Midterm 2 Flashcards
What is mobile edge computing primarily focused on?
Decreasing latency. Local processing and data storage is decreased due to the cloud.
What does a 4G to 5G migration entail?
Minimum hardware changes. Primarily cloud-based software functions added to the 4G hardware.
What is roaming?
Roaming is connecting to a visitor network.
What is handover?
Handover occurs when cells(serving network) change.
What is hard HO?
Break in data path prior to path change to target. Break before make. Some level of interruption is acceptable in user traffic transmission. Applicable to voice applications allowing packet error rate. Between different cell stations.
What is soft HO?
Make before break. No interruption with continuous user traffic transmission. Applicable to data applications requiring low packet error rate.
Where does the RRC protocol happen?
RRC protocol happens between the UE and gnB. The GnB uses NG-AP for control signal and GTP-U for user plane with core.
Where does NAS-SM protocol happen?
Between the UE and SMF
Where does NAS-AM protocol happen?
Between the UE and AMF
How does RU-DU-CU processing work?
5G core connects through backhaul to CU which connects through midhaul to DU which connects through fronthaul to RRU.
5GC-BH-CU-MH-DU-FH-RRU
Where is the control/user plane split applied?
the gNB and the core.
Compare Xn based handover to NG-N2 based.
Xn requires less processing and switching in X2HO and is therefore faster.
What does the Master Information Block do(MIB)?
MIB contains the information on how to read the SIB information. The master system information about gNB is sent by the gNB using the MIB.Necessary
What does the System Information Block do?
SIB includes configurations for the UE, such as cell selection and reselection, random access (RA) parameterization and permissions such as access barring and configuration of broadcast services such as warning messages.
What is a registration area?
A registration area consists of multiple tracking areas.
When is deregistration carried out?
When it is switched off and when energy consumption needs to be reduced, or when subscription information is lost (if there is not signal)
When is paging carried out by the gNB?
When the UE is in idle or inactive mode
How do we avoid data loss during handover?
Buffering and retransmission
Can a network slice have multiple PDUs?
Yes, a network slice can have multiple PDUs but a PDU cannot have multiple slices. A slice flow consists of multiple PDUs.
What is network slicing based off of?
Network slicing is based on NFV and SDN but also requires control/user plane separation. Processing is handled differently in control and user planes.
What type of PDU sessions are established in 5G?
Three types - IP, Ethernet, and Transparent
How are 4G and 5G systems different?
The levels, priorities and profiles are different
What does reflective QoS imply?
It imply that the UE derives its QoS characteristics from incoming streams
