Specifications

Summit WM Getting Started Guide, Software Version 5.1 71
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 method, the beginning of each symbol is preceded by a guard interval. As long as the echoes
falls within this interval, they will not affect the safe decoding of the actual data, as data is 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 improved MAC layer protocol that reduces the overheads (in the MAC layer
protocol) and the contention losses. This again results in increased throughput.
NOTE
The Altitude 802.11n AP is backward-compatible with existing 802.11a/b/g networks.
NOTE
The Altitude 802.11n AP cannot operate as a stand-alone access point.
The 802.11n AP is available in the following two models:
● Altitude 450 – Three internal antennas
● Altitude 451 – Three external antennas
NOTE
The 802.11n AP cannot be deployed in an outdoor environment.
Wireless AP’s default IP address and first-time configuration
Wireless APs are shipped from the factory with a default IP address — 192.168.1.20. The default IP
address simplifies the first-time IP address configuration process for Wireless APs. The Wireless AP
returns to its default IP address if it is not successful in its discovery process.
The Wireless APs can have their IP addresses assigned using either of the following two methods — a
Dynamic Host Configuration Protocol (DHCP) server assigns the IP address, or an administrator assigns
the IP address using the static configuration option. The DCHP IP address assignment method is the