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1 State and Future of Wireless Communications and Networking Ender Ayanoglu UC Irvine EECS/CPCC/Calit2 11/14/2012 UCI EECS Colloquium.

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Presentation on theme: "1 State and Future of Wireless Communications and Networking Ender Ayanoglu UC Irvine EECS/CPCC/Calit2 11/14/2012 UCI EECS Colloquium."— Presentation transcript:

1 1 State and Future of Wireless Communications and Networking Ender Ayanoglu UC Irvine EECS/CPCC/Calit2 11/14/2012 UCI EECS Colloquium

2 2 Slides Available from My personal Web page Scroll down to the bottom of the page for My EECS Colloquium Slides Fall 2012

3 3 Communications in the 90s-00s Hot research, development, commercialization due mainly to the introduction and popularity of – Cellular voice wireless – Internet

4 4 Many New Products and Services Voiceband modems (V.34, V.90, V.92) Digital subscriber line modems (DMT, CAP) Cable TV and cable Internet access 100 Mb/s, 1 Gb/s Ethernet 2 nd -4 th Generation (digital) cellular voice Optical amplifiers Dense Wavelength Division Multiplexing for fiber optic transmissions Smart phones, tablets

5 5 Enabling Technologies: Code Division Multiple Access (CDMA) Each user bit is expanded by the use of a code, unique to a user and orthogonal among users Signal spectrum is expanded (spread) Sum of interference by all other users appears as additive Gaussian noise to a particular user Receiver employs the same code as the transmitter and pulls transmitted information from below all noise and interference Powerful technique for voice communication Used by cellular services of Sprint and Verizon in US, some others worldwide Also used in 802.11b

6 6 Enabling Technologies: Orthogonal Frequency Division Multiplexing (OFDM) Employs IFFT and FFT to translate the transmitted message into the frequency domain Estimates the frequency response of the channel and equalizes the channel in the frequency domain Best technique for broadband frequency selective channels Employed in 801.11a/g, ADSL, DAB, DVB, etc

7 7 Enabling Technologies: Multi-Input Multi-Output (MIMO) Multiple transmit and receive antennas to – Increase transmission rate – Improve BER vs SNR performance Part of 802.11n Under consideration in upcoming standards Single- and multi-user versions

8 8 How Much Fading is There? Fading can cause 30-40 dB loss in received signal power! Power link budgets in wireless communications require corresponding fading margins (assume received power can go down by 10 3 -10 4 times!)

9 9 Wireless LANs: IEEE 802.11

10 doc.: IEEE 802.11-10/0692r0 SubmissionSlide 10 IEEE 802.11 Standards Pipeline PHY Sponsor Ballot MAC Study groups 802.11k RRM 802.11r Fast Roam 802.11b (99) 11 Mbps 2.4GHz Published Standard a 54 Mbps 5GHz g 54 Mbps 2.4GHz e QoS i Security f Inter AP h DFS & TPC 802.11V Network Management 802.11s Mesh 802.11u WIEN 802.11Y Contention Based Protocol TG Letter Ballot 802.11 -2007 802.11mb Maintenance k+r+y 802.11aa Video Transport 802.11ac VHT 5GHz 802.11ad VHT 60GHz TG without draft Discussion Topics Published Amendment 802.11ae QoS Mgmt Frm 802.11n High Throughput (>100 Mbps) 802.11W Management Frame Security 802.11z TDLS 802.11p WAVE 802.11af TVWS Smart Grid FIA S1G

11 11 Wireless LANs: IEEE 802.11

12 12 New Standard: IEEE 802.11ac Currently under development which will provide high throughput in the 5 GHz band Will enable multi-station WLAN throughput of at least 1 Gb/s and a maximum single link throughput of at least 500 Mb/s. Accomplished by extending the air interface concepts embraced by 802.11n: wider RF bandwidth (up to 160 MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation (up to 256 QAM) Devices with the 802.11ac specification are expected to become common by 2015 with an estimated one billion spread around the world A number of companies already announced chips

13 13 IEEE 802.11ac Features Only for the 5 GHz band Wider channel bandwidths –80 MHz and 160 MHz channel bandwidths (vs. 40 MHz in 802.11n) 80 MHz mandatory for stations (STAs), 160 MHz optional More MIMO spatial streams –Support for up to 8 spatial streams (vs. 4 in 802.11n) Multi-user MIMO (MU-MIMO) –Multiple STAs, each with one or more antennas, transmit or receive independent data streams simultaneously Space Division Multiple Access (SDMA): streams not separated by frequency, but instead resolved spatially, analogous to 11n-style MIMO –Downlink MU-MIMO (one transmitting device, multiple receiving devices) included as an optional mode Modulation –256-QAM, rate 3/4 and 5/6, added as optional modes (vs. 64-QAM, rate 5/6 maximum in 802.11n) Other elements/features –Single sounding and feedback format for beamforming (vs. multiple in 802.11n) –MAC modifications (mostly to support above changes) –Coexistence mechanisms for 20/40/80/160 MHz channels, 11ac and 11a/n devices

