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Mobile Broadband Wireless Access. Dr. Muid Mufti 20 December 2006. History of Wireless. First Ever Wireless Communication ? First Mobile Radio Telephone 1924 Phenomenal growth with the turn of the century. Global. Satellite. Suburban. Urban. In-Building. Picocell. Microcell.
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Mobile Broadband Wireless Access Dr. Muid Mufti 20 December 2006
History of Wireless • First Ever Wireless Communication ? • First Mobile Radio Telephone1924 • Phenomenal growth with the turn of the century
Global Satellite Suburban Urban In-Building Picocell Microcell Macrocell Basic Terminal PDA Terminal Audio/Visual Terminal The Wireless Experience
Advantages of Wireless • Low cost • Low maintenance • Quick deployment • Reduced sunk cost • Mobility
Disadvantages of Wireless • Non secure • Environmentally vulnerable • Frequency reuse issues
Ubiquitous Networks • MBWA based product • Cell phone TV • Streaming Multimedia • Video on Demand • MBWA based Services • Mobile medical aid • Train entertainment systems • Surveillance • Strategic MBWA business
Defining Broadband • High dates rates ? • FCC definition of broadband: Connections with speed exceeding 200 Kb/s in at least one direction • PTA definition of broadband: High speed, ‘always on’ Internet connection. Speed of connection ranging from 128 Kbps to 2 Mbps or higher. • Refers to the ability of the user to view content across the internet that includes large files, such as video, audio, multimedia and 3D graphics • QoS Support
Mobile vs. Wireless Wireless Mobile
Mobility • Range of mobility • Geographic range • Across networks • IP mobility • Speed of mobility • Personal mobility • Vehicular mobility • Frequency of mobility • Mobility Overhead
MBWA • Be able to support broadband data rates with given QoS with mobility • Mobility speed • Personal mobility • 100+ km/h – high speed trains, cars, buses etc.
Mobile Broadband Development Streams • UMTS-TDD (WCDMA-TDD) • FDD W-CDMA • TD-SCDMA • 1x EVDO • WiMAX (802.16e) • 802.20 (MobileFi)
Global Wireless Data Standards WUSB 802.16 WiMax 802.15 Zigbee Data Rates 802.11 Wifi 802.20 MobileFi Bluetooth UMTS GPRS Range
UMTS-TDD • Up to 12Mbps • More than 3 times higher than any other commercial mobile platform. • True N=1 frequency reuse • Network operator can deploy a network with multiple towers using only one RF Channel • 5 MHz RF channel for a 3.84 Mcps system • 10 MHz channel for a 7.68 Mcps system. • Mobility up to 120 km/hr within the network footprint • Tower-to-tower handoff roaming • Network-to-network roaming
FDD W-CDMA • Frequency band:1920 MHz -1980 MHz and 2110 MHz - 2170 MHz (Frequency Division Duplex) • Minimum frequency band required: ~ 2x5MHz • Frequency re-use: 1 • Carrier Spacing: 4.4MHz - 5.2 MHz • Maximum number of (voice) channels on 2x5MHz: ~196 (spreading factor 256 UL, AMR 7.95kbps) / ~98 (spreading factor 128 UL, AMR 12.2kbps) • Voice coding: AMR codecs (4.75 kHz - 12.2 kHz, GSM EFR=12.2 kHz) and SID (1.8 kHz) • Channel coding: Convolutional coding, Turbo code for high rate data • Duplexer needed (190MHz separation), Asymmetric connection supported • Tx/Rx isolation: MS: 55dB, BS: 80dB • Receiver: Rake • Receiver sensitivity: Node B: -121dBm, Mobile -117dBm at BER of 10-3 • Data type: Packet and circuit switch • Modulation: QPSK • Pulse shaping: Root raised cosine, roll-off = 0.22 • Chip rate: 3.84 Mcps
