LTE notes

The LTE Network Architecture - Alcatel-Lucent | At the Speed of Ideas
http://www3.alcatel-lucent.com/wps/DocumentStreamerServlet?LMSG_CABINET=Docs_and_Resource_Ctr&LMSG_CONTENT_FILE=White_Papers/CPG0599090904_LTE_Network_Architecture_EN_StraWhitePaper.pdf




eNodeB (evolved NodeB)
UE (user equipment)
PDN (packet data network)
EPC (evolved packet core)
EPS (evolved packet system)
EPS bearer: an IP packet flow with a defined QoS between the gateway and the UE
CN (core network)
SAE (system architecture evolution): evolution of non-radio aspect.

EPC is consist of the following logical nodes:

• P-GW (PDN Gateway)
• S-GW (Serving Gateway)
• MME (Mobility Management Entity)
• PCRF (Policy Ccontrol and charging Rules Functions)
• HSS (Home Subscriber Server)

NAS (Non Access Stratum)
AS (Access Stratum) protocol: The protocol running between eNodeBs and UE
S-TMSI (SAE Temporary Mobile Subscriber Identification)
TA (Tracking Area)




S1 interface: Interface that connect eNodeB and EPC
S1-MME interface: Interface that connect eNodeB and MME
S1-U interface: Interface that connect eNodeB and S-GW
X2 interface: eNodeB interconnected to each other by X1.
S1-flex: the feature of S1 interface linking the access network to the CN
MME/S-GW pool: The set of MME/S-GW nodes that serves a common area.
pool area: the area covered by MME/S-GW pool


TR-196: Femto Access Point Service Data Model
http://www.broadband-forum.org/technical/download/TR-196.pdf
[wiki] TR-196
http://en.wikipedia.org/wiki/TR-196

As a bidirectional SOAP/HTTP-based protocol, it provides the communication between customer-premises equipment (CPE) and Auto Configuration Servers (ACS). TR-069 is a more generic which address various devices such as modems, routers, gateways, set-top box, and VoIP-phones. TR-196 primary objective is to provide data model very specific to Femto Access Point(FAP)

E-UTRAN: responsible for radio-related functions:

• RRS (Radio resource management)
• Header Compression
• Security
• Connectivity to the EPC

RAN (Radio Access Network)
PMIP (Proxy Mobile Internet Protocol)
PLMN (Public Land Mobile Network)

blue region of the stack is the E-UTRAN user plane protocol stack

GTP (GPRS Tunnel Protocol): 3GPP-specific protocol over CN interfaces, S1 and S5/S8.
PDCP (Packet Data Convergence Protocol)
RLC (Radio Link Control)
MAC (Medium Access Control)

blue region of the stack indicate the AS protocol.

RRC (Radio Resource Control) protocol

Bearers:

• GBR (Minimum guaranteed bit rate)
• Non-GBR

QCI (QoS class identification)
ARP (Allocation and Retention Priority)

AM (Acknowledge Mode)
LTE-Uu: radio interface

EPS bearer
S5/S8 bearer
S1 bearer
radio bearer

TFT (Traffic Flow Template)
UL TFT (Uplink TFT)
DL TFT (Downlink TFT)

PCEF (Policy Control Enforcement Function)

bearer level QoS parameter value is passed from:
PCRF -> P-GW -> S-GW -> --(S11)--> MME

PCC (Policy Control and Charging)

SONs (Self-optimizing networks)
SS7 (Signal System #7)

S1 Control plane:

SCTP(Stream Control Transmission Protocol)/IP
S1-AP (Application Protocol)


S1 User Plane:

TEID (Tunnel End ID)
TNL (Transport Network Layer)
HOL (Head-of-line blocking)

[wiki] Head-of-line blocking
http://en.wikipedia.org/wiki/Head-of-line_blocking

NNSF (NAS Node Selection Function)

X2 handover
S1 handover

UMTS Serving Radio Network Subsystem (SRNS) relocation procedure


S1 handover:

ANRF (automatic neighbor relation function)
PCI (Physical Cell Identity)

eNB Configuration Transfer procedure
automatic self-configuration of the PCIs
O&M (Operation and Maintenance)
SN (Sequence Number)
HFN (Hyper Frame Number)



selective retransmissions
multiple preparation
RRM (Radio resource management)