Wireless Internet Access

Zsoldos Gábor <gabor_zsoldos@hu.ibm.com>

IBM

Two basic applications of wireless networks:

• Wireless local area networks (WLAN)

• Connecting LAN segments: Wireless Bridges

  • This presentation is dealing with the latter one.

Characteristics of ISM (Industrial, Scientific, Medical) frequency range

Spread Spectrum applications: features of Direct Sequence modulation

The principles and main characteristics of the applied method will be presented;

channels, frequency ranges, data rates.

Features of point-to-point configuration

Features of point-to-multipoint configuration

Comparison of p2p and p2mp topologies

Propagation characteristics of the applied radio waves (line-of-sight, Fresnel zone)

Some typical questions:

• Antennae, antenna-gain

• Bandwith considerations at point-to-multipoint configurations

• Distance stretching by application of repeater stations

• Other methods to increase the range

Data security: WEP (Wire Equivalent Privacy) extension: 802.1x, dynamic key distribution

Lightning protection

Regulations, restrictions

• The base of regulations: the radiated power (EIRP)

• Characteristics of FCC (USA) regulation

• Characteristics and restrictions of ETSI (Eu) regulation