wireless deployable network system (widens)nikaeinn/files/widens/widens.pdf · 4.9 regulation in...

1

Wireless Deployable Network System (WIDENS)An Ad Hoc Network for Public Safety Application

www.widens.org

Navid Nikaein and Raymond KnoppInstitut Eurecom

http://manet.eurecom.fr

http://manet.eurecom.fr/

http://www.widens.org/

http://www.eurecom.fr/

http://www.thalesgroup.com/home/home/index.html

http://www.ua.ac.be/

http://www.eads.net/

http://www.hut.fi/English

http://www.tid.es/

http://www.multitel.be/

http://www.upc.es/

http://www.widens.org/

@July 1st, 2005 ©Navid Nikaein2

WIDENS

European 6th Framework Information Society Technologies (IST) Collaborative Industry/Academia Research ProjectDescription:

Rapidly-deployable reconfigurable Wireless Ad Hoc communication system for future public safety, emergency and disaster applications

Time frame : February 2004 – January 2006Total Research Funding: 2,9 MeuroProject Cost : 5,9 Meuro


Motivation

Interest among PMR players in US and Europe in broadband rapidly deployable systems

e.g. 4.9 GHzInterest of military manufactures

First ad hoc deployable system, e.g. SURAN, GloMo, JTRC

MESA Project ETSI/TIA standardization effort


Introduction to Widens

ObjectivesPropose and prototype a new generation of interoperable public safety systemDesign a self-organised communication infrastructure anticipating and responding to future emergency applications and servicesParticipation on Joint TIA/ETSI MESA activities (standardization issue)

ChallengesPublic Safety users

Identify core functionalities of such systemCollaborate with specialists and professional organisationsIncrease their efficiency during emergency operations

Technological aspectsDesign a scalable communication system, rapidly deployableValidate its feasibility through a prototype and the definition of scenarios

Market interestsPropose ad-hoc hotspots as access networks to existing PMR


Broadband Target

1996 1998 2000 2002 2004 20060.01

0.1

1

10

100

1000

2.4Ghz

5 Ghz

60 Ghz

HIPERLAN/1 802.11b

HIPERLAN/1 802.11a

Piconets, scartternets

WLAN

Ultrawideband

PAN

Cellular HSDC GPRS

EDGE

UMTS

Space/time coding Bluetooth

Home RF

WIDENS


Project Structure:Focus WP4

- Mobile ad Hoc system architecture - Integration of the system in a single terminode prototype plat-form - Validation in open air field trial- Contribution to MESA standards

WP2:System

Architecture

WP5:Integration and

evalutaion

WP6 : Dissemination

WP3:Scalable auto-

configurable network

WP4:Ad Hoc Mac and Phy

adaptations

WP1 : Project Management

Results of the project


RF Issues:4.9 Regulation in USA

Feb.14 2002, Confirmed May 2, 2003 : FCC transfers 4.9 GHz band (4940-4990 MHz) from Federal Government use to systems in support of public safetyTo be used for a variety of broadband applications

both temporary and permanent operationsboth fixed and non-aeronautical mobile applicationspermits “hot spot” operationspermits operation of temporary fixed links (< 1 year)

Largest single FCC offering for public safety spectrum in history – direct result of 911 and lobbying by Motorola/APCO


4.9 GHz:Frequency Utilization

1 MHz Channels 5 MHz Channels

UWB (unlicensed)

Licensees authorized to use 50 MHz of spectrum in 4.9GHz band.

Ten 1 MHz channels and eight 5 MHz channelsAggregation to 20 MHz permittedTime-Division Duplexing in spirit (although FDD not explicitly ruled out)


First Link Budget (5.85GHz)

Tx/Rx Separation

(m)

5.85 GHz Outdoor

Path Loss wrt1m FS(dB)

Receive Power(dBm)

Maximum Bitrate (Mbps)BER=10e-5,Gemtek 802.11a receiver

Normalized to 7.68 msps

10 30 -41 20.8

20 38 -50 20.8

30 45 -57 20.8

40 47 -59 20.8

50 50 -62 20.8

60 52 -64 20.8

70 54 -66 20.8

80 56 -68 20.8

90 58 -70 20.8

100 60 -72 18.5

200 67 -79 13.8

250 70 -82 9.2

300 72 -84 6.9

400 75 -87 4.6

500 79 -91 2.3

600 81 -93 <2.3 (undefined for 802.11a), timing synch still possible





•Measurements performed at

Virginia Tech (MPRG 1998)

•NLOS flat suburban area, foliage, houses, 5.5m TX antenna

•Results for 25 dBm/11.5dBi TX, 0dBi RX


User Studies

Collaboration with professionals (fire services, police, ambulance)Characteristics identification (structure, deployment and applications)

Preliminary resultsDetailed organisational structure varies between different public safety forcesCommon characteristics

Deployed in small groups of several units interacting among each otherMainly following a hierarchical structureBut, direct communication should also be provided to increase the autonomy of each players

Deployment topology depends on the type and on the size of the emergency scenePublic Safety deployment scenarios fall into four groups

Concentration around a point (e.g. a bus crash)Front line (e.g. forest fires, floods)Ring: working around a place (e.g. urban fires, bomb deactivation)Random Distribution (e.g. an earthquake)


Typical Scenarios:Concentration, Front, Ring, Random


Requirements of Public Safety Applications

Broadband, reliable, and secure linksReconfigurable and rapidly deployable systemAdaptive and optimized layer interaction: cross-layerSupport for organizational structure of public safety users

User interactions Network topologyUsers’ priority

Support for user requirementsHard QoS for multimedia applications

Note: Firefighters, peacekeeping forces, emergency doctors, rescue teams are typical public safety users


