205583569 gb-interface-detailed-planning-final

1 © NOKIA 2000 Gb interface detailed planning

Core Network PlanningGb Interface Detailed Planning


Agenda

• Gb interface introduction

• Gb review ( protocol stack / ntw layers )

• Gb in detail ( NSE / logical connections )

• Frame relay interface planning

• BSC dimensioning

• Frame relay dimensioning

• SGSN dimensioning

• Gb Detail planning ( e.g. Topology )

• Exercise 1: case study Nortel BSS – Nokia SGSN

• Exercise 2: detailed planning


Gb Interface

BSC

PCU

BSS

SGSN

PAPU

GPRS

Frame R elay

Gb interface


Gb Interface Review

D O C U M E N T T Y P E

T y p e U n i t O r D e p a r t m e n t H e r eT y p e Y o u r N a m e H e r e T y p e D a t e H e r e

o t h e r P L M N

M S C / V L R H L R

E I R

S G S N

G G S N

G G S N

S G S N

P D N T E

S M S - G M S CS M S - I W M S C

M S B S SG iG n

G n G p

G b

G d

U m

G cG rG s

G f

CE

D

A

S i g n a l l i n g &D a t a T r a n s f e r

S i g n a l l i n g

G P R S I n t e r f a c e s


Gb Interface ReviewGPRS Protocol Stack / transmission plane

SGSNBSS

SNDCP

APP

TCP/UDP

IP

MAC

GSM RF

RLC

LLC

MS

MAC NS

GSM RF L1

RLC BSSGP

GTP

UDP

IP

SNDCP

LLC

BSSGP

NS

L1 L1

LLC/SNAPMAC

Radiointerface

Um Gb Gn Gi

G703Frame Relay

100 MbpsEthernet

GGSN

USERPAYLOAD

GTP

UDP

IP

L1

LLC/SNAPMAC

APP

TCP/UDP

IP

L2

L1Relay

Relay

GPRS IP Backbone Internet

•SNDCP: Sub-Network Dependent Convergence Protocol

The primary function of BSSGP is to provide the radio-related, QoS, and routing information that is required to transmit user data between a BSS and an SGSN. A secondary function is to enable two physically distinct nodes, the SGSN and BSS, to operate node management control function .

•BSSGP: Base Station System GPRS Protocol

•NS: Network Service

•SNAP: Subnetwork access protocol


Gb Interface ReviewNetwork Layers

GPRS

TCP/IP

ATM & FR

Transport/SDH

BSCSGSN SGSN

BSC

GbIntra-site

GnInter-site

Gn Gb

GPRS IPBackboneNetwork


Gb Interface ReviewGb Interface

BSC

PCU

SGSN

Frame Relay

Gb

PAPUBSS GPRS


Gb Interface; planning issues

2 Mbps Channelised E1 link2 Mbps Channelised E1 link

NS-VC capacity: 16 kbps…1.92 NS-VC capacity: 16 kbps…1.92 MbpsMbps

FR Bearer channel: 64 kbps… 1.92 FR Bearer channel: 64 kbps… 1.92 MbpsMbps


NSE= (PCU)

NSE

Gb Interface ReviewNetwork Service Entity (NSE)

BSCSGSN

NS-VC

NS-VC

NS-VC

NS-VC

BVC 0for

signalling

Own BVCfor

each cell

Own BVCfor

each cell

BVC 0for

signalling

Own BVCfor

each cell

Own BVCfor

each cell

BVC = BSSGP Virtual ConnectionBSSGP = Base Station Subsystem GPRS ProtocolNSE = Network Service EntityNS-VC = Network Service Virtual ConnectionFR = Frame Relay

FR Bearer Channel

Physical Link (= PCM TSL)

DLCI Data Link Connection Identifier(FR address)

NS-VCDLCI Data Link Connection Identifier

(FR address)

Load Sharing FR Bearer Channel

Physical Link (= PCM TSL)


