Asus Router WL-320gE User Manual

							
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DSSS PHY frequency channel plan
         (Regulatory Domains)
CH ID  Frequency  X’10’    X’20’  X’30’  X’31’     X’32’   X’40’                  FCC   IC      ETSI  Spain      France   MKK
 1     2412 MHz   Yes      Yes      Yes     -         -             Yes
 2     2417 MHz   Yes      Yes      Yes    -         -             Yes
 3     2422 MHz   Yes      Yes      Yes    -         -             Yes
 4     2427 MHz   Yes      Yes      Yes    -         -             Yes
 5     2432 MHz   Yes      Yes      Yes    -         -             Yes
 6     2437 MHz   Yes      Yes      Yes    -         -             Yes-
 7     2442 MHz   Yes      Yes      Yes    -         -             Yes
 8     2447 MHz   Yes      Yes      Yes    -         -             Yes
 9     2452 MHz   Yes      Yes      Yes    -         -             Yes
 10     2457 MHz   Yes      Yes      Yes   Yes
            Yes     Yes
 11     2462 MHz   Yes      Yes      Yes    Yes
            Yes     Yes 
 12     2467 MHz   -      -      Yes    Yes 
 13     2472 MHz   -      -      Yes    Yes
            Yes
 14     2484 MHz   -      -      -    -
                        Yes 
						

							
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Glossary
Access Point (AP)
A networking device that seamlessly connects wired and wireless networks. 
Access Points combined with a distributed system support the creation of 
multiple radio cells that enable roaming throughout a facility.
Ad Hoc
A wireless network composed solely of stations within mutual communication 
range of each other (no Access Point).
AES(Advance Encryption Standard)
AES  is  the  U.S.  government’s  next-generation  cryptography  algorithm, 
which will replace DES and 3DES. This encryption key protocol is applied in 
802.1i standard to improve WLAN security. AES will require new hardware, 
in contrast with TKIP that can be used on existing wireless devices.
Basic Service Area (BSS)
A set of stations controlled by a single coordination function.
Broadband
A type of data transmission in which a single medium (such as cable) carries 
several channels of data at once.
Channel
An instance of medium use for the purpose of passing protocol data units 
that may be used simultaneously, in the same volume of space, with other 
instances of medium use (on other channels) by other instances of the same 
physical  layer,  with  an  acceptably  low  frame  error  ratio  due  to  mutual 
interference.
Client
A client is the desktop or mobile PC that is connected to your network.
COFDM (for 802.11a or 802.11g)
Signal power alone is not enough to maintain 802.11b-like distances in an 
802.11a/g  environment.  To  compensate,  a  new  physical-layer  encoding 
technology was designed that departs from the traditional direct-sequence 
technology being deployed today. This technology is called COFDM (coded 
OFDM). COFDM was developed specifically for indoor wireless use and 
offers  performance  much  superior  to  that  of  spread-spectrum  solutions. 
COFDM  works  by  breaking  one  high-speed  data  carrier  into  several  
						

