6 kbps for 10 to 100 users within a few kilometer

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: pment that are part of the LAN. A wireless LAN may be further connected to a more extensive fixed network such as LAN, WAN, the Internet, etc. The primary component of a wireless LAN is the wireless interface card that has an antenna. This interface card can be connected to the mobile unit as well as to the fixed network. Wireless LANs have limited range and are designed to be used only in local environments such as a building, hallway, park, or office complex. The main advantage is the flexibility and mobility supported by a wireless LAN; bandwidth considerations are secondary. Unlike cellular networks with allocated channels (frequencies), users in WLANs have to share frequencies, which may eventually lead to collisions. The choice of frequency depends on whether microwave, spread-spectrum, or infrared communication will be used. Interference and security depend on the type of communications method used in the WLAN. The following three are the primary WLAN standards: 1. IEEE 802.11. The IEEE 802.11 standard supports 1 Mbps data rate and several choices of physical medium such as spread spectrum and infrared. It also supports prioritized access to the medium. An additional feature of this standard is battery conservation for inactive or idle wireless users. Many universities and companies are encouraging the use of IEEE 802.11-based LANs for accessing campus computing systems and the Internet. The IEEE 802.11 standard is being enhanced to support 11 Mbps data rate. 2. HiperLAN. The HiperLAN standard can be used to support 23.5 Mbps channel rates. It, however, allows the use of only spread spectrum physical medium. Like IEEE 802.11, it also supports prioritized access to the medium. 3. HiperLAN2. Another emerging WLAN standard is HiperLAN2, which is being standardized by ETSI (European Telecommunications Standard Institute). An exciting feature of this standard is that it provides for use of connections that offer different quality of service for different applications. It uses time-division multiplexing of unicast, multicast, and broadcast connections. Many major players in the WLAN area have formed HiperLAN2 Global Forum to advance and complement the ETS1 standardization process. Wireless Local Loops (WLLs) Wireless Local Loops (WL...
View Full Document

This document was uploaded on 04/07/2014.

Ask a homework question - tutors are online