analysis to the wimax multi-carrier networking solution

7/30/2019 Analysis to the Wimax Multi-Carrier Networking Solution

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Product name Confidentiality level: INTERNAL

WIMAX Department Name: Solution Development Dept.

Product version

Total 20 pages

Analysis to the Wimax Multi-Carrier Networking

SolutionFor internal use only

Prepared by Hu Wenli Date 2006-11-17

Reviewed by Date yyyy-mm-dd

Reviewed by Date yyyy-mm-dd

Granted by Date yyyy-mm-dd

Huawei Technologies Co., Ltd.

All rights reserved


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Analysis to the Wimax Multi-Carrier Networking Solution INTERNAL

Contents

1 Revision Record............................................................................9

2 Overview....................................................................................10

2.1 Purpose...................................................................................................................................................................10

2.1 Purpose...................................................................................................................................................................102.2 Conclusion..............................................................................................................................................................10

2.2 Conclusion..............................................................................................................................................................10

3 Basic Frequency Reuse Patterns of the Wimax Network.................11

3.1 PUSC 1X1 Frequency Reuse Pattern......................................................................................................................11

3.1 PUSC 1X1 Frequency Reuse Pattern......................................................................................................................11

3.1.1 Advantage............................................................................................................................................. ......... ...11

3.1.1 Advantage............................................................................................................................................. ......... ...11

3.1.2 Disadvantage....................................................................................................................................................12

3.1.2 Disadvantage....................................................................................................................................................12

3.1.3 Applicable Scenario..........................................................................................................................................12


3.2 FFR Frequency Reuse Pattern................................................................................................................................12

3.2 FFR Frequency Reuse Pattern................................................................................................................................12

3.2.1 Advantage................................................................................................................................................. ........12

3.2.1 Advantage................................................................................................................................................. ........12

3.2.2 Disadvantage....................................................................................................................................................13

3.2.2 Disadvantage....................................................................................................................................................13

3.2.3 Applicable Scenario..........................................................................................................................................133.2.3 Applicable Scenario..........................................................................................................................................13

3.3 1X3 Frequency Reuse Mode..................................................................................................................................13

3.3 1X3 Frequency Reuse Mode..................................................................................................................................13

3.3.1 Advantage................................................................................................................................................. ........14

3.3.1 Advantage................................................................................................................................................. ........14

3.3.2 Disadvantage....................................................................................................................................................14

3.3.2 Disadvantage....................................................................................................................................................14



2013-05-23 Huawei Confidential No spreading without permission Page 2 of 20


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4 Multi-Carrier Wimax Networking..................................................15

4.1 Capacity Expansion (Multi-Carrier Networking) for the Hotspots...................................................................... ..15

4.1 Capacity Expansion (Multi-Carrier Networking) for the Hotspots...................................................................... ..15

4.1.1 Scenario Description.........................................................................................................................................15


4.1.2 Networking Solution.........................................................................................................................................16


4.2 Capacity Expansion (Multi-Carrier Networking) for a Large Scale Area..............................................................17

4.2 Capacity Expansion (Multi-Carrier Networking) for a Large Scale Area..............................................................17





5 Networking Solutions for Varied Frequency Resources ..................19

6 Documentation Reference............................................................20


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Figures

PUSC 1X1 frequency reuse pattern.................................................11

FFR frequency reuse pattern..........................................................12

1X3 frequency reuse pattern..........................................................13

Networking....................................................................................16

Networking....................................................................................17



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TablesTypical networking solutions...........................................................10

Networking solutions.....................................................................19



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1Revision Record

Date Version

Description Author

2006-11-18dd 1.00 Initial release. Hu Liwen



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2 Overview2.1 Purpose

This document is the input to the final Wimax network planning released at the end of the

year. It provides varied solutions according to the spectrum bandwidth resources of the operators.

This document is written in a short time (only one and a half day) and provides a few multi-carriernetworking solutions. It is for your reference only. It will be supplemented later.

