Efficient mobile backhaul
Download as PPTX, PDF1 like4,579 views
The document discusses the efficiency challenges in mobile backhaul, highlighting that dedicated backhaul links often operate at only 25% efficiency due to bursty traffic patterns and low correlation in demand across nodes. It suggests that utilizing a point-to-multipoint architecture can optimize resource usage by sharing bandwidth rather than using dedicated links, resulting in significant savings in spectrum and power. The findings indicate that adopting this approach can enhance overall network performance and reduce operational costs.
Efficient mobile backhaul
- 1. www.cbnl.com Next generation thinking Efficient Mobile Backhaul John Naylon Mobile World Congress, Barcelona - 29 February 2012
- 2. The Problem Space: Mobile Backhaul • Need to connect mobile base stations 100% (node Bs) to core network − Could use copper, fibre or microwave radio − Microwave is the dominant choice 75% − ~0.5M new microwave backhaul connections per annum 50% 25% 0% '08 '09 '10 '11 '12 '13 '14 '15 Microwave Fibre Copper Worldwide Mobile Backhaul Connections Source: Infonetics Research www.cbnl.com Commercial in confidence 2
- 3. The Problem Space: Mobile Backhaul Traffic Properties Sample backhaul demands for 3 tri-cell node Bs in a live, busy HSPA+ network: Mbps Can we exploit statistical properties of this data to make our backhaul more efficient? www.cbnl.com Commercial in confidence 3
- 4. First Property: Data is Bursty • Data is bursty, i.e. has sharp transient peaks and a much lower mean − This characteristic is driven by user and application behaviour − Burstiness still present when traffic is aggregated within a node B/eNode B Mbps Handset traffic (one iPhone 4) Peak: 11.44 Mbps Mean: 0.14 Mbps Ratio: 79.20 Mbps Handset traffic (10 Devices) Peak: 12.07 Mbps Mean: 1.44 Mbps Ratio: 8.37 Mbps Node B backhaul traffic Peak: 23.31 Mbps Mean: 5.54 Mbps Ratio: 4.20 Mbps www.cbnl.com Commercial in confidence 4
- 5. First Property: Data is Bursty (2) • Network-wide average of peak-to-mean ratio is approximately 4:1 in this HSPA+ example network − Major implication for efficiency since it is mandatory to provision backhaul that can accommodate the offered peak load − However if we have a dedicated link the mean utilisation de facto cannot be greater than the mean offered load − Therefore the mean utilisation will be approximately in the ratio of 1:4 to the peak, i.e. approximately 25% − So the data’s properties mean that: Dedicated backhaul links are 75% idle! www.cbnl.com Commercial in confidence 5
- 6. Second Property: Peak Demand is not Synchronised • Peak bandwidth demand does not occur simultaneously at adjacent node Bs − Peaks are of short duration (seconds, not hours like the daily ‘swells’) − Peaks arise from random, independent actions of network end users Mbps www.cbnl.com Commercial in confidence 6
- 7. Second Property: Peak Demand is not Synchronised (2) • Peak bandwidth demand does not occur simultaneously at adjacent node Bs − Peaks are of short duration (seconds, not hours like the daily ‘swells’) − Peaks arise from random, independent actions of network end users − In the studied HSPA+ network, average cross-correlation factor of pairs of node Bs in geographical proximity is 0.16 indicating very weak correlation (network-wide correlation is even lower, at 0.06) www.cbnl.com Commercial in confidence 7
- 8. Using These Properties to Improve Backhaul Efficiency • Non-uniform data rate and absence of correlation lets us share, or multiplex, resources instead of using dedicated resources (just as we do in the RAN) Point-to-Point Point-to-Multipoint Dedicated radio + Shared radio + Dedicated RF antenna per link Shared RF channel antenna for all links channel per link for all links www.cbnl.com Commercial in confidence 8
- 9. Savings from Point-to-Multipoint Architecture: Spectrum • We examine measured backhaul profiles from a group of eight node Bs − Live network, large middle-eastern operator, heavy data usage − HSPA+ tri-cellular node Bs − Theoretical maximum throughput 64.8Mbps per site • Consider the amount of spectrum needed for each of the two topologies − Use the bare minimum of spectrum to carry exact data profile (no ‘headroom’) www.cbnl.com Commercial in confidence 9
