslot Usage - ConfigurationRules

This Abis LAPD Concentration can be used from GSM 8.0 onwards and on the BTS-2000 (with MRIF)and BTS-2000/2C, but is not usable on the BTS-2000P (with RIF) or the RBS-900. The maximum recommended concentration rate is 4:1 (i.e. one BTC and three RT signaling slots perAbis timeslot or four RT signaling slots per Abis timeslot). If a cell (BTS) requires more than one Abis timeslot containing signaling channels (i.e. cells with morethan 3 RTs) then the load (number of signaling channels) per Abis timeslots should be balanced (asdescribed in table opposite).


1 2 3 4 5 6 7 8 9 10

Maximum TRXs 12 12 12 12 12 12 12 11 11 10

TimeslotsRequired

28 28 30 28 29 30 31 30 31 30

Table 2: E1 Timeslot allocation summary (with LAPD concentration)



2-5

No. of TRXsper cell

No of used Abis

timeslots * Usage Concentration

rate 1 1st Abis TS BTC, RT:0 2 2 1st Abis TS BTC, RT:0, 1 3

3 1st Abis TS BTC, RT:0,1, 2

4

1st Abis TS BTC, RT:0, 1 3 4

2nd Abis TS RT:2, 3 2 1st Abis TS BTC, RT:0, 1 3

5 2nd Abis TS RT:2, 3, 4 3 1st Abis TS BTC, RT:0,

1, 2 4

6 2nd Abis TS RT:3, 4, 5 3 1st Abis TS BTC, RT:0,

1, 2 4

7 2nd Abis TS RT:3, 4, 5, 6 4 1st Abis TS BTC, RT:0, 1 3 2nd Abis TS RT:2, 3, 4 3 8 3rd Abis TS RT:5, 6, 7 3 1st Abis TS BTC, RT:0,

1, 2 4

2nd Abis TS RT:3, 4, 5 3 9

3rd Abis TS RT:6, 7, 8 3 1st Abis TS BTC, RT:0,

1, 2 4

2nd Abis TS RT:3, 4, 5, 6 4 10

3rd Abis TS RT:7, 8, 9 3 1st Abis TS BTC, RT:0,

1, 2 4

2nd Abis TS RT:3, 4, 5, 6 4 11

3rd Abis TS RT:7, 8, 9, 10 4 1st Abis TS BTC, RT:0,

1, 2 4

2nd Abis TS RT:3, 4, 5 3 3rd Abis TS RT:6, 7, 8 3

12

4th Abis TS RT:9, 10, 11 3 * Abis timeslot containing signaling channels, this column doesn’t describethe absolute timeslot number.

Table 3: Balancing the Abis load

• The Abis timeslots containing BTC signaling information will be configured on Abis

timeslots 31, 30 and downwards.

• Abis timeslots 1, 2 and upwards will be configured as traffic slots (containing trafficchannels). If an additional RT signaling slot is required, the Abis timeslot behind thelast used “traffic” timeslot will be used.

• Each BTC requires it’s own Abis timeslot. It is impossible to concentrate BTC signalingslots (of different cells) into one 64kbit/s Abis timeslot.

• Due to FEICE-4881 there will be no merge of signaling channels of different cells(BTSs) into one Abis timeslot.

• The Abis timeslots containing BTC signaling channels will be filled with signalingchannels for up to 3 RTs (the number of RT signaling channels depends on thenumber of RTs per cell and is given in Table 1).




RT signaling and traffic channels:

For each RT a signaling channel is set first and then the traffic channels are created. The first RTsignaling channels will be set to the Abis timeslot containing the BTC signaling channel of the appropriatecell (e.g. timeslot 31). If this Abis timeslot is already filled (as described in Table 1) then a new Abis

timeslot (containing RT signaling channels) will be created, followed by the Abis timeslots containing RTtraffic channels. The same Abis configuration will be used for both BSS types: BCE-2000 and BCF-2000. Remarks:

• This Configuration Rule will be used by the Site Independent Scripts to support thecreation of new BTSs.

