Channels and Authentication
Interface
Wildcard
Network
Mobility
100

SMS is sent on what logical channel when the handset is in a traffic channel already?

Slow Associated Control Channel (SACCH). 

100

The frequency difference between the uplink and downlink in GSM is called what?

Offset.

100

What are the two types of radio interference encountered in GSM?

Co-channel interference – occurs when the same ARFCN is used and two towers and the handset cannot differentiate between them.

Adjacent-channel interference – two different channels are used but are too close each other causing interference at the channel’s edges.

100

What is the purpose of frequency reuse?

To maximize users without buying more frequency and avoiding Co-channel interference.

100

What identity is used on the PCH?

Temporary Mobile Subscriber Identity (TMSI).

200

What logical channel initiates a handover?

Fast Associated Control Channel (FACCH).

200

What duplex scheme does GSM use?

Frequency Division Duplex (FDD), Half-Duplex.

200

What are the CONUS GSM bands?

850 MHz, 1900 MHz.

200

What is the PLMN for AT&T?

310 410.

200

What network parameter makes an ARFCN look artificially worse?

Temporary Offset (For the duration of the Penalty Timer).

300

Which authentication vector authenticates a handset?

Signed Response (SRES).

300
What are the three Broadcast Channels (BCH)?

Frequency Correction Channel (FCCH), Synchronization Channel (SCH), Broadcast Control Channel (BCCH).

300

What are the OCONUS GSM bands?

900 MHz, 1800 MHz.

300

What is the PLMN for T-Mobile?

310 260.

300

Which network parameter dictates periodic registration?

T3212 Timer.

400

Which Authentication vector is used for encryption?

Kc (Ciphering Key).

400

What are the three Common Control Channels (CCCH)?

Paging Channel (PCH), Random Access Channel (RACH), Access Grant Channel (AGCH).

400

What is the Traffic Channel (TCH) used for?

It is used for all user traffic to include voice calls, texts and data.

400

What is an LAI and what is it comprised of?

Location Area Identity. MCC/MNC/LAC.

400

Which network parameter prevents unnecessary registrations at LAC boundaries?

Cell Reselection Hysterisis (CRH).

500

In which logical channel does authentication occur?

Standalone Dedicated Control Channel (SDCCH).

500

What are the three Dedicated Control Channels (DCCH)?

Standalone Dedicated Control Channel (SDCCH), Slow Associated Control Channel (SACCH), Fast Associated Control Channel (FACCH).

500

The BSIC is sent on what logical channel?

Synchronization Channel (SCH).

500

What is a GCI and what is it comprised of?

Global Cell ID. MCC/MNC/LAC/CI.

500

What is reject code 6?

Illegal IMEI.