lecture lifi.pdf
- 1. Overview • This Lecture – LiFi – Network on Chips – Quantum network 1
- 2. Overview • This Lecture – LiFi • Introduction of LiFi • Potential Applications • Challenging Problems – Network on Chips – Quantum network 2
- 3. • Optical Wireless Communication(OWC) 3 Optical Communications: The Backbone of Telecommunications Optical fibers around the world Introduction of LiFi
- 4. Introduction of LiFi • Optical Wireless Communication(OWC) 4 Wireless Communications: The most common wireless technologies use radio waves (Wifi, Cellular network)
- 5. • Optical Wireless Communication(OWC) – a form of optical communication in which unguided visible, infrared (IR), or ultraviolet (UV) light is used to carry a signal 5 Introduction of LiFi
- 6. • Visible light communications (VLC) – Li-Fi ----Light Fidelity, Prof. Harald Haas during his TED Global talk, 2011 (https://www.youtube.com/watch?v=ujO3hq0_tJ0) – a light-based Wi-Fi, uses LED light instead of radio waves to transmit information. 6 Introduction of LiFi
- 7. • Switching bulbs on and off within nanoseconds • Switching on is a logic al ‘1’, switching it off is a logical ‘0’, so fast that human eye doesn’t notice (thousands of times per second) • A demo of “Wi-fi makes room for Li-fi” (https://www.youtube.com/watch?v=trYBogpHHGY) 7 Introduction of LiFi
- 8. • Li-Fi uses LED lamps that can light a room as well as transmit and receive information. (https://www.youtube.com/watch?v=AKvvEqm9Nv4) 8 http://phys.org/news/2012-10-li-fi-edinburgh-prof-seeds.html Introduction of LiFi
- 9. Introduction of LiFi § Advantages Ø Safe for health Ø Secure Ø No interference on radio wave signals Ø High speed (>10 Gbps, meaning one can download a full high- definition film in just 30 seconds )
- 10. Introduction of LiFi § Disadvantages Ø Li-Fi doesn’t work in the dark Ø cannot move to other rooms unless there are wired bulbs too Ø low-mobility Ø small-coverage
- 12. Overview • This Lecture – LiFi • Introduction of LiFi • Potential Applications • Challenging Problems – Network on Chips – Quantum network 12
- 13. Potential Applications • LiFi can provide network access at home, office, shopping center, plane, hospital, convention centers • A demo of VLC wireless LAN system (https://www.youtube.com/watch?v=GH-xnS8yG8M) 13
- 14. 14 n WiFi Spectrum Relief - Providing additional bandwidth in environments where licensed and/or unlicensed communication bands are congested (complementary to WiFi) Potential Applications
- 15. 15 n Smart Home Network – Enabling smart domestic/industrial lighting; home wireless communication including media streaming and internet access Potential Applications
- 16. 16 n Commercial Aviation – Enabling wireless data communications such as in-flight entertainment and personal communications Potential Applications
- 17. 17 n Hazardous Environments- Enabling data communications in environments where RF is not available, such as oil & gas, petrochemicals and mining Potential Applications
- 18. 18 n Vehicles & Transportation: Street lamps, signage and traffic signals are also moving to LED. This can be used for vehicle-to-vehicle and vehicle-to- roadside communications. This can be applied for road safety and traffic management. Potential Applications
- 19. 19 n Hospital and Healthcare – Li-Fi emits no electromagnetic interference and so does not interfere with medical instruments, nor is it interfered with by MRI scanners. Potential Applications
- 20. 20 n Underwater Communications: Due to strong signal absorption in water, RF use is impractical. Li-Fi provides a solution for short-range communications. Potential Applications
- 21. 21 § Defence and Military Applications – Enabling high data rate wireless communication within military vehicles and aircraft § Corporate and Organisational Security – Enabling the use of wireless networks in applications where (WiFi) presents a security risk § Location-Based Services – Highly accurate location- specific information services such as advertising and navigation that enables the recipient to receive appropriate, pertinent information in a timely manner. § Toys – Many toys incorporate LED lights and these can be used to enable extremely low-cost communication between interactive toys Potential Applications
- 22. Models • Li-Fi Consortium defined Giga Dock, Giga Beam, Giga Shower, Giga Spot and Giga MIMO models to tackle different user scenarios.