• If an additional RT will be installed at a existing BTS the operator is not forced to useTable 1 (For example, if there is a BTS containing 3 RTs with all signaling channelsin TS31 it is not necessary to move the RT signaling channel of RT:2 to the Abis

timeslot containing the signaling information for the new RT:3).

• Possible restrictions in reference to the feature “BTS-2000/2C extension to 10 TRX”are not considered in this Configuration Rule.



2-7

Example 1

For a 3-sectored (4,4,4) site:Traffic Timeslots required = 2 x # TRXs = 2 x 12 = 24

Perform the signaling timeslot calculation on a per cell basis.

# Signaling Timeslots for cell A = # TRX + 1 = 4 + 1= 2 4 4

Signaling Timeslots required for cell B and C are the same in this example.

Total # signaling channels required = 3 x 2 = 6

Total # Timeslots required = # Signaling timeslots + # Traffic timeslots = 6 + 24 = 30

The situation is shown schematically in Figure 4.

SYNC S01 S4T T T T T T T T T S02 S4T T T T T

T T T T S03 S4T T T T T T T TT

TR

X3

Where T =Traffic Channel SnT = Signalling for n TRXs


TR

X1

TR

X2

TR

X4

TR

X11

TR

X9

TR

X10

TR

X12

TR

X7

TR

X8

TR

X5

TR

X6

Cell 1

Cell 3Cell 2

Cell 2

Figure 4: Timeslot allocation for 4,4,4 configuration, with Release 5 release.




Example 2

For a 2 x 2-sectored 3,3 on a single Abis:

Traffic Timeslots required = 2 x # TRXs = 2 x 12 = 24


# Signaling Timeslots for cell A = # TRX + 1 = 3 + 1 therefore 1 timeslot required

4 4




SYNCS3T+S01

T T T T T T S3T+S02

T T T T T T

S3T+S03 T T T T T T

S3T+S04 T T T T TT

TR

X3

Where T =Traffic Chanel SnT = Signalling for n TRXs


TR

X1

TR

X2

TR

X4

TR

X11

TR

X9

TR

X10

TR

X12

TR

X7

TR

X8

TR

X5

TR

X6

Cell 1

Cell 4Cell 3

Cell 2

Figure 5: Timeslot allocation for 2 x 2 sectored 3,3 on a single Abis, using release Release 5 software.

The Lucent BSS configuration at Release 5 allows a maximum of 7 multi-dropped BTSs on a single Abis

Interface connection.



2-9

Example 3

4-4-4 Multicell or Multidrop



# Signaling Timeslots for cell A = # TRX + 1 = 4 + 1 = 2 4 4



Total # Timeslots required = # Signaling timeslots + # Traffic timeslots = 6 + 24 = 30.

The situation is shown schematically in Table 2 below.

Timeslot Cell 4:1 concentration1 RT:0 Traffic2

TRX1RT:0 Traffic

3 RT:1 Traffic4

TRX2RT:1 Traffic

5 A Signaling RT:2,36 RT:2 Traffic7

TRX3RT:2 Traffic

8 RT:3 Traffic9

TRX4RT:3 Traffic

10 RT:0 Traffic11

TRX1RT:0 Traffic

12 RT:1 Traffic13

TRX2RT:1 Traffic

14 B Signaling RT:2,315 RT:2 Traffic16

TRX3RT:2 Traffic

17 RT:3 Traffic18

TRX4RT:3 Traffic

19 RT:0 Traffic20

TRX1RT:0 Traffic

21 RT:1 Traffic22

TRX2RT:1 Traffic

23 C Signaling RT:2,324 RT:2 Traffic25

TRX3RT:2 Traffic

26 RT:3 Traffic27

TRX4RT:3 Traffic

2829 C Signaling BTC, RT:0,130 B Signaling BTC, RT:0,131 A Signaling BTC, RT:0,1

Table 4: Performing a Timeslots calculation on a per cell basis (4-4-4Multicell)




Example 4

6-6 Multicell or Multidrop




Signaling Timeslots required for cell B are the same in this example.



