Theory Flashcards
LTE theory summary
Rel. 8 introduced this…
Reference Signal Received Power (RSRP)
Rel. 9 introduced this…
Reference Signal Received Quality (RSRQ)
Rel. 10 advancement was…
LTE Advanced (True 4G)
Rel. 15+ is…
5G
The PLMN is now/also known as…
The Evolved Packet System (EPS)
This is the Network side of the LTE architecture…
Evolved Packet Core (EPC)
Name the five parts that make up the Evolved Packet Core (EPC).
MME, HSS, S-GW, PDN-GW, PCRF
What are the responsibilities of the MME?
Call setup/tear-down; control plane for 2G/3G access; authentication; controls one or more Tracking Areas.
What does the Serving Gateway (S-GW) do?
Routes and forwards data packets; stores IP addresses
What are the responsibilities of the Packet Data Network Gateway (PDN-GW)?
Assigns IP addresses; packet screening; non-3GPP tech support (ie. CDMA2000)
What is the role of the Policy Charging/Rules Function (PCRF)?
Sets the Quality of Service (QoS) standards for different types of data sessions.
Name the components of the E-UTRAN.
eNodeB
What are the four types of eNodeB identifiers?
eNB ID; Cell ID; ECI (E-UTRAN Cell ID); ECGI (E-UTRAN Cell Global ID)
What are the two components of a Tracking Area Identifier?
Tracking Area Code (TAC); MCC/MNC (PLMN)
What is a TAI List?
A group of TACs that a UE does not need to perform a TAC update while within its boundaries.
Define OFDMA
Orthogonal Frequency Division Multiple Access
What are the three benefits of using OFDMA?
Increased spectral efficiency
Robust/Resistant to multi-path fading
Scalable bandwidth
What are the three limitations of OFDMA?
Guard Space requirement of 10% (22% for 1.4MHz band)
Sensitive to time/frequency shifts
High Peak to Average Power
How does LTE overcome time domain shifts?
Cyclic prefix
How does LTE overcome frequency domain shifts?
Orthogonal subcarriers
What is SC-FDMA and how is it used in LTE?
Single Carrier Frequency Division Multiple Access.
It is only used on the uplink to increase the battery life of the UE and negate the use of expensive radio technology.
What are the two techniques used on the downlink in MIMO technology?
Spatial Multiplexing; Transmit Diversity
Define Spatial Multiplexing.
Takes a signal and divides it up to transmit over different antennas.
Define Transmit Diversity.
Transmits a signal over multiple antennas for redundancy.
