802-11 qos-ps.pdf

802-11qos-ps.pdf

Agenda
l Introduction & IEEE 802.11 standards
l Challenges of Wireless Networks
l Cross-Layer wireless Networks
l Multimedia multi-path diversity

IEEE 802.11 wireless standards
l 802.11- The IEEE standard for wireless Local Area Networks. It uses three
different physical layers, 802.11a, 802.11b and 802.11g.
l 802.11a– Operating in the 5 GHz band, 802.11a supports a maximum theoretical
data rate of 54 Mbps, but more realistically it will achieve throughput somewhere
between 20 Mbps to 25 Mbps in normal traffic conditions adds OFDM (orthogonal
frequency division multiplexing) to the standard for high data rates in the U-NII
band
l 802.11b– operates in the 2.4 GHz band and adds 5.5 Mbps and 11 Mbps
capability to the original standard
l 802.11e – future extension to maintain quality-of-service capability for some
applications
l 802.11g – future extension for 2.4 GHz links using OFDM for 22 Mbps data rate
l 802.11h- future of MAC to comply with European regulations for 5GHz WLANs.
l 802.11i– future extensions for security. It defines new encryption key protocols
including the Temporal Key Integrity Protocol (TKIP) and the Advanced Encryption

l 802.11c
Modified 802.1d -- MAC level bridging
l 802.11d seeks to help create standards that will be approvable in as many different
countries as possible.
l 802.11f
Inter-access point roaming protocol. Will let you move through a wireless LAN with
multiple access points from different manufacturers, and maintain your connection.
l 802.11k
A recently started project to standardise the way 802.11a, b and g networks report
measurements of radio and network conditions to other parts of the network stack
and new applications. Should be good for network management, fault finding and
other
l 802.11m
A collection of maintenance releases for 802.11 as a whole. Internal IEEE
housekeeping.