Describes an overview of the Samsung system, working, and all major
functionalities.
Document Version 2.0
April 2017
Document Number: 2600-00KGZQGA2
This manual should be read and used as a guideline for properly installing and/or operating the
product. Owing to product variations across the range, any illustrations and photographs used in
this manual may not be a wholly accurate depiction of the actual products you are using.
This manual may be changed for system improvement, standardization and other technical
reasons without prior notice.
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must be kept confidential. No part of this document shall be photocopied, reproduced, stored in a
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No warranty of accuracy is given concerning the contents of the information contained in this
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any direct or indirect loss or damage caused by omissions from or inaccuracies in this document.
SAMSUNG Electronics Co., Ltd. reserves the right to change details in this publication without notice.
SNMTC-v3-0312
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Contents
Preface vi
Conventions in this Document ........................................................................................................ vi
New and Changed Information ...................................................................................................... vii
Revision History .............................................................................................................................. vii
Organization of This Document ..................................................................................................... viii
Personal and Product Safety ........................................................................................................... ix
Chapter 1Samsung LTE System Overview 1
Introduction to Samsung LTE System ............................................................................................... 1
State of California Proposition 65 Warning (US only)
WARNING: This product contains chemicals known to the State of California to
cause cancer and birth defects or other reproductive harm.
California USA Only
This Perchlorate warning applies only to primary CR (Manganese Dioxide)
Lithium coin cell batteries in the product sold or distributed ONLY in California
USA.
Perchlorate Material-special handling may apply. See www.dtsc.ca.gov/hazardous
waste/perchlorate.
Samsung LTE system supports 3GPP LTE (hereinafter, LTE) based services.
The LTE is a next generation wireless network system which solves the
disadvantages of existing 3GPP mobile systems allows high-speed data service at
low cost regardless of time and place.
Samsung LTE system supports Orthogonal Frequency Division Multiple Access
(OFDMA) for downlink, Single Carrier (SC) Frequency Division Multiple Access
(FDMA) for uplink, and scalable bandwidths for various spectrum allocation and
provides high-speed data service. It also provides high-performance hardware for
improved system performance and capacity and supports various functions and
services.
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Samsung LTE system is based on the Rel-8 and Rel-9 standards of LTE 3rd
Generation Partnership Project (3GPP).
Samsung LTE system consists of evolved UTRAN Node B (eNB), Evolved Packet
Core (EPC) and LTE System Manager (LSM).
The eNB exists between EPC and User Equipment (UE). It establishes wireless
connections with UE and processes packet calls according to LTE air interface
standard. The eNB manages UE in connected mode at the Access Stratum (AS)
level. The EPC is the system, which is located between eNB and Packet Data
Network (PDN) to perform various control functions. The EPC consists of
Mobility Management Entity (MME), Serving Gateway (S-GW), and PDN
Gateway (P-GW). The MME manages UE in idle mode at the Non-Access Stratum
(NAS) level. Also, S-GW and P-GW manages user data at the NAS level and
interworks with other networks.
The LSM provides man-machine interface; manages the software, configuration,
performance, and failures. Also, it acts as a Self-Organizing Network (SON)
server.
The figure below shows the functional distinctions between eNB of E-UTRAN,
MME, S-GW, and P-GW according to the 3GPP standard. The eNB has a layer
structure and EPC has no layer.
Figure 1. Functional Distinctions of E-UTRAN and EPC
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eNB
The eNB is a logical network component of Evolved UTRAN (E-UTRAN), which
is located on access side in LTE system.
The eNBs can be interconnected with each other by X2 interface. The eNBs are
connected by S1 interface to Evolved Packet Core (EPC).
The wireless protocol layer of eNB is divided into layer 2 and layer 3. The layer 2
is subdivided into Media Access Control (MAC) layer, Radio Link Control (RLC)
layer, and PDCP layer, each of which performs independent functions. Also,
layer3 has Radio Resource Control (RRC) layer.
The MAC layer distributes air resources to each bearer according to its priority.
Also, it performs multiplexing function and HARQ function for the data, which is
received from the multiple upper logical channels.
The RLC layer performs the following functions:
Segments and reassembles the data, which is received from PDCP layer under
the size specified by MAC layer
Requests retransmission to recover if data transmission fails in the lower layer
(ARQ)
Reorders the data recovered by performing HARQ in MAC layer (re-ordering)
The PDCP layer performs the following functions:
Header compression and decompression
Encrypts/decrypts user plane and control plane data
Protects and verifies the integrity of control plane data
Transmits data including sequence number related function
Removes data and redundant data based on a timer
The RRC layer performs mobility management within the wireless access network,
maintaining and control of Radio Bearer (RB), RRC connection management, and
system information transmission, and so on.
