Kostas Tsagkaris N.Koutsouris, A.Galani, P.Demestichas

Session 12a, 16 June 2010 Future Network & Mobile Summit 2010 Copyright 2010 E3 ICT-2007-216248

Performance Assessment of a Spectrum and Radio Resource Management Architecture for

Heterogeneous Wireless Networks

Kostas TsagkarisN.Koutsouris, A.Galani, P.Demestichas

Telecommunication Networks & Integrated Services Lab

Dept of Digital Systems, University of Piraeus,

Piraeus, Greece


Outline

• Motivation, problem area

• Overview of considered S&RR management architecture

• Research approach, methodology

• Information flow definition

• Experimentation platform setup

• Indicative scenario & results


Motivation, problem area

• Disparate emerging landscape – heterogeneous wireless networks

(Cognitive) (Cognitive) Access PointAccess Point

(Cognitive) (Cognitive) Base StationBase Station

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RANN

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Motivation, problem area (cont.)

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RAT?spectrum?frequency? radio resources?…

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RAN/RAT?spectrum?frequency? radio resources?…



• How to optimally select and use spectrum and radio resources?


Motivation, problem area (cont.)

• The IEEE/SCC41 P1900.4 Working Group was born to solve the problem

• In Jan 2009, the group has standardised [*] a management architecture (System/Functional Architecture + Information model) for efficiently managing cognitive/heterogeneous wireless networks and terminals

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• Little work on the performance assessment of 1900.4 standardised architecture so far

• This work places focus on the assessment of signalling load/delays that the management architecture causes to the network that it operates in.

[*] [*] IEEE Std 1900.4™-2009, IEEE Standard for Architectural Building Blocks Enabling Network-DeviceIEEE Std 1900.4™-2009, IEEE Standard for Architectural Building Blocks Enabling Network-Device Distributed Decision Making for Distributed Decision Making for Optimized Radio Resource Usage in Heterogeneous Wireless Access NetworksOptimized Radio Resource Usage in Heterogeneous Wireless Access Networks


Overview of 1900.4: System Architecture

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RAN1

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orkOSM

NRM

RMC

RRC

TRC

TRM

TMC

Radio Enabler

TRM – Terminal Reconfiguration ManagerTRC – Terminal Reconfiguration ControllerTMC – Terminal Measurement Collector

OSM – Operator Spectrum ManagerNRM – Network Reconfiguration ManagerRRC – RAN Reconfiguration Controller RMC – RAN Measurement CollectorRAN – Radio Access Network


Overview of 1900.4: Interfaces


RAN1

RANN

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NRM

RMC

RRC

TRC

TRM

TMC

Radio Enabler

Policies/Context

Context

Reconfigurations

Reconfigurations

Context


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RAN context information:• RAN radio resource optimization objectives• RAN radio capabilities• RAN measurements• RAN transport capabilities

Radio Resource selection policies

Terminal context information:• User preferences• Required QoS levels per application• Terminal capabilities• Terminal measurements• Terminal geo-location information• Geo-location based terminal measurements

RAN context information

RAN context information

Spectrum AssignmentPolicies


Overview of 1900.4: Functional Architecture

• Focus on the NRM Functional architecture

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RAN1

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RMC

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Radio Enabler



NRM


Overview of 1900.4: Functional Architecture

• …Focus on NRM • .... and particularly, on the interfaces among NRM and its external

entities

RAN1

RANN

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NRM

RMC

RRC

TRC

TRM

TMC

Radio Enabler

Policies/Context

Context



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Research approach, Methodology

Methodology:

1. Define the exact information flowing in the above interfaces• Parameters

2. Setup experimentation platform for the performance assessment of the management architecture • 1900.4 architecture implementation based on distributed agents