Timeslot Cell 4:1 concentration1 TRX1 RT:0 Traffic2 RT:0 Traffic3 TRX2 RT:1 Traffic4 RT:1 Traffic5 TRX3 RT:2 Traffic6 RT:2 Traffic7 A Signaling RT:3, 4, 58 TRX4 RT:3 Traffic9 RT:3 Traffic10 TRX5 RT:4 Traffic11 RT:4 Traffic12 TRX6 RT:5 Traffic13 RT:5 Traffic14 TRX1 RT:0 Traffic15 RT:0 Traffic16 TRX2 RT:1 Traffic17 RT:1 Traffic18 TRX3 RT:2 Traffic19 RT:2 Traffic20 B Signaling RT:3, 4, 521 TRX4 RT:3 Traffic22 RT:3 Traffic23 TRX5 RT:4 Traffic24 RT:4 Traffic25 TRX6 RT:5 Traffic26 RT:5 Traffic27282930 B Signaling BTC, RT:0,1,231 A Signaling BTC, RT:0,1,2

Table 5: Performing a Timeslots calculation on a per cell basis (6-6 Multicell)



2-11

Example 5

2-2-2-2-2-2 Multidrop (e.g. 6 x BTS-2000/2C)




Signaling Timeslots required for cell B, C, D, D, E, and F are the same in this example.


Total # Timeslots required = # signaling timeslots + # Traffic timeslots = 6 + 24 = 30.


TRX1 RT:0 Traffic

3 RT:1 Traffic4

ATRX2

RT:1 Traffic5 RT:0 Traffic6

TRX1 RT:0 Traffic

7 RT:1 Traffic8

BTRX2


TRX1 RT:0 Traffic

11 RT:1 Traffic12

CTRX2


TRX1 RT:0 Traffic

15 RT:1 Traffic16

DTRX2


TRX1 RT:0 Traffic

19 RT:1 Traffic20

ETRX2


TRX1 RT:0 Traffic

23 RT:1 Traffic24

FTRX2

RT:1 Traffic2526 F Signaling BTC, RT:0,127 E Signaling BTC, RT:0,128 D Signaling BTC, RT:0,129 C Signaling BTC, RT:0,130 B Signaling BTC, RT:0,131 A Signaling BTC, RT:0,1

Table 6: Performing a Timeslots calculation on a per cell basis (2-2-2-2-2-2 Multicell)




Example 6

8-4 Multicell or Multidrop




# Signaling Timeslots for cell B = # TRX + 1 = 8 + 1 = 3 4 4

Total # signaling channels required = 2 + 3 = 5



TRX1 RT:0 Traffic

3 RT:1 Traffic4

TRX2 RT:1 Traffic

5 Signaling RT:2, 3, 46 RT:2 Traffic7

TRX3 RT:2 Traffic

8 RT:3 Traffic9

TRX4 RT:3 Traffic

10 RT:4 Traffic11

TRX5 RT:4 Traffic

12 Signaling RT: 5, 6, 713 RT:5 Traffic14

TRX6 RT:5 Traffic

15 RT:6 Traffic16

TRX7 RT:6 Traffic

17 RT:7 Traffic18

A

TRX8 RT:7 Traffic

19 RT:0 Traffic20

TRX1 RT:0 Traffic

21 RT:1 Traffic22

TRX2 RT:1 Traffic

23 Signaling RT: 2, 324 RT:2 Traffic25

TRX3 RT:2 Traffic

26 RT:3 Traffic27

B

TRX4 RT:3 Traffic

282930 B Signaling BTC, RT:0, 131 A Signaling BTC, RT:0, 1

Table 7: Performing a Timeslots calculation on a per cell basis (8-4Multicell)



2-13

Example 7

12 Omnicell






TRX1 RT:0 Traffic

3 RT:1 Traffic4

TRX2 RT:1 Traffic

5 RT:2 Traffic6

TRX3 RT:2 Traffic


TRX4 RT:3 Traffic

10 RT:4 Traffic11

TRX5 RT:4 Traffic

12 RT:5 Traffic13

TRX6 RT:5 Traffic


TRX7 RT:6 Traffic

17 RT:7 Traffic18

TRX8 RT:7 Traffic

19 RT:8 Traffic20

TRX9 RT:8 Traffic


TRX10 RT:9 Traffic

24 RT:10 Traffic25

TRX11 RT:10 Traffic

26 RT:11 Traffic27

A

TRX12 RT:11 Traffic

28293031 A Signaling BTC, RT:0,1,2

Table 8: Performing a Timeslots calculation on a per cell basis (12Omnicell)




This page is intentionally left blank


3-1

3 Dimensioning the AbisInterface for T1

Dimensioning the Abis Interface

Lucent BTS-2000 products can have up to 3 Abis interface connections (e.g. 3 x T1 1.544Mbit/s links).