							
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lower-speed subcarriers, which are then transmitted in parallel. Each high-
speed carrier is 20 MHz wide and is broken up into 52 subchannels, each 
approximately  300  KHz  wide.  COFDM  uses  48  of  these  subchannels  for 
data, while the remaining four are used for error correction. COFDM delivers 
higher data rates and a high degree of multipath reflection recovery, thanks 
to its encoding scheme and error correction.
Each subchannel in the COFDM implementation is about 300 KHz wide. 
At the low end of the speed gradient, BPSK (binary phase shift keying) is 
used to encode 125 Kbps of data per channel, resulting in a 6,000-Kbps, or 
6 Mbps, data rate. Using quadrature phase shift keying, you can double the 
amount of data encoded to 250 Kbps per channel, yielding a 12-Mbps data 
rate. And by using 16-level quadrature amplitude modulation encoding 4 bits 
per hertz, you can achieve a data rate of 24 Mbps. The 802.11a/g standard 
specifies that all 802.11a/g-compliant products must support these basic data 
rates. The standard also lets the vendor extend the modulation scheme beyond 
24 Mbps. Remember, the more bits per cycle (hertz) that are encoded, the 
more susceptible the signal will be to interference and fading, and ultimately, 
the shorter the range, unless power output is increased.
Device Name
Also known as DHCP client ID or network name. Sometimes provided by 
an ISP when using DHCP to assign addresses.
DHCP (Dynamic Host Configuration Protocol)
This protocol allows a computer (or many computers on your network) to 
be automatically assigned a single IP address from a DHCP server.
DNS Server Address (Domain Name System)
DNS  allows  Internet  host  computers  to  have  a  domain  name  and  one  or 
more IP addresses. A DNS server keeps a database of host computers and 
their respective domain names and IP addresses, so that when a user enters 
a  domain name into the Internet browser,  the user  is  sent  to the  proper  IP 
address.  The  DNS  server  address  used  by  the  computers  on  your  home 
network is the location of the DNS server your ISP has assigned.
DSL Modem (Digital Subscriber Line)
A  DSL  modem  uses  your  existing  phone  lines  to  transmit  data  at  high 
speeds.
Direct-Sequence Spread Spectrum (for 802.11b)
Spread  spectrum  (broadband)  uses  a  narrowband  signal  to  spread  the 
transmission  over  a  segment  of  the  radio  frequency  band  or  spectrum.  
						

							
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Direct-sequence is a spread spectrum technique where the transmitted signal 
is spread over a particular frequency range. 
Direct-sequence  systems  communicate  by  continuously  transmitting  a 
redundant pattern of bits called a chipping sequence. Each bit of transmitted 
data  is  mapped  into  chips  and  rearranged  into  a  pseudorandom  spreading 
code  to  form  the  chipping  sequence.  The  chipping  sequence  is  combined 
with a transmitted data stream to produce the output signal.
Wireless  mobile  clients  receiving  a  direct-sequence  transmission  use  the 
spreading code to map the chips within the chipping sequence back into bits 
to recreate the original data transmitted by the wireless device. Intercepting 
and decoding a direct-sequence transmission requires a predefined algorithm 
to associate the spreading code used by the transmitting wireless device to 
the receiving wireless mobile client.
This  algorithm  is  established  by  IEEE  802.11b  specifications.  The  bit 
redundancy  within  the  chipping  sequence  enables  the  receiving  wireless 
mobile client to recreate the original data pattern, even if bits in the chipping 
sequence are corrupted by interference. The ratio of chips per bit is called the 
spreading ratio. A high spreading ratio increases the resistance of the signal 
to interference. A low spreading ratio increases the bandwidth available to 
the user. The wireless device uses a constant chip rate of 11Mchips/s for all 
data rates, but uses different modulation schemes to encode more bits per chip 
at the higher data rates. The wireless device is capable of an 11 Mbps data 
transmission rate, but the coverage area is less than a 1 or 2 Mbps wireless 
device since coverage area decreases as bandwidth increases.
Encryption
This provides wireless data transmissions with a level of security.
Extended Service Set (ESS)
A set of one or more interconnected basic service set (BSSs) and integrated 
local  area  networks  (LANs)  can  be  configured  as  an  Extended  Service 
Set.
ESSID (Extended Service Set Identifier)
You  must  have  the  same  ESSID  entered  into  the  gateway  and  each  of 
its  wireless  clients.  The  ESSID  is  a  unique  identifier  for  your  wireless 
network.
Ethernet
The most widely used LAN access method, which is defined by the IEEE 
802.3 standard. Ethernet is normally a shared media LAN meaning all devices  
						

