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Master’s Thesis Seminar. Backhaul Transport Technologies for Broadband Wireless Access. Pasi Kolkkala 2.11.2009. Introduction. Main infrastructure for mobile backhaul has been TDM (E1, PDH microwave, etc.) Good for speech but bad for packet data
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Master’s Thesis Seminar Backhaul Transport Technologies for Broadband Wireless Access Pasi Kolkkala 2.11.2009
Introduction • Main infrastructure for mobile backhaul has been TDM (E1, PDH microwave, etc.) • Good for speech but bad for packet data • HSPA & LTE require much more capacity from backhaul (some say up to 1 Gbps!) • Complexity of available options • Packet based backhaul
Objectives of this Thesis • Compare various physical media based on their capacity and reach • Apply provider bridging Carrier Ethernet on a backhaul network • Construct a step-by-step technology selection process
Transmission technologiesfor backhaul • Synchronous transport • PDH, SDH, Next Generation SDH • OTN, GFP, VCAT, LCAS
Transmission technologiesfor backhaul • PON (Passive Optical Network) • APON, BPON, EPON, GPON, … • Packet based RAN
850 nm optical signal loss due to weather (note the logarithmic scale) dB loss/km 100 Relative transmission distance 10 15 m 65 m 190 m 400 m 1 km 2 km 4 km 17 km 40 km 1 0.1 Densefog Thickfog Moderatefog Lightfog Thinfog Heavyrain Moderaterain Lightrain Drizzle Veryclear Transmission technologiesfor backhaul • Wireless transmission • Microwave (adaptive modulation, mm-wave) • Free Space Optical (line-of-sight operation)
Transmission technologiesfor backhaul • How about native Ethernet? • Ethernet in the First Mile • VDSL2, enhanced SHDSL • Aggregation of multiple pairs 200 150 Mbps 100 50 0 500 1000 1500 Distance (m) Downlink transmission Uplink transmission
Carrier Ethernet • Metro Ethernet Forum • Pseudowires • MPLS • Provider bridging • Q-in-Q • MAC-in-MAC • PBB-TE • GMPLS for path provisioning
Backhaul designer toolbox • Hybrid backhaul • Partially meshed networks • Synchronization over Ethernet
Selection of optimal backhaul Questions • What is the currently needed amount of capacity for this backhaul? • What is the distance to the nearest fibre network point-of-presence? • How much scalability is expected from the backhaul in the future? • What level of reliability is required from the backhaul connection? • How soon is the upgraded backhaul deployment expected to be completed? • What level of resource sharing is going to be done with other operators (base station tower, backhaul link, radio access network)? • Is interoperability with existing SDH based OAM systems crucial? • Is the quality of available synchronization over Ethernetsolutions sufficient?
Selection of optimal backhaul Physical medium selection Copper FSO Microwave Fiber Transport capacity Fair Good Good Excellent Transmission distance Low Low Good Excellent Data rate scalability Fair Good* Good* Excellent Reliability Fair Low Fair Excellent Completion schedule Very fast Fast Fast Slow * Wireless transmission is seeing fast paced development which promises good scalability for the future
SDH switching Carrier Ethernet Interoperability with existing management systems Very good in case large existing MSPP install base Low, may need separate management systems Support for network synchronization Inherently good and proven Under standardization and still unproven Support for complex Ethernet switched networks Low, although this depends on specific vendor systems High, depends largely on the level of personnel competence Operation expertise compared to circuit switched networks Similar, only evolutionary new features of NG-SDH (OTN, VCAT, LCAS, ...) Different, requires packet switching knowhow(except for PBB-TE) Selection of optimal backhaul Transport technology selection
Conclusions • Fiber, enhanced microwave, FSO and VDSL2 provide needed bandwidth • Optimal solution is the result of • Interoperability between different vendors • Low cost future upgrades of hardware • Price negotiations, etc… • SDH still has it’s place in future backhaul • Ethernet evolution makes it a valid option in the near future • With a lower cost than SDH