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Self Configuring Networks
Flexible spectrum sharing for
Home Base Station
in
Next generation Mobile Telecommunication Systems
(VDA - VI)
1
Project Investigator
Dr. Suvra Sekhar Das
&
Prabhu ChandharResearch Associate
G.S.Sanyal School of Telecommunications
IIT Kharagpur
03/06/2010
What is the objective of the project ?
Objective: as mentioned in the project proposal:
• To provide guidelines for HeNB (Femtocell) improved deployment of HBs
• To develop methods for improved deployment for self organized network deployment
Expected Deliverables:•Signaling protocols to enable Self Configuration of HBS using concepts of cognitive radio and spectrum sharing •Physical Layer algorithms for enabling HBS•Regulation and policies for HBS. •Contribution to Standards•IP generation•Algorithms and Procedures for HBS
03/06/2010
Introduction:
Femtocells --> Data access points installed by home users
Benefits:
For users
Provides better coverage
• Provides high data rate
For operators Increased network capacity
Reduced traffic in macro cell
Data offloading
• Lower capital cost
Technical Issues:• Interference
• Access control
• Frequent hand over
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Picture source: www.femtoforum.org
17 % of total users are in outage21 % of outdoor users are in outage21 % of indoor users are in outage
What is the big Picture ?
3GPP Long Term Evolution (Advanced) includes Femto Cells
03/06/2010
Introduction:
Femtocells --> Data access points installed by home users
Benefits:
For users
Provides better coverage
• Provides high data rate
For operators Increased network capacity
Reduced traffic in macro cell
Data offloading
• Lower capital cost
Technical Issues:• Interference
• Access control
• Frequent hand over
4
Picture source: www.femtoforum.org
17 % of total users < 0 dB21 % of outdoor users < 0 dB21 % of indoor users < 0 dB
What is the big Picture ?
3GPP Long Term Evolution (Advanced) includes Femto Cells
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•Deployment Guidelines
•Capacity Estimates
•Enhancements to standards as per requirement of deployment by Operators
•Tell us the problems you foresee
• AND OF VALUE TO VODAFONE
Deployment configurations:
Channel Assignment:
• Dedicated channel assignment
• Co-channel assignment
Access method:
• Open access
• Closed access
What is the value for the Industry ?
Who is the prime customer / recipient of the work?
• INDUSTRY (Hopefully Vodafone ! )
• Guidelines for deployment of future networks
• (currently dependent only on Equipment Manufacturers)
• Network capacity Estimation
• Performance evaluation due to perturbation of the system
• Network optimization
• Enhancement of the standards are per requirement of operators
• Gov. of India through proper representation
• Policy Making
• TCOE (India , VEICET)
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03/06/2010
Project plan:
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Jan 2010-May 2010
May 2010
June 2010 -- Onwards
What is the route / plan to achieve the objectives of the project &
what are the key milestones / deliverables ?
03/06/2010
SINR & Capacity Analysis
Downlink
Uplink
Enterprise femtocells
Capacity improvement
Self configuration and self optimization
Solution for Hand Over issues
RRM Techniques
Adaptive power control
MIMO processing
Randomizing frequency use
Deduction based resource allocation
Collaborative resource sharing
Creating Model for Capacity Analysis
Signalling issues
Idle state
Active state
Done
Ongoing
To Be Done
Project plan:
Need Manpower
Jan 2010 - May 2010
June 2010-Dec 2010
What is the route / plan to achieve the objectives of the project &
what are the key milestones / deliverables ?
03/06/2010
Status of the work:
Work Done: (Jan 2010- May 2010) Downlink
Cellular and Femto Layout models
Channel Model – As per ITU
Non – Over-lapped Femto Cells
Closed Access
SINR interference Analysis (Effect of )
increasing the Femto Cell Density increasing the Load factor in each of the Femto Cells Femtos close to the Macro Base Station Femtos close to the Cell Edge
Capacity Analysis
Framework for fast analysis of effect on capacity loss due to femtos Different Scheduling Algorithms
RR, Max C/I, PF and CF for best effort service Open Access
All cases as above
Enterprise femto Cells
Some Early Guidelines
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What is the route / plan to achieve the objectives of the project &
what are the key milestones / deliverables ?