- 10. Savings from Point-to-Multipoint Architecture: Spectrum Peak: 11.29 Mbps Mean: 2.47 Mbps Point-to-Point Microwave Radio, Star Topology Point-to-Multipoint Microwave Radio Cumulative Peak: 11.3 Mbps Cumulative Peak: 11.3 Mbps Cumulative Mean: 2.5 Mbps Cumulative Mean: 2.5 Mbps www.cbnl.com Commercial in confidence 10
- 11. Savings from Point-to-Multipoint Architecture: Spectrum Peak: 15.12 Mbps Mean: 4.18 Mbps Point-to-Point Microwave Radio, Star Topology Point-to-Multipoint Microwave Radio Cumulative Peak: 26.4 Mbps Cumulative Peak: 19.5 Mbps Cumulative Mean: 6.6 Mbps Cumulative Mean: 6.6 Mbps www.cbnl.com Commercial in confidence 11
- 12. Savings from Point-to-Multipoint Architecture: Spectrum Peak: 17.45 Mbps Mean: 7.61 Mbps Point-to-Point Microwave Radio, Star Topology Point-to-Multipoint Microwave Radio Cumulative Peak: 43.9 Mbps Cumulative Peak: 30.9 Mbps Cumulative Mean: 14.2 Mbps Cumulative Mean: 14.2 Mbps www.cbnl.com Commercial in confidence 12
- 13. Savings from Point-to-Multipoint Architecture: Spectrum Peak: 14.51 Mbps Mean: 4.64 Mbps Point-to-Point Microwave Radio, Star Topology Point-to-Multipoint Microwave Radio Cumulative Peak: 58.4 Mbps Cumulative Peak: 42.9 Mbps Cumulative Mean: 18.9 Mbps Cumulative Mean: 18.9 Mbps www.cbnl.com Commercial in confidence 13
- 14. Savings from Point-to-Multipoint Architecture: Spectrum Peak: 15.83 Mbps Mean: 5.69 Mbps Point-to-Point Microwave Radio, Star Topology Point-to-Multipoint Microwave Radio Cumulative Peak: 74.2 Mbps Cumulative Peak: 51.7 Mbps Cumulative Mean: 24.6 Mbps Cumulative Mean: 24.6 Mbps www.cbnl.com Commercial in confidence 14
- 15. Savings from Point-to-Multipoint Architecture: Spectrum Peak: 17.85 Mbps Mean: 6.67 Mbps Point-to-Point Microwave Radio, Star Topology Point-to-Multipoint Microwave Radio Cumulative Peak: 92.0 Mbps Cumulative Peak: 60.2 Mbps Cumulative Mean: 31.2 Mbps Cumulative Mean: 31.2 Mbps www.cbnl.com Commercial in confidence 15
- 16. Savings from Point-to-Multipoint Architecture: Spectrum Peak: 15.98 Mbps Mean: 2.93 Mbps Point-to-Point Microwave Radio, Star Topology Point-to-Multipoint Microwave Radio Cumulative Peak: 108.0 Mbps Cumulative Peak: 67.8 Mbps Cumulative Mean: 34.2 Mbps Cumulative Mean: 34.2 Mbps www.cbnl.com Commercial in confidence 16
- 17. Savings from Point-to-Multipoint Architecture: Spectrum Peak: 15.18 Mbps Mean: 5.49 Mbps Point-to-Point Microwave Radio, Star Topology Point-to-Multipoint Microwave Radio Cumulative Peak: 123.2 Mbps Cumulative Peak: 77.9 Mbps Cumulative Mean: 39.7 Mbps Cumulative Mean: 39.7 Mbps www.cbnl.com Commercial in confidence 17
- 18. Savings from Point-to-Multipoint Architecture: Spectrum Point-to-Point Point-to-Multipoint Cumulative Peak: 123.2 Mbps Cumulative Mean: 39.7 Mbps Cumulative Peak: 77.9 Mbps Cumulative Mean: 39.7 Mbps • Spectrum required = 15.4 MHz • Spectrum required = 9.7 MHz * 256-QAM assumed www.cbnl.com Commercial in confidence 18
- 19. Savings from Point-to-Multipoint Architecture: Spectrum Point-to-Point Point-to-Multipoint Cumulative Peak: 123.2 Mbps Cumulative Mean: 39.7 Mbps Cumulative Peak: 77.9 Mbps Cumulative Mean: 39.7 Mbps • Efficiency = 32.2% • Efficiency = 51.0% www.cbnl.com Commercial in confidence 19
- 20. Savings from Point-to-Multipoint Architecture: Power Point-to-Point 37W per radio, 2 radios per link 74W per link 40% power saving per link www.cbnl.com Commercial in confidence * Figures reflect market leaders in both categories 20
- 21. Conclusions • Mobile broadband backhaul traffic • Dedicated backhaul links operate at has specific properties we can exploit a very low efficiency: ~25% (!!) to design more efficient backhaul something blah something different networks something • Point-to-multipoint architecture • Less equipment deployed means dramatically improves spectral additional environmental, capex efficiency and power efficiency and opex benefits per link VectaStar from Cambridge Broadband Networks is the market leader in point-to-multipoint www.cbnl.com 21