casestudy-ltesmallcelltransportcapacityplanning

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Copyright 2012 AIRCOM International - All rights reserved. No part of this work, which is protected by copyright, may be reproducedin any form or by any means - graphic, electronic or mechanical, including photocopying, recording, taping or storage in aninformation retrieval systemwithout the written permission of the copyright owner.

Case Study

LTE Small Cell transport capacityplanning using I-VIEW DIMENSION

AIRCOM InternationalCassini Court, Randalls Way,

Leatherhead, KT22 7TWUnited Kingdom

www.aircominternational.com
http://www.aircominternational.com/http://www.aircominternational.com/


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LTE Small Cell transport capacity planning using I-VIEW DIMENSION AIRCOM International, 2012

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Table of Contents

1 Executive Summary .................................................................................................... 32 Introduction ............................................................................................................... 43 Configuration ............................................................................................................. 5

3.1 Analysis Area ..................................................................................................... 53.2 Network Topology .............................................................................................. 6

3.2.1 Existing Macro Cell Layer ................................................................................. 63.2.2 Macro Cell and Small Cell Layer Short-Term Scenario ........................................ 83.2.1 Macro Cell and Small Cell Layer Long-Term Scenario ........................................ 9

3.3 Traffic Model .................................................................................................... 103.4 Traffic Forecasting ............................................................................................ 11

4 Capacity Analysis ...................................................................................................... 124.1 Current Capacity .............................................................................................. 124.2 Increased Capacity1stYear ............................................................................ 13

4.2.1 Bottlenecks in Existing Macro Cell Network ..................................................... 134.2.2 Bottlenecks in Short-Term Scenario ............................................................... 14

4.3 Increased Capacity5 Year Plan ...................................................................... 144.3.1 Bottlenecks in Short-Term Scenario ............................................................... 144.3.2 Bottlenecks in Long-Term Scenario ................................................................ 15

4.4 Scenario Comparison and Bottlenecks ................................................................ 165 Conclusion ............................................................................................................... 176 Glossary .................................................................................................................. 187 Appendix AAbout the tool used in this case study ................................................... 19

7.1 I-VIEW DIMENSION ......................................................................................... 197.1.1 Schematic Visualisation ................................................................................. 197.1.2 Mobile Layer Capacity Planning and Dimensioning .......................................... 20

7.1.3 Multi-layer Transmission Planning and Capacity Management .......................... 207.1.4 IP/Eth Planning ............................................................................................ 217.1.5 Equipment Modelling and Inventory ............................................................... 217.1.6 Scenario Planning ......................................................................................... 21


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1 Executive Summary

With wireless data already predicted to exceed wired data in the next few years and networkcapacity demands to increase 20-40 fold over the next 5 years, mobile operators are under

pressure to dramatically increase their network capacity and maintain data throughput rates,in a cost effective manner. Embracing a Small Cell strategy seems to be the most commonapproach to achieve this across the Worlds operators.

Small Cell technology (which includes femto, pico and micro cells) is currently in use by 67%of operators according to the Small Cell Forum and usage will increase from 4.3 million smallcells to 36.8 million by 2016. Operators need a planning strategy to ensure capacity issuesare addressed and throughput rates are maintained for continued positive customerexperience.

Small cells can offer additional capacity and provide improved indoor coverage but carefulplanning of the transport network is critical to ensure that the backhaul and backbone

networks can support the increased data volumes and deliver good data rates.

A case study will be presented on how the LTE Small Cells transport capacity can be plannedusing AIRCOMs end-to-end capacity planning tool, I-VIEW DIMENSION. This will be doneusing a high-traffic, high-density area of central London, in the United Kingdom, whichcontains both Small Cells and Macro Cells.

The case study will demonstrate how to plan the transport capacity for a Small Cell LTE layeron top of an existing UMTS/LTE Macro Cell layer and how to choose the best backhaultopology and routing. It will also show that simple link upgrades may not be a sufficient andlong-term solution for the expected data rates. New topologies and transport technologiessuch as DWDM and IP/MPLS will be required to provide a viable solution for the nextgeneration transport network.

It will also highlight how scenario planning and proper dimensioning will be the key to ensurethat the maximum return on investment is achieved and how if those steps are done correctlythe transport network will be able to cope with the expected growth in high speed data-centric services.

The RF planning of the Small Cell layer used can be performed using AIRCOMs radioplanning tool, ASSET. This is not covered in this case study but was addressed in a previousone which can be obtained by contacting us if you missed it.


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2 Introduction

This document demonstrates how an LTE Small Cells transport network can be planned withAIRCOMs End-to-end capacity planning tool, I-VIEW DIMENSION. For this case study we areusing a high-traffic, high-density area of central London, in the United Kingdom, which

contains both Small Cells and Macro cells. The Macro Cell sites locations are real onesobtained from the UKs regulators published data.

We will show in I-VIEW DIMENSION the topology of this network segment, the served trafficon the network elements and links as well as the utilisation of each link for the existing UMTSand LTE Macro Cell network. The served traffic on each cell which is then routed on thetransport network is taken from an RF planning tool but it can also be taken from realnetwork statistics.

