IEEE Comm. Magazine, Jan. 2010 Student: Mike Advisor: J.h Chen

1. On Femto Deployment Architecture and Macrocell Offloading Benefits in Joint Macro-Femto Deployments IEEE Comm. Magazine, Jan. 2010 Student:Mike Advisor: J.h Chen

2. Outline • Motivation • Introduction • Femtocell Deployment Architectures/Scenarios • QoS Level Settings • Degradation • Assessment of Macro-Offloading Benefits • Main Contribution • UMTS Case Study • WiMAX Case Study • Conclusion

3. Motivation • Personal • Macro handover to femto • Understand femto • Femto system settings • Deployment system design • Bandwidth sparing • Author • Analysis of joint deployment • Potential enhancement in quality of radio signals • Macro network • Joint macro-femto deployment • Acquire better data rate (throughput) • Include more users

4. Introduction • Femtocells • Low-power low-cost user-deployed base stations • Provide high quality cellular service • Residential or enterprise • Extensive auto-configuration • Self-optimization capability to enable simple plug-and-play deployment • Automatically integrate in macro-cellular network • Reduce traffic of macro-cellular network • Network operator as capital expenditures (CAPEX)

5. Femtocell Deployment Architectures/Scenario • Standalone femtocell • Integrated femto • Femtocell, home router and DSL modem are built within same physical device • QoS level guarantee settings

6. QoS Level Settings • Common Wireless and Wireline Operator • Same operator owns network path • From femtocell to femto gateway • Operator can manage wireline access network to guarantee QoS required for femto service • QoS statically allocate bandwidth to femto traffic • Sufficient for low-bandwidth • Voice, multimedia traffic, and dynamic bandwidth • QoS management is necessary to achieve efficient network capacity usage for QoS-oriented wireless traffic with higher bandwidth requirements (Mobile video)

7. QoS Level Settings • Separate wireless and wireline operators with a service level agreement • Wireline access provider different from wireless operator • Service level agreement (SLA) • For femtocell QoS within access network • Wireless and wireline operator with no SLAs • No QoS guarantee • All service served as best effort • Current over-the-top VoIP services • Access network < Network Capacity  Good QoS • Access network > Network Capacity  Degradation

8. Degradation • Femtocell placement • Femto placed between Router and DSL modem • Femtocell provide its own traffic • Bottleneck • Home to DSL access multiplexer (DSLAM) • Femtocell can shape traffic to fit access link capacity • Need to keep track of maximum available bandwidth • Handover to macro network • Measure available bandwidth toward femto gateway • Available bandwidth < threshold • Macro network handover to femto

9. Degradation • Throttlingfemto data traffic • Voice packets are given priority over data packets • Femtocell data packets cause extra delay at bottleneck • Solved by throttling down femtocell data traffic when voice quality degradate • QoS-aware femto gateway selection • Multiple femto gateways available, femtocell can be assigned to gateway with best path to femtocell • Femto gateway change dynamically • Don’t work well when gateway is congested

10. Assessment of Macro-Offloading Benefits • User in buildings • Propagation losses are more significant • Result in poorer QoS in indoor • High impact on type of environment • Deployment of femto • Improve usage of macrocell network

11. Main Contribution • Analysis of qualitative and quantitative macrocell offloading benefits • Under which conditions can the macrocell capacity be increased through offloading offloading of indoor users to femtocells • By how much can be macrocell capacity be increased by increased by increasing the fraction of served indoor users through femtocells

12. UMTS Case Study (Simulation Scenario) • Monitor the quantify the macrocell offloading gains • Simulation • 7 macrocells with three sectors • Total of 5000 houses placed in uniform distribution • Two different types of house • Detached house and terraced house • Co-channel is possible with only minimal interference impact on macrocellular network • System-level simulations perform to derive the resulting signal-to-interference-plus noise ratio (SINR) • Different macrocell transmit signal-to-noise ration (SNR) from 0 to 30 dB

13. UMTS Case Study (Graphic)

14. UMTS Case Study (Mean throughput) • Outdoor throughput reach a threshold at 10dB • Indoor throughput reach a threshold at 25 dB • Caused by interference

15. UMTS Case Study (Offload capacity gain) • Offloading gain disappear when SNR exceed 25dB

16. WiMAXCase Study • Performed a quantitative assessment of macro offloading gain • Simulation • Multicell simulation • Starting by using all users served by macro network • Comparing 6 scenarios • 10 users per sector (50% uses indoor)

17. Conclusion • Advantage • Explaining the deployment of femtocell • Monitored throughput of performance • Disadvantage • No particular handover is monitored • Femto and base station share same bandwidth • I need to make it standalone femto