WiMAX White Paper - V1 - Approved

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White Paper

WiMAX Planning

The AIRCOM Perspective

Author: Nishita Hathi Date: 12 September 2005 Ref: I-PE-IN-WiMAX - WiMAX White Paper Version: 1 Status: Approved Sec. Class: Customer Confidential

AIRCOM International Customer Confidential

Author: Nishita Hathi WiMAX Planning Page 2 of 17 Date: 12/08/2005 I-PE-IN-WiMAX - WiMAX White Paper

Contents

1 Introduction......................................................................................................................... 3 2 WiMAX Overview................................................................................................................ 3

2.1.1 WIMAX Standard ................................................................................................. 3 2.1.2 Application and Deployment ................................................................................ 3 2.1.3 WiMAX Network Parameters ............................................................................... 4 2.1.4 WiMAX Technologies........................................................................................... 4

3 Planning a WiMAX Network with the Enterprise Suite ....................................................... 5 3.1 Microwave Backhaul Planning...................................................................................... 5

3.1.1 Equipment............................................................................................................ 6 3.1.2 Point-to-point link Creation................................................................................... 7 3.1.3 Height Profiler ...................................................................................................... 8 3.1.4 Interference Analysis ........................................................................................... 9

3.2 Access Network Planning............................................................................................. 9 3.2.1 Propagation Models ............................................................................................. 9 3.2.2 Equipment.......................................................................................................... 11 3.2.3 WiMAX Base Stations........................................................................................ 11 3.2.4 Signal Strength Calculation ............................................................................... 12 3.2.5 Interference Analysis ......................................................................................... 13

3.3 WiMAX Network Optimisation .................................................................................... 15 3.3.1 Site Selection ..................................................................................................... 15 3.3.2 Antenna and Power Optimisation ...................................................................... 16

4 Summary .......................................................................................................................... 17 5 Glossary ........................................................................................................................... 17



1 Introduction

WiMAX (Worldwide Interoperability for Microwave Access) is a fixed wireless access technology which can support high throughput broadband connections over long distances for portable, nomadic and eventually mobile users. It operates in several licensed and un-licensed bands and supports multiple channel bandwidths in the range of 1.75 MHz 20 MHz.

The WiMAX standard is developed by the WiMAX forum, an industry group set up by equipment manufacturers and component vendors to create a single interoperable standard. The common standard is expected to result in lower equipment costs and wider deployment.

WiMAX supports a number of different applications. These include microwave backhaul for hotspots and other commercial services, fixed wireless access for broadband services and mobile access for broadband services.

This document provides an overview of WiMAX technology and describes the WiMAX planning capabilities of AIRCOMs ENTERPRISE suite.

2 WiMAX Overview

2.1.1 WIMAX Standard

The WiMAX standard is being developed by the WiMAX forum. All equipment which complies with the WiMAX standard and meets the interoperability requirements will be certified as WiMAX by the WiMAX forum.

The WiMAX standard is based on IEEE802.16 MAN (Metropolitan Area Network) standards and ETSI HIPERMAN standards.

The IEEE802.16 family of standard consists of three key profiles: IEEE802.16a, IEEE802.16d and IEEE802.16e. Initial WiMAX networks are based on 802.16a and 802.16d. The 802.16e is a mobile extension of 802.16d and will be introduced after 2005.

The WiMAX forum has chosen a workable subset of the IEE802.16 and the HIPERMAN standard for the sub 11GHz range. The standard supports NLOS communication using OFDM modulation and will be able to support mobility in the near future.

2.1.2 Application and Deployment

There are three key applications for WiMAX: Microwave Backhaul, Fixed Broadband Access and Mobile Access. The first phase of WiMAX deployment will provide fixed wireless connections via outdoor antennas which can be used for cellular network backhaul, hotspots and other commercial services. The second phase will support outdoor and indoor installations which can be used for fixed BWA networks. The third and final phase will support roaming and mobility.



