1 © NOKIA 2000 Gb interface detailed planning
Core Network PlanningGb Interface Detailed Planning
2 © NOKIA 2000 Gb 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
3 © NOKIA 2000 Gb interface detailed planning
Gb Interface
BSC
PCU
BSS
SGSN
PAPU
GPRS
Frame R elay
Gb interface
4 © NOKIA 2000 Gb interface detailed planning
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
5 © NOKIA 2000 Gb interface detailed planning
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
7 © NOKIA 2000 Gb interface detailed planning
Gb Interface ReviewNetwork Layers
GPRS
TCP/IP
ATM & FR
Transport/SDH
BSCSGSN SGSN
BSC
GbIntra-site
GnInter-site
Gn Gb
GPRS IPBackboneNetwork
8 © NOKIA 2000 Gb interface detailed planning
Gb Interface ReviewGb Interface
BSC
PCU
SGSN
Frame Relay
Gb
PAPUBSS GPRS
9 © NOKIA 2000 Gb interface detailed planning
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
10 © NOKIA 2000 Gb interface detailed planning
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)
12 © NOKIA 2000 Gb interface detailed planning
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
13 © NOKIA 2000 Gb interface detailed planning
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
14 © NOKIA 2000 Gb interface detailed planning
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
15 © NOKIA 2000 Gb interface detailed planning
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)
16 © NOKIA 2000 Gb interface detailed planning
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
17 © NOKIA 2000 Gb interface detailed 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
18 © NOKIA 2000 Gb interface detailed planning
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
19 © NOKIA 2000 Gb interface detailed planning
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
20 © NOKIA 2000 Gb interface detailed planning
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
21 © NOKIA 2000 Gb interface detailed planning
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
22 © NOKIA 2000 Gb interface detailed planning
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
23 © NOKIA 2000 Gb interface detailed planning
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
24 © NOKIA 2000 Gb interface detailed planning
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
25 © NOKIA 2000 Gb interface detailed planning
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
27 © NOKIA 2000 Gb interface detailed planning
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)
36 Mbit/s90 000 subscr.768 Gb IF (64kbit/s)
48 Mbit/s120 000 subscr.1024 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.
28 © NOKIA 2000 Gb interface detailed planning
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
29 © NOKIA 2000 Gb interface detailed planning
Gb INTERFACE DETAILED PLANNING
30 © NOKIA 2000 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
31 © NOKIA 2000 Gb interface detailed planning
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
32 © NOKIA 2000 Gb interface detailed planning
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
33 © NOKIA 2000 Gb interface detailed planning
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
34 © NOKIA 2000 Gb interface detailed planning
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
35 © NOKIA 2000 Gb interface detailed planning
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
36 © NOKIA 2000 Gb interface detailed planning
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
37 © NOKIA 2000 Gb interface detailed planning
DEDICATED PCM SIGNAL
•Time Slot allocation of a dedicated E1 signal for carrying the Gb / Frame Relay traffic to the SGSN.
38 © NOKIA 2000 Gb interface detailed planning
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
39 © NOKIA 2000 Gb interface detailed planning
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
40 © NOKIA 2000 Gb interface detailed planning
PHYSICAL TOPOLOGY - 2
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
41 © NOKIA 2000 Gb interface detailed planning
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.
PHYSICAL TOPOLOGY - 3
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
42 © NOKIA 2000 Gb interface detailed planning
PHYSICAL TOPOLOGY - 4
• 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
43 © NOKIA 2000 Gb interface detailed planning
PHYSICAL TOPOLOGY - 5
• 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
44 © NOKIA 2000 Gb interface detailed planning
EXAMPLE BSC / PCU CONFIGURATION
45 © NOKIA 2000 Gb interface detailed planning
EXAMPLE SGSN/PAPU Configuration
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Nortel BSS - Nokia SGSN
Exercise 1 - Case Study
47 © NOKIA 2000 Gb interface detailed planning
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
48 © NOKIA 2000 Gb interface detailed planning
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
49 © NOKIA 2000 Gb interface detailed planning
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
50 © NOKIA 2000 Gb interface detailed planning
51 © NOKIA 2000 Gb interface detailed planning
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
52 © NOKIA 2000 Gb interface detailed planning
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
53 © NOKIA 2000 Gb interface detailed planning
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
54 © NOKIA 2000 Gb interface detailed planning
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
55 © NOKIA 2000 Gb interface detailed planning
Detailed planning exercise
Exercise 2
56 © NOKIA 2000 Gb interface detailed planning
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
57 © NOKIA 2000 Gb interface detailed planning
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.
58 © NOKIA 2000 Gb interface detailed planning
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
59 © NOKIA 2000 Gb interface detailed planning
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
60 © NOKIA 2000 Gb interface detailed planning
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
61 © NOKIA 2000 Gb interface detailed planning
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
62 © NOKIA 2000 Gb interface detailed planning
Thank you !!!
63 © NOKIA 2000 Gb interface detailed planning
BSC
HLR/AC/EIR
TCSM
MSC/VLR
BTS
AbisInterface
AterInterface
AInterface
AirInterface
TC
Ater’Interface
GSM architecture
BSS NSS
O&MInterface
NMS
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