14 14 State of Wireless LANs Wireless LANs are a very successful area and will remain so for many years

15 15 Mobile Cellular Networking Generations First Generation (1G, Analog Voice) – Analog System – AMPS, NAMPS (US), NMT 450, NMT 900 (Eu), N-TACS (J) Second Generation (2G, Digital Voice) – Digital System – TDMA [IS-136], CDMA [IS-95] (US), GSM (Eu), PDC (J) 2.5G – Evolution to 3G – GPRS (Global Packet Radio Service), EDGE (Enhanced Data GSM Environment) Third Generation (3G, Data Rides on Digital Voice) – High-speed packetized voice and data – IMT2000 req.: 144K vehicular, 384K pedestrian, 2M indoor – WCDMA (GSM), CDMA2000 (IS-95), TD-SCDMA (C) Fourth Generation (4G, Everything Rides on Data Packets) – WiMAX, LTE

16 16 Wallet MP3 Player Game Console FM Radio PDA Voice Pager PC Bar Scanner CamcorderWalkie-Talkie Television Newspaper Rolodex Glucometer GPS Device Photo Album Camera Cell-phone: The one device that everyone carries

17 17 Handset Sales Predictions New and more powerful handsets every year, customers will likely replace handsets every 2 years (Asia-Pacific)

18 18 Evolution to 3G cdma2000 1x GSM TDMAGSM/GPRS GSM/GPRS/EDGE WCDMA cdmaOne cdma2000 1xEV-DV cdma2000 1xEV-DO TD-SCDMA PDC

19 19 2G Cellular Market Share

20 20 Verizon – EV-DO (Evolution – Data Optimized) – 400-700 kb/s down, 50-70 kb/s up – $60/mo. unlimited use – About 84 US markets, 426 US airports Sprint – EV-DO – $40/mo. Up to 40 MB/mo., $60/mo. Unlimited use – About 48 US markets Cingular (including AT&T Wireless) – UMTS (WCDMA) – 220-320 kb/s down, 400-700 after upgrade to HSDPA (Hi-Speed Downlink Pkt Acc.) CDMA well-suited for voice but not for data Another high-speed technology will likely be needed 2005: 3G is Being Rolled Out



23 23 3G-4G Story Japanese service provider DoCoMo proposed W-CDMA as the 3G standard to 3GPP, accepted As demand increased newer techniques introduced GPRS, EDGE, HSDPA, HSUPA 3GPP2 developed versions of EV-DO Rev 0, A-C As demand kept increasing, it was realized that CDMA-based technologies would not suffice. DoCoMo suggested technology similar to what was developed in WiMAX (802.16e)

24 Source: WiMAX Forum 2009

25 25 Evolution to 4G

26 26 3GPP Long Term Evolution (LTE) 3GPP Release 8 ratified as a standard, oriented towards 4G. Peak download 326.4 Mbit/s for 4x4 antennas, 172.8 Mbit/s for 2x2 antennas for every 20 MHz Peak upload 86.4 Mbit/s for every 20 MHz At least 200 active users in every 5 MHz cell (i.e., 200 active data clients) Sub-5ms latency for small IP packets Spectrum slices as small as 1.4 MHz (and as large as 20 MHz) supported Optimal cell size of 5 km, 30 km w/ reasonable performance, up to 100 km w/ acceptable performance Co-existence with legacy standards Supports MBSFN (Multicast Broadcast Single Frequency Network). Can deliver services such as Mobile TV using the LTE infrastructure (competitor for DVB-H) Transition from the existing UMTS circuit + packet switching combined network, to an all-IP flat architecture

27 LTE PHY Layer Methods to combat multipath – OFDM – MIMO New access method scheme – OFDMA – SC-FDMA (Single Carrier – Frequency Division Multiplexing) OFDM breaks the bandwidth into multiple narrower QAM-modulated subcarriers. As a result, each subcarrier faces a much less distorted channel. This, and a number of associated signal processing techniques simplify equalizing the channel substantially

28 28 OFDMA: Orthogonal Frequency Division Multiple Access Multiplexing scheme for LTE DL A number of subcarriers are assigned to each user for a specific time interval (Physical Resource Block) (time-frequency dimension) PRB is the smallest element for resource allocation. It contains 12 consecutive subcarriers for one slot duration Resource Element: One subcarrier for each symbol period LTE Reference signals are interspersed among Resource Elements

29 29 2D Time and Frequency Grid

30 30 Downlink Channel Mapping

31 31 Uplink Channel Mapping

32 32 Single Carrier Frequency Domain Equalization OFDM has a large Peak-to-Average Power ratio. This results in the use of power amplifiers such that they are kept in their linear operating region, in an inefficient mode. As a result, OFDM causes transmitters to be expensive. This is a problem on the uplink. There is a way to modify the OFDM transmitter and receivers such that this problem disappears. The TX and RX are very similar to OFDM, with additional blocks. This system keeps the equalization advantages of OFDM. LTE chose this solution for the TX in the MS. M > N