The MME interworks with E-UTRAN (eNB) to process the Stream Control
Transmission Protocol (SCTP)-based S1 Application Protocol (S1-AP) signalling
messages for controlling call connections between MME and eNB. Also, MME
process the SCTP-based NAS signalling messages for controlling mobility
connection and call connection between UE and EPC.
The MME is responsible for collecting/modifying the user information and
authenticating the user by interworking with HSS. It is also responsible for
requesting the allocation/release/change of the bearer path for data routing and
retransmission with GTP-C protocol by interworking with S-GW.
The MME interworks with 2G and 3G systems, Mobile Switching Center (MSC),
and Serving GPRS Support Node (SGSN) for providing mobility and Handover
(HO), Circuit Service (CS) fallback, and Short Message Service (SMS).
The MME is responsible for inter-eNB mobility, idle mode UE reachability,
Tracking Area (TA) list management, choosing P-GW/S-GW, authentication, and
bearer management.
The MME supports mobility during inter-eNB handover and inter-MME handover.
It also supports SGSN selection function upon handover to 2G or 3G 3GPP
network.
S-GW
The S-GW acts as the mobility anchor during inter-eNB handover and inter-3GPP
handover, and routes and forwards user data packets. The S-GW allows the
operator to apply application-specific charging policies to UE, PDN or QCI and
manages the packet transmission layers for uplink/downlink data.
The S-GW also supports GPRS Tunnelling Protocol (GTP) and Proxy Mobile IP
(PMIP) by interworking with MME, P-GW, and SGSN.
PDN Gateway (P-GW)
The P-GW is responsible for charging and bearer policy according to the policy
and manages charging and transmission rate according to the service level by
interworking with PCRF. The P-GW also performs packet filtering for each user,
IP address allocation for each UE, and downlink data packet transmission layer
management.
Samsung LTE system consists of eNB, LSM, and EPC. Also, it comprising
multiple eNBs and EPCs (MME, S-GW/P-GW) is a subnet of PDN, which allows
User Equipment (UE) to access external networks. In addition, Samsung LTE
system provides LSM and self-optimization function for operation and
maintenance of eNBs.
The following figure shows Samsung LTE system architecture:
Figure 2. Samsung LTE System Architectures
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eNB
The eNB is located between UE and EPC. It processes packet calls by connecting
to UE wirelessly according to LTE air standard. The eNB is responsible for
transmission and receipt of wireless signals, modulation and demodulation of
packet traffic signals, packet scheduling for efficient utilization of wireless
resources, Hybrid Automatic Repeat Request (HARQ)/ARQ processing, Packet
Data Convergence Protocol (PDCP) for packet header compression, and wireless
resources control.
In addition, eNB performs handover by interworking with EPC.
The EPC is a system, which is located between eNB and PDN. The
subcomponents of EPC are MME, S-GW and P-GW, Multimedia
Broadcast/Multicast Service Gateway (MBMS GW).
MME: Processes control messages using the NAS signaling protocol with eNB
and performs control plane functions such as UE mobility management,
tracking area list management, and bearer and session management.
S-GW: Acts as the anchor for user plane between 2G/3G access system, LTE
system, and manages and changes the packet transmission layer for
downlink/uplink data.
P-GW: Allocates an IP address to UE, acts as the anchor for mobility between
LTE and non-3GPP access systems, and manages/changes charging and
transmission rate according to the service level.
LTE System Manager (LSM)
The LSM provides user interface for the operator to operate and maintain eNB.
The LSM is responsible for software management, configuration management,
performance management and fault management, and acts as a SON server.
Core System Manager (CSM)
The CSM provides user interface for the operator to operate and maintain MME,
S-GW, and P-GW.
Master SON Server (MSS)
The MSS interoperates with local SON server as its higher node, making
optimized interoperation possible for the multi-LSM. The MSS can work with
Operating Support System (OSS) of the service provider who can decide whether
to link them.
Home Subscriber Server (HSS)
The HSS is a database management system that stores and manages the parameters
and location information for all registered mobile subscribers. The HSS manages
key data such as the mobile subscriber’s access capability, basic services and
supplementary services, and provides a routing function to the subscribed receivers.
Policy and Charging Rule Function (PCRF)
The PCRF server creates policy rules to dynamically apply the QoS and charging
policies differentiated by service flow, or creates the policy rules that can be
applied commonly to multiple service flows. The P-GW includes Policy and
Charging Enforcement Function (PCEF), which allows application of policy rules
received from PCRF to each service flow.
