GSM Chapter 3: Cellular Networks and GSM Fundamentals

What happens when the SRES generated by the AUC and MS are compared and found to be the same?

The MS is authenticated. (correct)
The Kc key is generated.
The AUC is authenticated.
The SIM card is declared as genuine.

What is the purpose of the A8 algorithm?

To decrypt ciphered frames.
To encrypt over-the-air transmissions.
To generate a session key (Kc). (correct)
To initialize the stream cipher.

What is used to initialize the stream cipher for every frame sent?

The MSC's authentication code.
The secret key (Kj) and the random challenge RAND.
The session key (Kc) and the frame number. (correct)
The SIM card's unique identifier.

What changes during a call to generate a unique key stream for every frame?

The 22-bit frame number. (B) Signup and view all the answers

What is the purpose of the A5 algorithm?

To encrypt over-the-air transmissions. (C) Signup and view all the answers

What is generated by both the MS and the network end using the A8 algorithm?

The session key (Kc). (A) Signup and view all the answers

What is the main function of Mobility Management (MM) in GSM?

Managing the mobility of the subscriber and the user (D) Signup and view all the answers

What algorithm is used for encryption in GSM?

A5 algorithm (C) Signup and view all the answers

What is the purpose of the A3 algorithm in GSM?

Authentication of the mobile subscriber (B) Signup and view all the answers

What is the term for moving from one point of attachment to another point of attachment within the same network operator?

Handover (D) Signup and view all the answers

What is the term for moving from one point to another point between two different network operators?

Roaming (D) Signup and view all the answers

What is the purpose of the Authentication Center (AUC) in GSM?

To authenticate the mobile subscriber (B) Signup and view all the answers

What is the main purpose of the Global System for Mobile Communication (GSM)?

To describe the protocols for 2G digital cellular networks (B) Signup and view all the answers

What is the primary reason for subdividing an area into cells in a cellular network?

To increase the frequency reuse efficiency (A) Signup and view all the answers

What is the role of the Base Station Controller (BSC) in the GSM system hierarchy?

To control multiple BTSs and assign cell groups (B) Signup and view all the answers

What is the purpose of the Authentication Center (AUC) in the GSM system?

To authenticate and authorize mobile devices (B) Signup and view all the answers

What is the process of rearranging a group of bits in a particular way to improve the performance of error-correction mechanisms called?

Interleaving (C) Signup and view all the answers

What is the term for the communication channel that connects two or more devices in a GSM network?

Telecommunication link (B) Signup and view all the answers

What is the role of the Visitor Location Register (VLR) in the GSM system?

To store information about the mobile device's location (A) Signup and view all the answers

What is the purpose of the Mobile Switching Center (MSC) in the GSM system?

To handle calls originating from or terminating in a fixed network (A) Signup and view all the answers

What is the term for the process of digitizing user speech in the GSM system?

Digitizer and source coding (D) Signup and view all the answers

What is the purpose of the Gateway MSC (GMSC) in the GSM system?

To handle calls originating from or terminating in a fixed network (C) Signup and view all the answers