• 2 Abis interfaces to a BCF-2000• 1 Abis link output to provide the multidrop capability

Alternatively:

• 1 Abis interface to a BCF-2000• 2 Abis interface outputs to provide the multidrop capability

One exception is the Lucent BTS-2000/2C which has a maximum of 2 Abis interfaces:

• 1 Abis interface to a BCF-2000• 1 Abis link output to provide the multi-drop capability.

Dimensioning the Abis Interface for T1 Abis Interface Engineering Guideline




Releases prior to NR8.0

Each TRX connected via the Abis interface requires three timeslots:

• 2 for voice traffic/data• 1 for signaling

Each Cell/Sector connected via the Abis interface requires 1 timeslot for O&M signaling.

Example: for a 3-sectored (2,2,2) site;

# Timeslots = (3 x # TRXs) + # Cells

= (3 x 6) + 3 = 21 timeslots required

The Lucent BSS configuration allows a maximum of 7 multi-dropped BTS-2000s on a single Abis

Interface connection.4

The maximum number of TRXs which can be placed on a single Abis is 7.

i.e. (3 x # TRXs) + # Cells

= (3 x 7) + 1 = 22 timeslots required

A single cell cannot be split across different Abis links.


1 2 3 4 5 6

Maximum TRXs 7 7 7 6 6 6

TimeslotsRequired

22 23 24 22 23 24

Table 9: T1 Timeslot allocation summary (without LAPD concentration)

4 Multidrop indicates that more that one BTS can utilise the same Abis interface connection



3-3

ST T T ST T T S01

TRX6

TRX7

Where T =Traffic Channel ST = TRX Signalling


ST T T ST T T ST T T ST T T ST T T

TRX1

TRX2

TRX3

TRX4

TRX5

Figure 6: Timeslot allocation with Release 4 software release.


From release NR 8.0

Network Release 8.0 provides the LAPD Link Concentrator Function. This allows the concentration of 4logical signaling links onto one physical timeslot on the Abis Interface (i.e. .4 x 16Kbit/s subrate slots).This allows a more economical use of the Abis transmission capacity. Both TRX related signaling andcell (O&M) related signaling can be combined into a single timeslot, but all signaling channels sharing atimeslot must be in the same cell.

Each TRX connected via the Abis interface requires:

• 2 timeslots for voice traffic/data• 1 timeslot for signaling. 1 timeslot can accommodate signaling for:

− up to 4 TRXs (all TRXs must be in the same cell)

or

− 3 TRXs + 1 O&M ( all TRXs must be in the same cell and O&M must relate tothat cell)

With these capacity increases, a single Abis interface can support up to 10 TRXs in multicell or singlecell configurations




Abis Timeslot Usage - ConfigurationRules

This Abis LAPD Concentration for T1 can be used from GSM 8.0 onwards and on the BTS-2000 (withMRIF2) and BTS-2000/2C, but is not usable on the BTS-2000P (with MRIF, RIF) or the RBS-900. The maximum recommended concentration rate is 4:1 (i.e. one BTC and three RT signaling slots perAbis timeslot or four RT signaling slots per Abis timeslot). If a cell (BTS) requires more than one Abis timeslot containing signaling channels (i.e. cells with morethan 3 RTs) then the load (number of signaling channels) per Abis timeslots should be balanced (asdescribed in table opposite).


