Self-optimisa Self-optimisation in tion in futur future mobile access netw e mobile access networ orks ks Remco Litjens Senior scientist Mobile Network Optimisation 2008 November 4, 2008 TNO Information and Communication Technology Delft, The Netherlands Hôtel Palais Stéphanie, Cannes, France
OUTLINE • INTRODUCTION • DRIVERS • VISION • EXPECTED GAINS • USE CASES • CHALLENGES • WHO IS WHO? • CONCLUDING REMARKS 2 WWW.FP7-SOCRATES.EU
OUTLINE • INTRODUCTION • DRIVERS • VISION • EXPECTED GAINS • USE CASES • CHALLENGES • WHO IS WHO? • CONCLUDING REMARKS 3 WWW.FP7-SOCRATES.EU
INTRODUCTION • Current networks are largely manually operated • Separation of network planning and optimisation • (Non-)automated planning tools applied • Site selection, optimisation of radio parameters • ‘Over-abstraction’ of applied technology models • Manual configuration of sites • Radio (resource management) parameters updated weekly/monthly • Performance indicators with limited relevance • Time-intensive experiments with limited operational scope • Delayed, manual and poor handling of cell/site failures • Future wireless access networks will exhibit a significant degree of self-organisation • Self-configuration, self-optimisation, self-healing • Broad attention 3GPP, NGMN, FP7, … 4 WWW.FP7-SOCRATES.EU
OUTLINE • INTRODUCTION • DRIVERS • VISION • EXPECTED GAINS • USE CASES • CHALLENGES • WHO IS WHO? • CONCLUDING REMARKS 5 WWW.FP7-SOCRATES.EU
DRIVERS • Technogical perspective • Complexity of future/contemporary wireless access networks • Multitude of tuneable parameters with intricate dependencies • Multitude of RRM mechanisms on different time scales • Complexity is needed to maximise potential of wireless access networks • Higher operational frequencies • Multitude of cells to be managed • Growing suite of services with distinct char’tics, QoS req’ments • Heterogeneous access networks to be cooperatively managed • Common practice in network planning and optimisation → labour-intensive operations delivering suboptimal solutions! • Enabler • The multitude and technical capabilities of base stations and terminals to perform, store, process and act upon measurements increases sharply 6 WWW.FP7-SOCRATES.EU
DRIVERS • Market perspective • Increasing demand for services • Increasing diversity of services • Traffic characteristics • QoS requirements • Need to reduce time-to-market of innovative services • Reduce operational hurdles of service introduction • Pressure to remain competitive • Reduce costs (OPEX/CAPEX) • Enhance resource efficiency • Keep prices low 7 WWW.FP7-SOCRATES.EU
OUTLINE • INTRODUCTION • DRIVERS • VISION • EXPECTED GAINS • USE CASES • CHALLENGES • WHO IS WHO? • CONCLUDING REMARKS 8 WWW.FP7-SOCRATES.EU
VISION • Minimise human involvement in planning/optimisation • Significant automation of network operations • Key components • Self-configuration • Self-healing • Self-optimisation 9 WWW.FP7-SOCRATES.EU
VISION • Self-configuration • Incidental, intentional events • ‘Plug and play’ installation of new base stations or features • E.g. download of initial radio network parameters, neigh- bour list generation, trans- port network discovery and configuration, … • Self-healing • Incidental, non-intentional events • Automatic fault detection • Automatic minimisation of coverage/capacity loss in case of cell/site failures • Enhanced robustness/resilience • Alarm bells 10 WWW.FP7-SOCRATES.EU
VISION • Self-optimisation • Measurements • Gathering via terminals, eNBs, probes • Propagation, traffic, mobility aspects • Performance indicators • Continuous self-optimisation of radio parameters • In response to observed changes in conditions and/or performance • In order to provide service availability and quality targets most efficiently • Smart on-line algorithms • E.g. tilt, azimuth, power, RRM thresholds, scheduling weights, neighbour cell lists • Triggers/suggestions in case capacity expansion is unavoidable 11 WWW.FP7-SOCRATES.EU
OUTLINE • INTRODUCTION • DRIVERS • VISION • EXPECTED GAINS • USE CASES • CHALLENGES • WHO IS WHO? • CONCLUDING REMARKS 12 WWW.FP7-SOCRATES.EU
EXPECTED GAINS • OPEX reductions … • Primary objective! • Less human involvement in • Network planning/optimisation • Performance monitoring, drive testing • Troubleshooting • About 25% of OPEX is related to network operations • x00 million € savings potential per network 13 WWW.FP7-SOCRATES.EU
