LTE EPC Dimensioning Principle

Soc Classification level 1 © Nokia Siemens Networks Presentation / Author / Date

LTE EPC Dimensioning


EPC deployment as overlay

LTE

2G/3G SGSN

GGSN

MME

SAE GW

Overlay Evolved Packet Core (EPC) allows introducing LTE technology with minimum touch to the existing production system.

Content and service networks,corporate intranets

2G/3G

Existing 2G/3G traffic served by

GGSN

LTE capable UE in 2G/3G/LTE access traffic served by SAE GW


Key aspects for EPC deployment

Centralized controlCentralized/distributed gateways

Evolved Packet Core elements optimized according

to their roles in 3GPP R8:

MME:Mobility

management

S-GW and P-GW:Broadband connectivity

Policy Enforcement

Scalability

MME

Subscribers

Transactions

S-GW/P-GW

Throughput Gbit/s

Throughput pps

Signaling


Network deployment and topology

Neighborhood eNode-B

Region S-GW & P-GW

P-GWMME Pool

Internet

CorporateOperator services

Operator services (VoIP)

Data center

Soc Classification level 5 © Nokia Siemens Networks

3GPP R8 introduces more flexibilityin core network design and site solutions

S-GW

Flexi NG

Standalone S-GW

P-GW

Flexi NG

Standalone P-GW

S-GW

Flexi NG

P-GW

Combined S-GW and P-GW with open S5

S-GW and P-GW deployment options:

S-GW

Flexi NG

P-GW

Flexi NG

MME

Flexi NS

Optimized forControl plane

Optimized forUser plane

Both centralized anddistributed site solutions

are supported


LTE Distribution Site Connectivity

3G SGSN

2G/3G/LTE

Internet

VPN

PGW

Operator

Services

IMS

BSC

SGSN

S1-US12

IP

ConnectivityDesignated

S1- MMElu

S3

Gb

S4

S5

PSTN/PLMN

VoIP breakout

GRX

Outbound roaming, home Routed traffic

Gp/S8

PGW

PGW

SGW

2G/3G/LTE

Site 3Site 2

Site 1

2G/3G/LTE

S3

SGSNS5

S5S5

S4 Gb

S1- MMElu

S1-US12

S1-MMElu

S1-US12

BSC

Abis

Abis

SGW

MME

AbisS11

SGWPGW

S11


Dimensioning Overview

• Evolved Packet Core dimensioning is fundamentally different from dimensioning a traditional 2G/3G GPRS network.

• 3GPP R8 mandates flat architecture that induces multiple changes to network dimensioning.

SAE GW

All IP

eNB

MME


Key dimensioning parameters

• MME dimensioning is simplified as it is a pure control element dimensioned according to– Number of subscribers / bearers

– Transactions without user plane traffic burden

• Gateway dimensioning as user plane gateway elements able to optimally adapt to the changes in usage patterns and traffic load in network dimensioned according to– Throughput in Gbit/s to support non-real-time services and packets per

second to support real-time services

– Number of subscribers to allow high subscriber density

– Number of transactions per second to support subscriber mobility


Key dimensioning scale


LTE EPC dimensioning assumption• Subscribers profile

– Number of total subscribers 2G subscribers 3G subscribers LTE subscribers

– Attached EPS bearer / Attached Subscriber – ratio of total subscribers– IP-CAN bearer / PDP Context – ratio of attached EPS bearers

• Traffic profile– Traffic type per subscriber in BH

Voice / Video call traffic in kbps Mobile data traffic in kbps PC data traffic in kbps

– Percentage traffic distribution among IP-CAN bearer / PDP Context in BH Voice traffic / Video call Mobile data traffic PC data traffic

– 1 IP-CAN Bearer / PDP Context per active attached EPS bearer– Traffic parameters

Packet size = 512 Bytes Signaling overhead = 1% of user traffic


LTE EPC dimensioning assumption• Outgoing traffic connection locations

– Internet IP transit traffic, ISPs– Corporate access traffic / VPN

• Roaming traffic – 1% of total throughput

• Network element profile– Load factor of network element – 80%– Redundancy

• Geographical profile– Existing 2G & 3G core network locations– MME & SAE-GW centralized/de-centralized architecture– Coverage area

