16-Wirless Networking Technologies Dr. John P. Abraham Professor UTPA
Personal area networks (PAN) Bluetooth – short distance InfraRed – line-of sight ISM wireless – communication using frequencies set aside for industrial scientific and medical devices.
Wireless Lan Technologies and Wi-Fi Already discussed speeds and frequency bands. See prior lectures.
Spread Spectrum Technologies Direct sequence spread spectrum (DSSS) Frequency Hopping spread spectrum (FHSS) Orthogonal Frequency Division multiplexing Standards – 802.11e, h, I, k, n, p, r, and s.
Wireless LAN architecture Access Point (base stations) connect to a switch or router. Wireless hosts connects to access points. Those hosts within the range of an access point are called Basic Service Set (BSS) Ad hoc – wireless hosts communicate among themselves without a base station. Infrastructure – stations connect to a base station.
Overlap, Association and 802.11 frame If access points are too far apart, we have a dead zone in the middle. If too close, overlap exist. But a host should only connect to a single access point. In wireless phone service there is a seamless handoff. Access points can coordinate like that. Cheaper access points do not coordinate and the user will have to pick.