User manual

USER MANUAL OF WEBEE WIRELESS N ROUTER Version:1.1
Firmware Type 2
P/N: 60291092
78
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 motors, … etc.
• Add additional WLAN Access Points if necessary.
6.8. 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
.
6.9. WHAT IS WEP?
An optional IEEE 802.11 function 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.
6.10. WHAT IS FRAGMENT THRESHOLD?
The proposed protocol uses the frame fragmentation mechanism defined in IEEE 802.11
to achieve parallel transmissions. A large data frame is fragmented into
several
fragments each of size equal to fragment threshold. By tuning the fragment threshold
value, we can get varying fragment sizes. The determination of an efficient fragment
threshold is an important issue in this scheme. If the fragment threshold is small, the
overlap part of the master and parallel transmissions is large. This means the spatial
reuse ratio of parallel transmissions is high. In contrast, with a large fragment threshold,
the overlap is small and the spatial reuse ratio is low. However high fragment threshold
leads to low fragment overhead. Hence there is a trade-off between spatial re-use and
fragment overhead.
Fragment threshold is the maximum packet size used for fragmentation. Packets larger
than the size programmed in this field will be fragmented.
If you find that your corrupted packets or asymmetric packet reception (all send packets,
for example). You may want to try lowering your fragmentation threshold. This will cause