1 2 3 4 5 6 7 8

Maximum TRXs 10 10 10 10 9 9 8 8

TimeslotsRequired

23 24 24 24 23 24 23 24

Table 10: T1 Timeslot allocation summary (with LAPD concentration)



3-5

No. of TRXs

per cell No of used Abis

timeslots * Usage Concentration

rate 1 1st Abis TS BTC, RT:0 2 2 1st Abis TS BTC, RT:0, 1 3

3 1st Abis TS BTC, RT:0, 1,2

4

1st Abis TS BTC, RT:0, 1 3 4

2nd Abis TS RT:2, 3 2 1st Abis TS BTC, RT:0, 1 3

5 2nd Abis TS RT:2, 3, 4 3 1st Abis TS BTC, RT:0, 1,

2 4

6 2nd Abis TS RT:3, 4, 5 3 1st Abis TS BTC, RT:0, 1,

2 4

7 2nd Abis TS RT:3, 4, 5, 6 4 1st Abis TS BTC, RT:0, 1 3 2nd Abis TS RT:2, 3, 4 3 8 3rd Abis TS RT:5, 6, 7 3 1st Abis TS BTC, RT:0, 1,

2 4

2nd Abis TS RT:3, 4, 5 3 9

3rd Abis TS RT:6, 7, 8 3 1st Abis TS BTC, RT:0, 1,

2 4

2nd Abis TS RT:3, 4, 5, 6 4 10

3rd Abis TS RT:7, 8, 9 3 * Abis timeslot containing signaling channels, this column doesn’t describethe absolute timeslot number.

Table 11: Balancing the Abis load

• The Abis timeslots containing BTC signaling information will be configured on Abis

timeslots 24, 23 and downwards.

• Abis timeslots 1, 2 and upwards will be configured as traffic slots (containing trafficchannels). If an additional RT signaling slot is required, the Abis timeslot behind thelast used “traffic” timeslot will be used.

• Each BTC requires it’s own Abis timeslot. It is impossible to concentrate BTC signalingslots (of different cells) into one 64kbit/s Abis timeslot.

• Due to FEICE-4881 there will be no merge of signaling channels of different cells(BTSs) into one Abis timeslot.

• The Abis timeslots containing BTC signaling channels will be filled with signalingchannels for up to 3 RTs (the number of RT signaling channels depends on thenumber of RTs per cell and is given in Table 1).

RT signaling and traffic channels:

For each RT a signaling channel is set first and then the traffic channels are created. The first RTsignaling channels will be set to the Abis timeslot containing the BTC signaling channel of the appropriatecell (e.g. timeslot 31). If this Abis timeslot is already filled (as described in Table 1) then a new Abis

timeslot (containing RT signaling channels) will be created, followed by the Abis timeslots containing RTtraffic channels.




The same Abis configuration will be used for both BSS types: BCE-2000 and BCF-2000. Remarks:

• This Configuration Rule will be used by the Site Independent Scripts to support the

creation of new BTSs.• If an additional RT will be installed at a existing BTS the operator is not forced to

use Table 1 (For example, if there is a BTS containing 3 RTs with all signalingchannels in TS31 it is not necessary to move the RT signaling channel of RT:2 tothe Abis timeslot containing the signaling information for the new RT:3).

• Possible restrictions in reference to the feature “BTS-2000/2C extension to 10TRX” are not considered in this Configuration Rule.



3-7

Example 1

For a 3-sectored (3,3,3) site:Traffic Timeslots required = 2 x # TRXs = 2 x 9 = 18






The situation is shown schematically in Figure 7

T T

T T T TT T

Where: T =Traffic Channel SnT = Signaling for n TRXs S0n = Signaling for Cell n

S01 +S3T T T T T T T

TR

X3

TR

X1

TR

X2

TR

X7

TR

X9

TR

X6

TR

X8

T T T T

TR

X4

TR

X5

Cell 1

Cell 3

Cell 2

S02 +S3T

S03 +S3T

Figure 7: Timeslot allocation for 3,3,3 configuration, using release Release 5 software.