2.2 ConclusionFigure 1.1 lists some typical networking solutions applicable to different scenarios.

Figure 1.1 Typical networking solutions

SpectrumResourcesAvailable tothe Operator

Suggested Networking Solution

Dense UrbanAreas

Urban Areas SuburbAreas/Village

5/10 MHz 1X1 FFR (Single-

ARFCN PUSC +FUSC hybrid

networking)

1X1 FFR (Single-

ARFCN PUSC +FUSC hybrid

networking)

1X1 PUSC (Single-

ARFCN PUSCnetworking)

15 MHz 1 x 3 (5 MHz) 1 x 3 (5 MHz) 1X3 (5 MHz)

20 MHz 1X1 FFR + overlay

networking

1X1 FFR + overlay

networking

1X1 FFR

30 MHz 1X3 (10 MHz) 1X3 (10 MHz) 1X3 (10 MHz)

> 40 MHz Multi-carrier

networking

Multi-carrier

networking

Multi-carrier

networking



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3Basic Frequency Reuse Patterns

of the Wimax Network

According to the research conclusion described in chapter 1, the Wimax network uses

primarily the following three frequency reuse patterns.

3.1 PUSC 1X1 Frequency Reuse PatternIn the PUSC 1X1 frequency reuse pattern, that is the single-ARFCN PUSC networking, all

the BTSs share an Absolute Radio Frequency Channel Number (ARFCN). A BTS isconfigured with three sectors, each sector is assigned 1/3 channel bandwidth (RF1, RF2, RF3)

in the PUSC 1X1 frequency reuse pattern.

Figure 1.1 shows the PUSC 1X1 frequency reuse pattern.

Figure 1.1 PUSC 1X1 frequency reuse pattern

RF3

RF1

RF2

RF3

RF1

RF2

RF3

RF1

RF2

RF3

RF1

RF2

RF3

RF1

RF2

RF3

RF1

RF2

RF3

RF1

RF2

3.1.1 Advantage

Minor system interference and no sub-carrier conflict between neighbor sectors in a

same BTS



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Fast network deployment, easy interference control, and simple network planning andoptimization

Same frequency in a network, easy soft handoff

Little system overhead, and simple implementation

In this pattern, the complicated sub-carrier permutation and dispatch algorithm is notrequired.

Wider coverage area, lower cost for initial network deployment, and lower risk

3.1.2 Disadvantage

Low spectrum usage

Small network capacity

3.1.3 Applicable Scenario

The pattern is applicable to initial network deployment. It is especially applicable to the areasthat require wide coverage and small capacity, for example, suburb and village areas.

3.2 FFR Frequency Reuse PatternIn the FFR frequency reuse pattern, that is the single-ARFCN PUSC plus PUSC with all SC

hybrid networking, a BTS is configured with three sectors, all subchannels are available toeach sector and part of the subchannels are used for the interference control outside each

sector. Subchannel are dispatched according to the measurement and judgment of the CINR of

the subscriber.. Each BTS consists of three sectors and the BTSs reuse sub-channels. These

BTS clusters consist of the seamless coverage network..

Figure 1.1 shows the FFR frequency reuse pattern.

Figure 1.1 FFR frequency reuse pattern

3.2.1 Advantage

High spectrum usage

Soft handoffs available



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Load sharing between sectors

Flexible sub-channel dispatch, excellent sub-channel dispatch mechanism, and maximumuse of channel resources

3.2.2 Disadvantage Complicated sub-carrier permutation and sub-channel dispatch algorithm

High probability of channel conflict and co-channel interference with high load

Neighbor sectors in a BTS have co-channel interference.

The system interference is correlated with the quality of the sub-channel dispatchmechanism.


The networking in this frequency reuse pattern is preferred by the Wimax 16e. It is applicable

to the initial network deployment in the dense urban areas and urban areas that have moderate

or high traffic.