SGSN

BSS 1

Bearer Channel_1

Bearer Channel_2

DLCI_16

DLCI_17

DLCI_16

DLCI_17

DLCI_18

Bearer Channel_3

DLCI_16

Bearer Channel_5

Bearer Channel_6

DLCI_16

DLCI_17PAPU 3

PAPU 2

PAPU 1 PCU 1

PCU 2

PCU 3

LA

RA 1

BTS_6

BTS_3

RA 2

BTS_8

BTS_22Bearer Channel_4

DLCI_16

DLCI_17

BSS 2

PCU 3 LA

RABTS_22

NSEI_7NS-VCI_6

NS-VCI_9

NSEI_3NS-VCI_4

NS-VCI_1

NS-VCI_11

NSEI_2NS-VCI_5

NS-VCI_8

NS-VCI_3

NSEI_1NS-VCI_7

NS-VCI_2

NSEI_7NS-VCI_6

NS-VCI_9

NSEI_3NS-VCI_4

NS-VCI_1

NS-VCI_11

NSEI_2NS-VCI_5

NS-VCI_8

NS-VCI_3

BSSGPNSFR

SignalData

Data & Signal

NSEI_1

BVCI_22

BVCI_0

BVCI_22

BVCI_0

BVCI_8

BVCI_8

BVCI_6

BVCI_0

BVCI_0

BVCI_22

BVCI_6

BVCI_0

BVCI_0

BVCI_3

BVCI_22

BVCI_0

NS-VCI_7

NS-VCI_2BVCI_3

BVCI_0

Gb Interface ReviewLogical Structure

Id Unique in NSE

own BVC for each cell

Id Unique in bearer

NS_VCI unique in SGSN


FR bearer channels, 1…31 TSL

NS-VCs, CIR=16…1.984 Mbit/sBVCs

• FR bearer channels run on PCM links (64…1984 kbit/s)• Max. 4 NS-VCs configured on FR bearers (CIR of each 16…1984 kbit/s)

•CIR doesn‘t stand in relation to subscriber datarate / cell • Max. 4 NS-VCs per NSE (PCU), and 256 NS-VCs per PAPU

PCM Link 32 TSL

PCU

Gb Interface ReviewLogical Channels in Physical Link


Frame Relay Link Parameters - 1• BVC

- 1 BVC (BVCI) for each CELL - unique within an NSE

- 1 BVC (BVCI) can be mapped into 2 NS-VC (load sharing)

- 1 or MORE BVCs (BVCI's) are mapped into 1 or more NS-VC

- 1 SIGNALING BVC per PCU, BVCI = 0000HEX• NS-VC

- NS-VCI = DLCI and FR BEARER CHANNEL IDENTIFIER

- 1…4 NS-VCs per NSE (=PCU)

- up to 256 per PAPU

- 1 NS-VC supports several BVC

- capacity controlled by CIR in steps of 16 Kbps up to the BEARER CHANNEL capacity

- NS-VCI is unique within a SGSN, identical on BOTH ENDS (end to end) ; range 0…65535

• PCU

- 1 PCU = 1 NSE (NSEI)- 1 PCU handles maximum 64 cells


Frame Relay Link Parameters - 2• NSE

- NSEI is unique within a BSC, identical on BOTH ENDS (end to end) range 0…65535

- on BOTH ENDS are connected by 1 or MORE NS-VC

- within 1 NSE, NS-VCs are shared by all BVCs

• DLCI

- up to 124 DLCI on 1 BEARER CHANNEL - unique within 1 BEARER CHANNEL, identical on BOTH SIDES

- range 16…991

• BEARER CHANNEL

- capacity from 64 to 1984 Kbps (1 to 31 TS of an E1) in multiples of 64Kbps

• PAPU

- supports up to 64 PCU per PAPU

• SGSN

- number of NS-VCs in SGSN = number of DLCI (up to 256 per PAPU)


Gb Inteface Planning

• BSC Planning - defining the number of active PCUs

• Frame Relay Link Planning

– Topology Planning

– Frame Relay Link Dimensioning

• SGSN Dimensioning - defining the number of PAPU & SGSN equipments and extension units

3 Sections of Gb Inteface Planning


Gb Inteface Planning Selecting the Protocol Overhead

Gb I/F Protocol Stack Percentage of Overhead in GPRS Traffic at the Gb Interface Protocol Min Header size (oct.) Max Header size (oct.) ReferenceSNDCP 3 4 GSM 04.65

LLC 5 40 GSM 04.64BSSGP 12 54 GSM 08.18

NS 4 4 GSM 08.16FR 6 6 GSM 03.60

Total 30 108 Packet size Min OH % Max OH %50 60.00 216.0060 50.00 180.00

100 30.00 108.00150 20.00 72.00200 15.00 54.00256 11.72 42.19300 10.00 36.00400 7.50 27.00512 5.86 21.09750 4.00 14.40

