Lecture 01 Introduction to WMC.pdf
- 1. Lecture #01: Introduction to WMC DR ABUL KHAIR BIN ANUAR Dept of Communication Engineering Faculty of Electrical and Electronic Engineering Universiti Tun Hussein Onn Malaysia, Johor 1
- 2. OUTLINES History Services Wireless Demand Wireless System Challenges of wireless communication 2
- 3. A Compressed History of Wireless Ancient systems – pigeons, marathon, ravens? Use of light as communication heliographs, flags (semaphore), ... 150 BC smoke signals for communication; (Greece) 1794, optical telegraph, Claude Chappe Electromagnetic Wave 1831-79 Faraday and Maxwell demonstrates electromagnetic induction and theory of electromagnetic fields H. Hertz (1857-94): demonstrates the wave character of electrical transmission through space 3
- 4. First trans-Atlantic transmission 1896 Guglielmo Marconi first demonstration of wireless telegraphy long wave transmission, high transmission power necessary ( +200kw) 1907 Commercial transatlantic connections huge ground stations (30 by100m antennas) 1915 Wireless voice transmission NY - SF 1920 Discovery of short waves (< 100m) by Marconi reflection at the ionosphere (cheaper) smaller sender and receiver, possible due to the invention of the vacuum tube (1906, Lee DeForest and Robert von Lieben) 4
- 5. 1920 First commercial radio broadcast in Pittsburgh, PA. 1928 many TV broadcast trials 1933 Frequency modulation (E. H. Armstrong) 1935 First telephone call around the world 1958, then 1972 A-Netz and B-Netz in Germany analog, 160MHz, connection setup from the fixed network too (but location of the mobile station has to be known) 1974 FCC allocates 40Mhz for Cellular telephony 1982 Start of GSM-specification in Europe (Global System for Mobile communication) 1983 Start of the American AMPS (Advanced Mobile Phone System, analog) 1984 CT-1 standard (Europe) for cordless telephones 5
- 6. 1986 C-Netz in Germany analog voice, 450MHz, hand-over possible, digital signaling, automatic location of mobile device still in use today (as T-C-Tel), services: FAX, modem, X.25, e-mail, 98% coverage 1991 Specification of DECT Digital European Cordless Telephone (today: Digital Enhanced Cordless Telecommunications) ~100-500m range, 120 duplex channels, 1.2Mbit/s data transmission, voice encryption, authentication 1992 Start of GSM fully digital, 900MHz, 124 channels automatic location, hand-over, cellular roaming in Europe - now worldwide in more than 100 countries services: data with 9.6kbit/s, FAX, voice, ... 6
- 7. 1994 E-Netz in Germany GSM with 1800MHz, smaller cells, supported by 11 countries 1996 HiperLAN (High Performance Radio Local Area Network) standardization of type 1: 5.15 - 5.30GHz, 23.5Mbit/s recommendations for type 2 and 3 (both 5GHz) and 4 (17GHz) as wireless ATM-networks (up to 155Mbit/s) 1997 Wireless LAN - IEEE802.11 IEEE-Standard, 2.4 - 2.5GHz and infrared, 2Mbit/s already many products (with proprietary extensions) 1998 Specification of GSM successors for UMTS (Universal Mobile Telecommunication System) as European proposals for IMT-2000 7
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- 11. 2G – Global System for Mobile Communication GSM was introduced in 1991, first 2G standard. Supervise by ETSI, Groupe Systém Mobile changed to Global System for Mobile Communication in 1992. It is designed to unify standards across Europe Before GSM, countries used different standard Made it possible for a subscriber to use a single unit throughout the continent Currently the world most popular standard More than 1 billion user in 2002 Average 1.7 million new subscribers everyday (3GSM World) Uses 3 set of frequencies 900 MHz (890 – 915 MHz, 935 – 960 MHz) GSM900 Extended band (880 -890 MHz, 925 – 935 MHz) 1800 MHz (1710 -1785,1805 – 1880 MHz) PCS1800 or DCS1800 1900 MHz (1850 – 1910 MHz, 1930 – 1990MHz) PCS1900 MCMC allocates 880 – 915MHz and 925 – 960MHz for GSM networks in Malaysia. 11
- 12. GSM SYSTEM ARCHITECTURE GSM System Base Architecture
- 13. 2G – 3G Migration 13
- 14. 3G 14
- 15. UMTS FREQUENCY SPECTRUM WRC-92 designated frequency bands 1885 – 2025 MHz and 2110 – 2200 for IMT -2000. 1980 – 2010MHz and 2170 – 2200MHz to be used for satellite component. Adopted by MCMC (pp 265 of MCMC Spectrum Plan) In Europe, bands for terrestrial UMTS are 1900 – 1980MHz, 2010 – 2025MHz and 2110 – 2170MHz
- 17. The electronics boom Figure 1.1 The growth of mobile telephony as compared with other popular inventions of the 20th century. 17
- 18. Cellular subscribers IC Insights currently estimates that there are 4.4 billion unique cellphone users in the world today, representing about 60% of the 7.3 billion worldwide population in 2014. 8 billion users today - Wireless revolution - Ubiquitous voice, data and multimedia - Increasing users in 3rd world countries 18
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- 24. Current/Next-Gen Wireless Systems Current: 4G Cellular Systems (LTE-Advanced) 4G Wireless LANs/WiFi (802.11ac) mmWave massive MIMO systems Satellite Systems Bluetooth Zigbee WiGig Emerging 5G Cellular and WiFi Systems Ad/hoc and Cognitive Radio Networks Energy-Harvesting Systems Chemical/Molecular Much room For innovation 24