3.3 1X3 Frequency Reuse ModeIn the 1X3 frequency reuse mode, totally three ARFCNs are used. A BTS is configured withthree sectors and each sector uses a different ARFCN (F1, F2, or F3). All the BTSs reuse the

three ARFCNs.

Figure 1.1 shows the 1X3 frequency reuse pattern.

Figure 1.1 1X3 frequency reuse pattern

F3

F1

F2

F3

F1

F2

F3

F1

F2

F3

F1

F2

F3

F1

F2

F3

F1

F2F2

F3

F1

F2



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3.3.1 Advantage

Fully used dispersive frequency resources of the operator

Little system overhead, and simple implementation

In this pattern, the complicated sub-carrier permutation dispatch algorithm is notrequired.

Minor system interference and no co-channel interference between neighbor sectors in a

BTS

Minor probability of sub-channel conflict and minor interference in co-channel cells

Fast network deployment, easy interference control, and simple network planning andoptimization

3.3.2 Disadvantage

Low spectrum usage

According to the emulation test result, the spectrum usage of the 1X3 frequency reusepattern is only 0.56 bit/s/Hz/sector, similar to that of the PUSC 1X1 frequency reuse

pattern.

Hard handoff available, soft handoff gain unavailable


The pattern is applicable to the operator that has rich frequency resources (at least 30 MHz)

and applicable to the large-capacity coverage in urban areas or dense urban areas.



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4 Multi-Carrier Wimax NetworkingWith the increasing traffic requirement, the network capacity of the single-carrier networkingfails to meet the requirement. Therefore, the multi-carrier networking is required in order to

increase the system capacity. In the multi-carrier networking, the sectors in a BTS usemultiple different carriers.

The following describes some common scenarios of multi-carrier networking:

4.1 Capacity Expansion (Multi-CarrierNetworking) for the Hotspots

4.1.1 Scenario Description

The hotspots refer to the areas that have dense buildings, dense population, and very high

traffic. Generally, political, economic, commercial, finance, and culture centers are hotspots.The rapid traffic increase in the hotspot area, for example, office building, hotels, and airports,

requires capacity expansion. But the areas outside the hotspots area do not require capacity

expansion. Therefore, you can configure dual-carrier or multi-carrier for the BTS in thehotspot area to expand the capacity. But the BTSs in the vast areas outside the hotspots remain

single-carrier configuration.



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4.1.2 Networking Solution

Figure 1.1 illustrates the networking. The rectangle in grey indicates the cell that has dense

traffic and is configured with multiple carriers in the hotspot area. The rectangle in white

indicates the cell that is configured with single carrier in the area outside the hotspot area.

Figure 1.1Networking

Traffic Assignment The carriers added to the cell in the hotspot areas share the traffic. Co-channel

interference does not exist between the cell that is added with more carriers and the

neighbor cells, therefore, the conversation quality in the cell that is added with morecarriers is better. The subscribers in the cell are easily to have higher data rate using

advanced modulation method. VIP subscribers and higher-service-priority subscribers

can be forcedly configured with additional carriers F2 and F3.

In the initial Wimax network development, a large amount of long-term or short-termsubscribers may have high requirements for the service rate but not for the mobility.

Therefore, these subscribers can be configured with additional carriers F2 and F3.

Services are preferred to be assigned to the additional carriers of the cell. Then, the

number of subscribers assigned to the basic carrier F1 decreases. The interference

between the carrier F1 in the cell and the carrier F1 in neighbor cells decreases. Theaverage throughput of the whole network increases.

Inter-Frequency Handover Configuration Configure common channels, such as paging channels, in carrier F1. Do not configure

paging channels in the additional carriers. And soft handoffs are available when

subscribers require because the basic carrier F1 covers the whole area of the cell.

The overhead of the common channel in the carrier F1 is not large because only the cellsin the hotspot area is configured with multiple carriers and the common channel

overhead in the cell that is configured with multiple carriers is not large.

