Data Centric Backhaul

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Data Centric Backhaul

  1. 1. www.cbnl.comNext generation thinkingData Centric BackhaulJohn NaylonOctober 2011
  2. 2. Contents• The quality of experience problem space• Architectures compared• Applicability to next generation networks• Conclusionswww.cbnl.com 2
  3. 3. The Problem Space: Data is Dominant• Mobile traffic is now dominated by data − Data overtook voice in 2009 − Data volume is growing exponentially• It costs the same to backhaul a byte of voice as a byte of data − But user price for a data byte is much lower• Efficient data backhaul is a critical issue for mobile operators today Mobile Data Growth, Actual and Forecast Sources: Cisco VNIwww.cbnl.com 3
  4. 4. Smartphones, Tablets and Cloud Apps are the Norm • 78% of tablets shipped will have a 3G/4G modem in 2015 • By 2015, 65% of e-readers worldwide will ship with an embedded 3G/4G modem. • Approximately 16 million portable and computing devices shipped with 3G/4G cellular connectivity in 2010 • 70% of the companies currently using cloud- based services plan to move additional tools to the cloud in the next 12 months • 63% of cloud users say being on the cloud has decreased performance issues • SandHill survey of 500 IT decision-makers; 50% say their primary reason for adopting cloud applications is business agility. Source: Gartner, In-Stat 4www.cbnl.com 3rd party logo’s and trademarks acknowledged
  5. 5. End of the PC?iPhone was an awakening ...all it needed was a bigger screen• By the time we got to the iPhone 3Gs, • ...And the iPad was people realised they were spending born. As more people more time on their phones doing more buy iPhones (18m per than they ever dreamt! quarter), more people will buy iPads!The PC replaced the typewriter Cloud OS and apps are next• It took PC’s 15 years to replace • Chrome OS has almost no identifiable typewriters... now we use several need for anything but minimal amounts of local storage. Cloud computing demands computers each day, some are high performance networks to deliver a stationary, others are mobile, most good experience are embedded. Networks will enable itwww.cbnl.com
  6. 6. The Problem Space: Wireless dominant in the last mile• Need to connect mobile base stations (node Bs) to core network 100% − Could use copper, fibre or microwave radio − Microwave is the dominant choice − Circa 500k microwave backhaul connections 75% per year 50% 25% 0% 08 09 10 11 12 13 14 15 Year Microwave Fibre Copper Worldwide Installed Mobile Backhaul Connections Source: Infonetics Researchwww.cbnl.com 6
  7. 7. The Problem Space: Shape of Data• Data is “bursty”, uncorrelated, asymmetric − This characteristic is driven by user and application behaviour − Burstiness still present when traffic is aggregated within a node B 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 Mbpswww.cbnl.com 7
  8. 8. The Problem Space: Peak to Mean Ratio• RAN air interfaces are becoming more sophisticated, with larger * carriers − Potential peak upload and download speeds increase• Peak-to-mean ratio of backhaul traffic averages 3.9:1 across a broad range of peak speeds − We must provision at least the peak, and the mean utilisation of the link is at most equal to the mean offered load − Therefore mean utilisation of point-to- point links to node Bs limited to ~25% − To improve on this utilisation, we must use PMP to take advantage of other properties of the traffic (see section 2) * HSPA+ 21.6 tri-cellular nodeBswww.cbnl.com 8
  9. 9. Challenge: Deliver a superior customer experience• Changing customer behaviours and devices demand high peak download speeds, low latency• Cloud-based applications and storage increases pressure on network performance• Backhaul solutions need to be high capacity and low latency to retain customers and low opex to deliver business casewww.cbnl.com Commercial in confidence 9
  10. 10. Contents• The quality of experience problem space• Architectures compared• Applicability to next generation networks• Conclusionswww.cbnl.com Commercial in confidence 10
  11. 11. Architecture 1: Point-to-Point Microwave Radio, Star Topology• The most common microwave topology in use today − For N links, 2N radios − Dedicated RF channel for each node B served − Circuit-switched architecture is well-suited to constant bit rate traffic − Conventional and E-Band frequencieswww.cbnl.com 11