• Existing network infrastructure information– Technologies used– Space capacity available– Site distribution


Subscribers dimensioning principles

Subscribers Phase 1 Phase 2 Phase 3Attached

EPS BearerIP-CAN Bearer

# of IP-CAN Bearer per attached EPS

Bearer

2G Subscribers 2,000,000 2,500,000 3,000,000

3G Subscribers 2,000,000 2,500,000 3,000,000

LTE Subscribers 1,000,000 1,500,000 2,000,000

2G IP-CAN Data services

120,000 150,000 180,000 30% 20% 1

3G IP-CAN Data services

120,000 150,000 180,000 30% 20% 1

LTE IP-CAN Data services

60,000 90,000 120,000 30% 20% 1

Indicates the total number voice and data subscribers on 2G, 3G and LTE network

Subscribers


Subscribers dimensioning principles Site distribution

Phase 1 Phase 2 Phase 3

Site Distribution 100% 100% 100%

Site 1 45% 45% 45%

Site 2 40% 40% 40%

Site 3 15% 15% 15%

Indicates the site distribution of 2G, 3G and LTE subscribers


Subscribers dimensioning principles Attach EPS Bearers and IP-CAN Bearers per site

Area

# of 2G Attach EPS

Bearers

# of 3G Attach EPS

Bearers

# of LTE Attach EPS

Bearers

Total Attach EPS Bearers

# of 2G IP-CAN Bearers

# of 3G IP-CAN Bearers

# of LTE IP-CAN

Bearers

Total IP-CAN

Bearers

Phase 1

Site 1 270,000 270,000 135,000 675,000 54,000 54,000 27,000 135,000

Site 2 240,000 240,000 120,000 600,000 48,000 48,000 24,000 120,000

Site 3 90,000 90,000 45,000 225,000 18,000 18,000 9,000 45,000

Total 600,000 600,000 300,000 1,500,000 120,000 120,000 60,000 300,000

Phase 2

Site 1 337,500 337,500 202,500 877,500 67,500 67,500 40,500 175,500

Site 2 300,000 300,000 180,000 780,000 60,000 60,000 36,000 156,000

Site 3 112,500 112,500 67,500 292,500 22,500 22,500 13,500 58,500

Total 750,000 750,000 450,000 1,950,000 150,000 150,000 90,000 390,000

Phase 3

Site 1 405,000 405,000 270,000 1,080,000 81,000 81,000 54,000 216,000

Site 2 360,000 360,000 240,000 960,000 72,000 72,000 48,000 192,000

Site 3 135,000 135,000 90,000 360,000 27,000 27,000 18,000 72,000

Total 900,000 900,000 600,000 2,400,000 180,000 180,000 120,000 480,000

Indicates the total number of Attach (subset of total registered 2G, 3G and LTE subscribers) and IP-CAN (subset of Attach that has activated data

transfer)


Traffic dimensioning principles

Traffic Type Voice Mobile Data PC Data

Per Sub BH (Kbps)

8.00 256.00 512.00 Total Per site(Gbps)

Subs Distribution 5.0% 50.0% 45.0%

Site 1 (Mbps) 52.73 16875.00 30375.00 46.19

Site 2 (Mbps) 46.88 15000.00 27000.00 41.06

Site 3 (Mbps) 17.58 5625.00 10125.00 15.40

Total Throughput 234.38 37125.00 74250.00 102.65

Indicates the subscribers distribution BH traffic base on voice, mobile data and PC data.