For the cell that is configured with multiple carriers, inter-frequency handovers

frequently occur on the borders between the additional carrier sectors of the cell and the

neighbor cells. You can reduce the power and the coverage area of the multiple-carriercell and set reasonable handoff threshold for neighbor cells.


F3

F2F1

Hotspots Areas outside the

hotspot area


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Power Configuration

After configuring multiple-carrier for a cell, increase the BTS power to maintain originalcoverage area.

4.2 Capacity Expansion (Multi-CarrierNetworking) for a Large Scale Area

4.2.1 Scenario Description

For the dense urban areas or some urban areas that have dense population and high traffic,

such as the dense residential district, old urban area, and shopping center that is not in the city

center, the traffic increase in these areas require capacity expansion to the multi-carrierconfiguration. But the BTSs in other areas remain a little traffic and single-carrier

configuration.

4.2.2 Networking Solution

Figure 1.1 illustrates the networking.

Figure 1.1Networking

Traffic Assignment Set reasonable load threshold to balance the traffic between different carriers and

configure the lightest-load carrier for a sector.

Because the Wimax network bearing is based on services, service-based hard assignment

is applicable to the Wimax network. For example, assign higher-priority (lower delay orhigher bandwidth requirement) subscribers to carrier F3 and set carriers F1 and F2 to

common data service preferred carriers. Common data services are preferred to beaccessed to the lowest-load carrier between carriers F1 and F2 and preferred to be

accessed to the lowest-load carrier among carrier carriers F1, F2, and F3 when the loads

of both carrier F1 and carrier F2 exceed the hard assignment threshold. Higher-priority

data services are preferred to be accessed to carrier F3 and preferred to be accessed to thelowest-load carrier among carriers F1, f2, and F3 when the load of carrier F3 exceeds the

hard assignment threshold.

Inter-Frequency Handover Configuration Configure common channels, such as paging channels, in carrier F1. Do not configure

paging channels in the additional carriers. And soft handoffs are available when


F1

F2

F3

Dense urban areas Urban areas Suburb areas


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subscribers require because the basic carrier F1 covers the whole area of the cell.

The coverage areas of the multiple carriers are strong correlated because the PA power isaveraged among multiple carriers. When hard handoff between carriers is required, direct

handoff to the basic carrier in the cell is preferred. The hard handoff success ratio is very

high because the target cell is specific and the inter-frequency measurement is notrequired.

According to the previous analysis, soft handoff from the basic carrier to the neighbor

cell is available when the subscribers moves in the border area between the hotspot area

that is configured with multiple carriers and the area that is configured with single carrier

or dual carriers.

Power Configuration After configuring multiple-carrier for a cell, increase the BTS power to maintain original

coverage area.

For the BTSs that are configured with different number of carriers, ensure that every

carrier (different carriers in the same BTS and carriers of the BTSs that are configuredwith different number of carriers) is configured with the same power.



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5 Networking Solutions for VariedFrequency Resources

Based on the analysis of the basic frequency reuse pattern and the multi-carrier networking

solutions, Huawei recommends the following networking solutions for varied spectrum and

bandwidth resources of the operators.

Figure 1.1Networking solutions

SpectrumResourcesAvailable tothe Operator

Suggested Networking Solution

Dense UrbanAreas

Urban Areas SuburbAreas/Village

5/10 MHz 1X1 FFR (Single-

ARFCN PUSC +

FUSC hybrid

networking)

1X1 FFR (Single-

ARFCN PUSC +

FUSC hybrid

networking)

1X1 PUSC (Single-

ARFCN PUSC

networking)


20 MHz 1X1 FFR + overlaynetworking

1X1 FFR + overlaynetworking

1X1 FFR


>40 MHz Multi-carrier networking

Multi-carriernetworking

Multi-carriernetworking



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6Documentation Reference

[1] Mobile WiMAX Frequency Design Scheme by Hu Liwen, 2006.10.


analysis to the wimax multi-carrier networking solution

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