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RURAL TELECON ’07
A HYBRID SECTORAL/AD HOC MESH NETWORK ARCHITECTURE FOR RURAL
BROADBAND WIRELESS COMMUNICATIONS
OCTOBER 15, 2007
KEN SCHLAGER, Ph.D., P.E.SOUTHEASTERN WISCONSIN REGIONAL PLANNING COMMISSION
WAUKESHA, WISCONSIN
and
PRESIDENTHIERCOMM, INC.
HARTLAND, WISCONSIN
Supported by:SBIR PHASE II GRANT
U.S. DEPT. OF AGRICULTURECOOPERATIVE STATE RESEARCH, EDUCATION AND EXTENSION SERVICE
GRANT NUMBER: 2006-33610-16317
#131426
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Agenda
• Sectoral Cellular Broadband Wireless– Fourth Generation (4G) Performance– Low Infrastructure Costs– High Gain Active Antennas
• Sectoral Cellular Weaknesses– Serves only fixed users– Lacks redundancy
– 99.9% reliability (?)– Enter adaptive mobile mesh network– A Hybrid Sectoral/Adaptive Mesh
Network
• Public Safety Communications and the 9/11 – Katrina Problem
– Consistent failure of communications networks in major public emergencies
– Ad Hoc Mesh Networks and the DOD– The Kenosha County 4.9/5.8 GHz
Public Safety Communications Project
• Wirlwind– An Ad Hoc Routing System– Architecture Technology Corp.– USDA SBIR Grant
• Kenosha County Project– Fusion of Sectoral/Cellular and
dynamic mobile mesh topologies– Long range, high performance
WiFi– Wirlwind Ad Hoc networking
• The Hybrid Solution– Basic Sectoral Cellular Network– Peer-to-Peer Connect– The User Routing Node– Redundant, Reliable High
Performance Network
• Current Status and Plans
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Conceptual Sectoral Cellular Network
Source: SEWRPC.
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Conceptual Mesh Network
Source: Tropos and SEWRPC.
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Sectoral Cellular Network – Costand Performance
• Infrastructure Cost– Town of Wayne, Wisconsin– Land Area – 36 square miles– Access Point Infrastructure– Four (4) APs– AP Density = 0.1/square mile– Total Cost = $80,000 - $2,200/square mile– Including
– Internet gateway– Network management system– Engineering, installation and training
• Mesh Network Alternative Costs– 16 to 80 APs/square mile– Areal cost: $100,000 - $250,000/square mile
• Sectoral/Cellular Network Performance– 10 – 30 megabits per second range
• Mesh Network Alternative Performance– 1 – 3 megabits per second
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Sectoral Cellular Network – Costand Performancecontinued
Basis of Technology
• Network Topology– Allows for use of higher gain directional antennas– Omnidirectional antenna
– 5 – 8 dBi– Directional antenna
– 14 – 17 dBi– 8 times the signal intensity
• Active Antenna– Antenna with high gain, low noise amplifier– Additional gain of 20 dBi and more– 100 times the signal intensity
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Four Access Point Locations, Town of Wayne, Wisconsin
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Backhaul Network, Town of Wayne, Wisconsin
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Sectoral Cellular SystemWeakness and Remedies
• Limited to Fixed Users– Directional antenna requires fixed location– Nomadic and mobile users require omnidirectional antennas– Limited distance from access point
• Lack of Redundancy– No alternative transmission paths– Reliability goal of 99.9%– Wireless networks now far below this target
• Solution: Users as Nodes– If each user could serve as a node to pass on signals to the sectoral AP, the
performance of the network for nomadic users would be greatly enhanced– Enter Peer-to-Peer wireless communications and dynamic, mobile Ad Hoc
mesh networks
• Solution: Higher Performance Laptop Computers– The Active Omnidirectional Antenna– As a laptop computer attachment– For 25 -30 dBi gain
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Public Safety Wireless Communications and the 9/11 – Katrina Problem
• Consistent Failure of Public Safety Communicationsin Major Public Emergencies
– Oklahoma City– 9/11– Katrina
• Causes of Failure– Power outages– Tower damage– Flooding– Network saturation
• Problem with Current Public SafetyCommunications Systems
– Very low data transfer rates– Networks do not survive a disaster event
• Solution– Networks that are independent of fixed infrastructure– Peer-to-Peer communications
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SEWRPC/HierComm/Architecture Technology Corp.and Kenosha County, Wisconsin