1000 3.00 10.801250 2.40 8.641500 2.00 7.20

216

180

108

4.0 3.0 2.4 2.0

15.020.0

50.030.0

11.7 10.0 7.5 5.9

60.0

72

5442 36

27

79111421

0

50

100

150

200

250

300

100 150 200 256 300 400 512 750 1000 1250 1500

Packet length (octets)

Ov

erh

ea

d (

%) Ohmax

OHmin


Gb Inteface Planning Selecting the Burst Margin

Actual traffic load, X %

Burst Margin, 100 - X %

Discarded data

Throughput

time

• Packet data traffic is bursty in nature

• Nokia PCU implements a Static Frame Relay

• Data above the CIR is discarded (EIR = 0)

• CIR calculation should include burst margin

CIR

EIR=0


ET

5C

ET

5C

ET

5CB

CS

UB

CS

U

BC

SU

BC

SU

BC

SU

BC

SU

BC

SU

WD

DC

CLO

C

CLA

C

ET

5C

ET

5C

PSA20PSFP

PSA20PSFP

OM

UM

CM

U

MC

MU

SW

1C

SW

1C

BC

SU

ET

5C

WD

DC

BC

SU

ET

5C

• All BSC's BCSU units must be fully equipped with PCUs (max. 8+1 per BSC)

• GSWB expanded from 128 to 192 PCMs (if not already done)

• BSC2E/A: Extra ET5C Cartridges to increase PCMs from 80 to 112

• PCU controls cells, not TRXs like BCSU PCU does not handle the same TRXs as the BCSU where it is located

PCU HW in every BCSU

BSC DimensioningPacket Control Unit - PCU

3rd SW64B cartridges

ET5Ccartridges


BSC DimensioningDefining the active number of PCUs

• Dimensioning Criteria for the number of active PCUs:

1. Each BSC in GPRS coverage area has to contain at least one active PCU (minimum requirement)

2. PCU can supports 256 TCHs

3. PCU Data processing capacity is 2 Mbit/s

4. PCU can support up to 64 cells

5. PCU can supports 128 TRX's


Inp

ut

BSC DimensioningSimple Dimensioning Example (PCU)

• 3 BSC (with capacity of 128 TRXs )

• Coverage area contains 60 BTS sites, each having 2+2+2 cell/TRX configuration

• 4 TCHs/cell used by GPRS on average

• Estimated GPRS traffic: 15 Mbit/s + 19% Overhead = 18.5 Mbit/s

• Packet size of 400 bytes assumed

1. Minimum requirement: 3 BSC => 3 PCUs required (each for 128 TRX)2. 60 x 3 cells = 180 cells, 180/64=2.8 => 3 PCUs required3. 12 TCH/BTS x 60 BTS=720 TCH, 720/256 => 3 PCUs required4. GPRS traffic: 18.5 Mbit/s / 2 Mbit/s = 9.3 =>10 PCUs required C

alc

ula

tion

sR

esu

lt

• Take the biggest of the results above, I.e. 10 active PCUs required in total


Frame Relay Link Planning Link Dimensioning

• Frame Relay traffic is carried in logical 64 kbit/s PCM time slots.

• Each active PCU has its own separate Gb interface connection, I.e. FR connection

• Capacity: n * 64 kbit/s, where n = 1…31.

• 64 kbit/s … 1.984 Mbit/s (E1 speed)

• At least one 64 kbit/s PCM TSL is required per active PCU


Frame Relay Link Planning Link Dimensioning

• Dimensioning criteria for the number of 64kbit/s links:

1. At least two 64 kbit/s channels per BSC is recommended (due to bursty nature of data)

2. At least one 64 kbit/s channel per active PCU

3. Dimensioning is based on estimated GPRS traffic during the Busy Hour, + the estimated protocol overhead on the Gb interface traffic + margin for bursting


Gb Link DimensioningSimple Dimensioning Example (Gb links)

• Total number of PCUs in 3 BSCs: 10 PCUs• Estimated total GPRS traffic during the BH: 15 Mbit/s• Overhead correction: + 19%

