TDMA within the Air Interface Flashcards
How many timeslots are in each ARFCN?
8 timeslots, numbered 0 to 7
What is being described by a complete cycle of timeslots?
A frame
What is the duration of each frame?
4.62ms
If each frame is equal to 4.62ms, what is the duration of one timeslot?
4.62/8 = 577 Micro seconds
What timeslot is the Broadcast Control Channel associated with?
Timeslot 0
What is the primary timeslot used to control all functions of a given cell?
Timeslot 0
Name all relevant information the BTS will broadcast via the BCCH
MCC MNC Cell Idents LAC Encryption type NCC - Network Colour Code BCC - Base Station Colour Code
Name and explain the two states that timeslots 1-7 can exist in
Dedicated Control Channel (DCCH) - SMS/Incoming calls
Traffic Channel (TCH) - The phone call
How is the MS informed of it’s timeslot allocation?
Via the BTS
Explain the TA value ranges
0-63
0 - being up to 550m
Maximum of 35km, 64 x 550m
What is a timing advance value dependent on?
The distance of the RF path
What is meant if an MS is known the network as being in a detached state?
The MS is turned off/powered down and not connected to the network.
Once the MS is registered with the network what state is it in?
An attached state, it now has full use of it’s authorised network services.
What will the MS be doing whilst in an Idle state?
Monitoring timeslot for signalling information and incoming calls.
Whilst in an Idle and Attached state to the network what is the MS said to be doing?
Camping on the network
Name one advantage of mobile phone over a PSTN
It’s able to transit within the coverage area whilst maintaining network coverage.
What is the BA List?
A list of up to 32 ARFCN broadcasted by the BTS for the MS to monitor
The MS is programmed to select the 6 strongest frequencies from the BA List, what is this known as?
Neighbours List
What will the MS automatically calculate every 5 seconds?
The Received Signal Strength Indicator
When will the BSC perform a hand off?
When the signal quality drops below the predetermined quality threshold whilst in call.
How long will the BSC monitor the quality of the new ARFCN for before deciding to move it onto the MS
5 seconds