- 23. Overview • This Lecture – LiFi • Introduction of LiFi • Potential Applications • Challenging Problems – Network on Chips – Quantum network 23
- 24. Challenging Problems • Challenging Problems – Shadowing (easily blocked by somebody simply walking in front of LED source)
- 25. Challenging Problems • Challenging Problems
- 26. Challenging Problems • Challenging Problems
- 27. Challenging Problems • Challenging Problems – LED layout problem (Lifi requires line of sight, limited coverage, different indoor/outdoor conditions)
- 28. Challenging Problems • Challenging Problems Ø Connectivity while moving (transferred from one light source to another, seamless handover) Ø Multiuser support (multiplexing)
- 29. Summary of LiFi • IEEE 802.15.7 visible light communication • VLC technology has been proven to work by a number of companies (Lifi Consortium, Purevlc.., ) and research establishments. (See Demos of Pure LiFi at Mobile World Congress 2014/2015) • Amazing Fact about Li-Fi – Every light source in homes and offices could potentially be a “Li-Fi” within 20 years. – When this technology becomes feasible like the WiFi, then our life will be awesome on earth. – “This is the technology that could start to touch every aspect of human life within a decade”
- 30. Overview • This Lecture – LiFi • Introduction of OWC • Potential Applications • Challenging Problems – Network on Chips • Introduction of NoC • Types of NoC • Challenging Problems 30
- 31. • many cores on a single chip (e.g. processors, GPUs), such as, Cisco QuantumFlow (40), Intel Teraflops (80), Tilera Tile (100), Cisco SPP (188), CSX700 (192), PicoChip (300), etc. • It has been predicted more than 1000 cores will be integrated on a single chip. Introduction of NoC 2005, Pentium D 2006, Core 2 Duo (Conroe) 2006, Core 2 Quad (Kentisfield) 2007, TILE64 (Tilera) Multicore processor with more and more cores!! 2015. 256 cores Intel, Sun
- 32. International Technology Roadmap for Semiconductors (ITRS) Predictions in 2010 Introduction of NoC
- 33. Introduction of NoC • Evolution of on-chip communication architectures
- 34. Introduction of NoC • NoC exemple Processor Master Global Memory Slave Global I/O Slave Global I/O Slave Processor Master Processor Master Processor Master Processor Master Processor Master Processor Master Processor Master Processor Master Routing Node Routing Node Routing Node Routing Node Routing Node Routing Node Routing Node Routing Node Routing Node
- 35. Introduction of NoC • NoCs: scale down the concepts of large scale networks, and apply them to the embedded system-on-chip (SoC) domain (demo example) • NoC Properties – Regular geometry that is scalable – Flexible QoS guarantees – Higher bandwidth – No long global wires – Reliable electrical and physical properties
- 36. Overview • This Lecture – LiFi • Introduction of OWC • Potential Applications • Challenging Problems – Network on Chips • Introduction of NoC • Design of NoC • Challenging Problems 36
- 37. Types of NoC • Networks with new constraints – Need to accommodate interconnects in a 2D layout – Cannot route long wires – area and power – Use as few buffers as possible 37
- 38. NoC Topology • Mainly adopted from large-scale networks and parallel computing • A good topology allows to fulfill the requirements of the traffic at reasonable costs • Topology classifications: 1. Direct topologies 2. Indirect topologies 38
- 39. Types of NoC • 2D mesh is most popular topology – all links have the same length – area grows linearly with the number of nodes – must be designed in such a way as to avoid traffic accumulating in the center of the mesh 39 PE PE PE PE PE PE PE PE PE PE PE PE R R R R R R R R PE PE PE PE R R R R R R R R
- 40. Types of NoC • Torus topology, also called a k-ary n-cube, is an n- dimensional grid with k nodes in each dimension – k-ary 1-cube (1-D torus) is essentially a ring network with k nodes 40
- 41. Types of NoC • k-ary 2-cube (i.e., 2-D torus) topology is similar to a regular mesh except that nodes at the edges are connected to switches at the opposite edge via wrap- around channels 41 PE PE PE PE PE PE PE PE PE PE PE PE R R R R R R R R PE PE PE PE R R R R R R R R
- 42. Types of NoC • Folding torus topology overcomes the long link limitation of a 2-D torus – links have the same size 42 PE PE PE PE PE PE PE PE PE PE PE PE R R R R R R R R PE PE PE PE R R R R R R R R Fold PE R PE R PE R PE R PE R PE R PE R PE R PE R PE R PE R PE R R PE R PE R PE R PE