• Packet size of 400 bytes assumed• 15 Mbit/s * 19% = 18.5 Mbit/s

Inp

ut

1. Two 64 kbit/s links per PCU (10 * 2) => 20 links

2. GPRS traffic: 18.5 Mbit/s / 64 kbit/s = 289.1 => 290 links

Calc

ula

tion

s

• Take the bigger of the results above, I.e. 290 links (á 64 kbit/s) required in total (equals to 10 E1 PCM links)R

esu

lt


SGSN DimensioningDX 200 SGSN

D O C U M E N T T Y P E

T y p e U n i t O r D e p a r t m e n t H e r eT y p e Y o u r N a m e H e r e T y p e D a t e H e r e

S G A C S G B C

C LS U

P A P U1

P A P U2

P A P U9

P A P U1 0

G S W0

G S W1

P A P U3

P A P U4

M C H U0

M C H U1

P A P U0

E T 0( 3 2 * E T 2 E / A )

0

1

2

3

4

5

6

7

8

9

S DM C H U

0

S DM C H U

1

P D F U 0 P D F U 1

S DO M U

0

S DO M U

1

O M U1

O M U0

P A P U1 1

P A P U1 2

E T 1( 2 8 * E T 2 E / A )

P D F U 0 P D F U 1

C LB U1

P A P U6

P A P U7

P A P U5

P A P U1 6

S M M U0

S M M U1

S M M U2

S M M U3

S M M U4

P A P U8

P A P U1 3

P A P U1 4

P A P U1 5

1 0

C LB U0

One fully equipped SGSN element has the following design targets concerning connectivity:

• 120 physical 2Mbps E1-PCMs• PCMs are freely selectable between Gb-interface and SS7 based interfaces (Gs, Gr, Gd, Gf)• 96 SS7 signalling links (24 per SMMU)• 1024 64kbps Frame Relay links for Gb-interface use (64 in each PAPU)• E.g 100 BSCs each having 8x64kbps Gb-interface connection could be connected into one SGSN• 16 100-baseTX Ethernet connections for Gn-interface use (one in each PAPU)• Maximum of 16 000 Routing Areas, 2 000 Location Areas


SGSN DimensioningSGSN Configuration Levels

4 PAPUs, 1 SMMU

4 PAPUs, 1 SMMU

4 PAPUs, 1 SMMU

4 PAPUs, 1 SMMU

SGSN 12 Mbit/s30 000 subscr.256 Gb IF (64kbit/s)

24 Mbit/s60 000 subscr.512 Gb IF (64kbit/s)



Basic Unit

ExtensionUnits

Capacities:

SGSN can be configured in four steps. The right configuration level for each case is determined by the dimensioning rules.


Gb Interface DimensioningSimple Dimensioning Example (Summary)

4 PAPUs, 1 SMMU

4 PAPUs, 1 SMMU

4 PAPUs, 1 SMMU

SGSN

1 Basic Unit &2 Extension Unitsin the SGSN

290 links (64kibt/s) in 10 E1 PCM links

BSC

10 active PCUsin 3 BSCs

BSC

BSC


Gb INTERFACE DETAILED PLANNING


GPRS Dimensioning Considerations

• FUTURE SCENARIOS

- Operator's short and long term plans concerning the network expansions and evolution to new technologies

• CAPACITY DEMAND

- Subscriber volume

- GPRS traffic estimation

- GPRS coverage area

• EXISTING NETWORK INFRASTRUCTURE

- Existing Transmission, Data Communication backbone and GSM network infrastructures


Topology and Dimensioning Requirements

• BSC Distribution

• PCU Distribution among MSC sites

• Network Topology

• Network Architecture

• Subscriber Distribution

• GPRS Traffic Distribution

• Overhead % Requirement

• Burst Margin

• Future Network Expansion


GPRS Coverage Planning

From the requirements stated on the previous slide we can determine the following :

- GPRS coverage areas

- Topology and Capacity of the Frame relay links in a GPRS service area

- GPRS network dimension per coverage areas


BSC & PCU Distribution Among MSC Sites

BSC Distribution Among MSC Sites

Number of BSCs in year

Subscriber Percentage of regional BSCs 2000 2001 2002 2003 2004

1 City A 13.9% 89.4% 55 70 70 70 702 City B 1.7% 10.6% 6 8 8 8 8 REGIONS3 City C 14.0% 75.3% 50 65 65 65 65 South4 City D 4.6% 24.7% 17 21 21 21 21 East5 City E 11.2% 40.3% 33 43 43 43 43 Mid6 City F 8.0% 28.9% 24 31 31 31 31 South7 City G 10.8% 74.4% 37 48 48 48 48 West8 City H 8.6% 36.4% 33 42 42 42 429 City I 8.5% 30.8% 26 33 33 33 3310 City J 9.6% 40.6% 37 47 47 47 4711 City K 5.4% 23.0% 21 27 27 27 2712 City L 3.7% 25.6% 13 16 16 16 16