3. Performance assessment• Indicative scenarios • Results w.r.t. measured signalling load/delays


Definition of information flow – Example

RAN1

RANN

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NRM

RMC

RRC

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Radio Enabler

Policies/Context

Context



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Experimentation platform

RAN1

RANN

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NRM

RMC

RRC

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TRM

TMC

Radio Enabler

Policies/Context

Context



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RANagent

GENERATORagent

NRMagent

OSMagent

RAN agent

Generated Traffic Information

Spectrum Assignment &Rules

NetworkStatus &Policies

MTagent(s)

MT agents

Network Status & PoliciesSpectrum

UsageInfo

MT StatusNotification

RANagent

GENERATORagent

NRMagent

OSMagent

RAN agent




MTagent(s)MTagent(s)

MT agentsMT agents


UsageInfo


• After identifying and describing the exact info to be conveyed…

• Setup a platform to experiment on a IEEE 1900.4-based architecture, functionality and interfaces

• Multi-agent environment based on JADE (Java Agents DEvelopment framework)

– fully JAVA and FIPA compliant framework for developing distributed agent systems

• Agents act as high level interfaces between the involved entities and the environment and ensure their communication through the asynchronous exchange of messages (according to the FIPA ACL message structure specification)


RANagent

GENERATORagent

NRMagent

OSMagent

RAN agent




MTagent(s)

MT agents


UsageInfo


RANagent

GENERATORagent

NRMagent

OSMagent

RAN agent




MTagent(s)MTagent(s)

MT agentsMT agents


UsageInfo


Experimentation platform (cont.)

• In order to carry out the experiments in the JADE based platform:

• A set of messages have been defined

– structures that contain the defined parameters

– proper message names

• These messages are then encapsulated in the ACL messages according to the FIPA specifications and in order to flow within the agent platform

• Overhead in the total number of bytes that are conveyed for management reasons is taken into account


Indicative scenario – Description

• Heavy loaded RAN situation

• Trigger for RAN reconfiguration

• Messages (parameters) are exchanged until all MTs will be informed about the new RAN context and are provided with the new policies

Objective: Measurement of signalling load

and time delays induced to the managed network


Indicative scenario – Description (cont.)

• RAN becomes overloaded and sends a Context&ConfigurationNotification message to the NRM.

• Information Collection & Processing Function sends to every other RAN that covers the same geographical area a Context&ConfigurationRequest message, so as to receive the corresponding Context&ConfigurationResponse with the network status information

• SpectrumEvaluationFunction detects that a spectrum reallocation may be necessary, so it sends the evaluation results to OSM agent with SpectrumUsageEvaluation

• OSM agent sends to NRM the new allocation of the available frequencies to RATs with NewSpectrumAssignment message.


Indicative scenario – Description (cont.)

• Network Reconfiguration Decision & Control Function makes the decision on how the overloaded RAN should be reconfigured

• NRM sends ReconfigurationRequest message to the RAN

• RAN sends to the NRM a ReconfigurationExecutionNotification message after reconfiguration takes place

• NRM derives new policies (Policy Derivation Function) and sends them together with new RAN context information to MTs using NetworkStatus&Policies message


Results - Bandwidth calculation

• The management burden is low, providing evidence on the viability of The management burden is low, providing evidence on the viability of the architecturethe architecture

• Of special importance are the results concerning the NRM – MT Of special importance are the results concerning the NRM – MT interface since it is the interface encompassing the air-interface interface since it is the interface encompassing the air-interface

Bandwidth needed for management


USERUSERGenerator agent RAN agentNRM agentOSM agent MT agent

Context&ConfigurationResponse

Context&ConfigurationRequest

Context&ConfigurationNotification

Context&ConfigurationNotificationAck

SpectrumUsageEvaluation

NewSpectrumAssignment

ReconfigurationRequest

ReconfigurationRequestAck

ReconfigurationExecutionNotification

ReconfigurationExecutionNotificationAck

NetworkStatusAndPolicies

Simulated Traffic

RAN agentRAN agentRAN agent

Simulated Traffic

RAN Reconfiguration

Decision Function

Spectrum Evaluation Function

Information Collection & Processing

Function

Policy Derivation Function

Overloaded RAN

Other RANs in the area

NR

M reaction tim

e

Other RAN Reconfiguration

Results – Reaction time of the NRM

• Focus is now placed on the “NRM reaction time” i.e. time that the NRM, needs in order to resolve a problematic situation

• Dependence on – the number of APs in the

area– the number of active MTs – processing power of the

machine where the algorithmic part of the described functionality is executed

• Focus on the influence of the number of APs and MTs.


