Drahtlose Ad-hoc-Netze: Simulation, Implementation und Test
Introduction
Winter Semester 2018/19 Organisation
Content
• Introduction
• Wireless networks (recap) and introduction to ad-hoc networks
• Media access control – problems specific for ad-hoc networks
• Topology control and routing in wireless ad-hoc networks
• Wireless sensor networks – algorithms and applications
• Vehicular networks – algorithms and applications
• Implementation of wireless ad-hoc networks (real time operating
systems)
Introduction
• Wireless communication (ambiguous?)
• Early solutions
• Wireless radio communication!!!
Wireless network – informal definition
• Wireless network – an interconnected system using radio waves as means of communication
• Radio waves = electromagnetic waves
• No physical cable or wire connecting the parts of the system
Wired networks vs wireless networks
• Advantages of wireless networks over wired networks
• Mobility – not limited to fixed place
• Flexibility and scalability – easy to add new users/parts of the network
• Installation (cost and speed) – no drilling, no cabling
• Reach – radio signal can get to the places which cables cannot reach
• Disadvantages
• Speed – nowadays wireless communication is getting faster but…
• Reliability – transmission of radio signals
• Security – transmission of radio signals
Typical parts of wireless network
Wireless network – mode
• Infrastructure mode
• All network nodes are connected to others via Wireless Access Point
• Star topology
Wireless network – mode
• Infrastructure mode
• All network nodes are connected to others via Wireless Access Point
• Star topology
• Ad-hoc mode
• Each node can communicate directly to the other nodes
• In general mesh topology
Communication parameters
• Speed
• How quick we can reliably transfer information from one network node to another
• Range
• What is the area that we can cover?
Wireless network – speed
• Dependent on:
• The distance between the network nodes
• Interferences – other electronic devices and communication from the other network nodes
• Number of nodes
• Power of transmission
• Obstacles – specially solid object made of metal
• Standard
Wireless network – range
• Power of transmission
• Interference
• Number of nodes in the network
• Obstacles
Wireless network – range
• Power of transmission
• Interference
• Number of nodes in the network
• Obstacles
• Can we increase the range of a wireless network?
• Signal booster?
• Using access points (more access points?)