2.1.3 WiMAX Network Parameters

The table below shows the key parameters for the various standards:

802.16 802.16a 802.16d 802.16e HIPERMAN



Error Correction techniques

Reed Solomon coding, Convolution coding and interleaving are used to detect and correct errors and thus improve throughput.

Power Control

Power control is implemented at the base station. The base station sends power control information to each of the CPEs so that the power received by the base station is at a predetermined level. Power control reduces the overall power consumption at the CPE and the potential interference with other co-located base stations.

The WiMAX standard also supports some optional technologies, including:

Sub-channelisation

Sub-channelisation allows the link budget to be balanced such that the system gain is balanced on the uplink and the downlink. Sub-channelisation concentrates the transmit power into fewer OFDM carriers.

Transmit and receive diversity

Transmit and receive diversity increases system availability. Transmit diversity uses space time coding to reduce the fade margin requirement. Receive diversity uses various combining techniques to improve the availability of the system

Adaptive antenna systems

Adaptive antenna systems have beamforming properties that can steer their focus in a particular direction. They also suppress co-channel interference from other locations.

3 Planning a WiMAX Network with the Enterprise Suite AIIRCOMs Enterprise suite of tools can be used to plan and analyse the various different WiMAX profiles.

3.1 Microwave Backhaul Planning Point-to-point networks for backbone can be modelled and analysed using AIRCOMs microwave link planning tool, CONNECT.



3.1.1 Equipment

The equipment used for the WiMAX backbone can be set up from within the tool or imported into the tool in a number of different formats.

Figure 1 : Backhaul Equipment Parameter Specification



3.1.2 Point-to-point link Creation

Link templates can be defined to be used as basis for the point to point link creation.

Figure 2: Point to Point link template



LOS Analysis

The LOS between a location and other locations can be determined using the LOS wizard. The wizard allows users to determine the LOS links for a single property or for a number of properties.

Figure 3; LOS Analysis for Property 36

3.1.3 Height Profiler

The height profiler shows the two dimensional cross section of the terrain between two points or the cross section of an existing link. It can also be used to determine the optimum height of the antennas, check clearance over terrains and objects and analyse the effects of terrain reflection.

Figure 4; Height profile for link 11 and link 2 displaying building heights, LOS and

clearance of 1st and 2nd Fresnel Zones



3.1.4 Interference Analysis

Interference calculations can be performed for each individual link or for a collection of links in the network.

Interference can be calculated for both sides of the link.

Figure 5; Results of the interference analysis for link 11 from property 29 and property 30

3.2 Access Network Planning Fixed wireless broadband access networks at WiMAX frequencies can be modelled and analysed using AIRCOMs network planning tool, ASSET3G

Wide range and close range analysis can be performed by choosing the most appropriate propagation model and cartographic data.

3.2.1 Propagation Models

WiMAX profiles support LOS and NLOS transmission at a number of different carrier frequencies with different channel bandwidths.

The Enterprise suite supports a number of empirical and deterministic propagation models for the analysis of the different WiMAX network profiles.

Empirical Model

The Okumura Hata model is supported as standard for wide range analysis and can be calibrated at WiMAX frequencies. A number of diffraction algorithms can be considered to account for the obstacles between the base station and the CPE. In order to further improve the accuracy of the analysis, specific loss values can be applied to each clutter type.



Figure 6; Okumura Hata Model parameter specification

Deterministic Models

A number of deterministic models are supported within the tool. The Siradel Volcano model has been verified at WiMAX frequencies and allows the users to perform close range network analysis using high resolution cartographic data. Reflection from surfaces and diffraction by edges can also be modelled.

Figure 7; Volcano Model Parameter Specification



3.2.2 Equipment

The WiMAX equipment can be defined from within the tool or can be imported into the tool using various different formats.