ModemsUSB, PC Cards, Routers

HandsetsPS Data

512 Kbps

HandsetsCS Voice

256 Kbps8 Kbps


Traffic dimensioning principles Throughput profile

Phase 1 Phase 2 Phase 3Data

Services Distribution

2G Data services Gbps

1.03 1.54 3.08 1%

3G Data services Gbps

40.03 60.05 120.10 39%

LTE Data services Gbps

61.59 92.39 184.78 60%

Indicates the data services distribution BH traffic base on 2G, 3G and LTE Data services in Gbit/s

2G 3G LTE

Internet

Application


Interface dimensioning principles

2G

3G

Gb

IuS4

S1-MME

S1-U S11

S5 SAE Gateway

LTE

S3

SGSN

BSC

RNC

S10eNode-B

S12

MME

ServingGW

PDNGW

S8

PDNGW

vPLMN

LTE EPC data traffic dimensioning covers the following interfaces for different network:

• U-Plane S4 for 2G network

• U-Plane S12 for 3G network

• U-Plane S1-U for LTE network

• U-Plane S8 for Roaming network

User planeControl plane

SGi

Contentand service

networks


Interface dimensioning principles Interface throughput – w/o overhead

PhaseS4 Throughput (w/o OH) Gbps

S12 Throughput (w/o OH) Gbps

S1-U Throughput (w/o OH) Gbps



Phase 1

Site 1 0.46 18.02 27.72 46.19 0.46

Site 2 0.41 16.01 24.64 41.06 0.41

Site 3 0.15 6.01 9.24 15.40 0.15

Phase 2

Site 1 0.69 27.02 41.57 69.29 0.69

Site 2 0.62 24.02 36.96 61.59 0.62

Site 3 0.23 9.01 13.86 23.10 0.23

Phase 3

Site 1 1.39 54.05 83.15 138.58 1.39

Site 2 1.23 48.04 73.91 123.18 1.23

Site 3 0.46 18.02 27.72 46.19 0.46

S4 traffic indicates 2G, S12 traffic indicates 3G & S1-U traffic indicates LTE Payload throughput requirement for each region’s SAE-GW, excluding the

signaling and payload overhead


Interface dimensioning principles Interface overhead

Overheads % Packet Size 512 bytes

S4 Overhead 8%

S12 Overhead 8%

S1-U Overhead 8%

S5 Overhead 8%

S8 Overhead 8%

S-GW Sig 1% NSN's assumption

P-GW Sig 1% NSN's assumption

Configuration/layer OH (bytes)

GTP 12

UDP 8

IP 20

S4 OH 40

GTP 12

UDP 8

IP 20

S12 OH 40

GTP 12

UDP 8

IP 20

S1-U OH 40

GTP 12

UDP 8

IP 20

S5 OH 40

GTP 12

UDP 8

IP 20

S8 OH 40

• IPv4, UDP and GTPv1-U overhead base on packet size.• 1 % of SAE-GW signaling is accounting for

– Bearer set up (activation) procedure– Bearer release (deactivation) procedure– Bearer modification

Octets/BytesPayload 512GTPv1-U 12UDP 8IPv4 20

Total overhead 40Total payload 552Overhead = (552 – 512) / 512 x 100% = 8%

GTPv1-U

UDP

IP


Interface dimensioning principles Interface throughput – with overhead

Area

Throughput to S4 Gbps


Throughput to S1-U Gbps



Phase 1

Site 1 0.50 19.62 30.18 50.30 0.50

Site 2 0.45 17.44 26.83 44.71 0.45

Site 3 0.17 6.54 10.06 16.77 0.17

Total 1.12 43.59 67.07 111.78 1.12

Phase 2

Site 1 0.75 29.43 45.27 75.45 0.75

Site 2 0.67 26.16 40.24 67.07 0.67

Site 3 0.25 9.81 15.09 25.15 0.25

Total 1.68 65.39 100.60 167.67 1.68

Phase 3

Site 1 1.51 58.85 90.54 150.90 1.51

Site 2 1.34 52.31 80.48 134.14 1.34

Site 3 0.50 19.62 30.18 50.30 0.50

Total 3.35 130.78 195.83 335.34 3.35

S4 traffic indicates 2G, S12 traffic indicates 3G & S1-U traffic indicates LTE Payload throughput requirement for each region’s SAE-GW, including the

signaling and overhead

Documents

LTE EPC Dimensioning Principle