User's Guide

Table Of Contents
hwc_apstartup.fm
Configuring the Wireless AP
Wireless AP overview
9034530-02,
March 2010
HiPath Wireless Controller, Access Points and Convergence Software V7.11, User Guide 93
interference. The radios of 802.11n AP can use two channels at the same time to
create a 40 MHz wide channel. By using the two 20 MHz channels in this manner,
the 802.11n AP achieves more than double throughput. The 40-MHz channels in
802.11n are two adjacent 20-MHz channels, bonded together. This technique of
using two channels at the same time is called channel bonding.
Shortened guard interval
The purpose of the guard interval is to introduce immunity to propagation delays,
echoes and reflections of symbols in orthogonal frequency division multiplexing
(OFDM) — a method by which information is transmitted via a radio signal in
Wireless APs.
In OFDM, the beginning of each symbol is preceded by a guard interval. As long
as the echoes fall within this interval, they will not affect the safe decoding of the
actual data, as data are only interpreted outside the guard interval. Longer guard
periods reduce the channel efficiency. The 802.11n AP provides reduced guard
periods, thereby increasing the throughput.
MAC enhancements
The 802.11n AP also has an improved MAC layer protocol that reduces overhead
(in the MAC layer protocol) and contention losses. This results in increased
throughput.
Models
The Wireless 802.11n AP is available in the following two models:
Model AP3610 – Six internal antennas
Model AP3620 – Three external antennas
Note: Any Wireless 802.11n AP model number in the Hardware Version box on
the Properties tab that ends with -1 is a Wireless 802.11n AP that has its DFS
channels disabled. For more information, see Appendix B.
Environment
The Wireless 802.11n AP cannot be deployed in an outdoor environment.
4.1.3.1 HiPath Wireless 802.11n AP’s radios
The HiPath Wireless 802.11n AP is equipped with two radios — Radio 1 and
Radio 2. The following is a block diagram of the HiPath Wireless 802.11n AP
equipped with external antennas.