Figure 8; Access network equipment parameter specification

3.2.3 WiMAX Base Stations

Each sector of the WiMAX base station can be set up independently within the tool and is stored within a database for ease of management

Figure 9; WiMAX base station parameter specification



3.2.4 Signal Strength Calculation

In order to serve a given coverage area, WiMAX base stations can be deployed as a single isolated base station or in a multi base station configuration. Both deployment strategies can be evaluated in the planning tool.

Figure 10; Received signal strength plots for isolate and multi base station

configuration

Individual coverage plots can be generated for various different CPE types.

Figure 11; Signal Strength for indoor and outdoor CPE

Indoor Outdoor



Different minimum received signal levels can be specified for each of the modulation and coding schemes, for the different CPE types.

Figure 12; Threshold specification for signal strength plots

The coverage can also be analysed in the form of a statistics report. The report produces percentage statistics in terms of individual clutter categories and sector coverage areas.

Figure 13: Coverage statistics report

3.2.5 Interference Analysis

The interference can be analysed in terms of the C/I ratio.

Carriers can be assigned to WiMAX sectors manually or using the automatic frequency planner, ILSA.



Figure 14: Manual Assignments of carriers Figure 15: ILSA Frequency Planer The C/I can be calculated and displayed on the map view for the individual CPE types.

Figure 16: Results of interference calculation

In addition to viewing the interference on the map view, the user can generate a statistics report. The report provides a breakdown of the interference per clutter type, over a specified threshold.

The C/I thresholds for each of the modulation and coding schemes can be adjusted by the user.



Figure 17: Interference statistics report

3.3 WiMAX Network Optimisation

WiMAX networks can be optimised using AIRCOMs network optimisation tool, ADVANTAGE. The tool allows planners to determine the most appropriate location for the WiMAX sites based on several different criteria. It also allows planners to optimise antenna parameters and transmit power to improve the performance of the WiMAX network.

3.3.1 Site Selection

The number of WiMAX sites required can be optimised by choosing the best site location from a number of predefined candidate locations.

Figure 18: Optimising site location through site selection

The selection of the optimum sites can be based on a number of different objectives such as coverage, interference and traffic served.



3.3.2 Antenna and Power Optimisation The antenna tilt, azimuth and height can be optimised to improve the network coverage, reduce interference or maximise the number of CPEs served in a network.

Figure 19: Optimising Antenna parameters

The total power transmitted from a base station can also be optimised to maximise capacity for the range of services and throughput demands.



4 Summary

The WiMAX standard, endorsed by the WiMAX forum will provide a unified standard for the deployment of broadband wireless services. The broad range of spectrum options in the licensed and un-licensed bands will provide a favourable climate for equipment manufacturers and service providers.

This document provided an overview of the WiMAX standard and presented the WiMAX planning capabilities of AIRCOMs Enterprise suite.

5 Glossary WiMAX Worldwide Interoperability for Microwave Access

LOS Line Of Sight

NLOS Non Line OF Sight

OFDM Orthogonal Frequency Division Multiplexing

FWA Fixed Wireless Access

BWA Broadband Wireless Access

QPSK Quadrature Phase Shift Keying

QAM Quadrature Amplitude Modulation

CPE Customer Premises Equipment

SNR Signal to Noise Ratio

ILSA IntelligenT Local Search Engine

IntroductionWiMAX OverviewWIMAX StandardApplication and DeploymentWiMAX Network ParametersWiMAX Technologies

Planning a WiMAX Network with the Enterprise SuiteMicrowave Backhaul PlanningEquipmentPoint-to-point link CreationHeight ProfilerInterference Analysis

Access Network PlanningPropagation ModelsEquipmentWiMAX Base StationsSignal Strength CalculationInterference Analysis

WiMAX Network OptimisationSite SelectionAntenna and Power Optimisation

SummaryGlossary

WiMAX White Paper - V1 - Approved

Documents

wimax overview

wimax standard

wimax technologies

white paper wimax

wimax network optimisation

wimax network parameters

wimax base stations

access network planning