Cellular Acronym Evolution
==========================
Harald Welte
:copyright: Harald Welte (Liense: CC-BY-SA)
:backend: slidy
:max-width: 45em

== Classic GSM

GSM:: Global System for Mobile Communications (was: Groupe Special Mobile)

Network is split in

BSS:: Base Station Subsystem
NSS:: Network Switching Subsystem

== Classic GSM Networks: Subscriber Side

ME:: Mobile Equipment
SIM:: Subscriber Identity Module
MS:: Mobile Station (ME + SIM)

Um:: User interface (mobile)

== Classic GSM Networks: BSS

BSS:: Base Station Subsystem

BTS:: Base Transceiver Station
Abis:: Interface BTS - BSC
BSC:: Base Station Controller
A:: Interface BSC - MSC

== Classic GSM Networks: NSS

MSC:: Mobile Switching Center
VLR:: Visitor Location Register
HLR:: Home Location Register
SMSC:: SMS Service Center

== GPRS extends GSM

CCU:: Circuit Control Unit
PCU:: Packet Control Unit
Gb:: Interface PCU - SGSN
SGSN:: Serving GPRS Support Node
GGSN:: Gateway GPRS Support Node

== UMTS

UMTS:: Univesal Mobile Telephony System
WCDMA:: Wideband Carrier Division Multiple Access

Network is split in RAN + CN

RAN:: Radio Access Network
CN:: Core Network

== UMTS Subscriber Side

ME:: Mobile Equipment (no change)
UICC:: Univresal Integrated Chip Circuit
USIM:: UMTS SIM (Application on UICC), successor of SIM
UE:: User Equipment (Successor of MS)

Uu:: User interface, universal. Successor of Um

== UMTS Radio Access Network (RAN)

RAN:: Successor of BSS
GERAN:: GPRS/EDGE RAN (legacy part)
UTRAN:: Universal Telephony RAN (UMTS RAN)
NodeB:: Successor of BTS
Iub:: Interface NodeB - RNC (Successor of Abis)
RNC:: Successor of BSC
Iu-CS:: Interface RNC - MSC (Successor of A)
Iu-PS:: Interface RNC - SGSN (Successor of Gb)

== UMTS Core Netwokr (CN)

MSC:: Mobile Switching Center
VLR:: Visitor Location Register
HLR:: Home Location Register
SMSC:: SMS Service Center
SGSN:: Serving GPRS Support Node
Gn:: Interface between SGSN and GGSN
GGSN:: Gateway GPRS Support Node

(no acronym changes)

== UMTS Release 4

The MSC functionality is split between control and user plane;

MSS:: Mobile Switching Center Server
MGW:: Media GateWay

== LTE (Long Term Evolution)

After your network is already universal, what else can happen? It
*evolves*...

LTE UE:: UserEquipment (no rename)
LTE Uu:: LTE User interface (universal)
E-UTRAN:: Evolved UTRNA (successor to UTRAN)
eNodeB:: Evolved NodeB (successor to NodeB)
S1:: Interface between eNodeB and MME (successor to Iu-PS)

== LTE (Long Term Evolution)

MME:: Mobility Management Engine (partial successor to SGSN)
S11:: Interface between MME and S-GW
S-GW:: Serving GateWay (partial successor to SGSN)
S5:: Interface between S-GW and P-GW (successor to Gn)
P-GW:: Packet Data Network GateWay (successor to GGSN)

(RNC has completely been removed, eNodeBs arrange hand-overs directly
among each other)

== Radio Interface Protocol Stacks

[options="header"]
|===
| GSM | GPRS | UMTS | LTE
| - | SNDCP | PDCP | PDCP
| RR | GRR | RRC | LTE RRC
| LAPD | RLC/MAC | RLC/MAC | LTE RLC/MAC
| Um | Um | Uu | LTE Uu
|===

== Radio Interface Logical Channels

[options="header"]
|===
| GSM | GPRS | UMTS | LTE
| BCCH | (P)BCC | BCCH | BCCH
| CCCH | (P)CCCH | CCCH | CCCH
| SDCCH | - | DCCH | DCCH
| TCH | - | DTCH | DTCH
| - | PCCH | PCCH | PCCH
|===

In GSM, logical channels are directly on top of the physical layer,
while UMTS and LTE introduce complex physica and transport channel
concepts underneath the logical channel.

==  UMTS Physical / Transport / Logical Channels

image::765px-UMTS_Channels.svg.png[]

By Timothy Colgan - Own work, CC BY-SA 3.0,
https://commons.wikimedia.org/w/index.php?curid=19454393


== The End

Questions?
