Overview of Cellular Networks Mobile Ad hoc Networks Sensor Networks

WIRE- LINE NETWORK WIRE- LINE NETWORK Base Station (BS) Cell Wireless Links Wired Links Mobile Switching Center (MSC) Mobile unit Cellular Architecture - Infrastructure-based networks - All units are fixed in location except mobile units - BS and MSC are connected via wirelines - Communication between BS and mobile unit is wireless

 Characteristics - Infrastructure-less - All nodes are potentially mobile - Network topology is dynamic - All nodes act as individual routers  Examples - Disaster recovery situations - Battle field communications - Law enforcement operations - Civilian applications -  Objectives - Maintain connectivity between mobile devices - Provide congestion-free routing for multimedia traffic - Support scalability - Minimize memory, bandwidth and energy consumption Why Mobile Ad hoc Networks?

Mobile Ad hoc Networks transmission range

 Use infrastructure when convenient  Use ad hoc connectivity when necessary or superior E A BS1BS2 X Z infrastructure Ad hoc connectivity Hybrid Environments © 2001 Nitin Vaidya

Symmetric environments Symmetric environments Asymmetric capabilities Asymmetric capabilities Asymmetric responsibilities Asymmetric responsibilities Traffic characteristics Traffic characteristics May co-exist (and collaborate) with an infrastructure-based network May co-exist (and collaborate) with an infrastructure-based network Mobility patterns Mobility patterns Mobility characteristics Mobility characteristics Variations © 2001 Nitin Vaidya

 Characteristics - low-cost, low-power, small in size - two-ways of deployment: pre-determined and random - densely deployed - prone to failures  Application Areas - Military - Environmental - Health - Home  -  Objectives - Monitor activities - Gather and fuse information - Communicate with global data processing unit Sensor Networks

 Clustering –Partitioning of the network –Identification of vital nodes (clusterheads)  Routing –Discovering routes from source to destination –Maintaining the routes –Rediscovery and repair of routes  Topology management –Maintain the links –Minimize the changes in underlying graph  Security Research Problems in Ad hoc and Sensor Networks

 Medium Access Control Protocols  Sensor management  Power conservation/energy consumption  Data fusion and dissemination of sensor data  New applications for ad hoc and sensor networks Research Problems in Ad hoc and Sensor Networks