Results – Reaction time of the NRM (cont.)

• The general outcome drawn is that the architecture is able to optimize The general outcome drawn is that the architecture is able to optimize efficiently areas encompassing several APs and a high number of MTs as efficiently areas encompassing several APs and a high number of MTs as wellwell

• The dependence on the number of the involved APs is greater than the The dependence on the number of the involved APs is greater than the dependence on the number of MTs that exist in the areadependence on the number of MTs that exist in the area

Influence on the management reaction time of the number of APs and MTs in the area


USERUSERGenerator agent RAN agentNRM agentOSM agent MT agent

Context&ConfigurationResponse

Context&ConfigurationRequest

Context&ConfigurationNotification

Context&ConfigurationNotificationAck

SpectrumUsageEvaluation

NewSpectrumAssignment

ReconfigurationRequest

ReconfigurationRequestAck

ReconfigurationExecutionNotification

ReconfigurationExecutionNotificationAck

NetworkStatusAndPolicies

Simulated Traffic

RAN agentRAN agentRAN agent

Simulated Traffic

RAN Reconfiguration

Decision Function

Spectrum Evaluation Function

Information Collection & Processing

Function

Policy Derivation Function

Overloaded RAN

Other RANs in the area

Other RAN Reconfiguration

Informing MTs

Results – Handling a large number of connected MTs

• Handling a large number of connected MTs

• Focus on the ”Informing time (delay)” = the time needed to inform all the interested MTs about the new network status and policies


Results – Handling a large number of connected MTs (cont.)

Less than 1 sec is needed in most of the cases, confirming that the Less than 1 sec is needed in most of the cases, confirming that the management information flow will not be blocked or bottlenecked and management information flow will not be blocked or bottlenecked and that the MTs will obtain all the necessary information in timethat the MTs will obtain all the necessary information in time

Time needed to inform all interested MTs about the new network status and policies


Conclusion and outlook

• An experimentation platform was setup to assess the performance of a IEEE 1900.4-based management architecture

• The platform is based on distributed agents implemented in the Java Agents Development (JADE) framework

• Indicative scenario and results show that the signaling and time delays induced into the managed network will not aggravate the overall network operation


Further reading

[1] A.Galani, K.Tsagkaris, N.Koutsouris, P.Demestichas, “Design and Assessment of Functional Architecture for Optimized Spectrum and Radio Resource Management in Heterogeneous Wireless Networks”, International Journal of Network Management, to appear

[2] S.Buljore, H.Harada, P.Houze, K.Tsagkaris, et al., “Architecture and Enablers for Optimised Radio Resource usage: The IEEE P1900.4 Working Group” Communications Magazine, IEEE, Vol 47, no. 1, pp. 122-129, January 2009

[3] IEEE Std 1900.4™-2009, IEEE Standard for Architectural Building Blocks Enabling Network-Device Distributed Decision Making for Optimized Radio Resource Usage in Heterogeneous Wireless Access Networks, Jan. 2009

[4] IEEE Standards Coordinating Committee 41 (SCC41), http://grouper.ieee.org/groups/scc41/


Acknowledgment

This work was performed in the project E³ which has received research funding from the

Community's Seventh Framework programme. This paper reflects only the authors' views and the

Community is not liable for any use that may be made of the information contained therein. The

contributions of colleagues from the E³ consortium are hereby acknowledged.


Thank you…

….Questions?

Contact details:Dr. Kostas TsagkarisUniversity of Piraeus

Department of Digital SystemsE-mail: [email protected]

Documents

Kostas Tsagkaris N.Koutsouris, A.Galani, P.Demestichas