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Planning Base Station and Relay Station Locations in IEEE 802.16j

Multi-hop Relay Networks

Yang Yu, Seán Murphy, Liam Murphy

Department of Computer Science and InformaticsUniversity College Dublin, Ireland

IEEE CCNC 2008

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Outline

Introduction Planning Model Problem Formulation Simulation Conclusion

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Introduction

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Introduction

Relays can be developed at significantly lower cost than Base Stations (BSs)

While 3G network planning has been well studied, the base radio technology on which it is based differs from that of 802.16

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Goal

To determine the optimal placement of BSs and Relay Stations (RSs) given the following : a set of candidate sites user demand cost information

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Planning Model

The following inputs are assumed: a set of candidate BS and RS sites user demand, modelled by a set of discrete Test Points (TP

s) a suitable propagation model a set of costs associated with BS and RS the multihop concept is limited to nodes which are at most

two hops from the BS SSs can connect to an RS which is connected to the BS, or

they can connect directly to the BS

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Problem Formulation _ Definitions

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Problem Formulation _ Definitions

Propagation factor of the radio link between TP i and candidate site of BS j;

Propagation factor of the radio link between TP i and candidate site of RS j;

Propagation factor of the radio link between candidate site of RS i and candidate siteof BS j

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Problem Formulation _ (1)

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Problem Formulation _ (2)

Cost of BS Cost of RSTP to BS

TP to RS RS to BS

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This problem can be solved by using the branch and bound algorithm

It’s still a NP-Hard Problem So more constrains is to reduce the problem

state space

Problem Formulation _ (3)state space reduction

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Problem Formulation _ (3)state space reduction

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Simulation_ parameter(1)

The size of area is 3km * 3km The locations of each BSs, RSs and T

Ps is chosen randomly BS cost is random

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20 candidate BSs, 60 candidate RSs and 200 TPs10 BSs are selected with 36 RSs

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Simulation_ (2) Calculation time when three parameters scaling in the mean time

The numbers of BSs are varied The numbers of RSs are 3 times The numbers of TPs are 10 times

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The numbers of BSs is scaling The numbers of RSs are 90 The numbers of TPs are 300

Simulation_ (3) Calculation time when only the number of BS is scaling

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Simulation_ (4) Calculation time when only the number of

RS is scaling

The numbers of BSs are 30The numbers of RSs is scaling The numbers of TPs are 300

Number of RSs

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Simulation_ (5) Calculation time when only the number of TP is scaling

The numbers of BSs are 30The numbers of RSs are 90 The numbers of TPs is scaling

Number of TPs

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Simulation_ (6) Comparison of the calculation time, with and without the additional constraints

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Conclusions

The proposed model is for planning 802.16-based relay networks

An integer programming formulation was developed

The results show that the standard branch and bound algorithm can find optimal solutions

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Thank you~