concevoir et maîtriser les systèmes complexes 1 urbanisme des radio-communications sp2, d2.1.2 :...
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Concevoir et maîtriser les systèmes complexes1
Urbanisme des Radio-Communications
SP2, D2.1.2:
Specifications of the Metrology Related to Radio Resources and Spectrum
Management
6 June 2007
Editor: PRiSM Lab
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Content of D2.1.2
Centralised/Decentralised Metrology Concepts: Pending
Definition of DSA Metrics: Pending Need of Cooperation between Different RATs
belonging to the same Operator: In progress Withdrawn Tasks:
Cooperation between Heterogeneous RATs and Different Operators
Spectrum Sharing and Utilisation of Unlicensed Bands
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Centralised/Decentralised Metrology Concepts
Resp: ENST Status: Pending Metrology Classification:
Centralised: At which network level/node(s)? Distributed: How to manage information
exchange and decisions? Metrology and DSA Metrology Related to Radio Measurements
in Île-de-France
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Definition of DSA Metrics
Resp: ENST; Other: PRiSM, INRETS, INT Status: Pending Possibilities of improving spectrum usage in Île-de-
France. Connection to the radio measurements campaign?? Input Measurements for DSA Operations: to be
completed Offered load of the RAN. At which level measurements are taken? Relating measurements to traffic and mobility
models (parameters estimation). Grade of Service, GoS related to traffic and
services Relation Application/Service <-> RAT
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Definition of DSA Metrics
Blocking probability:– reject of new calls– Handover failures
History of Offered load based on service nature– Streaming: Video– Telephony, visiophony– Interactive data– Elastic
Issue: How to relate a service demand to the needed bandwidth?
Interferences: connect interferences to service QoS degradation
User inputs:– Radio metrics: C/I, eventually absolute interference level.
=? Frame error rate.
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Definition of DSA Metrics
Metrics for DSA Performance Evaluation and Validation Testing (Output Metrics): Pending
Spectrum allocation: fairness issues Comparison between FSA and DSA schemes QoS perceived by final users Performance and cost metrics to be used by operator
Relation between Radio Measurements and DSA Metrics: Pending
Standards specifications of radio measurements and how to translate them into DSA metrics.
Take advantage of the measurements campaign Traffic measurements.
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Need of Cooperation between Different RATs belonging to the same
Operator
Resp: PRiSM; Other: ENST, INRETS, INT Status: In progress Space-Time Variation of RATs Spectrum Demands:
In progress Cooperation and Spectrum Exchange between
RATs: In progress Control and Management Information Exchange
between Heterogeneous Networks: to be completed Measurements and Metrics Implicated: Network oriented
and User oriented RRM functions and RRM cooperation protocols “Control
Network” for information exchange
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Time Variation of Spectrum Demand
Time-varying traffic Each service has its own temporal traffic patterns shape
related to the human activity:– Ex: telephone activity culminates at the busy hours. Video
demand increases in the evening.– The shape of a given service may depend on the
geographical location. Periodic/predictable variations (daily or seasonal
basis, ...) Exceptional variations (events, network problems, ...). Current spectrum status: FSA. Dimensionning and
spectrum allocation is done based on busy hours.
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Time Variable DSA (1)
Temporal DSA Take advantage of the temporal variations. Dynamically adjust allocated bandwidth to the
load.
General Conditions for DSA on 2 RATs Temporal peaks located at different times A negative correlation is favorable
Drive data Lisbon urban area: GSM
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Time Variable DSA (2)
Ideal DSA : Continuous measurements of offered load. Continuous spectrum values.
In fact, DSA is discrete in time and spectrum allocation:
What is the best period of DSA operation given a traffic shape?
The minimum spectrum exchange unity is a RAT carrier. General constraints and issues:
RATs may have different carrier sizes. GSM would have to free 40 carriers to activate a new DVB-T carrier.
RAN and users harware must operate at different frequencies. (software radio)
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Time Variable DSA (3)
The time varying nature of the traffic implies the following DSA functions:
Operational steps: Find the best temporal granularity that assures
a good tracking of the demand variations. DSA interval.
Load measurements and prediction:– Load histroy.– Prediction for the next DSA interval based on the
history (e.g. regression methods). Spectrum allocation (contention and fairness
issues).
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Time varying traffic related to other tasks
Relation to the measurement campaign: Get graphical shapes of daily load variations for
different technologies in Île-de-France. Possible measurements at Base Stations?
Relation to SP3: The simulator uses individual session/call
models for the demand and traffic. The session/call models and arrival rates must
be fitted so that their aggregation gives similar temporal shapes.
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Space Variation of Spectrum Demand
Spatial Spectrum demand depends on users traffic activity on each RAT and in each area
Traffic modelling in space and measurements to be used
Macroscopic granularity: call scale, i.e., minutes
A3 A4 A5
A7A6
A2A1
DVB-T
UMTS
A3
A4
A5
No overlap
No overlap
UMTSCarrier
DVB-TCarrier
ExtraGB
MinimumGB
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Spatial Spectrum Demand Distribution
Services/Applications used are space dependent and are strongly connected to underlying RATs Recreational Areas: DVB-T, HSDPA, WiMAX Business Areas: unicast, telephony -> GSM,
UTRAN. Regional traffic models combine:
Geographical distribution of terminal and traffic density
Distribution of Applications/activities: Which application activity distribution (itself connected to RAT) for each area
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Spatial DSA Constraints
DSA areas geometry and neighbourhood constraints (coordination)
Spatial gradient: different DSA schemes between adjacent areas Guard bands should be adapted when needed Reducing cell sizes to decrease a high spatial gradient
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Spatial DSA Constraints (2)
Integrate traffic correlation between areas Integrate traffic correlation between RATs Integrate total traffic demand parameter
T(total) = Sum(T(RATi)) variability Global mean GoS should be maximized in the
whole network Each area should enhance or at least equal
FSA GoS Optimisation problem: maximising GoS gain
under all listed constraints (interference, cost, guard band, …)
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Space-Time correlation and Mobility
Geographical traffic distribution is time-dependent Combine time and regional DSA. Rush hour:
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Control and ManagementMetrics
Measurements and Metrics Implicated Network oriented: at AN devices
– Load measurements– Global performance: blocking probabilities
User oriented: DSA may be involved when a global degradation of users QoS occurs => statistics collected from users
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Control and ManagementRRM
RRM functions and RRM cooperation protocols depend on the DSA nature:
Contiguous DSA: “Control Network” for information exchange
RRM inside a RAT, carriers redistribution. Readjustement of carriers (condensing)
Interference issues.
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Cooperation between Heterogeneous RATs and Different Operators
Defining a network architecture for control and spectrum exchange
Defining appropriate protocol for the control plane Centralised, distributed architecture? Coordination between different RAT and Areas
TD: Traffic Distribution IU: Interface Unit RS: RAN Selection SM: Service Manager EO: Efficiency Optimisation
Unit TM: Traffic Measurer TP: Traffic Predictor
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Cooperation between heterogeneous RATs and Different Operators
FT, TDF Common Architecture Definition for
Operators Cooperation (broker) Cooperation Constraints and Mechanisms
between different operators and heterogeneous Systems
Spectrum Sharing Mechanisms
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Spectrum Sharing and Utilisation of Unlicensed Bands
FT, ENST, INRETS, INT Unlicensed Bands Identification and
Characterisation Analysis and Study of DSA Achievability in
Unlicensed Bands