Example 2

For a 2 x 2-sectored sites, 2,2 configs on a single Abis:



# Signaling Timeslots for cell A = # TRX + 1 = 2 + 1 therefore 1 timeslot required

4 4




S3T+S01

T T T T

S3T+S03

T T T TS3T+S04

T T T T

TR

X3

Where: T =Traffic Channel SnT = Signaling for n TRXs S0n = Signaling for Cell n

TR

X1

TR

X2

TR

X4

TR

X8

TR

X7

TR

X5

TR

X6

S3T+S02

T T T T

Cell 1

Cell 4Cell 3

Cell 2

Figure 8: Timeslot allocation for 2 x 2 sectored 2,2 on a single Abis, using release Release 5 software.

The Lucent BSS configuration at Release 5 allows a maximum of 7 multi-dropped BTSs on a single Abis

Interface connection.



3-9

Example 3

3,3,3 Multicell or Multidrop







The situation is shown schematically in Table 2 below.


TRX1RT:0 Traffic

3 RT:1 Traffic4

TRX2RT:1 Traffic

5 RT:2 Traffic6

A

TRX3RT:2 Traffic

7 RT:0 Traffic8

TRX1RT:0 Traffic

9 RT:1 Traffic10

TRX2RT:1 Traffic

11 RT:2 Traffic12

B

TRX3RT:2 Traffic

13 RT:0 Traffic14

TRX1RT:0 Traffic

15 RT:1 Traffic16

TRX2RT:1 Traffic

17 RT:2 Traffic18

C

TRX3RT:2 Traffic

19202122 C Signaling BTC, RT:0,1,223 B Signaling BTC, RT:0,1,224 A Signaling BTC, RT:0,1,2

Table 12: Performing a Timeslots calculation on a per cell basis (3,3,3 Multicell)




Example 4

5,5 Multicell or Multidrop




Signaling Timeslots required for cell B are the same in this example.




TRX1RT:0 Traffic

3 RT:1 Traffic4

TRX2RT:1 Traffic

5 RT:2 Traffic6

TRX3RT:2 Traffic

7 RT:3 Traffic8

TRX4RT:3 Traffic

9 RT:4 Traffic10

TRX5RT:4 Traffic

11

A

Signaling RT: 0, 1, 212 RT:0 Traffic13

TRX1RT:0 Traffic

14 RT:1 Traffic15

TRX2RT:1 Traffic

16 RT:2 Traffic17

TRX3RT:2 Traffic

18 RT:3 Traffic19

TRX4RT:3 Traffic

20 RT:4 Traffic21

TRX 5RT:4 Traffic

22

B

Signaling RT: 0, 1, 223 B Signaling BTC, RT: 3, 424 A Signaling BTC, RT: 3, 4

Table 13: Performing a Timeslots calculation on a per cell basis (5,5 Multicell)



3-11

Example 5

2,2,2,2 Multidrop (e.g. 6 x BTS-2000/2C)




Signaling Timeslots required for cell B, C, D and E are the same in this example.


Total # Timeslots required = # signaling timeslots + # Traffic timeslots = 4 + 16 = 20.


TRX1 RT:0 Traffic

3 RT:1 Traffic4

ATRX2


TRX1 RT:0 Traffic

7 RT:1 Traffic8

BTRX2


TRX1 RT:0 Traffic

11 RT:1 Traffic12

CTRX2


TRX1 RT:0 Traffic

15 RT:1 Traffic16

DTRX2

RT:1 Traffic1718192021 D Signaling BTC, RT:0,122 C Signaling BTC, RT:0,123 B Signaling BTC, RT:0,124 A Signaling BTC, RT:0,1

Table 14: Performing a Timeslots calculation on a per cell basis (2,2,2,2Multicell)




Example 6

6, 4 Multicell or Multidrop




# Signaling Timeslots for cell B = # TRX + 1 = 4 + 1 = 2 4 4

Total # signaling channels required = 2 + 2 = 4



TRX1RT:0 Traffic

3 RT:1 Traffic4

TRX2RT:1 Traffic

5 RT:2 Traffic6

TRX3RT:2 Traffic

7 RT:3 Traffic8

TRX4RT:3 Traffic

9 RT:4 Traffic10

TRX5RT:4 Traffic

11 RT:5 Traffic12

TRX6RT:5 Traffic

13

A

Signaling RT:2, 3, 4, 514 RT:0 Traffic15

TRX1RT:0 Traffic

16 RT:1 Traffic17

TRX2RT:1 Traffic

18 RT:2 Traffic19

TRX3RT:2 Traffic

20 RT:3 Traffic21

TRX4RT:3 Traffic

22

B

Signaling RT: 2, 323 B Signaling BTC, RT:0, 124 A Signaling BTC, RT:0, 1

Table 15: Performing a Timeslots calculation on a per cell basis (6-4Multicell)