33 33 Single Carrier Frequency Division Multiple Access WiMAX uses OFDMA in both uplink and downlink. SC-FDMA can offer larger cell coverage, OFDMA can provide higher throughput, with SC-FDMA being less expensive. Example comparison with OFDMA

34 34 Carrier Adoption of LTE Carriers supporting GSM or HSPA networks can be expected to upgrade to LTE. However, several networks that don't use these standards are also upgrading to LTE Alltell, Verizon, China Telecom/Unicom and Japan's KDDI. These are CDMA carriers and have chosen to take the GSM evolution path as opposed to the 3GPP2 CDMA evolution path UMB Verizon Wireless plans to begin LTE trials in 2008 AT&T Mobility will upgrade to LTE as their 4G technology, but will introduce HSUPA and HSPA+ as bridge standards T-Mobile, Vodafone, France Télécom, Telia Sonera and Telecom Italia Mobile announced or talked publicly about their commitment to LTE Bell Canada plans to start LTE deployment in 2009-2010

35 Evolution of 3G Variants to LTE

36 Source: WiMAX Forum 2009

37 37 State of Mobile Cellular Networks Mobile cellular one of the most commercially successful technology introductions ever 2.5G and 3G rolled out, we are now seeing 4G LTE emerging as the common standard Very active field, will continue to be for a long time New technologies (antenna arrays, etc) are needed and will be introduced New modulation formats and increased bit rates are likely 4G is here, LTE-Advanced is very sophisticated

38 38 Federal Communications Commission (FCC) Ruling on White Space TV spectrum is large, many bands are unused This is especially true at UHF Fall 10: FCC opened these bands to unlicensed use, contingent on The ruling is expected to impact wireless transmission, possibly creating Super Wi-Fi coverage (better transmission in these bands) dBm Frequency -60 -100 White spaces 470 MHz750 MHz

39 39 IEEE 802 Wireless Space

40 40 ZigBee Wireless Personal Area Network

41 41 Likely Scenario for the Future of Wireless 802.11 is very successful 2.5G-3G services proliferated beyond expectations 802.11 public access service commonplace PDAs and laptops which integrate 802.11 and 2.5G-3G will be commonplace Roaming between 802.11 and 2.5G-3G is next Very high data rate 802.11 via modern processing (802.11ac) is next LTE major push

42 42 Future of Moores Law Feature sizes –90 nm today –65 nm in 2005-2007 –45 nm in 2007-2010 –32 nm in 2009-2013 –22 nm in 2011-2016 –Theoretically can shrink down to 4 nm (about 2023): Beyond which source and drain of a transistor are so close, electrons can drift on their own; losing reliability. –IBM announced a proof-of-concept transistor at 6 nm (20 Si atoms) in 2002 –However, before 4 nm, leakage current is a problem Ways to increase speed and reduce power consumption –Multicore processor architectures (New software will be needed, hard!) –3D stacked integrated circuits –Low-power circuit design techniques, e.g., sleep-transistor technology –Tri-gate transistor: Reduction in leakage current and power consumption –Better dielectrics –Hybrid semiconductors with nanowires

43 43 ITRS View: Extrapolation (Although Slowing Down)

44 44 Federico Faggins View: Architect of the First Microprocessor (4004)

45 45 Kurzweils Accelarating Returns Argument Evolution of computing has always occurred at exponential pace Future developments will occur at exponential speed too

46 46 If Exponential Development of Computing Speed Continues

47 47 A Conservative Outlook to the Future of Moores Law Rate of doubling slowed down to about 3 years, maybe more Current leading edge feature size is about 22 nm Next generations may follow a route of about 3 more generations until about 14 nm, 6-8 years Human ingenuity may take us further via a number of options

48 48 What is the Future of Communications? Broadband: Higher speed to home and business Home networking, esp. distribution of video in home Convergence of PDAs, pagers, cell phones, laptops, always on connectivity to the Internet and voice network Wearable computers Convergence of communications and computing IP will eventually carry more than best effort data VoIP will replace circuit-switched telephony Sensors everywhere

49 49 What a Communication Processor May Look Like in 15 Years

50 50 Sample Research Topics in Communications Multi-Input Multi-Output (Smart Antennas) – WLAN and cellular – Very hot research area Ad-hoc networks Mesh (multihop) networks Optical packet switching Wearable computing User interface (big bottleneck) – Speech and handwriting recognition, hard! Pervasive communications (machine-to-machine) Energy efficiency

51 51 Slides Available from My personal Web page Scroll down to the bottom of the page for My EECS Colloquium Slides Fall 2012


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