1. Intro Wireless vs. wire-based communication –Costs –Mobility Wireless multi hop networks Ad Hoc networking Agenda: –Technology background –Applications

2. Ad Hoc vs cellular

3. Ad Hoc network characteristics Multi hop wireless –Spectral efficiency => capacity –Latency? –Routing around obstructions Self-configuring –Minimal configuration, no infrastructure Signaling overhead –Network size  Node mobility Limitations: battery life, bandwidth

4. Radio Requirements: bandwidth, scalability, low costs, support of mobility, low power consumption, range IEEE 802.11 Wireless LAN, Bluetooth, HiperLAN/2 etc. Lower than expected scalability Mobility issues

5. Wireless network capacity Network size Capacity Ad Hoc, in theory using multiple Antennas, BLAST (linear scaling) Ad Hoc, in theory using single Antennas PTM radio, no scaling Ad Hoc, IEEE 802.11b, measured

6. Ad Hoc routing Multihop -- each node acts as a router Adapting to dynamic topology changes Overhead with large and mobile networks AODV, DSR, OLSR, TBRPF Scalability –Clustering and hierarchical routing

7. Security and QoS Unsecure wireless links Secure routing - redundancy Key management – distribution of trust QoS models - IntServ, DiffServ, FQMM QoS routing - redundancy QoS signalling - RSVP, INSIGNIA

8. Standardization Routing, QoS, security –IETF –RFCs, Internet-drafts Radio –IEEE 802.11 –ETSI: HiperLAN/2, Bluetooth

9. Technological challenges Common WLAN radio technologies badly suited for large scale or mobile multi hop wireless communication (IEEE 802.11b and especially bluetooth) Scalability of routing protocols Security and Quality-of-Service still far from standardization at IETF

10. Ad Hoc network apps. Mesh Networks Nokia, Radiant networks Intel,… Sony, Nokia,… Network Size Mobile data access, including vehicle networks Node mobility Fixed broadband Home and personal networks Sensor networks

11. Fixed broadband access Fixed wireless broadband vs. wired broadband Ad Hoc networks as access networks Radio technologies and routing protocols Fixed broadband with multi hop wireless routers –NLOS, higher throughput, low cost deployment –Nokia, Radiant Networks, etc

12. Mobile access Extending cellular infrastructure Higher throughput, extended coverage, lower power consumption Mobility vs. network size => scalability ? Standardization: popular WLAN technologies vs. ad hoc networking Mesh Networks Mesh Enabled Architecture –Wireless routers as access points, terminals act as routers

13. More applications Sensor networks –Low power sensor devices –Ad hoc networking for extended battery life Vehicle networks –Automobiles act as ad hoc network nodes –Fast mobility, still in research phase Home networks –Consumer electronics form self organizing networks

14. Timing Fixed wireless access, Military & emergency Now Sensor networks, Home networks Mobile access, Vehicle comm. 20042006 Personal comm., Portable access 2010 ?

15. Conclusions Ad Hoc networking increases the efficiency of wireless networks Ad Hoc networking can be applied to a wide range of applications Ad Hoc networking has the potential to radically change the way wireless networks operate

16. Thank you!