  12. 12. Architecture 2: Point-to-Multipoint Microwave Radio• The fastest growing microwave topology today − For N links, N+1 radios − Shared RF channel amongst all node Bs served − Packet-switched architecture is well-suited to variable bit rate (bursty) traffic − Well-suited to dense environmentswww.cbnl.com 12
  13. 13. Comparison: Installation and Maintenance Point-to-Point Point-to-Multipoint 2 ODUs per link 1 hub ODU plus 1 RT per link 2 truck rolls per link added 1 truck roll per link added 2 antenna rentals per link 1 hub site rental plus 1 per link 2 units power per link 1 unit power per hub plus 1 per link • 16 ODUs/truck rolls/antennas • 9 ODUs/truck rolls/antennas • 16 units of power consumption • 9 units of power consumptionwww.cbnl.com 13
  14. 14. Comparative Case Study• We examine measured backhaul profiles from a group of eight node Bs − Live network, large middle-eastern operator, heavy data usage − HSPA+ 21.6Mb/s tri-cellular node Bs − Theoretical maximum throughput 64.8Mbp/s 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 14
  15. 15. Comparison: Spectrum Required 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 in both caseswww.cbnl.com 15
  16. 16. Comparison: Channel Utilisation 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 16
  17. 17. Contents• The quality of experience problem space• Architectures compared• Applicability to next generation networks• Conclusionswww.cbnl.com 17
  18. 18. Backhaul for LTE•www.cbnl.com 18
  19. 19. LTE deployments will be macro and small cells• Demand for mobile traffic is increasing on average by about 100% per annum − So in the next 5 years we expect growth of about 20—40• Capacity is provided by network operators using the following parameters: Capacity = Spectrum Mean Spectral Efficiency Site Density• In the next 5 years: − Spectrum will almost double = 2 − 3G and 4G technology will roughly double mean spectral efficiency = 2 − This gives a capacity gain per site of = 4 − The only tool left in the box is site density and therefore I need = 5—10 higher site density to give the necessary result of network capacity = 20—40www.cbnl.com 19
  20. 20. PMP Advantages Increase with Site Density: Efficiency• PMP advantages increase as the RAN gets denser − More sources in a PMP sector results in more statistical multiplexing gain − Measured results from 922 node Bs backhauled across VectaStar PMP − Live network, HSPA+ 21Mpbs, very heavy data usagewww.cbnl.com 20
  21. 21. Comparison: Installation and Maintenance Point-to-Point Point-to-Multipoint 2 ODUs per link 1 hub ODU plus 1 RT per link 2 truck rolls per link added 1 truck roll per link added 2 antenna rentals per link 1 hub site rental plus 1 per link 2 units power per link 1 unit power per hub plus 1 per link • 16 ODUs/truck rolls/antennas • 9 ODUs/truck rolls/antennas • 16 units of power consumption • 9 units of power consumption At 8 Links = PMP Saving of 7 ‘units’www.cbnl.com 21
  22. 22. PMP Advantages Increase with Site Density: CAPEX and OPEX Point-to-Point Point-to-Multipoint 2 ODUs per link 3 hub ODUs plus 1 RT per link 2 truck rolls per link added 1 truck roll per link added 2 antenna rentals per link 3 hub site rental plus 1 per link 2 units power per link 3 unit power per hub plus 1 per link • 160 ODUs/truck rolls/antennas • 83 ODUs/truck rolls/antennas • 160 units of power consumption • 83 units of power consumption At 80 Links = PMP Saving of 77 ‘units’www.cbnl.com 22
  23. 23. Another Dimension: LOS or NLOSRequirement: Capacity Coverage Aggregating 10 cells to a PoP Cells in cluttered locations requires 10 mean cell capacity Uncertain LOS to PoPsImplications: High capacity and NLOS capability are mutually exclusive requirementswww.cbnl.com 23
  24. 24. Contents• The quality of experience problem space• Architectures compared• Applicability to next generation networks• Conclusionswww.cbnl.com 24
  25. 25. Summary• Data is bursty, uncorrelated, asymmetric and growing like crazy − Not easy to backhaul efficiently• Point-to-point microwave is fundamentally a circuit switched architecture − Packet data does not map onto circuits well (!) − Utilisation of the average point-to-point link backhauling mobile data is ~25%• Point-to-multipoint microwave provides true packet switching and: − The same user experience − More efficient utilisation of spectrum − Less equipment to install and maintain• Point-to-multipoint advantages are increasing with current RAN trends − Higher peak speeds imply better statistical multiplexing gain − Capex and Opex advantages scale with network densitywww.cbnl.com 25

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