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IIT Colloquium: NRC Ottawa, Canada A Vision for Evolving Local Wideband Wireless Networks Kaveh Pahlavan, Professor of Electrical and Computer Engineering and Director, CWINS/WLRL WPI, Worcester, MA http://www.cwins.wpi.edu. Outline. Applications and the market - PowerPoint PPT Presentation
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IIT Colloquium: NRCOttawa, Canada
A Vision for Evolving Local Wideband Wireless Networks
Kaveh Pahlavan, Professor of Electrical and Computer Engineering and
Director, CWINS/WLRLWPI, Worcester, MA
http://www.cwins.wpi.edu
CWINS
Outline
• Applications and the market• Existing technologies and limitations• Evolving standards • Overview of Global activities• Some research projects
Classification of Existing Wireless Networks
Voice Driven Networks • Low power, high quality, local services (PCS, wireless PBX, telepoint)-Result of
success in cordless telephone industry
• High power, low quality, wide area (Digital Cellular) -Result of demand for higher capacity for mobile radio
Data Driven Networks • High speed local (Wireless LAN) - A new approach for local area networking • Low speed wide area (mobile data) - Result of success in paging industry
Current Wireless Network Industry
CWINS@wpi
Voice ServicesTariff
Mobility
Service AreaSize/Power
Quality
IntelligentNetwork
Cellular PCS
CWINS@wpi
Data ServicesNo. Users
Mobility
Service AreaSize/Power
Data Rate
Interoperability
MobileData
WLANS
Wireless LANs
• Minimum data rate: 1Mbps (IEEE 802)• Designed for local indoor - less than 100m• Should interoperate with wired LANs• Does not need large investment on infrastructure and does
not collect service charges.• Transmission technology: spread spectrum, standard
radio, IR• Examples: Roamabout, WAVELan, Photolink, FreePort• Standards: IEEE 802.11, HIPERLAN
History of Wireless LANs
• Diffused Infrared - 1979 (IBM Rueschlikon Labs - Switzerland)• Spread Spectrum using SAW Devices - 1980 (HP Labs - California)• Wireless modems - early 1980's (Data Radio) • ISM bands for commercial spread spectrum applications - 1985 • IEEE 802.11 for Wireless LAN standards - 1990• Announcement of wireless LAN products - 1990 • Formation of WINForum - 1992• ETSI and HIPERLAN in Europe - 1992• Release of 2.4, 5.2 and 17.1-17.3GHz bands in EC - 1993• PCS licensed and unlicensed bands for PCS - 1993• 1996: .........
Three Views of WWLA
• Existing WLAN Applications• Vision for Military
Applications • Vision of the Service Providers
Service Scenarios
• Workplace - the main market of today, TCP/IP applications, legacy LAN backbone
• Home - universal access point: Internet connection, cordless telephone, flexible speakers, etc. backbone unknown (ATM preferred).
• Nomadic public access - backbone unknown, easier traffic policing and charging with WATM.
Wireless LAN TechnologiesTechnique DF/IR DB/IR RF DS/SS FH/SS
Data Rate 1 - 4 Mbps 10 - 155 Mbps 5 - 10 Mbps 2 - 20 Mbps 1 - 3 Mbps
Mobility Stationary/Mobile Stationary w/LOS Stationary/Mobile Stationary/Mobile Mobile
Range 50 - 200 ft 100 ft 40 - 130 ft 100 - 800 ft 100 - 300 ft
Freq./wavelength 800 - 900 nm 800 - 900 nm 18 GHz, ISM ISM bands ISM bands
Modulation OOK OOK FSK/QPSK QPSK GFSK
Access Method CSMA CSMA Res. ALOHA, CSMA CSMA CSMA
Manufacturer Spectrix InfraLAN (token ring) Motorola - Altair DEC ProximJOLT (pt-to-pt) AiroNet RDC
WaveLAN (mesh) XircomPersoftSolectekProximWindataWiLAN
Wireless LAN Market
0
200
400
600
800
1000
1200
1992 1993 1994 1995 1996
K-Unit
Local Wideband Wireless Activities
• Evolving Standard Technologies– IEEE 802.11– RES-10 HIPERLAN– Wireless ATM Forum
• International Activities– In the US
• WINForum, U-NII– In the EC
• MEDIAN, WAND, SAMBA and AWACS– In Japan
