1) Explain the Architecture and Working of Personal Digital Cellular (PDC) Technology. Discuss its Security Features and Potential Threats in Wireless.

• PDC:
  • PDC stands for Personal Digital Cellular
  • It is a Digital Cellular telecommunication system developed by Japan in the 1990s
  • PDC operates in the 800 MHz Frequency Bandwidth
  • PDC is designed to replace the analogue systems by improving voice clarity and removing background noise
  • It uses ATC for improving the voice clarity
  • ATC stands for Adaptive Transform Coding

Security Features:

Potential Threats in Wireless:

• Unauthorized Access
• Eavesdropping
• Man-In-The-Middle Attack
• Denial-Of-Service Attack

2) FDMA vs TDMA vs CDMA

FDMA (Frequency Division Multiple Access):

• FDMA stands for Frequency Division Multiple Access
• Each user gets a separate frequency band
• Divides the channel by frequency
• Synchronization is not required
• It only needs guard bands
• It is very simple to implement
• It is less flexible and has a low data rate

TDMA (Time Division Multiple Access):

• TDMA stands for Time Division Multiple Access
• Each user gets a different time slot
• Divides the channel by time
• Synchronization is required
• It only needs guard time
• It is simple to implement
• It is moderately flexible and has a moderate data rate

CDMA (Code Division Multiple Access):

• CDMA stands for Code Division Multiple Access
• Each user gets a unique code
• Divides the channel by code
• Synchronization is required
• It needs both guard bands and guard time
• It is complex to implement
• It is highly flexible and has a high data rate

3) Outline the Cellular Digital Packet Data Architecture and its Security Model

CDPD:

• CDPD stands for Cellular Digital Packet Data
• CDPD is a wireless technology for sending data over cellular networks.
• CDPD transmits data in packets, making communication efficient.

CDPD Architecture:

• The Architecture mainly consists of three main components:
• a) M-ES:
  • M-ES stands for Mobile-End System
  • The devices you use like Laptop, Mobile
  • Main Job: Transmits and receives the data by using a wireless signal
  • Communicates with the Network via A-Interface
• b) MDBS:
  • MDBS stands for Mobile Data Base Station
  • Base station that connects devices
  • Main Job: It helps to connect the devices
  • Communicates with M-ES over A-Interface
• c) MD-IS:
  • MD-IS stands for Mobile Data Intermediate System
  • Server that connects towers to the Internet
  • Main Job: Routes data between Towers and the Internet
  • Communicates with MDBS and external Networks

CDPD Interfaces:

• There are mainly three types of interfaces:
• a) A-Interface
• b) I-Interface
• c) E-Interface

4) Differentiate b/w IEEE 802.11 and IEEE 802.15 Standards in terms of Architecture and Security Mechanisms

IEEE 802.11 (Wi-Fi):

• It is designed for WLAN (Wireless Local Area Network)
• It ranges up to 100 meters
• It operates in the 2.4 to 5 GHz frequency bandwidth
• Data rate is up to 600 Mbps
• It uses higher power consumption

IEEE 802.15 (Bluetooth):

• It is designed for WPAN (Wireless Personal Area Network)
• It ranges up to 10 meters
• It operates in the 2.4 GHz frequency bandwidth
• Data rate is up to 3 Mbps
• It uses lower power consumption

5) Explain the Security Considerations while implementing Wireless LANs in enterprise computing designs.

It mainly focuses on three layers:

• Physical Layer Security
• Network Layer Security
• Application Layer Security

i) Physical Layer Security:

• In this layer, it stops outsiders from connecting to the wireless network.
• Uses shielding materials to reduce the strength of the signal.
• RF Coverage Area:
  • It ensures that the network signals cover only the right area.

ii) Network Layer Security:

• In this layer, it protects the wireless network from attackers.
• It uses protocols like WPA2 and WPA3.
• It uses 802.1X authentication and VPN for remote users.

iii) Application Layer Security:

• In this layer, it keeps the data safe and ensures that only authorized users can access the application.
• It uses protocols like HTTPS, SFTP, and SSH.
• It uses SSL/TLS and VPN to encrypt the data.

6) Apply the Concept of Wireless deployment strategies to design a Secure SOHO wireless network, including Key Components and Security mechanisms.

• SOHO:
  • SOHO stands for Small Office/Home Office
  • The aim of the SOHO Wireless Network is to provide internet access to homes and small offices.

Key Components:

• i) WAP:
  • WAP stands for Wireless Access Point
  • It is a central device that connects all the clients.
• ii) Firewall:
  • A firewall protects the wireless Network from attackers.
• iii) Devices:
  • Devices like laptops, computers, and printers are protected through antivirus and firewalls.

Security Mechanisms:

• i) Physical:
  • In this layer, it stops outsiders from connecting to the wireless Network.
  • Uses shielding materials to reduce the strength of the signal.
  • RF Coverage Area:
    • It ensures that the network signals cover only the right area.
• ii) Network:
  • In this layer, it protects the wireless Network from the attackers.
  • It uses protocols like WPA2, WPA3.
  • It uses 802.1X authentication and VPN for remote users.
• iii) Application:
  • In this layer, it keeps the data safe and ensures that only authorized users can access the Application.
  • It uses protocols like HTTPS, SFTP, and SSH.
  • It uses SSL/TLS and VPN to encrypt the data.
• iv) Encryption:
  • The process of converting plaintext to ciphertext by using a cryptographic algorithm is called as Encryption.
• v) Authentication:
  • The process of verifying the identity of a user or device is called as Authentication.
  • Only authorized users can access the data.