WIDENS MAC/PHY LayerTightly coupled MAC/PHY layer

Opportunistic scheduling based on wideband channel quality and traffic volume (temporal)Carrier and antenna multiplexing Cross-layer optimization

MAC defines a cluster-based topologyMAC frame is time-slotted, like TDMA

Network time synchronization is done by cluster-heads Hard QoS Support

MAC is Connection-lessChannel access is quasi random but contention-free due to feedback based scheduling

Fully reconfigurable MAC/PHY: SDR ConceptOFDM(A) & multi-antenna capable: Spectral Efficiency


Reconfigurability: Cluster Topology

Nodes are capable of multi-hop routingNodes can dynamically assume three roles

Cluster-head: regulate/coordinate traffic within a clusterRelay: interconnect to clustersGateway: interconnect to other networks

Cluster topology is built dynamically Geographic/Propagation characteristics of terminodesProcessing capabilities of nodes

DSP (e.g. MIMO)Multiple-frequency capacity (tune on several channels at once)Power-levels

Connectivity of nodes with other networksConnectivity with fixed and wireless networks


Illustrative Deployment: Example

ClusterheadsRelays

Cluster-head synchronization signal is designed to allow adjacent cluster, which are out of communication range, to synchronize to each other Cluster-head is not an AP or BS: no concept of UL & DLPossibility of nodes being connected to several cluster-heads

multi-hop Routing


Reconfigurability:RF Agility

Nodes need to tune over wide bandwidthsRegional differences in allocations

Same equipment for different nationsExploit temporary openings in spectrum for covering special events (Olympics, political event, etc.)Spectrum efficiency via dynamic channel allocation (network determines best frequency planning)Interoperability with cellular systems

Reuse of existing 2G/3G terminals in emergency scenarios by playing role of BTS/Node-B

Dual-band radios addressed in WIDENS2 GHz legacy radios (3G, narrowband tuning)4-6 GHz for new Ad Hoc MAC/PHY (wideband tuning)


Reconfigurability:Software Radio

No one air-interface/network topology is optimal for every emergency scenarios Radio parameters should be adjustable (at least offline prior to deployment)

Framing as a function of delay requirements (typical services), short (a few ms) or long (tens/hundreds of ms)Modulation/coding as a function of propagation environment (rich or no multipath, time-variation)

Example: Number of OFDM carriers, pilots, prefix length, subband-allocation possibilities


Reconfigurability: Algorithm Adaptation

Goal: Maximizing spectral efficiency (better services)Adapt as a function of a specific propagation environment

E.g.1: nodes adapt (or download from a peer in the network) DSP algorithm (e.g. MIMO) to suit multi-path richness (e.g. outdoor/indoor)E.g.2: nodes adapt different scheduling algorithms depending on the application senarios either at deployment or over-the-air


Channelization


MAC/PHY Channels

CHSCH – Synchronization ChannelTime (slot/frame) synch delivered by CHAllows for time/freq synchronization of cluster, detectable across clusters for multi-cluster synchronization

CHBCH – Beacon channelTemporal resource allocation (TxOps)

MCH – Measurement ChannelContention-free broadcast by each node (except CH)Relays wideband channel measurements (via pilots) to connectivity regionRelays QoS queueing information to CH for fair TxOps scheduling respecting L3 negotiated QoS1-hop link information (in support of L3 routing algorithms)2-hop Neighborhood information (in support of L3 routing algorithms)

SACH/SACCH – Scheduled Access Channel Node data channel granted by CH on slot-by-slot basis every frame (<20ms)Dynamic Allocation (Scheduling) on frequencies/antennas

Exploit both Multiuser Diversity and spatial multiplexingScheduling algorithms with both hard QoS (fixed rate/delay-limited multiuser diversity) Soft QoS guarantees (proportional fair, maximum throughput, maximum goodput, etc.)


Hierarchical Opportunistic Scheduling

Scheduling (polling) is a hierarchical process involving both the cluster-head that provides transmission opportunities (TxOps) and nodes themselves acting as routers that finely control physical resources

CH schedules TxOps based on QoS, traffic volume and wideband channel quality measurements Nodes maps their traffic queues over physical resources using reconfigurable scheduling policies satisfying different QoS based on wideband channel measurements w.r.t. their destinations

Indeed, the MAC sees the PHY as a resource over which several data flows can be finely scheduled


Hierarchical Scheduling

MCH feedback (Traffic Volume)

CH

Relay Relay

CH

CHBCH allocations (TxOps)

SACH allocations (spatial OFDMA)

Relay

CH

21

Legend2


Demonstration Equipment

For the WIDENS demonstrator, new reduced form-factor PCMCIA SDR modules have been developed

MIMO capable (two-antennas) multi-frequency capable

2 GHz today 4-6 GHz at end of project

An important part of signal processing can be performed on the onboard FPGA in order to reduce the burden on the host PC.

FPGA AD/DA

RF

WIDENS-specific equipment (2GHz,5GHz at end)


SDR Design Flow (L1/L2/L3)L1/L2 Specs L1/L2

C Implementation

PC Cluster RF Emulator L1/L2 Specs L1/L2C

Implement.

L3 Specs L1/L2/L3C Implemnt

In LinuxBased RTOS

Real-timePC-based Terminalswith real RF.

Port to SoPC(reconfigurable hardware)

Embedded system


Conclusion

WIDENS is the first European IST project in the area of future public safety communication and information systems The project will contribute to the development of future integrated European public safety systemdevelopment by providing system concept and technology platform for ad hoc broad band rapidly deployable network.Reconfigurability and cross-layer optimization are a built in feature in the design of the system and not only in its implementation

wireless deployable network system (widens)nikaeinn/files/widens/widens.pdf · 4.9 regulation in...

Documents