We will then demonstrate how the data increase according to the market analysis reports willimpact the existing Macro Cell network and we will highlight the expected bottlenecks. Thenwe will setup a Small Cell LTE layer on top of the Macro Cell one and present how various

different backhaul topologies will perform and where the upgrades have to take place. Finallywe will demonstrate how to future proof the backhaul network for the next five years in orderto achieve a long-term solution. For more details about the configuration and the simulationswhich were executed, please contact us.


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3 Configuration

3.1 Analysis Area

The Analysis Area covers a dense urban area of central London that includes Covent Gardenand Holborn and is bounded by Soho, Leicester Square and Tottenham Court Road.

The purple icons denote the existing Macro Cell sites while the red ones the new Small Cell

ones which were added manually in locations decided in the Radio Planning tool (ASSET) toimprove poor coverage and increase capacity.


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3.2 Network Topology

3.2.1 Existing Macro Cell Layer

All the Macro Cell sites are connected in a star topology with MW links (grey lines) to an

aggregation point which is then connected with a fibre link (red line) to a main transmissionsite which is part of the backbone network (not shown here).


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Having a look at the detailed schematic view of the network segment in I-VIEW DIMENSIONwe realize that the Macro Cell sites contain one NodeB and one eNodeB each, all of themconnected to radio equipment (one traffic node and one or more radios). The traffic is thenaggregated to the aggregation site and carried from an Optical ADM to the fibre backbonenetwork.


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3.2.2 Macro Cell and Small Cell Layer Short-Term Scenario

The Small Cell sites will have to be connected to the aggregation through new links which areplanned as part of this case study. As a short-term solution which will allow for quickdeployment we are assuming that all the Small Cells with be served using Point-to-Multi-Point

(PmP) NLOS links from the existing Macro Cell sites and Point-to-Point (PtP) links. New PmPantennas will have to be added to the existing network. The detailed planning of the linkbudgets and the interference analysis of the MW links can be performed in a MW Planningtool like AIRCOMs CONNECT(this will be the case study topic for next month).


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3.2.1 Macro Cell and Small Cell Layer Long-Term Scenario

In the long run and given the major increase in the required capacity that is expected, thePmP MW links will not be the most efficient solution. Fibre links will eventually have to bedeployed to ensure that the traffic will be served adequately. This will provide a long-term

and scalable solution, being able to adequately cope with the required capacity for the nextfew years.


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3.3 Traffic Model

The traffic model which is used in the case study is taken from the simulation results of theRadio Planning tool in order to represent traffic which will be captured by the cells during theBusy Hour (BH). In order to achieve even more realistic modelling the cell statistics from a

Performance Management tool could be used instead.

The cell level traffic has been used as the Demands to be routed by each Macro Cell NodeBand eNodeB via the aggregation site to the fibre network.

Cell Name Parent Base Station Technology Bitrate (Mbps)

00197804A 00197804 UMTS 0.7510608

00197804B 00197804 UMTS 0.511287

00197804C 00197804 UMTS 3.218079

00243055A 00243055 UMTS 1.537242

00243055B 00243055 UMTS 3.791781

00243055C 00243055 UMTS 3.107413

00245836A 00245836 UMTS 0.4068386

00245836B 00245836 UMTS 4.92806

00245836C 00245836 UMTS 1.992801

00245837A 00245837 UMTS 3.148421

00245837B 00245837 UMTS 3.31222

00245837C 00245837 UMTS 4.410731

00245841A 00245841 UMTS 1.088441

00245841B 00245841 UMTS 0.8030928

00245841C 00245841 UMTS 3.634284

00248434A 00248434 UMTS 2.971812

00248434B 00248434 UMTS 1.353941

00248434C 00248434 UMTS 0.6968108

e00197804A e00197804 LTE 2.145888

e00197804B e00197804 LTE 1.46082

e00197804C e00197804 LTE 9.194512

e00243055A e00243055 LTE 4.39212

e00243055B e00243055 LTE 10.83366

e00243055C e00243055 LTE 8.878322

e00245836A e00245836 LTE 1.162396

e00245836B e00245836 LTE 14.08017

e00245836C e00245836 LTE 5.693716

e00245837A e00245837 LTE 8.995488

e00245837B e00245837 LTE 9.463485

e00245837C e00245837 LTE 12.60209

e00245841A e00245841 LTE 3.10983

e00245841B e00245841 LTE 2.294551

e00245841C e00245841 LTE 10.38367

e00248434A e00248434 LTE 8.490891

e00248434B e00248434 LTE 3.868403

e00248434C e00248434 LTE 1.990888


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3.4 Traffic Forecasting

In order to model the expected data increase, data from standard market analysis reportswhich predict a non-linear increase over the next five years has been used.

Two different cases have been assumed in order to demonstrate the impact of the dataincrease. In the first one the increased traffic is expected to be carried by the existing LTEMacro Cell sites only and the expected bottlenecks are highlighted. In the second case theincreased traffic is assumed to be carried in its entirety by the newly added Small Cell Sitesand the different topologies and capacity upgrades are analysed and benchmarked.