Total 100.0% 352 451 451 451 451

PCU Distribution Among MSC Sites

Number of PCUs in year

Subscriber Percentage of regional PCUs 2000 2001 2002 2003 2004

1 City A 13.9% 89.4% 110 140 140 140 1402 City B 1.7% 10.6% 12 16 16 16 163 City C 14.0% 75.3% 100 130 130 130 130 REGIONS4 City D 4.6% 24.7% 34 42 42 42 42 South5 City E 11.2% 40.3% 10 12 12 13 13 East6 City F 8.0% 28.9% 7 9 9 9 9 Mid7 City G 10.8% 74.4% 74 96 96 96 96 South8 City H 8.6% 36.4% 66 84 84 84 84 West9 City I 8.5% 30.8% 7 10 10 10 1010 City J 9.6% 40.6% 74 94 94 94 9411 City K 5.4% 23.0% 42 54 54 54 5412 City L 3.7% 25.6% 26 32 32 32 32

Total 100.0% 562 719 719 720 720


GPRS Service Areas

SGSN AreasGPRS Subs Attached GPRS Subs Active GPRS Subs Active PDP Contexts

GPRS Traffic (Mbps)

2001 AREA 1 19 500 19 500 9 750 14 625 1.39 2001 AREA 2 28 850 28 850 14 425 21 638 2.05 2001 AREA 3 33 750 33 750 16 875 25 313 2.40 2001 AREA 4 14 750 14 750 7 375 11 063 1.05 2001 AREA 5 19 250 19 250 9 625 14 438 1.37 2002 AREA 1 49 200 49 200 24 600 36 900 3.50 2002 AREA 2 52 440 52 440 26 220 39 330 3.73 2002 AREA 3 57 600 57 600 28 800 43 200 4.10 2002 AREA 4 49 800 49 800 24 900 37 350 3.54 2002 AREA 5 55 800 55 800 27 900 41 850 3.97

Attached Subs 100%Active Subs 50%2 PDP Contexts 50%1 PDP Context 50%Mean PDP / sub 1.5PDCH per cell 3CS2 (Kbps) 13.4thru per cell (Kbps) 40.2traf_sub (KBytes BH) 50Overhead 25%thru_sub (Kbytes BH) 62.5thru_sub (Kbps) 142.22 SGSN fill rate 70%

Coding SchemesCS1 9.05CS2 13.4

CS3 15.6CS4 21.4

SGSN area 1 City 1SGSN area 2 Cities 2 and 3SGSN area 3 Cities 4, 5, 6, 7 and 8SGSN area 4 Cities 9, 10, 11 and 12SGSN area 5 Cities 13 and 14


SGSN AREA CALCULATIONSInitial Dimensioning Figures

Covered RegionsNumber of Subscribers

Number of CellsMin. No. of PDCH (during BHT)

SGSN area 1 19 500 1 115 3 345 City 1

Radio Network Estimates

Covered Regions Number of CellsMin. No. of PDCH (during BHT)

SGSN area 1 1 115 3 345 City 1

GPRS Traffic (Mbps)2001 1.392002 3.50

GPRS Attached Subscribers2001 19 500 2002 49 200

GPRS Active subscribers

Active PDP Contexts

2001 9'750 14'625 2002 24'600 36'900

Nokia BSC's 18Nokia BCSU's 162

Non-Nokia PCU 0Non-Nokia Gb Interface 0

Total Gb Interfaces 80

CALCULATION RESULTS2001 2002

PCU (Active) 18PCU (Hardware) 162Gb Interface Functionality 22 57SGSN 1PAPU (Active) 4 10PAPU (Hardware) 4 12

