Cells
What are the four sizes for a BTS, Largest to Smallest?
Macro, Micro, Pico, Femto
What network element is used for radio access and interface control?
Base Station Controller (BSC)
How many digits is an IMSI?
14-16
MCC(3), MNC(2-3), MSIN(9-10)
What is a Reject Cause Code of 13?
Roaming not allowed in LA
What cipher is used on an unencrypted network?
A5/0
How many TA rings are there and what is there theoretical width?
64 (0-63), TA0 is 350m, TA1-63 are 550m
What are three tasks the BSC is responsible for?
Radio resource allocation, handoffs between towers, and power control.
How long does a neighboring cell have to beat out the serving cell to prompt reselection?
5 sec.
What are the three handover types that an MS can experience?
Intra-BSC: handover between towers controlled by the same BSC; managed by the serving BSC.
Intra-MSC: handover between towers controlled by different BSCs located in the same LAC; managed by the serving MSC.
Inter-MSC: handover between towers in separate LACs; coordinated between the gaining and losing MSCs
What are "triplets"?
RAND, SRES, Kc
What makes up a BSIC?
Network Color Code (NCC); 0-7
Base Station Color Code (BCC); 0-7
NCC is multiplied by 8, then the BCC is added to create the BSIC; ie. 7, 5 would be 61
What components make up the NSS?
Gateway Mobile Switching Center (GMSC), Mobile Switching Center (MSC), Visitor Location Register (VLR), Home Location Register (HLR), Authentication Center (AUC), and Equipment Identity Register (EIR)
What are modern SIMs called?
Universal Integrated Circuit Cards (UICC)
What is Reject Cause Code 15?
No suitable cells in LA
How is the SRES generated?
Ki and RAND through the A3 algorithm.
What is a specialized cell used to prevent system performance degradation along highways and in other areas where there is a high rate of handoffs or registrations?
Umbrella cell
Which network component performs authentication for a MS?
Mobile Switching Center (MSC)
What occurs when a MS is first powered on?
IMSI attach and Cell Selection
What is Reject Cause Code 22?
Congestion
How is the Kc generated?
the Ki and RAND through the A8 algorithm.
What is a specialized cell used to provide service where there is no GSM tower, to accommodate extreme influxes of users to an area, or in cases of natural disasters?
Cell-On-Wheels (COW)
What network component is responsible for generating and assigning TMSIs?
Visitor Location Register (VLR)
How is a "Neighbor List" created by an MS?
The 6 ARFCNs with the best C1/C2 value from the BA list of the serving sell.
What four signaling channels can contain traffic on the uplink?
Random Access Channel (RACH), Standalone Dedicated Control Channel (SDCCH), Slow Associated Control Channel (SACCH), and Fast Associated Control Channel (FACCH)
What cipher uses an 128 bit key?
A5/3