Broadband Data Anytime, Anywhere: The Tropos Cellular Wi-Fi Mesh

1. Broadband Data Anytime, Anywhere:The Tropos Cellular Wi-Fi Mesh 09 February, 2004 Narasimha Chari Chief Architect

2. Agenda • Company background • Coverage and capacity • What determines capacity per end-user? • How to achieve uniformity of coverage? • Dense cellular approach provides uniform coverage together with high end-user capacity • Challenges with dense cellular approach • Tropos solution – synthesis of the best of WiFi, cellular and mesh • Case studies of some successful implementations • San Mateo Police Department • Cerritos, CA public access network

3. Company Background • Incorporated in 2000 • Raised $18.5M venture funding • Benchmark, Boston Millennia, Intel, Voyager, WK Technology • Experienced technical and management team • Cisco, IBM, Motorola, Nortel, Sycamore, 3Com • Caltech, Harvard, MIT, Stanford, UC-Berkeley, UI-UC • Patented Wireless Mesh Network Architecture • 1st product shipped mid 2002 • Sales into the U.S. public safety and ISP marketplace • Technical/Market Trials in Asia

4. Capacity per user: Cell size

5. Receiver Transmitter Wireless Medium Capacity per user: Shannon’s Law • Bandwidth of the medium • Signal Power (Receiver) • Noise Power (Receiver) Channel Capacity = Bandwidth x log (1 + Signal/Noise)

6. Capacity per user: SNR and Propagation Broadband requires uniform signal >> noise everywhere (≥ -90dBm for Wi-Fi) Signal drops off with inverse power law ~ (1/d)^n, 2<n<4 Obstacles create shadows, nulls, attenuation Reflections result in time-varying multipath fading Propagation through environment causes non-uniformity of coverage (SNR << 1)

7. Capacity per user: Conclusions • Uniform coverage requires signal above noise floor at receiver (SNR >> 1) • Signal power is lost to environmental absorption and scattering, working against the aim of uniformity • Large cells with high transmit power or focused beams/sectors require expensive hardware, but the resulting coverage isn’t necessarily uniform • Cell density determines aggregate capacity

8. Dense-Cells: Uniform Coverage with Capacity 1-10Mb/s+ 1-10Mb/s+ 1-10Mb/s+

9. Scalability challenges with dense cells • Economically, organizationally and physically impractical to deploy in large networks • Difficult and costly to manage Dense-Cells: Scalability Becomes Challenging

10. Wireless Network Architectures • 1970s: Wireless Mesh (military) • Self-Organizing • Rapid deployment • Resilient to failures • 1980s: Cellular Telephony (carriers) • Worldwide Adoption • Ubiquitous Coverage (licensed macro-cells) • 1990s: Wi-Fi (PC industry) • Unlicensed multi-megabit speeds • Open standard (IEEE) • Laptops, PDAs, Cell phones (very near future)

11. Combining the Best of • Wi-Fi • Cellular • Wireless Mesh Tropos Cellular Mesh: Metro-Scale Wi-Fi

12. Tropos Cellular Mesh: Metro-Scale Wi-Fi • eases deployment and scaling through a self-organizing IP network • allows wired backhaul to be added in line with subscriber growth by eliminating the need to wire every node • maximizes throughput, even in large networks • ensures reliability with an efficient self-healing architecture • offers accessibility and mobility to standard Wi-Fi clients.

13. Tropos 5110 Wi-Fi Cell with PWRP™ • Tropos Predictive Wireless Routing Protocol™ • IEEE 802.11b (Wi-Fi) • Carrier-grade Radio • Carrier-class Network Management • Easy to install and operate 9-16 per square mile

14. Market Focus: Public Safety • Need for more mobile bandwidth • To move applications from the office towhere they are needed – in the field • Less time in the office, more in the community • Tropos makes all HQ applicationsmobile • Police records, gang information,sex offender databases • Mug shots, fingerprints , Amber alerts • Maps, GIS data, floor plans, HazMat data • And enables some new ones • Real-time video surveillance and monitoring • Mobile, tactical broadband networks forincident command and control • Traffic management Improving Responsiveness, Efficiency and Safety

15. San Mateo PD Case Study • Hot zone installed in downtown and along major thoroughfare • Wi-Fi enabled laptops in patrol cars and Mobile Command Centers • Access to LAWNET, a county-wide law enforcement Intranet • Amber Alert Information • Sex Offender Database • CA Gang Database • DMV records, with high resolution photos • In-field photo lineups • Video monitoring in high-traffic areas “Our Wi-Fi network now allows officers to take their office mobile.Because our officers now have broadband access to critical information, they can more quickly solve crimes in our community.”Susan E. Manheimer, SMPD Chief of Police

16. Internet Service Provider: Cerritos, CA Shopping Center Cerritos College Industrial Jr. High Golf Course Industrial Park Industrial Elem Elem WS Elem GAHR HS Park Cemetery Valley Christian School Cerritos Towne Center City Hall & Library Lutheran School Park Elem Cerritos HS Park Los Cerritos Mall Cerritos Auto Square Elem Coverage area ~10 sq. miles Park Park Elem Elem Park Cerritos Regional County Park Park Park Edison Sub Station Jr. High Jr. High ROP

17. AiirMesh Cerritos Service Provider Case Study • AiirMesh is the service provider in Cerritos, CA • Offering public metro-scale Wi-Fi access • Managed service to businesses and residences • Roaming mobile add-on service • Service covers entire city • 9 sq. miles • 17,000 homes passed • Serves multiple market segments • Public service and safety access • In cooperation with City Manager • Network elements • Per user authentication and billing • Integrated 3rd party CPE device “Interference is a given in license-exempt bands, and mesh helps because it mitigates the effects of interference through self-organized re-routing.” John Greibling, CTO AiirMesh

18. ISP Network Back-end I Internet AAA Server Subscriber Page EMS/NMS Intrusion Detection Tropos Cells E-mail Server NOC Internet Service Provider: Cerritos, CA Public Access + Home Network CPE

19. Broadband Data Anytime, Anywhere:The Tropos Cellular Wi-Fi Mesh 09 February, 2004 Narasimha Chari Chief Architect