Wireless LAN
Wireless LAN stands for Wireless
Local Area Network or simply called as Local Area Wireless Network. WLAN is a
network in which a mobile user can connect to a Local Area Network (LAN)
through a wireless network or connection.
The IEEE 802.11 group of standards
defines the technologies and standards for wireless LAN and for other wireless network
protocols. For path sharing, 802.11 standard uses the Ethernet protocol and CSMA/CA
(carrier sense multiple access with collision avoidance). It also uses an
encryption method i.e., wired equivalent privacy (WEP) algorithm.
Wireless LANs use high frequency radio signals or lasers beams to communicate
between the workstations, access point, servers, or hubs. Each workstation or server
connected on a wireless network has some sort of transceiver/antenna to send
and receive the data. Information is relayed between transceivers as if they
were physically connected. Wireless communication is used for communicating at
a long distance using either a cellular network or by satellite communication.
Wireless networks are widely used in laptop computers, portable
devices, or remote computers to connect to the LAN. It is used in office or
building where installing cables is a hectic task.
The two most common types of infrared communications used in
schools are line-of-sight and scattered broadcast. Line-of-sight communication
means that access point or service providing device is in direct line of sight
with mobile user or receiving device. Scattered infrared communication is a
broadcasting technique in which transmissions sent out in multiple directions
that bounces off walls and ceilings until it each receiver.
Wireless Standards and Speed:
The Wi-Fi Alliance is a global, non-profit organization that helps
to ensure standards and interoperability for wireless networks often referred
to as Wi-Fi (Wireless Fidelity). The original Wi-Fi standard was adopted in
1997 and since then there are many modifications are done to increase the
transmission speed and for easy connection setup. Wi-Fi networks use the
Ethernet protocol.
|
Standard |
Max.
Speed |
Modulation
Scheme |
Frequency
(GHz) |
Range (Outdoor) |
|
802.11a |
54 MHz |
DSSS |
5 |
390 feet |
|
802.11b |
11 MHz |
OFDM |
2.4 |
460 feet |
|
802.11g |
54 MHz |
OFDM |
2.4 |
460 feet |
|
802.11n |
600
MHz |
MIMO-OFDM |
2.4/5 |
820 feet |
|
802.11ac |
3.466
GHz |
MIMO-OFDM |
5 |
115
feet (Indoor) |
Wireless Security:
Wireless Security is the prevention of unauthorized access or damage
to the internet using wireless network. Wireless network is much more
susceptible to unauthorized access or use than cabled networks. The most common
terms used in wireless network for defining the protection of any wireless
network is in terms of confidential, integrity and availability. Wireless network devices use radio waves to
communicate with each other. The greatest vulnerability to the network is that
rogue machines can do eavesdropping on the radio wave communications. Unencrypted
information transmitted can be monitored by a third-party which is available
with the downloaded tools can quickly gain access to your entire network, steal
valuable passwords to local servers and online services, alter or destroy data,
and/or access personal and confidential information stored in your network
servers. To minimize the possibility of this, all modern access points and
devices have configuration options to encrypt transmissions. These encryption
methodologies are still evolving, as are the tools used by malicious hackers,
so always use the strongest encryption available in your access point and
connecting devices.
Wired Equivalent Privacy (WEP):
Wired Equivalent Privacy is a security
algorithm for IEEE 802.11 wireless networks which is intended for providing
data confidentiality to the network. WEP uses the stream cipher RC4 for
providing confidentiality and cyclic redundancy check (CRC)-32 checksum for integrity.
The Standard 64-bit WEP uses a 40-bit key which is concatenate with 24 bit
initialization vector (IV) to form the RC4 key, latter 64-bit WEP is extended to
128-bit WEP protocol using a 104-bit key size.
Wi-Fi Protected Access (WPA):
Wi-Fi Protected Access (WPA), Wi-Fi Protected Access II (WPA2), and Wi-Fi Protected Access 3 (WPA3) are the three security and security
certification programs developed by the Wi-Fi
Alliance to
secure wireless computer networks. WPA was developed by the Wi-Fi
Alliance to
provide more sophisticated data encryption and better user authentication than
Wired Equivalent Privacy (WEP). it uses Rivest
Cipher 4 (RC4) and Temporal Key Integrity Protocol (TKIP) for encryption. WPA
key is 256-bits key.
Difference between WEP and WPA:
|
Wired Equivalent Privacy (WEP) |
Wi-Fi Protected Access (WPA) |
|
It uses 40 bits key and 24-bits initialization
vector. |
WPA key is 256-bits key. |
|
It is a security protocol for wireless
networks which provides data confidentiality comparable to a traditional
wired network. |
It is a security protocol which is used
in securing wireless networks and designed to replace the WEP protocol. |
|
It provides wireless security using
encryption key. |
It provides wireless security through
the use of a password. |
|
Encryption
method used is Rivest Cipher 4 (RC4). |
Encryption
method is Rivest Cipher 4 (RC4) and Temporal Key Integrity Protocol (TKIP). |
|
Authentication method in WEP is Open
system authentication or shared key authentication. |
Authentication method in WPA is WPA-PSK
and WPA-Enterprise. |
|
Data Integrity is provided through CRC 32. |
Data Integrity is provided through
Message Integrity code. |
|
Key Management is not provided in WEP. |
Key Management
is provided through 4-way handshaking mechanism. |
|
In WEP, no protection
against reply attacks. |
In WPA, sequence counter is implemented
for reply protection. |
Advantages of Wireless
Network:
Mobility –
A Wireless network can be access anywhere using the hotspot or using Wi-Fi
router.
Fast setup –
If your computer has wireless adapter installed in it, you can access or connect
to Wi-Fi by clicking on “Connect to the Network” and set as connected automatically
for the future.
Cost -
Setting up a wireless network can be much more cost effective than buying and
installing cables.
Expandability -
Adding new computers to a wireless network is as easy step (as long as you do
not exceed the maximum number of devices).
Disadvantages of Wireless
Network:
Security
- Be careful. Be vigilant. Protect your sensitive data with backups, isolated
private networks, strong encryption and passwords, and monitor network access
traffic to and from your wireless network.
Interference
- Wireless networks use radio signals and similar techniques for transmission
as they are susceptible to interference from lights and electronic devices.
Inconsistent connections
- "Wait a minute, I just lost my connection?" is a problem when your
connecting device is setup in crowded place. Because of the interference caused
by electrical devices and/or items blocking the path of transmission, wireless
connections are not nearly as stable as those through a dedicated cable.
Speed - The transmission speed of wireless networks is improving as the technology is improving. If you are only using wireless for internet access, the actual internet connection for your home or school is generally slower than the wireless network devices. It became a bottleneck for your connection setup.
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