							
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on the network segment share total bandwidth. Ethernet networks operate 
at 10Mbps using CSMA/CD to run over 10-BaseT cables. 
Firewall
A  firewall  determines  which  information  passes  in  and  out  of  a  network. 
NAT can create a natural firewall by hiding a local network’s IP addresses 
from the Internet. A Firewall prevents anyone outside of your network from 
accessing your computer and possibly damaging or viewing your files.
Gateway
A network point that manages all the data traffic of your network, as well 
as to the Internet and connects one network to another.
IEEE
The  Institute  of  Electrical  and  Electronics  Engineers.  The  IEEE  sets 
standards for networking, including Ethernet LANs. IEEE standards ensure 
interoperability between systems of the same type.
IEEE 802.11
IEEE 802.xx is a set of specifications for LANs from the Institute of Electrical 
and Electronic Engineers (IEEE). Most wired networks conform to 802.3, 
the  specification  for  CSMA/CD  based  Ethernet  networks  or  802.5,  the 
specification for token ring networks. 802.11 defines the standard for wireless 
LANs encompassing three incompatible (non-interoperable) technologies: 
Frequency  Hopping  Spread  Spectrum  (FHSS),  Direct  Sequence  Spread 
Spectrum (DSSS), and Infrared. 802.11 specifies a carrier sense media access 
control and physical layer specifications for 1 and 2 Mbps wireless LANs. 
IEEE 802.11a (Mbits/sec)
Compared  with  802.11b: The  802.11b  standard  was  designed  to  operate 
in the 2.4-GHz ISM (Industrial, Scientific and Medical) band using direct-
sequence spread-spectrum technology. The 802.11a standard, on the other 
hand, was designed to operate in the more recently allocated 5-GHz UNII 
(Unlicensed National Information Infrastructure) band. And unlike 802.11b, 
the 802.11a standard departs from the traditional spread-spectrum technology, 
instead using a frequency division multiplexing scheme that’s intended to 
be friendlier to office environments. 
The  802.11a  standard,  which  supports  data  rates  of  up  to  54  Mbps,  is  the 
Fast Ethernet analog to 802.11b, which supports data rates of up to 11 Mbps. 
Like  Ethernet  and  Fast  Ethernet,  802.11b  and  802.11a  use  an  identical 
MAC (Media Access Control). However, while Fast Ethernet uses the same  
						

							
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physical-layer encoding scheme as Ethernet (only faster), 802.11a uses an 
entirely  different  encoding  scheme,  called  OFDM  (orthogonal  frequency 
division multiplexing).
The  802.11b  spectrum  is  plagued  by  saturation  from  wireless  phones, 
microwave  ovens  and  other  emerging  wireless  technologies,  such  as 
Bluetooth. In contrast, 802.11a spectrum is relatively free of interference.
The  802.11a  standard  gains  some  of  its  performance  from  the  higher 
frequencies at which it operates. The laws of information theory tie frequency, 
radiated power and distance together in an inverse relationship. Thus, moving 
up to the 5-GHz spectrum from 2.4 GHz will lead to shorter distances, given 
the same radiated power and encoding scheme.
Compared with 802.11g: 802.11a is a standard for access points and radio 
NICs that is ahead of 802.11g in the market by about six months. 802.11a 
operates in the 5GHz frequency band with twelve separate non-overlapping 
channels. As a result, you can have up to twelve access points set to different 
channels  in  the  same  area  without  them  interfering  with  each  other.  This 
makes  access  point  channel  assignment  much  easier  and  significantly 
increases the throughput the wireless LAN can deliver within a given area. 
In addition, RF interference is much less likely because of the less-crowded 
5 GHz band.
IEEE 802.11b (11Mbits/sec)
In 1997, the Institute of Electrical and Electronics Engineers (IEEE) adopted 
the 802.11 standard for wireless devices operating in the 2.4 GHz frequency 
band. This standard includes provisions for three radio technologies: direct 
sequence spread spectrum, frequency hopping spread spectrum, and infrared. 
Devices that comply with the 802.11 standard operate at a data rate of either 
1 or 2 Mbps.
In  1999,  the  IEEE  created  the  802.11b  standard.  802.11b  is  essentially 
identical  to  the  802.11  standard  except  802.11b  provides  for  data  rates  of 
up to 11 Mbps for direct sequence spread spectrum devices. Under 802.11b, 
direct  sequence  devices  can  operate  at  11  Mbps,  5.5  Mbps,  2  Mbps,  or  1 
Mbps. This provides interoperability with existing 802.11 direct sequence 
devices that operate only at 2 Mbps.
Direct sequence spread spectrum devices spread a radio signal over a range of 
frequencies. The IEEE 802.11b specification allocates the 2.4 GHz frequency 
band into 14 overlapping operating Channels. Each Channel corresponds to 
a different set of frequencies.
IEEE 802.11g
802.11g is a proposed (to be finalized) new extension to 802.11b (used in  
						

