Which of the following is NOT a security mechanism used in cellular networks?1.0 MarksAuthenticationAccess controlFirewallIntrusion detectionEncryption

To determine which of the options is NOT a security mechanism used in cellular networks, we need to analyze each option one by one.

1. Authentication: Authentication is a security mechanism used in cellular networks to verify the identity of users or devices before granting access. It ensures that only authorized entities can connect to the network. Therefore, authentication is a security mechanism used in cellular networks.

2. Access control: Access control is another security mechanism used in cellular networks. It involves controlling and managing the permissions and privileges of users or devices to access specific resources or services. Access control helps prevent unauthorized access and ensures the security of the network.

3. Firewall: A firewall is a security device or software that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It acts as a barrier between the internal network and external networks, protecting against unauthorized access and potential threats. Therefore, a firewall is a security mechanism used in cellular networks.

4. Intrusion detection: Intrusion detection is a security mechanism used to detect and respond to unauthorized or malicious activities within a network. It involves monitoring network traffic and analyzing it for any signs of intrusion or suspicious behavior. Intrusion detection helps identify and mitigate potential security breaches. Therefore, intrusion detection is a security mechanism used in cellular networks.

5. Encryption: Encryption is a security mechanism used to protect the confidentiality and integrity of data transmitted over a network. It involves converting plain text into cipher text using encryption algorithms, making it unreadable to unauthorized entities. Encryption ensures that data remains secure even if intercepted by attackers. Therefore, encryption is a security mechanism used in cellular networks.

Based on the analysis above, the option that is NOT a security mechanism used in cellular networks is "Firewall."