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4 Capacity Analysis

4.1 Current Capacity

From this plot it can be seen that the current BH traffic loading of the existing Macro Cellnetwork segment is within a good operation limit.


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4.2 Increased Capacity 1stYear

4.2.1 Bottlenecks in Existing Macro Cell Network

From this plot it can be seen that after the first year, one of the MW links of the existingMacro Cell network segment will have to be upgraded as it will not be able to support theexpected traffic increase.


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4.2.2 Bottlenecks in Short-Term Scenario

From this plot it can be seen that by introducing the Small Cells, two of the existing MW linkswill have to be upgraded while 20 new PmP links will have to be deployed in order to connectthe Small Cells to the rest of the network. The Small Cells will however allow the network tohave improved coverage and support more users.

4.3

Increased Capacity 5 Year Plan

4.3.1 Bottlenecks in Short-Term Scenario

From this plot it can be seen that after 5 years all the links will have to be upgraded.


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4.3.2 Bottlenecks in Long-Term Scenario

From this plot it can be seen that by deploying fibres up to last mile it will provide enough

capacity to all Macro Cells and Small Cells for the next five years.


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4.4 Scenario Comparison and Bottlenecks

The next table gives us a quick comparison of the various different scenarios as well as anoverview of the expected bottlenecks for each scenario.


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5 Conclusion

This Case Study has shown that LTE Small Cells backhaul and backbone networks can beeffectively planned and analysed in I-VIEW DIMENSION. The non-linear increase in the trafficdemand will require immediate upgrades in the backhaul network. However simple link

upgrades may not be a sufficient and long-term solution for the expected data rates. Newtopologies and transport technologies such as DWDM and IP/MPLS will be required to providea viable solution for the next generation transport network.

Scenario planning and proper dimensioning will be the key to ensure that the maximumreturn on investment is achieved and that the transport network will be able to cope with thehigh speed data-centric services by making the best use of the infrastructure.

In addition to capacity planning, the introduction of the new technologies will require the datamodelling and planning of VLANs, MPLS LSPs and layer 3 topologies.

I-VIEW DIMENSION combines powerful data modelling and visualisation with multi-layer

capacity planning offering a unique solution for the planning and operation of the nextgeneration networks which support a number of different Radio Access Technologies anddifferent cell layers.


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6 Glossary

ADMAdd Drop MultiplexerBHBusy HourDWDMDense Wavelength Division Multiplexing

IPInternet ProtocolLOSLine of SightLSPLabel Switched PathLTE - Long Term Evolution, a technology from the 3GPP industry groupMPLSMulti Protocol Label SwitchingMW- MicrowaveNLOSNon Line of SightPmPPoint to Multi PointPtPPoint to PointRFRadio FrequencyUMTS - Universal Mobile Telecommunications SystemVLANVirtual Local Area Network


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7 Appendix A About the tool used in this case study

7.1 I-VIEW DIMENSION

I-VIEW Dimension is an End-to-end Visualisation and Capacity tool which is aimed at assistingthe mobile operators to:

Understand and visualise their entire network

Have a common storage location for data of various different domains, departments

and vendors

Perform capacity management and planning from the mobile layer to transmission

Plan the future upgrades for various scenarios and future growth in order to achieve

the maximum ROI

The main capabilities of I-VIEW DIMENSION can be summarised below:

7.1.1 Schematic Visualisation

Mobile layer

Mobility layers

Physical layer

IP layer

ATM layer

PDH layer

SDH layer

MW layer

Optical layer


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7.1.2 Mobile Layer Capacity Planning and Dimensioning

GSM/UMTS RAN and Core Network Element and Interface modelling and visualisation

Support for various 3GPP specifications Capacity planning of Network Elements, Interfaces and bottlenecks identification

Support for both ATM and IP protocol stacks

Flexible modelling of subscriber and traffic behaviour

7.1.3

Multi-layer Transmission Planning and Capacity Management PDH/SDH/ATM/IP/MPLS/Eth/PWE multi-layer modelling and visualisation

Multi-protocol demand modelling

Hybrid link modelling

Manual multi-layer fixed path routing

Automatic physical layer routing based on SPF

Link occupancy calculation and bottleneck identification

Powerful visualisation of the routing paths and hotspots


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7.1.4 IP/Eth Planning

Static and dynamic routing based on routing topologies and tables OSPF/IS-IS/BGP protocol modelling

Ethernet switching based on Switching table configurations

Routing domain and group modelling

IP and MAC Address modelling and visualisation

IP/Eth protocol stack modelling

Router, Switch and interface throughput related parameter calculations and

bottleneck identification

7.1.5

Equipment Modelling and Inventory

Vendor independent modelling

Site, Node, Subrack, Card, Slot, Port, Link modelling

Port to port connectivity

Functional status (In/Out-of-Service) and Planning status

(Planned/Commissioned/Live) modelling

7.1.6

Scenario Planning

What-if scenario planning for traffic growth, technology evolution and network

changes

Easy scenario comparison and merge

Ability to create any number of different scenarios for a given project

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