							
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majority of wireless LANs today) that broadens 802.11b’s data rates to 54 
Mbps within the 2.4 GHz band using OFDM (orthogonal frequency division 
multiplexing)  technology.  802.11g  allows  backward  compatibility  with 
802.11b devices but only at 11 Mbps or lower, depending on the range and 
presence of obstructions.
Infrastructure
A wireless network centered about an access point. In this environment, the 
access point not only provides communication with the wired network but 
also mediates wireless network traffic in the immediate neighborhood. 
IP (Internet Protocol)
The  TCP/IP  standard  protocol  that  defines  the  IP  datagram  as  the  unit 
of  information  passed  across  an  Internet  and  provides  the  basis  for 
connectionless  packet  delivery  service.  IP  includes  the  ICMP  control 
and  error  message  protocol  as  an  integral  part.  It  provides  the  functional 
equivalent of ISO OSI Network Services.
IP Address
An IP address is a 32-bit number that identifies each sender or receiver of 
information  that  is  sent  across  the  Internet. An  IP  address  has  two  parts: 
the  identifier  of  a  particular  network  on  the  Internet  and  an  identifier  of 
the  particular  device  (which  can  be  a  server  or  a  workstation)  within  that 
network. 
ISM Bands (Industrial, Scientific, and Medicine Bands)
Radio frequency bands that the Federal Communications Commission (FCC) 
authorized for wireless LANs. The ISM bands are located at 902 MHz, 2.400 
GHz, and 5.7 GHz.
ISP (Internet Service Provider)
An  organization  that  provides  access  to  the  Internet.  Small  ISPs  provide 
service via modem and ISDN while the larger ones also offer private line 
hookups (T1, fractional T1, etc.).
LAN (Local Area Network)
A communications network that serves users within a defined geographical 
area. The benefits include the sharing of Internet access, files and equipment 
like  printers  and  storage  devices.  Special  network  cabling  (10  Base-T)  is 
often used to connect the PCs together.  
						

							
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MAC Address (Media Access Control)
A  MAC  address  is  the  hardware  address  of  a  device  connected  to  a 
network.
NAT (Network Address Translation)
NAT  masks  a  local  network’s  group  of  IP  addresses  from  the  external 
network, allowing a local network of computers to share a single ISP account. 
This process allows all of the computers on your home network to use one 
IP  address.  This  will  enable  access  to  the  Internet  from  any  computer  on 
your  home  network  without  having  to  purchase  more  IP  addresses  from 
your ISP.
NIC (Network Interface Card)
A  network  adapter  inserted  into  a  computer  so  that  the  computer  can  be 
connected to a network. It is responsible for converting data from stored in 
the computer to the form transmitted or received.
Packet
A  basic  message  unit  for  communication  across  a  network.  A  packet 
usually  includes  routing  information,  data,  and  sometimes  error  detection 
information. 
PCMCIA (Personal Computer Memory Card International Association)
The Personal Computer Memory Card International Association (PCMCIA), 
develops standards for PC cards, formerly known as PCMCIA cards. These 
cards are available in three types, and are about the same length and width 
as credit cards. However, the different width of the cards ranges in thickness 
from  3.3  mm  (Type  I)  to  5.0  mm  (Type  II)  to  10.5  mm  (Type  III).  These 
cards can be used for various functions, including memory storage, land line 
modems and wireless modems. 
PPP (Point-to-Point Protocol)
PPP  is  a  protocol  for  communication  between  computers  using  a  serial 
interface,  typically  a  personal  computer  connected  by  phone  line  to  a 
server.
PPPoE (Point-to-Point Protocol over Ethernet)
Point-to-Point Protocol is a method of secure data transmission. PPP using 
Ethernet to connect to an ISP.
Radio Frequency (RF) Terms: GHz, MHz, Hz 
The international unit for measuring frequency is Hertz (Hz), equivalent to 
the  older  unit  of  cycles  per  second.  One  megahertz  (MHz)  is  one  million  
						

