WLAN
Extension of power saving according to IEEE 802.11e by Unscheduled Automatic Power Save Delivery (equivalent to WMM Power Save). U-APSD
supports the automatic switch of clients to a doze mode. Increasmed battery lifetime for telephone calls over VoWLAN (Voice over WLAN)
U-APSD/WMM Power Save
Maximum transmit and receive rates and an individual VLAN ID can be assigned to each WLAN client (MAC address)
Bandwidth limitation
If the link of a chosen LAN interface breaks down, a WLAN module can be deactivated to let the associated clients search for a new base station
Broken link detection
Detection of rogue AP's and the channel information for all WLAN channels during normal AP operation. The Background Scan Time Interval defines
the time slots in which an AP or Router searches for a foreign WLAN network in its vicinity. The time interval can be specified in either milliseconds,
seconds, minutes, hours or days
Background scanning
Rogue WLAN client detection based on probe requests
Client detection
Authentication of an access point in WLAN client mode at another access point via 802.1X (EAP-TLS, EAP-TTLS and PEAP)
802.1X supplicant
Layer-3 Tunneling in conformity with the CAPWAP standard allows the bridging of WLANs per SSID to a separate IP subnet. Layer-2 packets are
encapsulated in Layer-3 tunnels and transported to a LANCOM WLAN controller. By doing this the access point is independent of the present
infrastructure of the network. Possible applications are roaming without changing the IP address and compounding SSIDs without using VLANs.
Layer-3 Tunneling
The WLAN standard IEEE 802.11u (Hotspot 2.0) allows for a seamless transition from the cellular network into WLAN hotspots. Authentication
methods using SIM card information, certificates or username and password, enable an automatic, encrypted login to WLAN hotspots - without
the need to manually enter login credentials.
IEEE 802.11u
LANCOM Spectral Scan
Up to 13 channels (2.4 GHz) or up to 26 channels (5 GHz) (depending on national regulations and manual configuration)
RF spectrum scan (WLAN-2 only)
Illustration of signal strength on individual WLAN channels at a certain point of time
Signal strength of WLAN channels (WLAN-2
only)
IEEE 802.11n Features
MIMO technology is a technique which uses multiple transmitters to deliver multiple data streams via different spatial channels. Depending on the
existing RF conditions the throughput is multiplied with MIMO technology.
MIMO
Two adjacent 20 MHz channels are combined to create a single 40 MHz channel. Depending on the existing RF Conditions channel bonding doubles
the throughput.
40 MHz Channels
Support of coexisting accesspoints with 20 and 40MHz channels in 2.4GHz band.
20/40MHz Coexistence Mechanisms in the
2.4GHz Band
MAC Aggregation increase the 802.11 MAC efficiency by combining MAC data frames and sending it out with a single header. The receiver
acknowledges the combined MAC frame with a Block Acknowledgement. Depending on existing RF conditions, this technique improves throughput
by up to 20%.
MAC Aggregation and Block
Acknowledgement
Coding method according to IEEE 802.11n. The Space Time Block Coding improves reception by coding the data stream in blocks.
Space Time Block Coding (STBC) (WLAN-2
only)
Low Density Parity Check (LDPC) is an error correcting method. IEEE 802.11n uses convolution coding (CC) as standard error correcting method,
the usage of the more effective Low Density Parity Check (LDPC) is optional.
Low Density Parity Check (LDPC) (WLAN-2
only)
Maximal Ratio Combining (MRC) enables the receiver (access point), in combination with multiple antennas, to optimally combine MIMO signals
to improve the client reception at long-range.
Maximal Ratio Combining (MRC)
The guard interval is the time between OFDM symbols in the air. 802.11n gives the option for a shorter 400 nsec guard interval compared to the
legacy 800 nsec guard interval. Under ideal RF conditions this increases the throughput by upto 10%
Short Guard Interval
WLAN operating modes
Infrastructure mode (autonomous operation or managed by LANCOM WLAN Controller)
WLAN access point
Use of the LAN connector for simultaneous DSL over LAN, IP router, NAT/Reverse NAT (IP masquerading) DHCP server, DHCP client, DHCP relay
server, DNS server, PPPoE client (incl.Multi-PPPoE), PPTP client and server, NetBIOS proxy, DynDNS client, NTP, port mapping, policy-based routing
based on routing tags, tagging based on firewall rules, dynamic routing with RIPv2, VRRP
WLAN router
Transparent WLAN client mode for wireless Ethernet extensions, e.g. connecting PCs or printers by Ethernet; up to 64 MAC addresses. Automatic
selection of a WLAN profile (max. 8) with individual access parameters depending on signal strength or priority
WLAN client
By scanning the RF spectrum, non-WLAN intererences are automatically identified and graphically illustrated.
Spectral Scan (WLAN-2 only)
Firewall
Incoming/Outgoing Traffic inspection based on connection information. Trigger for firewall rules depending on backup status, e.g. simplified rule
sets for low-bandwidth backup lines. Limitation of the number of sessions per remote site (ID)
Stateful inspection firewall
Check based on the header information of an IP packet (IP or MAC source/destination addresses; source/destination ports, DiffServ attribute);
remote-site dependant, direction dependant, bandwidth dependant
Packet filter
Network Address Translation (NAT) based on protocol and WAN address, i.e. to make internal webservers accessible from WAN
Extended port forwarding
LANCOM OAP-322
Features as of: LCOS 8.82