SMMU 1 3


Ater TIMESLOT ALLOCATIONBits

TS 1 2 3 4 5 6 7 8

00 TS 0

01 LAPD 1 2 3

02 4 5 6 7

03 8 9 10 11

04 12 13 14 15 Channels of

05 16 17 18 19 ET2E 0,

06 20 21 22 23 interface 1

07 24 25 26 27

08 28 29 30 31

09 - 1 2 3

10 4 5 6 7

11 8 9 10 11

12 12 13 14 15 Channels of

13 16 17 18 19 ET2E 1,

14 20 21 22 23 interface 0

15 24 25 26 27

16 28 29 30 31

17 - 1 2 3

18 4 5 6 7

19 8 9 10 11 Channels of

20 12 13 14 15 ET2E 1,

21 16 17 18 19 interface 1

22 20 21 22 23

23 24 25 26 27

24 28 29 30 31

25 64 kbit/s

26 64 kbit/s

27 64 kbit/s Channels of

28 64 kbit/s ET2E 2,

29 64 kbit/s interface 0

30 64 kbit/s

31 64 kbit/s

TSs 25-31 can carry Frame Relay traffic (to the Gb interface).

Ater Time Slot Allocation

•Existing E1 lines are utilized for Frame Relay traffic

•Voice Traffic and Frame Relay Traffic combined

•Throughgoing 64Kbps TS for Frame Relay traffic


DEDICATED PCM SIGNAL

•Time Slot allocation of a dedicated E1 signal for carrying the Gb / Frame Relay traffic to the SGSN.


DN2 DXC EQUIPMENT OVERVIEW1 - Cross-connection Node

- 2 Mbit/s- 64 kbits- nx8 kbit/s- up to 40 2 Mbit/s interfaces

(G.703)

2 - Drop-and-Insert equipment (“in-built” DB 2)

3 - Primary Multiplexing Equipment (“in-built” DM 2)

Three cartridge sizes: 20 T (four units) 40 T (eight units) 19” Subrack (sixteen units)40-port DN 2 uses two subracks and

interconnecting cables

2 Mbit/s

DN 2

D DCH CH

2 Mbit/s


PHYSICAL TOPOLOGY - 1

Ethernet Switch

GGSN #1

GGSN #2

MSC

SGSN

Transcoders

MSC/SGSN site

BSC

FrameRelay Gb-int.

Ater

E1 PCM (Ater + Frame Relay)

Abis

Abis

Abis

MUX MUX

BSC

BSC

•Voice and Data Traffic are multiplexed on the same physical connection as used for the GSM traffic on the Ater interface



Ethernet Switch

GGSN #1

GGSN #2

MSC

SGSN

Transcoders

MSC/SGSN site

FrameRelay Gb-int.

AterMUX

BSC

E1 PCM for Ater traffic

Abis

Abis

Abis

MUX

BSC

BSC

Dedicated E1/ PCM for

Frame Relay traffic

•Voice and Data Traffic are allocated on separate E1 / PCM signal


Ethernet Switch

GGSN #1

GGSN #2

MSC

SGSN

Transcoders

MSC/SGSN Site 1

FrameRelay Gb-int.

Ethernet Switch

GGSN #1

GGSN #2

MSC

SGSN

Transcoders

MSC/SGSN Site 2

FrameRelay Gb-int.


Abis

Abis

Abis

MUX MUX

BSC

BSC

SGSN 1 SERVICE AREA

SGSN 2 SERVICE AREA

Ater

Ater

E1 PCM for Ater traffic

Dedicated E1/ PCM for

Frame Relay traffic

•Voice and Data Traffic are allocated on different E1s

BSC



• For large capacity networks such as SDH networks

• Separate E1s for Ater and Frame Relay traffic

Abis

Abis

Abis

MUX

BSC

BSC

SGSN 1 SERVICE AREA

SGSN 2 SERVICE AREA

Ethernet SwitchGGSN #1GGSN #2

MSC

SGSN

Transcoders

MSC/SGSN Site 1

FrameRelay Gb-int.

Ater

Ethernet SwitchGGSN #1GGSN #2

MSC

SGSN

Transcoders

MSC/SGSN Site 2

FrameRelay Gb-int.

AterMUX

TRANSPORTNETWORK

BSC

E1/PCM for FR

Ater

E1/PCM for FR

Ater

E1/PCM for FR

Ater

ADM

ADM

ADM



• GPRS traffic is concentrated and carried e.g. in a packet data network over the Gb interface

Ethernet Switch

GGSN #1

GGSN #2

MSC

SGSN

Transcoders

MSC/SGSN site

Abis

Gb Interface

Packet Data Network(FR, ATM, etc.)