EXPECTED GAINS • … and/or CAPEX reductions … • Via delayed capacity expansions • Smart eNodeBs may however be more expensive • … and/or performance enhancements • Enhanced service availability, service quality 14 WWW.FP7-SOCRATES.EU
EXPECTED GAINS • … and/or CAPEX reductions … • Via delayed capacity expansions • Smart eNodeBs may however be more expensive • … and/or performance enhancements • Enhanced service availability, service quality 15 WWW.FP7-SOCRATES.EU
OUTLINE • INTRODUCTION • DRIVERS • VISION • EXPECTED GAINS • USE CASES • CHALLENGES • WHO IS WHO? • CONCLUDING REMARKS 16 WWW.FP7-SOCRATES.EU
USE CASES • Definition of use cases • To guide development of solutions • Algorithms • Performance aspects • Impact on standards and operations • To help determine requirements • Technical requirements • Business requirements • Performance • Faster roll-out of LTE networks • Complexity • Simplified operational processes • Stability/robustness • Easy deployment of new services • Timing • End user quality/cost benefits • Interaction • Architecture/scalability • Required measurements 17 WWW.FP7-SOCRATES.EU
USE CASES • Non-exhaustive use case list • Self-configuration • Self-optimisation • Automatic NCL generation • Radio network optimisation • Intell. selecting site locations • Interference coordination • Automatic generation of • Self-optimisation of physical channels default parameters for NE • RACH optimisation insertion • Self-optimisation of Home eNodeB • Network authentication • GOS/QoS-related optimisations • Hardware/capacity extension • AC/CC/PS optimisation • Link level retx scheme optimisation • Self-healing • Coverage hole detection/compensation • Cell outage prediction • Handover related optimisation • Cell outage detection • Handover parameter optimisation • Cell outage compensation • Load balancing • Neighbour cell list • Others • Reduction of energy consumption • TDD UL/DL switching point • Management of relays and repeaters • Spectrum sharing 18 WWW.FP7-SOCRATES.EU • MIMO
USE CASES AUTOMATIC NEIGHBOUR CELL LIST GENERATION EXAMPLE EXAMPLE • Self-configuration/-optimisation use case • NCL indicates potential handover target cells • Typically limited to 32 cells • Missing neighbours induces call dropping or excessive interference A: {B,C,D} • Undesired neighbours cause unnecessary measurements • Self-optimisation based on e.g. B: {A,D,E} C: {A,D} • UE’s signal strength reports • eNB scans of neighbours • Call drops, handover failures D: {A,B,C,E} • Handover stats: used neighbours • Triggers E: {B,D} • Site/cell addition • Poor performance • Periodic optimisation 19 WWW.FP7-SOCRATES.EU
USE CASES PACKET SCHEDULING OPTIMISATION EXAMPLE EXAMPLE • Self-optimisation use case • Key radio resource management mechanism in LTE • All traffic all multiplexed over shared channels • Distinct QoS requirements • Rate requirements, latency tolerance, elasticity • A typical scheduler integrates proportional fairness and deadline-based principles • With various tunable parameters, e.g. • Capacity sharing between services • Degree of proportional fairness • Subscription-based priorities • Self-optimisation based on • Observed performance or efficiency issues • Observed ‘environmental’ changes • Traffic characteristics, traffic mix, spatial distribution • User mobility • Propagation effects 20 WWW.FP7-SOCRATES.EU
USE CASES CELL OUTAGE MANAGEMENT EXAMPLE EXAMPLE • Self-healing use case • Cell outage detection • Automatic detection of failures • eNodeB failure, cell failure, physical signal/channel failure • Generate alarms for automated compensation and manual repair • Indicate location, type and urgency of outage • Minimise detection time, probability of missed detection and false alarm • Measurements • UE measurement reports: pilots, interference levels • eNB hard/software reports, carried load, call drops, … 21 WWW.FP7-SOCRATES.EU
USE CASES CELL OUTAGE MANAGEMENT EXAMPLE EXAMPLE • Self-healing use case • Cell outage compensation • Automatic compensation of failures • Optimise ‘regional’ coverage, capacity and/or quality • Control parameters • Power settings • Downtilt, azimuth(?) • Intra/inter-RAT handover parameters, load balancing • Neighbour cell lists 22 WWW.FP7-SOCRATES.EU
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