- 25. 4G/LTE Cellular Much higher data rates than 3G (50-100 Mbps) 3G systems has 384 Kbps peak rates Greater spectral efficiency (bits/s/Hz) More bandwidth, adaptive OFDM-MIMO, reduced interference Flexible use of up to 100 MHz of spectrum 10-20 MHz spectrum allocation common Low packet latency (<5ms). Reduced cost-per-bit (not clear to customers) All IP network 25
- 26. Future wireless network Seamless connection between people and devices 26
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- 30. Future Cellular Phones Much better performance and reliability than today ‐ Gbps rates, low latency, 99% coverage, energy efficiency BS BS Phone System BS San Francisco Paris Nth-Gen Cellular Nth-Gen Cellular Internet LTE backbone is the Internet Everything wireless in one device Burden for this performance is on the backbone network 30
- 31. Wifi Networks Multimedia Everywhere, Without Wires 802.11ac Wireless HDTV and Gaming • Streaming video • Gbps data rates • High reliability • Coverage inside and out 31
- 32. Wireless LAN Standards 802.11b (Old – 1990s) Standard for 2.4GHz ISM band (80 MHz) Direct sequence spread spectrum (DSSS) Speeds of 11 Mbps, approx. 500 ft range 802.11a/g (Middle Age– mid-late 1990s) Standard for 5GHz band (300 MHz)/also 2.4GHz OFDM in 20 MHz with adaptive rate/codes Speeds of 54 Mbps, approx. 100-200 ft range 802.11n/ac/ax (current/next gen) Standard in 2.4 GHz and 5 GHz band Adaptive OFDM /MIMO in 20/40/80/160 MHz Antennas: 2-4, up to 8 Speeds up to 1 Gbps (10 Gbps for ax), approx. 200 ft range Other advances in packetization, antenna use, multiuser MIMO Many WLAN cards have (a/b/g/n) 32
- 33. Why does WiFi performance suck? Carrier Sense Multiple Access: if another WiFi signal detected, random backoff Collision Detection: if collision detected, resend 33 The WiFi standard lacks good mechanisms to mitigate interference, especially in dense AP deployments Multiple access protocol (CSMA/CD) from 1970s Static channel assignment, power levels, and carrier sensing thresholds In such deployments WiFi systems exhibit poor spectrum reuse and significant contention among APs and clients Result is low throughput and a poor user experience Multiuser MIMO will help each AP, but not interfering APs
- 34. Self-Organizing Networks for WiFi SoN-for-WiFi: dynamic self-organization network software to manage of WiFi APs. Allows for capacity/coverage/interference mitigation tradeoffs. Also provides network analytics and planning. SoN Controller ‐ Channel Selection ‐ Power Control ‐ etc.
- 35. Bluetooth Cable replacement RF technology (low cost) Short range (10m, extendable to 100m) 2.4 GHz band (crowded) 1 Data (700 Kbps) and 3 voice channels, up to 3 Mbps Widely supported by telecommunications, PC, and consumer electronics companies Few applications beyond cable replacement
- 36. IEEE 802.15.4/ZigBee Radios Low-rate low-power low-cost secure radio Complementary to WiFi and Bluetooth Frequency bands: 784, 868, 915 MHz, 2.4 GHz Data rates: 20Kbps, 40Kbps, 250 Kbps Range: 10-100m line-of-sight Support for large mesh networking or star clusters Support for low latency devices CSMA-CA channel access Applications: light switches, electricity meters, traffic management, and other low-power sensors.
- 37. Task 1 From your experience, discuss in your group the difference between wireless, mobile, portable and cellular system? Compare the number of mobile/wireless services in 1G, 2G, 3G, 4G and 5G. Discuss your observation and reasons the situations. 37
- 38. Challenges Network / Radio Challenges Gbps data rates with ‘no’ errors Energy efficiency Scarce/ bifurcated spectrum Reliability and coverage Heterogeneous networks Seamless inter-network handoff Device/ SoC Challenges Performance Complexity Size, Power, Cost High frequencies/ mmWave Multiple Antennas Multiradio Integration Coexistance AdHoc Short-Range 5 G Cellular Mem BT CPU GPS WiFi mmW Cog Radio 38
- 39. IoT – Internet of Things 39
- 40. Shannon’s Capacity Limit We are at the Shannon Limit “The wireless industry has reached the theoretical limit of how fast networks can go” K. Fitcher, Connected Planet “We’re 99% of the way” to the “barrier known as Shannon’s limit,” D. Warren, GSM Association Sr. Dir. of Tech. Shannon was wrong, there is no limit “There is no theoretical maximum to the amount of data that can be carried by a radio channel” M. Gass, 802.11 Wireless Networks: The Definitive Guide “Effectively unlimited” capacity possible via personal cells (pcells). S. Perlman, Artemis. Theoretical limit of maximum data rate · log 1 40
- 41. Shannon’s capacity We don’t know the Shannon capacity of most wireless channels… Time varying channels Channels with interference or relays Cellular systems Ad-hoc and sensor network Channels with delay/ energy/ $$$ constraints 41 Shannon theory provides design insights and system performance upper bounds
- 42. Conclusion The wireless vision encompasses many exciting applications Technical challenges transcend all system design layers 5G networks must support higher performance for some users, extreme energy efficiency and/or low latency for others Cloud-based software to dynamically control and optimize wireless networks needed (SDWN) Innovative wireless design needed for 5G cellular/WiFi, mmWave systems, massive MIMO, and IoT connectivity Standards and spectral allocation heavily impact the evolution of wireless technology 42