• Objectives– To bring broadband to public safety wireless communications– To solve the network survivability problem– To provide a public/private business model for broadband wireless
communications– To extend the sectoral/cellular network model to nomadic and fixed users
• Task #1 – Long Range 4.9 GHz Wireless Communications– To demonstrate extended range, high gain throughput performance at 4.9
GHz– In mobile public safety vehicles
• Task #2 – Peer-to-Peer Communications– To demonstrate adaptive peer-to-peer wireless communications– With and without infrastructure– Selecting the optimal transmission path– Using Architecture Technology Corp. (ATC) Wirlwind
4.9/5.8 GHz Public/Private Wireless Communications Project
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Project WirlwindWireless Wide Area Incident Network
Technical Partnership
HierComm – RF hardwareArchitecture Technology – Network software
USDA SBIR Grant Recipients
HierComm – Rural Wireless Broadband CommunicationsArchitecture Technology – Wirlwind for US Forest Service
Wirlwind
• Ad Hoc Mobile Mesh Network Software Package• Connects user to strongest signal node• Dynamic mobile or fixed location nodes• Project 25 compliant communications• Send/receive voice or data• Geolocation-based communications
– Two technologies– Ad Hoc routing Real-time geographic tracking of nodes and geomessaging
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Wirlwind: Ad Hoc Routing
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Wirlwind: Ad Hoc Routing—continued
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Wirlwind
Ad Hoc Routing
• SARA – Source Initiated Adaptive Routing Algorithm
• Advantages/Features– Implemented working algorithm
– Not just research– Multi-platform = Windows, Linux– Symmetric and Asymmetric Links
• DOD/DARPA funded
Geolocation
• ATC’s GeoTIDES– Geographically Targeted Information Dissemination System– Communication often involves many different groups at various locations and requires
knowledge of location of people and resources
• Advantages/Features– Dynamically tracks all nodes with GPS– Allows transmission of data to geographic coordinates or regions– Geotracking– Geocasting, Geomessaging
The Technology
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Wirlwind Phase I Prototype
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Kenosha County
Task I – Network Planning
• Preliminary County-Wide Network– Radio propagation modeling– Clutter database
• Demonstration Area Network– Two base Stations– Mobile vehicular users
Task II – Equipment Planning
• Base Station Equipment– 4.9 GHz Transceivers (3)– 5.8 GHz Transceivers (3)– Amplifier Augmentations (6) – 3 inch each frequency band– 4.9 GHz Sectoral Antenna (1)– 5.8 GHz Sectoral Antenna (1)
• Mobile Vehicular user Equipment (4.9 GHz only)– 4.9 GHz omnidirectional antenna– 4.9 GHz high gain amplifier– 4.9 GHz transceiver
4.9/5.8 GHz Public Safety/CommercialWireless Network Demonstration Project
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Kenosha County4.9/5.8 GHz Public Safety/CommercialWireless Network Demonstration Project—continued
Task III – Field Demonstration – High Performance, Low Base Station Density Network
• Test truck testing
• Public safety vehicular installation
• Public safety vehicular testing County-wide network plan confirmation
Task IV – Field Demonstration – Peer-to-Peer Communications
• Training
• Test Truck testing
• Public safety vehicular testing
• Public emergency simulated testing
Task V – Full-scale Deployment Planning
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The Upgraded Sectoral/Cellular Boardband Wireless Network
• Enhanced Sectoral/Cellular Network– Augmented by user repeater nodes– For service to nomadic (laptop) and mobile (cell phone) users– A cost effective solution
• A More Robust Network– For public safety– For commercial WiFi
• A Mostly Software Augmentation– Unlike the hardware-oriented Sectoral/Cellular Network– Wirlwind software in all fixed, nomadic and mobile nodes– Minor hardware adjustments
The Hybrid Solution
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Current Status and Plans
• Wayne, Wisconsin Network– As a model high performance, broadband wireless, rural
communications system– Technological demonstration
– Performance– Reliability
– Business model demonstration– Return on investment (ROI)– CPE cost problem
• Search for a National Partner– Convincing a major telecommunications partner of the viability of the
technology and the business model– Otherwise, progress will be slow