ITC254 Wireless Networks Assignment
Question1: Discuss the usage of a virtual private network in establishing an encrypted secure communications channel between two points on a public network.
Answer: Virtual private network is basically a technology which helps in creating safe as well as encrypted connection over a network such as internet. It basically provides one with online privacy and anonymity for creating a link between two different points on public network. VPN is used by the organization for maintaining the security of the information. All the organizational data which is shared via VPN can easily be shared without any security concerns. By using VPN, all the attacks might be faced while sharing the information such as denial of service, man in the middle etc. can easily be mitigated. VPN network is also used at workplace for creating servers through which geo-blocked websites can easily be accessed.
Question 2: Discuss the three different multiple access technologies used with 2G: time division multiple access (TDMA), code division multiple access (CDMA), and global system for mobile communications (GSM).
Answer: Multiple access techniques are basically used to allow large number of users for sharing the allocated spectrum in an effective and efficient manner. Sharing is basically used to enhance the cell capacity by allowing available bandwidth at the same time by various users.
Time division multiple access (TDMA): Time division multiple access is basically a channel access method which is used for shared medium network. This allows the users to share the same frequency channel as it divides the channel into different time slots. It basically allows multiple stations for sharing the same frequency channels. This also allows mobile station radio component for listening and broadcasting assigned time slots. Network measurements can easily be applied in detecting the surrounding transmitters into different types of frequencies.
Code division multiple access (CDMA): Code division multiple access refers to different type of protocols that are used in second and third generation wireless communication. It is basically a form of multiplexing which allows different signals to optimize available bandwidth and occupy single transmission. This particular technology is used in Ultra-high-frequency (UHF) cellular telephone systems. With this particular technology, all the audio inputs are digitized into binary elements. It is basically a scheme, which is also known as soft handoff. This minimizes single breakup. This technique is essentially a combination of digital as well as spread-spectrum modes. CDMA is compatible with all the other cellular technology as it allows nationwide roaming.
Global system for mobile communications (GSM): This is another digital mobile network which is used by most of the mobile phone users in Europe. This technique uses variation in time division multiple access. GSM basically digitize and send the data after which it is sent to another data stream. It operates at frequency band of 900 megahertz (MHz) or 1,800 MHz. It is part of evolution of wireless mobile technology which includes Universal Mobile Telecommunications Service, Enhanced Data GSM Environment, General Packet Radio Service, and High-Speed Circuit-Switched Data.
Question 4: What are the four components of WLAN? Explain and discuss two of them in details.
Answer: WLAN consists of many components that are similar to the Ethernet-wired LANs. All the factors are similar in both the cases. One of the major differences is that LAN requires wire for the transmission of data and sharing of information. Some of the components of WLAN are given below:
Radio NIC: This is one of the major components of WLAN, which provides wireless connectivity and operates within the computer devices. This component is sometime known as radio cards which implements 802.11 standard. The wireless LAN that implements multiple versions of the standard provides better interoperability.
Access points: This component includes radio card which helps the users to share the information on the wireless LAN as well as wired NIC which interfaces to distribution system which like Ethernet. This component basically bridges all the wireless LAN and distribution sites of the access point with each other. Degrees of management, Security, and installation are the three functions that are performed while using access points of WLAN.
Question 5: What happens as a cellular phone user moves around within a particular cell and into another cell?
Answer: Cell Phones have changed the way of an individual to live and work. It is basically an electronic device which is used for sharing the information over a cellular network of special base stations which are called as cell sites. It basically offers full duplex communication and transfers the link to another network station when user moves from one cell to anther cell.
Question 6: What is multipath distortion? If the radio system has been detected to have multipath distortion, please propose two solutions to minimize effect of multipath distortion with reasons.
Answer: Multiple distortion is mainly a form of RF interface which is formed when radio signal has more than one path for sharing the information between receiver and transmitter. This occurs in the cell with the help of RP reflective surfaces as well as metallic surfaces such as walls, furniture, coated glass. For sharing the information, radio frequency signal is transmitted. While sharing the information, user might have to face many obstacles. There are some of the ways with the use of which, effect of multipath distortion as well as security obstacles can easily be minimized.