FDD W-CDMA • Channel raster: 200 kHz • Maximum user data rate (Offered): 384 kbps (year 2002), higher rates ( ~ 2 Mbps) in the near future. HSPDA will offer data speeds up to 8-10 Mbps (and 20 Mbps for MIMO systems) • Channel bit rate: 5.76Mbps • Frame length: 10ms (38400 chips) • Number of slots / frame: 15 • Number of chips / slot: 2560 chips • Handovers: Soft, Softer, (interfrequency: Hard) • Power control period: Time slot = 1500 Hz rate • Power control step size: 0.5, 1, 1.5 and 2 dB (Variable) • Power control range: UL 80dB, DL 30dB • Mobile peak power: Power class 1: +33 dBm (+1dB/-3dB) = 2W; class 2 +27 dBm, class 3 +24 dBm, class 4 +21 dBm • Number of unique base station identification codes: 512 / frequency
TD-SCDMA • China Wireless Telecommunication Standards group (CWTS) • Approved by the ITU in 1999 • Developed by the Chinese Academy of Telecommunications Technology and Siemens • Frequency band: 2010 MHz - 2025 MHz in China (WLL 1900 MHz - 1920 MHz) • Minimum frequency band required: 1.6MHz • Frequency re-use: 1 (or 3) • Chip rate: 1.28 Mcps • Frame length: 10ms • Number of slots: 7 • Modulation: QPSK or 8-PSK
TD-SCDMA • Voice data rate: 8kbit/s • Circuit switched services: 12.2 kbits/s, 64 kbits/s, 144 kbits/s, 384 kbits/s, 2048 kbits/s • Packet data: 9.6kbits/s, 64kbits/s, 144kbits/s, 384kbits/s, 2048kbits/s • Receiver: Joint Detection, (mobile: Rake) • Power control period: 200 Hz • Number of slots / frame: 7 • Frame length: 5ms • Multi carrier option • Handovers: Hard • Uplink synchronization
1x EVDO (CDMA 2000) • Qualcomm USA. • Frequency band: Any existing band. • Minimum frequency band required: 1x: 2x1.25MHz, 3x: 2x3.75 • Chip rate: 1x: 1.2288, 3x: 3.6864 Mcps • Maximum user data rate: 1x: 144 kbps now, 307 kbps in the future 1xEV-DO: max 384 kbps - 2.4 Mbps, 1xEV-DV: 4.8 Mbps. • Frame length: 5ms, 10ms or 20ms • Power control rate: 800 Hz • Spreading factors: 4 ... 256 UL
802.16e • Mobile WirelessMAN • Approved by IEEE Feb 2006 • NLOS with Antenna Diversity • FDD / TDD • Multiple Convergence layers • IP • Ethernet • ATM
Adaptive PHY Burst-by-burst adaptivity not shown
Adaptive Burst Profiles • Burst profile • Modulation and FEC • Dynamically assigned according to link conditions • Burst by burst, per subscriber station • Trade-off capacity vs. robustness in real time • Roughly doubled capacity for the same cell area • Burst profile for downlink broadcast channel is well-known • All other burst profiles could be configured “on the fly” • Subscriber station capabilities recognized at registration
Duplex Scheme Support • On downlink , SS is associated with a specific burst • On uplink , SS is allotted a variable length time slot for their transmissions • Time-Division Duplex (TDD) • Downlink & Uplink time share the same RF channel • Dynamic asymmetry • SS does not transmit & receive simultaneously (low cost) • Frequency-Division Duplex (FDD) • Downlink & Uplink on separate RF channels • Static asymmetry • Half-duplex SSs supported • SS does not transmit & receive simultaneously (low cost)
Duplex Scheme Support • On downlink , SS is associated with a specific burst • On uplink , SS is allotted a variable length time slot for their transmissions • Time-Division Duplex (TDD) • Downlink & Uplink time share the same RF channel • Dynamic asymmetry • SS does not transmit & receive simultaneously (low cost) • Frequency-Division Duplex (FDD) • Downlink & Uplink on separate RF channels • Static asymmetry • Half-duplex SSs supported • SS does not transmit & receive simultaneously (low cost)
TDD Frame (10-66 GHz) n PS = (Symbol Rate x Frame Length) / 4 Downlink Subframe Uplink Subframe Adaptive PS 0 PS n-1 Frame j-2 Frame j - 1 Frame j Frame j+1 Frame j+1
TDD Downlink Subframe TDM Portion Broadcast Control DUIC = 0 TDM DUIC a TDM DUIC b TDM DUIC c Preamble Tx/Rx Transition Gap Preamble DL- MAP UL-MAP DIUC: Downlink Interval Usage Code
Burst FDD Framing DOWNLINK UPLINK Frame Broadcast Half Duplex Terminal #1 Full Duplex Capable User Half Duplex Terminal #2 Allows scheduling flexibility