FR Switch

FR Switch

BSC

BSC

BSC


EXAMPLE BSC / PCU CONFIGURATION


EXAMPLE SGSN/PAPU Configuration


Nortel BSS - Nokia SGSN

Exercise 1 - Case Study


Tasks for Exercise

• Make a draft of 2 BSCs connected to Nortel PCU

• Nortel PCU interfaces Nokia SGSN

• You can assume 10 timeslots of traffic in E1 frame per BSC (10 x 64kbps)

• Allocate bearer channels, NS-VCs, DLCIs, SGSN, PAPUs

• Show some redundancy options


Background to Encountered Problems

Frame Relay over E1 must be used•Timeslots reserved for FR bearer channels are specified in SGSN

•Nokia assumes that channelised FR is supported by Nortel PCU, as it is a standard FR feature and normally supported by Nortel Passport.

Nortel BSS - Nokia SGSN interoperability tests not complete enough•Tests were carried out with one NSE/bearer channel so the full

capability of Nokia SGSN was not tested

Nokia SGSN supports several NSEs per bearer channel•Blu in Italy, upto 5 NSEs/bearer channel

•Depending in the FR capabilities of the PCU in question, Nokia may deploy different FR solutions


Solution

Nokia and Nortel together implement the technical solutions proposed in the following slides in the Dutchtone network•Both vendors will document the test results for

Dutchtone and for their own interoperability documentation

Nokia proposes to take an action point to •Carry out the interoperability test with Nortel in the

Dutchtone network

•Fully document the SGSN Frame Relay capabilities

•Changes to SGSN software or Change Deliveries would not de-activate the solution in future


NSE2NS-VC2

NSE1NS-VC1

BSC 1

BSC 2

BSC 2

BSC 1

NORTEL PCU SGSN

E1 E1

DLCI_16

PAPU_1

NSE1

NSVC_1

DLCI_17

2 BSCs terminated into same PAPU

NSE2

NSVC_2

BEARER CH. 1

CIR n x64 kbps

CIR (31 - n) x64 kbps

Remarks:• A Bearer channel can be associated to several NSEs, channel rate n x 64 Kbps• Bearer channel minimum rate = 64 Kbps• EIR set to null• Maximum 50 NS-VCs/bearer channel• If NS-VCs are terminated into same PAPU, they can be carried over same bearer channels


NSE2NS-VC1

NSE1NS-VC1

BSC 1

BSC 2

BSC 2

BSC 1

NORTEL PCU SGSN

E1 E1

BEARER CH. 1

DLCI_16

PAPU_1

PAPU_2

CIR n x64 kbps, n=1..31

CIRDLCI_17

Remarks:• A Bearer channel can be associated to several NSEs, channel rate n x 64 Kbps• Bearer channel minimum rate = 64 Kbps• EIR set to null• Maximum 50 NS-VCs/bearer channel• If NS-VCs are terminated into different PAPUs, they have to be carried over separate bearer channels

2 BSCs terminated into different PAPUs

BEARER CH. 2(31 - n) x64 kbps

IF 50% of E1 per BSC,FULL E1 REQUIRED

NSE1NSVC_1

NSE2

NSVC_1


Typical Gb

NSE2NS-VC2

NSE1NS-VC1

BSC 1

BSC 2

BSC 2

BSC 1NORTEL PCU

SGSN

E1 E1

DLCI_16

PAPU_1NSE1NSVC_1

DLCI_17

BEARER CH. 1CIR n x64 kbps

CIR

(31 - n) x64 kbps

NSE3NS-VC3

BSC 3

BSC 3

DLCI_18

BEARER CH. 2

NSE2NSVC_2

PAPU_3

E1 E1

NSE5NS-VC5

NSE4NS-VC4

BSC 4

BSC 5

BSC 5

BSC 4

NSE6NS-VC6

BSC 6

BSC 6

E1 E1

DLCI_20

DLCI_21

BEARER CH. 3

DLCI_19

CIR n x64 kbps

NSE5NSVC_5

NSE6NSVC_6

PAPU_2

NSE3NSVC_3

NSE4NSVC_4

REMARKS:• About 1/2 E1 required per BSC • PAPU processing capacity 3 Mbps -> 1 BSC can be connected into same PAPU, each occupying 15 x 64 k FR