• MMAC (High-Speed WirelessAccess and Ultra High-Speed Radio LAN)
802.11 PHY
802.11 MAC 802.3 MAC
802.3 PHY802.11 PHY
802.11 MAC
IP
TCP
Applications Applications
TCP
IP
802.3 MAC
802.3 PHY
802.11 PHY
802.11 MAC
802.11 PHY
802.11 MAC
IP
TCP
ApplicationsApplications
TCP
IP
(a)
(b)
LANE
AAL5
ATM
PHY
AAL
Custom PHY
WATM
Custom PHY
WATM
IP
TCPApplications Applications
TCP
IP
(c)
ATM
PHY
AALAAL
Mobile Terminal
Server
Fixed Terminal
Backbone Network
Access Point
ATM
PHY
ATM
PHY
Interconnection between WLAN/WATM to backbone
ESS
Existing Wired LAN
APAP
BSS 3BSS 2
Infrastructure Network
BSS 1BSS 2
Ad Hoc Networks
BSS 1
AP
802.11 Configurations
IEEE 802.11 and ISM bands
• Media Access Protocol (MAC) for both peer-to-peer and centralized topologies
• Uses 2.4 MHz ISM bands• Supports DSSS (BPSK and QPSK), FHSS (GFSK), and DFIR (OOK)• Data rates are 1 and 2 Mbps for DSSS and FHSS, 1Mbpsfor DFIR• For DSSS the band is divided in two groups:
Group I centralized at: 2412, 2442, and 2472 MHzGroup II centralized at: 2427, and 2457 MHz
• For FHSS three patterns of 22 hops out of 79 available I MHz bands with GFSK. Minimum hop rate is 2,5 hops/second
• Provide interoperatability among all stations
IAPP (Supported byLucent, Aironet, Digital Ocean)
• The IAPP specification defines how access points from different vendors communicate with each other to support mobile stations roaming across cells and how they communicate across the backbone network to hand over mobile stations.
• The IAPP specification builds on the baseline capabilities of the IEEE 802.11 standard.
• The IAPP specification tackles higher-level OSI layers such as logical link control that facilitates inter-access point communications.
• The IAPP specification supports interoperability between products.
• Should be applicable to large infra-structures
F
F
F
RIBNIBHIBAIBSMRIBTIB
RIBNIBHIBAIBSMRIBTIB RIB
NIBHIBAIBSMRIBTIB
RIBNIBHIBAIB
RIBNIBHIBAIB
RIBNIBHIBAIB
1 2
3
4
5
6
HIB {HDest , HStatus , HNext }
RIB {RDest , RNext , RDist }
NIB {NNbour , NStatus }
AIB {AOri , AAlias }
SMRIB {SSMR , SSeq }
TIB {TDest , TLast , TSeq }
is SM
R of
is SMR
of
is SMR
of
HIPERLAN 1
HIPERLAN 2Neighborhood
Hiperlan ad-hoc network configuration
ETSI Res-10: HIPERLAN
• MAC for both peer-to-peer and centralized networks
• Uses 5.25-5.3 GHz and 17.1-17.3 GHz• Uses GMSK modulation with DFE• Data rates are 10-20 Mbps• The maximum range is 50m• Supports asynchronous data as well as
isochronous voice
Wireless ATM Architecture [WATM Working Group Presentation]
Frequency Band Modulation Technique
Data Rate Access Method Topologies MAC Services QoS Availibility
WIRELESS
802.11
Spread Spectrum Direct Sequence: 2.4-2.4835 GHz, Frequency Hopping: 2.4-2.4835 GHz; Diffused Infrared: 850-950 nanometer
Spread Spectrum Direct Sequence: DBPSK, DQPSK; Spread Spectrum Frequency Hopping: 2GFSK, 4GFSK BT=0.5; Diffused Infrared: 16 and 4 PPM
1 and 2 Mbps
Basic CSMA/CA, RTS/CTS, PCF with polling list, 20 frames
Ad-hoc, Infra-structure
Authentication, Encryption, Power conservation, Time bounded services
No explicit support for QoS, but includes infrastructure topology and priority scheme in PCF that are useful for quality assurance.
Technial standard finalized. Final administrative approval under progress. Products (e.g DEC Roamabout) and chipsets (e.g. Harris PRISM and Raytheon RAYLINK) are available.
LAN
HIPERLAN
5.15-5.30 GHz Low bit rate: FSK; High bit rate:GMSK (BT=0.3)
1.47 and 23.53 Mbps
Non-Preemptive Multiple Access (NPMA), 10 PDU
Ad-hoc Encryption, Power conservation, Routing and forwarding, Time bounded services
Advanced user priority scheme and packet lifetime mechanism to support QoS
Standard is finalized. No product in the market. Two prototypes: HIPERION, fully standards compliant, and LAURA, not fully compliant [Wil96].