- 43. Types of NoC • Octagon topology messages being sent between any 2 nodes require at most two hops 43 PE PE PE PE PE PE PE PE SW
- 44. Types of NoC • hypercube topology Arrange N=2n nodes in n- dimensional cube –At most n hops from source to destination –log(number of nodes) 44
- 45. Types of NoC • Fat tree topology (Indirect) – nodes are connected only to the leaves of the tree – more links near root, where bandwidth requirements are higher SW SW SW SW SW SW SW PE PE PE PE PE PE PE PE
- 46. Types of NoC • Fat tree topology – nodes are connected only to the leaves of the tree – more links near root, where bandwidth requirements are higher
- 47. Types of NoC • k-ary n-fly butterfly network – multi-stage network; kn nodes, and n stages of kn-1 k x k crossbar. e.g. 2- ary 3-fly butterfly 47 SW PE PE PE PE PE PE PE PE SW SW SW SW SW SW SW PE PE PE PE PE PE PE PE SW SW SW SW
- 48. Types of NoC • (m, n, r) symmetric Clos network: m is the no. of middle-stage switches; n is the number of input/output nodes on each input/output switch; r is the number of input and output switches; e.g. (3, 3, 4) Clos network 48 SW 0 2 SW 0 2 SW 1 1 SW 3 5 SW 3 5 SW 4 4 SW 6 8 SW 6 8 7 7 SW 9 11 SW 9 11 SW 10 10
- 49. Types of NoC • Irregular or ad hoc network topologies – customized for an application – usually a mix of shared bus, direct, and indirect network topologies – e.g. reduced mesh, cluster-based hybrid topology 49
- 50. NoC Routing Routing algorithm determine path(s) from source to destination. 50
- 51. NoC Routing • NoC Routing Algorithm Attributes: – Number of destinations • Unicast, Multicast, Broadcast • Objectives: – Maximize throughput: How much load the network can handle – Minimize routing delay between source and destination: Minimize hop count 51
- 52. Types of NoC • Deterministic Routing in a 2D- mesh NoC – XY routing – the message travels horizontally from the source node to the column containing the destination, where the message travels vertically. – east-north, east-south, west-north, and west- south.
- 53. NoC Routing S D • Dimension-Ordered Routing (DOR) (also called XY routing)
- 54. NoC Routing • DOR (XY) Routing: Traffic crossing bisection uniformly distributed across K channels.
- 55. NoC Routing • DOR (XY) Routing: Traffic crossing bisection uniformly distributed across K channels.
- 56. NoC Routing • Valiant Load-Balancing (VAL) randomly chosen intermediate node minimal XY routing to any intermediate node, then minimal XY routing to destination node S D
- 57. 57 NoC Routing use both minimal XY and YX routing to the destination (0.5 XY + 0.5 YX) S D • O1TURN
- 58. Overview • This Lecture – LiFi • Introduction of OWC • Potential Applications • Challenging Problems – Network on Chips • Introduction of NoC • Types of NoC • Challenging Problems 58
- 59. • Energy has become one of the primary concerns – Energy efficiency doesn't scale with the number of cores; Power consumption grows faster than performance • On-chip electrical interconnect becomes a primary bottleneck • Dec. 2012, IBM announced its technology - silicon nanophotonics https://www.youtube.com/watch?v=LU8BsfKxV2klist=PLCFC05F2A230A80B5 Challenging Problems
- 60. Challenging Problems • Characteristics of ONoCs: Bufferless/Concurrent transmission/Special on-chip optical router Ó›Ú –Œ—–—Õ¤‹ Œ¤Õ¤flŒ›ÿ –ƪ¥øÆªÊ fl —“±› ¨±±¥±ß ø æª ÆªÆªª Fast-Start Contact PI's Surname In Proposal Chen Y
- 61. • Jan. 2013, Intel announced the use of a silicon photonic architecture to define the next generation of servers • Apr. 2013, Intel demonstrated its first inexpensive optical chip • In 2015, IBM to demonstrate first on-package silicon photonics, Mar 2015 61 Challenging Problems
- 62. • Application mapping (map tasks to cores) • Floorplanning (within the network) • Buffer sizing (size of queues in the routers) • Simulation (Network simulation, traffic/delay/power modeling) • 2D to 3D 62 Challenging problems 2D to 3D
- 63. Overview • This Lecture – LiFi • What is? How does it work? • What are the future applications? – Network on Chips • What is NoC? • What are the types of NoC? – Quantum network 63
- 68. References • https://www.engr.colostate.edu/~sudeep/.../commbook_c hap12.pp • www.tlc.polito.it/~nordio/seminars/2006_05_05_Casu.p pt • http://www.ida.liu.se/~petel/NoC/lecture-notes/lect2.pdf • http://www.cs.ust.hk/~hamdi/Class/CSIT560- S13/lecture_notes.htm • http://www.cwc.ucsd.edu/~billlin/classes/ECE284/oblivi ous-routing.pptx • http://quantumrepeaters.eu/quantumrepeaters.eu/images/ attachments/qurep_quantum_communication/index.pdf