03/06/2010
Need Inputs and discussion On:
Work To Be Done:
Uplink (June 2010 Onwards)
Channel Model
Analysis Framework
Analytical and Simulation
SINR and Capacity Analysis
Interference Management (Covers Enterprise femto)
by RRA techniques (Jul 2010 – Dec 2010) : Spectrum Sharing
MIMO signal processing in femto-cells
Self Configuration of Radio Parameters
Coordinated Scheduling between Femtos
Femto and Macro
Contribution to Deployment
Contribution to Standards
Solution for signaling issues
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03/06/2010
Results
What is the status in relation to the plan ?
03/06/2010 12
Simulation Parameters
Simulation Parameters
Cell layout 19 cells, 3 sectors, Wrap around
Scenario Urban Micro
Inter Site Distance 200 m
Carrier frequency 2 GHz
Macrocell Transmit power 41 dBm
Bandwidth 10 MHz
Pathloss model ITU-R M2135
% of outdoor users 50
% of indoor users 50
Femtocell Transmit power 20 dBm
Femtocell Access mode Closed access, Open access
03/06/2010
Simulation layout:
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03/06/2010
Downlink SINR (Calibrated with 3GPP Evaluation Results):
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03/06/2010
Spatial capacity distribution:
03/06/2010
Macrocell performance with different femtocell locations:
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28/03/2010
Macrocell performance with different femtocell densities:
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28/03/2010
Macrocell performance for varying load in femtocells:
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03/06/2010
Cell edge user performance with Closed and Open access:
03/06/2010
Cell edge user performance with Closed and Open access:
03/06/2010
Cell edge throughput performnace for varying load in HeNB -Closed access:
03/06/2010
Cell edge throughput performnace for varying HeNB density -Closed access & Open access:
03/06/2010
Closed Access and Open Access - Comparison:
Number of femtos(100% load)
Closed access Open access
10 11.2 dB 3 dB
20 14.2 dB 4.9 dB
50 18.3 dB 7.2 dB
80 20.4 dB 8.72 dB
SINR loss for cell edge users:
03/06/2010
Throughput comparison without SchedulingClosed Access and Open Access - Comparison:
Number of femtos(100% load)
Closed access Open access
10 90 % 39 %
20 95 % 58 %
50 96.5 % 76 %
80 98.5 % 81 %
% Throughput loss for cell edge users:
% Mean throughput loss in macro cell:
Number of femtos(100% load)
Closed access Open access
10 55 % 44 %
20 70 % 55 %
50 75 % 73 %
80 88 % 82 %
CLOSED ACCESS Throughput Considering Capacity Fair – Proportional Fair:
Number of femtos(100% load)
CF PF
10 64 % 75 %
20 71 % 71 %
50 82 % 82 %
80 82.3 % 82.3 %
% Throughput loss for cell edge users:
Number of femtos(100% load)
CF PF
10 12 % 31 %
20 36 % 41 %
50 56 % 46 %
80 64 % 54 %
% Mean throughput loss for macrocell users:
Similar results for OPEN ACCESS Mode
Immediate Next evaluation on Impact on throughput
• Fix the total number of users in a Cell,
– Move certain users under the influence of HeNB
– Remaining Users under Macro eNB
– Now use Packet Scheduler algorithms for the remaining users in Macro Cell
• Compare Performance (throughput) Loss / Improvement
ENTERPRISE FEMTO CELLS
03/06/2010
Enterprise femtocell:
Deployment used in Analysis
03/06/2010
Downlink SINR – Enterprise femtocell:
03/06/2010
User Throughput (no Scheduling) – Enterprise femtocell:
03/06/2010
Conclusion:
• Downlink co-existence between HeNBs and macro UEs has been studied bySINR & capacity analysis.
With closed access, UEs served by HNBs experience high data rates.However the UEs served Macro base station are significantly degraded.Interference mitigation techniques should be used to improve SNIR of themacro served UEs.
• Results shows that the macro UEs at the cell edge performnace can beimproved by,
allowing macro UEs to connect to the HeNBs (Open access) limiting the maximum output power of HeNBs
Open access mode reduces the interference problem but other issues(frequent hand over) to be solved.
03/06/2010
Thank You
33
03/06/2010
Capacity Analysis By
RRA techniques
03/06/2010
Macrocell user throughput performanceat cell center and cell edge:
40 femtos20 dBm transmit powerFull load
03/06/2010
Cell throughput – RRA Techniques:
03/06/2010
Cell throughput Round Robin Scheduling:
03/06/2010
Cell throughput - Proportional Fair Scheduling:
03/06/2010
Cell throughput – Max(C/I) scheduling:
