Wireless networking

Topic 3. Network

Wireless networking


Outline the advantages and disadvantages of wireless networks.

（wireless networks have led to changes in working patterns, social activities and raised health issues.）

Advantages:

  • Easier and cheaper to install than cable  
  • Easier to set up temporary links·
  • Easier to add new devices to network  
  • Can connect mobile devices, which are more convenient and portable

Disadvantages:

  • Relatively slow communication as signals travel through air ·
  • Weaker security privacy and protection
  • Higher error rates
  • Health concerns about long term exposure to electromagnetic waves

Describe the hardware and software components of a wireless network.

Modem:

Allows you to connect to internet
A device that has the ability to connect to the wireless network: such as a PC, laptop, sensor, smart phone, printer, etc.

Wireless router:

Similar function to traditional routers in wired network but also has Wireless Access Point (WAP) to connect to allow wireless data transfer between device and network

Wireless repeater (signal boosters or range expanders):

Receives signal from router or access point and rebroadcasts it

Dynamic Host Configuration Protocol (DHCP):

Allows server to automatically assign an IP address to client device.

Wireless Application Protocol (WAP):

Provides protocols for accessing info over a mobile wireless network, used in mobile devices to access internet, emails etc.

Firewall:

a network security that determines what data comes in and out of a network or a PC

Service Set Identification(SSID): 

Set of 32 characters to differentiate one WLAN from another and is case sensitive

NIC drivers:

Operates hardware of the Network Interface Card. Translator between card and applications/ operating system of device

Web browser:

Software to receive and display content on WWW

Describe the characteristics of wireless networks.

WiFi:

Short range wireless network offering high bandwidth for data transfer worldwide

Interoperability for Microwave Access (WiMAX):

Serves long-range networking, even in remote areas (30-40mbps)

3G mobile: 

Is the third generation of mobile networking and telecommunications technology and it focuses on cellular telephones and internet access. (200kbps)

4G mobile:

 Is the fourth generation of mobile networking and telecommunications technology. It doesn’t support traditional circuit-switched telephony service but only IP-based communication like IP telephony.(100mbps of high mobility and 1gbps of low mobility)

Long Term Evolution (LTS):

is a 4G network, as well as a standard for wireless communication of high speed data for smartphones and mobile data terminals. (300mbps)
Future Networks: 5G or tactile internet

Describe the different methods of network security.

Wireless networks have led to concerns about the security of the user’s data.

Encryption types

Altering a message into form not understandable to unauthorised person. Only person with the correct key can decode the message and read it.
#Symmetric-key encryption (single/secret key):
 Device has a key to encrypt packets, the receiving device has the same key to decrypt. E.g. Data Encryption Standard (DES)
#Public-key encryption (asymmetric key): 
Has a public key for encryption and a private one for decryption, both mathematically linked. Secure Socket Layer (SSL) and Transport Layer Security (TLS) encryption protocols used on internet

User ID

Use password to access device and/or password to access web interface used to set up wireless routers or access points

Trusted Media Access control (MAC) addresses

Medium Access Control. Every device in a network (their NIC) has a unique MAC address of 12 characters. Network permits access only to specified, trusted devices based on their MAC address. MAC address of an untrusted is device blocked so it cannot connect to the network.

Evaluate the advantages and disadvantages of each method of network security.

Encryption types

#Symmetric-key encryption
· +Faster than public-key
· +Uses less computer resources
· -Keys must be shared before used
-Danger of key becoming known by unauthorised individuals, another one must be used
#Public-key encryption ·
+Two sides don't need to share secret key in order to communicate ·
-Messages take longer to encrypt and decrypt ·
-Authenticity of public key needs to be verified

User ID

Easy to use ·
Prevents unauthorized access ·
With web interface password, person cannot access web-based utility page of router/
modem/ access point unless they have the password ·
Entering password each time may be time-consuming ·
Weak password is easy to crack

Trusted Media Access control (MAC) addresses

Extra security ·
Danger of allowed list of MAC addresses being discovered ·
Difficult to manage the list as it grows

*Network topologies

*Read p168-169