3-13

Example 7

10 Omnicell






TRX1 RT:0 Traffic

3 RT:1 Traffic4

TRX2 RT:1 Traffic

5 RT:2 Traffic6

TRX3 RT:2 Traffic

7 Signaling RT: 3, 4, 5, 68 RT:3 Traffic9

TRX4 RT:3 Traffic

10 RT:4 Traffic11

TRX5 RT:4 Traffic

12 RT:5 Traffic13

TRX6 RT:5 Traffic


TRX7 RT:6 Traffic

17 RT:7 Traffic18

TRX8 RT:7 Traffic

19 RT:8 Traffic20

TRX9 RT:8 Traffic

21 RT:9 Traffic22

A

TRX10 RT:9 Traffic

2324 A Signaling BTC, RT:0,1,2

Table 16: Performing a Timeslots calculation on a per cell basis (10Omnicell)




Summary

Table 17 gives a brief summary of the Abis maximum capacities:

Max. BTSs on drop & insert Max. No. of TRXsE1 T1 E1 T1

NR to 8.0 (without LAPD concentration)LM4

7 (see note 2) 6 (see note 2) 10 (see note 1) 7 (see note 1)

NR from 8.0(with LAPD concentration) LM5 10 (see note 2) 8 (see note 2) 12 (see note 1) 10 (see note 1)

Table 17: A summary of the Abis maximum capacities

Note 1: Figures are based on a single cell containing the maximum number of TRXs.

Note 2: Figures are based on the maximum number of cells each containing one TRX.


4-1

4 References

References

[Ref. 1] BSS Network Configuration Training Course (WL9011), Issue A, June 19 1997

[Ref. 2] Lucent Network Design Tool (NDT). Available through Offer Engineering, Swindon,England

[Ref. 3] Network Configuration Guidelines

[Ref. 4] Abis signalling link concentration (EG 1)

References Abis Interface Engineering Guideline



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5-1

5 Acronyms

Acronyms

ACC Advanced Communications Cards

ACE Antenna Coupling Equipment

ACU Accessory Control Unit

BCF Base station Controller Frame

BHCA Busy Hour Call Attempts

BSS Base station Sub-System

BTC BTS Central Controller

BTS Base Transceiver Frame

DCE Data Communications Equipment

DFU Digital Facility Unit

DTE Data Terminal Equipment

GOS Grade Of Service

GMSK Gaussian Minimum Shift Keying

GSM Global System for Mobile communications

HP Hewlett Packard

ITU-T International Telecommunications Union - Telecommunications

LAPD Link Access Procedural type D

MSC Mobile service Switching Centre

MRIF Mini Rack Interface

Acronyms Abis Interface Engineering Guideline



NDT Network Design Tool

NSAP Network service Access Point

O&M Operations & Maintenance

OMC Operations and Maintenance Centre

PCM30 Pulse Code Modulation

RBS-900 Radio Base Station 900

RIF Rack Interface

RT Radio Terminal

SDFU Sub-rate Digital Facility Unit

SS7 ITU-T Signaling System No. 7

STF Speech Transcoding Frame

TRX Transceiver

BCF Base Controller Frame

BSS Base Station System

BTC BTS Central Controller

BTS Base Transceiver System

GSM Global System for Mobile communication

ITU-T International Telecommunications Union - Telecommunications

LAPD Link Access Procedural type D

MRIF Mini Rack Interface

NDT Network Design Tool

O&M Operations & Maintenance

PCM30 Peripheral Module Channel

RBS-900 Radio Base Station 900

RIF Rack Interface

RT Radio Terminal

TRX Transceiver

Comments Form Abis Interface Engineering Guideline


5-3

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