WIRELESS
MII Bahama
900 MHZ (Proposed 5 GHz U-NII Bands)
OFDM or GMSK with LMS or RLS Equalization
2-20 Mbps between laptop and PBS, and Gbps between PBSs
Distributed Queue Reservation Updated Multiple Access (DQRUMA): Reservation and Piggybacking
Infrastructure, ad hoc base station placement (optional)
Scheduling, piggybacking etc.
Base station responsible for checking and guaranteeing QoS, connections with or without QoS guarantees possible.
Prototype at Bell labs in Lucent Technologies
NEC
2.4 GHz ISM Bands
/4 - QPSK with decision feedback equalization
8 Mbps TDMA/TDD with Slotted ALOHA
Infrastructure based
Scheduling, multiplexing and demultiplexing of VCs
ABR, UBR, VBR and CBR slots are available but QoS support is not finalized
Prototype at NEC USA's C&C Research Laboratories, Princeton, NJ.
ATM
Magic WAND
5.2 GHz 16 Channel OFDM > 24 Mbps Reservation, Slotted ALOHA: Mobile Access Scheme based on Contention and Reservation (MASCARA)
Infrastructure Based
Scheduling, radio resource management and under further study
Worst case QoS estimate (cell delay or cell loss) to be used for determining the connection
Prototyping under the European ACTS AC085 project
Comparison of WLAN and WATM
Wireless ATM ActivitiesWATM System SWAN1 MII/BAHAMA1 Olivetti NEC WAND
Frequency Bands 2.4 GHz ISM Bands 900 MHz (Proposed5 GHz : U-NII)
2.4 GHz ISM Bands 2.4 GHz ISM Bands 5.2 GHz
Data Rate 625 kbps 2-20 Mbps 10 Mbps 8 Mbps 24 MbpsModulation Scheme Frequency Hopping (suggested OFDM
or GMSK withLMS/RLS)
QPSK /4 - QPSK withDFE
16 channel OFDM
Medium Access Each mobile has afixed channel; tokenpassing
Distributed queuereservation updatedmultiple access(DQRUMA)
Reservation withSlotted Aloha andpiggy-backing ondata cells
TDMA/TDD withSlotted Aloha
Reservation withSlotted Aloha
PacketFormat/Addressing
Various types oflink cells
Custom wirelessand LANE
see [POR94] see [RAY97] LANE
Handoffs/roaming Mobile initiated Mobile initiated Mobile initiated(with Mobile Manager)Infrastructureinitiated (with MobileRepresentative)
Mobile initiated Mobile initiated
Techniques forreliability
FEC with (8,4)linear codes
FEC (proposedReed-SolomonCodes for real-timetraffic andFEC/retransmissiosfor data
16 bit CRC andARQ
Data Link Controlfor error recovery
FEC
QoS MAC supports QoS Supported Priority for certaintraffic
Fixed slots availablefor QoS support
Worst case QoSestimate to be used
References [AGR96] [ENG95],[AYA96] [POR96],[POR94] [RAY97] [WAND96]
Table 3.3.1: Wireless ATM Activities
1 Lucent Bell Labs
European Wideband Wireless ActivitiesTable 4.3.1: European Wireless Wideband Activities
Project Full Name andNumber
Objective Details
MEDIAN AC006Wireless Broadband
CPN/LAN forProfessional and
ResidentialMultimedia Services
Evaluate andimplement a highspeed WLAN formultimediaapplications anddemonstrate it inreal user trials
Multicarrier modulation(512 channels + OFDM)
60 GHz band One base station at 155
Mbps, two portables, one at34 Mbps and one at 155Mbps
WAND AC085Wireless ATM
NetworkDemonstrator
Develop andevaluate a realisticWATMtransmissionfacility at 5 GHz
Data rates from 20 Mbps to155 Mbps
See previous section
SAMBA AC204System for
Advanced MobileBroadband
Applications
Demonstratemobile userapplications at upto 34 Mbps andprove the MBSconcept
Trial platform of 2 base and2 mobile stations operatingat 40 GHz
Design state of the artASICs
Implement mobilitymanagement and handoverfunctions
AWACS Advanced WirelessATM
CommunicationsSystems
Development ofsystem conceptand testbeddemonstration oftetherless publicaccess to B-ISDNservices
Low mobility terminalsoperating at 19 GHz
Data rates of up to 34 Mbps Transmission range of
100m Contribution to standards
development
Japanese Wideband Wireless ActivitiesTable 4.4.1: Proposed MMAC systems and their parameters
MMAC System High-Speed Wireless Access Ultra High-Speed Radio LANService Area Indoors and outdoor IndoorConnected Networks Public networks or private