FDD Downlink Subframe TDM Portion Broadcast Control DUIC = 0 TDM DIUC a TDM DIUC b TDM DIUC c Preamble TDMA Portion TDM DIUC d TDM DIUC e TDM DIUC f TDM DIUC g Preamble Preamble Preamble Preamble Burst Start Points DL-MAP UL-MAP Preamble
Fragmentation • Partitioning a MAC SDU into fragments transported in multiple MAC PDUs • Each connection can be in only a single fragmentation state at any time • Contents of the fragmentation sub-header: • 2-bit Fragmentation Control (FC) • Unfragmented, Last fragment, First fragment, Continuing fragment • 3-bit Fragmentation Sequence Number (FSN) • required to detect missing continuing fragments • continuous counter across SDUs
Packing • The process of combining multiple MAC SDUs (or fragments thereof) into a single MAC PDU • On connections with variable length MAC SDUs • Packed PDU contains a sub-header for each packed SDU (or fragment thereof) • On connections with fixed length MAC SDUs • No packing sub-header needed • Packing and fragmentation can be combined • Can, in certain situations, save up to 10% of system bandwidth
Classes of Service Characteristic of the Service Flow • Unsolicited Grant Services (UGS) • for constant bit-rate (CBR) or CBR-like service flows (SFs) such as T1/E1 • Real-time Polling Services (rtPS) • for rt -VBR-like SFs such as MPEG video • Non-real-time Polling Services (nrtPS) • for nrt SFs with better than best effort service such as bandwidth-intensive file transfer • Best Effort (BE) • for best-effort traffic
UGS • No explicit bandwidth requests issued by SS • Prohibited from using any contention requests • No unicast request opportunity provided • May include a Grant Management (GM) sub-containing header containing • Slip indicator: indicates that there is an backlog in the buffer due to clock skew or loss of maps • Poll-me bit: indicates that the terminal needs to be polled (allows for not polling terminals with UGS-only services).
RTPS • Intended for rt-VBR-like service flows such as MPEG video • Prohibited from using any contention requests • Terminals polled frequently enough to meet the delay requirements of the SFs • Bandwidth requested with BW request messages (a special MAC PDU header) • May use Grant Management sub-header • new request can be piggybacked with each transmitted PDU
NRTPS • Intended for non-real-time service flows with better than best effort service • e.g. bandwidth-intensive file transfer • Works like rt-polling except that polls are issued less frequently • Allowed to use contention requests • May use Grant Management sub-header • new request can be piggybacked with each transmitted PDU
BE • Generic data • e.g. HTTP, SMTP, etc. • No QoS guarantees • Allowed to use contention requests • May use Grant Management sub-header • new request can be piggybacked with each transmitted PDU
Request/Grant Scheme • Self Correcting • No acknowledgement • All errors are handled in the same way, i.e., periodical aggregate requests • Bandwidth Requests are always per Connection • Grants are either per Connection (GPC) or per Subscriber Station (GPSS) • Grants (given as durations) are carried in the UL-MAP messages • SS needs to convert the time to amount of data using information about the UIUC
Aperto • 2.5 GHz, 3.3 GHz , 3.5 GHz, 5.3GHz , 5.8 GHz • Deployed/trialed by: • Iberbanda, Spain; • Enertel, Holland; • Sequelle Communications Alliance, USA
Alvarion • 3.5 GHz, 5.8 GHz, 2.5 GHz • Summerside Community Network, USA • Telekom Serbia, Israel • Axtel, Mexico
Nex-G • Target licensed exempt bands initially e.g. 5.8 GHz. Subsequently licensed bands e.g. 3.5 Ghz, 2.5 Ghz
Redline Communications • 3.5 GHz, 5.4 GHz, 5.8 GHz • Telabria, UK • I-Netlink Wireless, Canada; • Thirteen WNET/New York, USA
WiLAN • 2.4 GHz, 3.5 GHz, 5.8GHz • Marathon Oil, USA • TM Net Sdn. Bhd, Malaysia