Online Charging System (OCS)
The OCS collects online charging information by interfacing with S-GW and PGW.
When a subscriber for whom online charging information is required makes a call,
P-GW transmits and receives the subscriber’s charging information by
interworking with OCS.
Offline Charging System (OFCS)
The OFCS collects offline charging information by interfacing with S-GW and PGW.
The OFCS uses GTP’ (Gz) or Diameter (Rf) interface to interface with S-GW and
P-GW.
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Multi-cell/Multicast Coordination Entity (MCE)
The MCE is located between MME and eNB. It is responsible for session control
signaling, admission control, radio resource allocations for eMBMS. M2 and M3
interface is used to interwork with eNB and MME.
The inter-NE protocol stack of the eNB is as follows:
Protocol Stack between UE and eNB
The user plane protocol layer consists of PDCP, RLC, MAC, and PHY layers.
The user plane is responsible for transmission of user data (e.g. IP packets)
received from the upper layer. In user plane, all protocols are terminated in eNB.
The control plane protocol layer is composed of the NAS layer, RRC layer, PDCP
layer, RLC layer, MAC layer, and PHY layer. The NAS layer is located on the
upper wireless protocol. It performs UE authentication between UE and MME,
security control, and paging and mobility management of UE in LTE IDLE mode.
In control plane, all protocols except for the NAS signal are terminated in eNB.
Figure 3. Protocol Stack between UE and eNB
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Protocol Stack between eNB and EPC
The eNB and EPC are connected physically through FE and GE method, and the
connection specification should satisfy LTE S1-U and S1-MME interface.
In user plane, GTP-User (GTP-U) is used as the upper layer of the IP layer; and in
Control plane, SCTP is used as the upper layer of the IP layer.
The figure below shows the user plane protocol stack between eNB and S-GW:
Figure 8. Interface Protocol Stack between eNB and LSM
Protocol Stack between eNB and MCE Server
The eNB must provide the interface for the interoperation with the MCE server.
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GE is used for physical connection between the eNB and MCE server. The
connection specification must satisfy the STCP interface.
Figure 9. Protocol Stack between eNB and MCE Server
Protocol Stack between MCE Server and MME
GE is used for physical connection between the MME and MCE server. The
connection specification must satisfy the STCP interface. The protocol stack
between the MCE server and MME is as follows:
Figure 10. Protocol Stack between MCE Server and MME
Protocol Stack between MCE Server and LSM
GE is used for physical connection between the LSM and MCE server. The
connection specification must satisfy the FTP/SNMP/UDP interface. The
following diagram shows the interface protocol stack between the MCE server and
LSM.
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Figure 11. Protocol Stack between MCE Server and LSM
In LTE system, eNB is located between UE and EPC. The eNB provides mobile
communications services to subscribers according to LTE air interface standard.
The eNB transmits/receives radio signals to/from UE and processes the
modulation and demodulation of packet traffic signals. The eNB is also
responsible for packet scheduling and radio bandwidth allocation and performs
handover via interface with EPC.
The eNB consists of Digital Unit (DU) and Radio Unit (RU).
The CDU is a digital unit (19-inch shelf) and can be mounted into indoor or
outdoor 19-inch commercial rack.
The RRH is a RF integration module consisting of a transceiver, power amplifier,
and filter. It transmits and receives traffic, clock information, and alarm/control
messages to and from the CDU. The RRH has 4Tx/4Rx, 2Tx/4Rx or 2Tx/2Rx
configurations supporting optic CPRI and can be installed on outdoor wall or pole.
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The main features of eNB are as follows:
High Compatibility and Interoperability
The eNB complies with the specifications released based on the 3GPP standard.
So, it has high compatibility and interoperability.
High-Performance Modular Structure
The eNB has high-performance with the use of high-performance processors.
It is easy to upgrade hardware and software because of its modular structure.
Support for Advanced RF and Antenna Solutions
The eNB adopts the power amplifier to support wideband operation bandwidth and
Multiple Input Multiple Output (MIMO).
Separation of CDU and RRH
The eNB consists of CDU and RRH separately for easy installation and flexible
network configuration. In case of connection between CDU and RRH, data traffic
signals and OAM information are transmitted/received through the Digital I/Q and
C & M interface based on the Common Public Radio Interface (CPRI). Physically,
optic cables are used.
The CDU and RRH are supplied DC -48 V DC power from a rectifier respectively.