networksPrivate networks only (ATM)
Transmission Speed Average 6-10 MbpsMaximum 25 Mbps
155 Mbps
Terminal Equipment Notebooks and PCs Desktop PCs and workstationsMobility Stationary or pedestrian
(handovers allowed)Stationary onlyRelocation handover permitted
Frequency Bands 25 or 40 or 60 GHz 60 GHzBandwidth 500-1000 MHz 1-2 GHzQuality bit error rate of 10-6 bit error rate of 10-8
MMAC: Multemedia Mobile Access Communications
Unlicensed PCS Activity (Spectrum Etiquette)
Three basic Principles:• Listen before talk (or transmit) LBT Protocol• Low transmitter power• Restricted duration of transmissions
Unlicensed National Information Infrastructure Devices
Table 4.2.1. FCC Requirements for the U-NII Frequency Bands
Band ofoperation
MaximumTx Power
Max. Powerwith antennagain of 6 dBi
Maximum PSD Applications:suggested and/or
mandated
Other Remarks
5.15 - 5.25 GHz 50 mW 200 mW 2.5 mW/MHz Restricted toindoorapplications
Antenna must bean integral partof the device
5.25 - 5.35 GHz 250 mW 1000 mW 12.5 mW/MHz Campus LANs Compatible withHIPERLAN
5.725-5.825 GHz 1000 mW 4000 mW 50 mW/MHz Communitynetworks
Longer range inlow-interference(rural) environs.
Issues in a Mobile Network• Type of roaming
– Intra-Net (802.11)– Inter-Net (GPRS)– Inter-Tech (between GPRS and 802.11)
• Type of mobility – Continual during a move– Access at different locations
• Type of connection – With a unique address (mobile IP) – With any address (cash IP)
• Type of initiation for roaming– From the terminal– From th network
Evolving Roaming Related Technologies
• Intra-Net Roaming– LANE in WATM– 802.11– Hiperlan
• Inter-Tech Roaming– MASE– Artour
• Inter-Net Roaming– Mobile-IP
Layers for Implementation
Physical
MAC
Network IP
Transportation TCP
Session
Presentation
Application
802.1
1, HIPERLAN,LANE
ARTour
Wins
ock
MASE{Mobile
IP
Mobile IP
Mobile HostMobile Host
Mobile HostMobile Host
MM
MM
SS
R1R1 R2R2 R3R3 R4R4
R20R20
RouterRouter Home AgentHome Agent
Foreign AgentForeign Agent
SenderSender
inform if possibleinform if possible
LCLocal cache
“IP in IP” Encapsulation
TCP and rest of packetTCP and rest of packet
IP Version number, and other header fields
IP Version number, and other header fieldsIP Version number, and other header fields
Tunnel Source IP address (home agent)
CARE-OF Address (foreign agent)
Original source IP addressOriginal source IP address
Home IP address of mobile hostHome IP address of mobile host
Why Client-Server is Important
• Most of the current legacy applications are client-server
• Facilitates implementation of mobility• Facilitates interoperability• Facilitates scaleability• Can support multiple platforms• Local optimization of the server to enhance reliability
and availability and results in reducing costs
Important Client-Server Applications
• Web search, • FTP, • Data base access, • Telnet, • Email
References
• K. Pahlavan , A. Zahedi, and P. Krishnamurty, “ Wideband Local Access: Wireless LAN and Wireless ATM”, invited paper, Speical Issue on WATM, IEEE Comm. Soc. Mag., Nov. 1997.
• K. Pahlavan and A. Levesque, Wireless Information Networks, New York: John Wiley and Sons, 1995. • K. Pahlavan, A. Falsafi, G. Yang, “Transmission Techniques for Wireless LANs”, IEEE JSAC, Speical Issue on
Wireless Local Communications, May 1996.
• K. Pahlavan and A. Levesque, “Wireless Data Communication”, Invited Paper, IEEE Proceedings, Sep. 1994. • K. Pahlavan, “Wireless Intra-Office Networks”, Invited paper, ACM Trans. on Office Inf. Sys., July 1988. (also
published as the opening paper in “Advances in Local and Metropolitan Area Networks”, edited by William Stalling, IEEE Press, 1994)
• K. Pahlavan, “Wireless Office Information Networks”, IEEE Comm. Soc. Mag, Sep. 1985. • K. Pahlavan, T. H. Probert, and M. E. Chase, “Trends in Local Wireless Networks”, Invited Paper, IEEE Comm. Soc.
Mag., March 1995.