User's Manual

- 67 -
WLAN Broadband Router
User Manual
Ad hoc mode (also called peer-to-peer mode or an Independent Basic Service Set, or IBSS) is simply a
set of 802.11 wireless stations that communicate directly with one another without using an
access point
or any connection to a wired network. This mode is useful for quickly and easily setting up a wireless
network anywhere that a wireless infrastructure does not exist or is not required for services, such as a
hotel room, convention center, or airport, or where access to the wired network is
barred (such
as for
consultants at a client site).
5.5 What is BSSID
Example 2: wireless Ad Hoc Mode
A six-byte address is that distinguish a particular a particular access point from others. Also know as
just SSID. Serve as a network ID or name.
5.6 What is ESSID
The Extended Service Set ID (ESSID) is the name of the network you want to access. It is used to
identify different wireless networks.
5.7 What are potential factors that may causes interference
Factors of interference:
Obstacles: walls, ceilings, furniture… etc.
Building Materials: metal door, aluminum studs.
Electrical devices: microwaves, monitors and electrical motors.
Solutions to overcome the interferences:
Minimizing the number of walls and ceilings.
Position the WLAN antenna for best reception.
Keep WLAN devices away from other electrical devices, eg: microwaves, monitors, electric
motorsetc.
Add additional WLAN Access Points if necessary.
5.8 What are the Open System and Shared Key authentications
IEEE 802.11 supports two subtypes of network authentication services: open system and shared key.
Under open system authentication, any wireless station can request authentication. The station
that needs
to authenticate with another wireless station sends an authentication management frame that contains the
identity of the sending station. The receiving station then returns a frame that indicates whether it
recognizes the sending station. Under shared key authentication, each wireless station is assumed to
have received a secret shared key over a secure channel that is independent from the 802.11 wireless
network communications channel.
5.9 What is WEP
An option of IEEE 802.11 function is that offers frame transmission privacy similar to a wired network.
The Wired Equivalent Privacy generates secret shared encryption keys that both source and destination
stations can use to alert frame bits to avoid disclosure to eavesdroppers.
WEP relies on a secret key that is shared between a mobile station (e.g. a laptop with a wireless
Ethernet card) and an access point (i.e. a base station). The secret key is used to encrypt packets before
they are transmitted, and an integrity check is used to ensure that packets are not modified in transit.