							
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Hertz. One gigahertz (GHz) is one billion Hertz. The standard US electrical 
power frequency is 60 Hz, the AM broadcast radio frequency band is 0.55-1.6 
MHz, the FM broadcast radio frequency band is 88-108 MHz, and wireless 
802.11 LANs operate at 2.4 GHz. 
RIP (Routing Information Protocol)
Routing Information Protocol(RIP1) is defined as a means by which routing 
equipment  can  find  the  best  path  for  transmitting  data  packets  from  one 
network to another. Upgrades have been made to the RIP1 protocol, resulting 
in Routing Information Protocol Version 2 (RIP2). RIP2 was developed to 
cover some of the inefficiencies of RIP1.
Metric: RIP  metric  is  a  value  of  distance  for  the  network.  Usually 
RIP  increments  the  metric  when  the  network  information  is  received. 
Redistributed  routes’  default  metric  offset  is  set  to  1.  These  rules  can  be 
used  to  change  the  metric  offset  only  for  the  matched  networks  specified 
or excluded in the Route Metric Offset table. But the metric offset of other 
networks is still set to 1.
SSID (Service Set ID)
SSID is a group name shared by every member of a wireless network. Only 
client PCs with the same SSID are allowed to establish a connection. 
Station
Any device containing IEEE 802.11 wireless medium access conformity.
Subnet Mask
A subnet mask is a set of four numbers configured like an IP address. It is 
used to create IP address numbers used only within a particular network.
TCP (Transmission Control Protocol)
The standard transport level protocol that provides the full duplex, stream 
service on which many application protocols depend. TCP allows a process 
or one machine to send a stream of data to a process on another. Software 
implementing TCP usually resides in the operating system and uses the IP 
to transmit information across the network.
TKIP (Temporal Key Integrity Protocol)
TKIP is used in WPA to replace WEP with a new encryption algorithm that 
is  stronger  than  the WEP  algorithm  but  that  uses  the  calculation  facilities 
present on existing wireless devices to perform encryption operations. 
						

							
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WAN (Wide Area Network)
A system of LANs, connected together. A network that connects computers 
located  in  separate  areas,  (i.e.,  different  buildings,  cities,  countries).  The 
Internet is a wide area network.
WECA (Wireless Ethernet Compatibility Alliance)
An  industry  group  that  certifies  cross-vender  interoperability  and 
compatibility of IEEE 802.11b wireless networking products and to promote 
that standard for enterprise, small business, and home environments.
WEP (Wired Equivalent Privacy)
The IEEE 802.11b standard specifies an optional encryption feature, known 
as Wired Equivalent Privacy or WEP, that is designed to provide a wireless 
LAN  with  a  security  level  equal  to  what  is  found  on  a  wired  Ethernet 
network. WEP encrypts the data portion of each packet exchanged on the 
802.11b  network  using  either  a  64-bit  or  128-bit  encryption  algorithm.  In 
addition,  WEP  is  also  used  in  conjunction  with  the  optional  Shared  Key 
Authentication algorithm to prevent unauthorized devices from associating 
with an 802.11b network.
WLAN (Wireless Local Area Network)
This  is  a  group  of  computers  and  other  devices  connected  wirelessly  in  a 
small area. A wireless network is referred to as LAN or WLAN.
WPA (Wi-Fi Protected Access)
Wi-Fi  Protected  Access  is  a  specification,  which  offsets  encryption  and 
authentication improvements that are stronger than the Wireless Encryption 
Protocol (WEP), which it is meant to replace.
WPA-PSK (Wi-Fi Protected Access – Pre-Shared Key)
WPA-PSK  is  a  special  mode  of  WPA  for  home  environment  without  a 
Remote  Authentication  Dial-In  User  Service  (RADIUS).  It  is  required 
to  enter  a  password  into  their  access  point  or  home  wireless  gateway  and 
each  clients  that  is  on  the  wireless  network  to  keeps  out  eavesdroppers 
and other unauthorized users by requiring all devices to have the matching 
password.