Gb with Redundancy

NSE1

BSC 1BSC 1

NORTEL PCUSGSN

E1 E1

DLCI_16

PAPU_1

DLCI_17

BEARER CH. 1

DLCI_18

BEARER CH. 2E1 E1

DLCI_19

NSVC_1

NSVC_2

NSVC_1 NSVC_2

NSE1

NSE2

BSC 2BSC 2

NSVC_3

NSVC_4

NSVC_3 NSVC_4

NSE2


Detailed planning exercise

Exercise 2


Input for exercise

BSC

• 2 BSCs (geographically split)

1. BSC ( 16 sites connected – each 2 cells)

2 BCSUs

8 x 64k TS GPRS traffic for 8 sites on each PCU

2. BSC (6 sites connected – each 2 cells)

1 BCSUs

6 x 64k TS GPRS traffic for 6 sites

SGSN• One PAPU

FR links• BSC

BSC1 is connected with 2 FR links while BSC2 has one FR link connection


Considerations for the planning

• Prepare an overview of the network

• Dimension FR links (Bearer channels)

• Allocated all ids‘ : NSEI,BVCIs, NS-VCIs, DLCIs, and define the capacity of all Bearer channels and DLCs. Also include some examples of load sharing or protection

• This is a freestyle exercise – so there is no really a right solution of this exercise.


Overview of the network - output

BSC 12 BCSUs

SGSN

PAPU_1

NSE3

NSVC_3/4

E1(1) E1(1)

DLCI_16DLCI_17

BEARER CH. 1

CIR

4 x64 kbps

CIR 3 x64 kbps

BSC 21 BSCU DLCI_16

DLCI_17

BEARER CH.3

PCU-1

PCU-2

DLCI_16

DLCI_17

16 TS = 16*64kbps

6 TS = 6*64kbps

22 TS = 22*64kbps

BEARER CH. 2

NSE2

NSVC_5/6

E1(2) E1(2)

E1(1) E1(1)

PCU-1

NSE1

NSVC_1/2


Overview of the network – output BC

BSC 12 BCSUs

SGSN

PAPU_1

NSE1

NSVC_1 /2

NSE2

NSVC_3/4

DLCI_16DLCI_17

BEARER CH. 1

BSC 21 BSCU DLCI_16

DLCI_17

BEARER CH.3

DLCI_16

DLCI_17

Bearer channel = 6*64kbps = 384kbps

BEARER CH. 2

NSE3

NSVC_5/6

Bearer channel = 8 TS = 8*64kbps = 512kbps

Bearer channel = 8 TS = 8*64kbps = 512kbps

Data link connection = 2x 3*64kbps = 2 x 128kbps

E1(1) E1(1)

E1(2) E1(2)

E1(1) E1(1)

CIR

4 x64 kbps

CIR 3 x64 kbps

PCU-1

PCU-2

PCU-1


Overview of the network – output NSEI/NS-VCI

BSC 12 BCSUs

SGSN

PAPU_1

NSE1

NSVC_1 /2

NSE2

NSVC_3/4

DLCI_16DLCI_17

BEARER CH. 1

CIR (31 - n) x64 kbps

BSC 21 BSCU

E1(1) E1(1)

DLCI_16

DLCI_17

BEARER CH.3

DLCI_16

DLCI_17

BEARER CH. 2

NSE3

NSVC_5/6

NSE1

NSVC_1 /2

NSE2

NSVC_3/4

NSE3

NSVC_5/6

E1(1) E1(1)

E1(2) E1(2)

CIR

4 x64 kbps

CIR 3 x64 kbps

PCU-1

PCU-2

PCU-1


Overview of the network – output BVCI

BSC 12 BCSUs

BSC 21 BSCU

PCU-1

PCU-2

PCU-1

BSC PCU 1 - 8 sitessite cell BVCI

1 1 11 2 22 3 32 4 43 5 53 6 64 7 74 8 85 9 95 10 106 11 116 12 127 13 137 14 148 15 158 16 16

BSC PCU 2 - 8 sitessite cell BVCI

1 1 11 2 22 3 32 4 43 5 53 6 64 7 74 8 85 9 95 10 106 11 116 12 127 13 137 14 148 15 158 16 16


Thank you !!!


BSC

HLR/AC/EIR

TCSM

MSC/VLR

BTS

AbisInterface

AterInterface

AInterface

AirInterface

TC

Ater’Interface

GSM architecture

BSS NSS

O&MInterface

NMS

205583569 gb-interface-detailed-planning-final

Technology

bearer ns

y gb interface

bearer channel capacity

hex nsvc

tsl nsvcs

bvc bvci

nsvc load sharing

vci unique