The document discusses Siemens' platform for supporting Internet of Things (IoT) and Narrowband IoT (NB-IoT) networks. It describes the growth of IoT and the need for specialized core network functionality to handle the diverse communication needs of IoT devices. The Siemens platform provides standards-compliant implementations of Service Capability Exposure Function (SCEF), Machine Type Communication Interworking Function (MTC-IWF), and MTC Authentication, Authorization and Accounting (MTC-AAA) to securely interface IoT/MTC applications with cellular networks. It also features scalability, redundancy and virtualization.

1. www.convergence-creators.siemens.com
Siemens Convergence Creators
Mobile Networks in a smart digital future –
deploying a platform for IoT and NB-IoT
Supporting 3GPP SCEF, MTC-AAA and MTC-IWF
The Internet of Things is set for astounding growth –
not in some distant future but rather just around the
corner. Boston Consulting Group predicts spending on
IoT technologies to reach €250B by 20201)
.
This dynamic is taking place across major industries,
driven by use cases about to impact the everyday life
of most people as well as businesses worldwide.
When deploying IoT, four principal infrastructure compo-
nents come into play. On one end, devices provide desir-
able client functions and/or data entry points. On the
other end, server applications collect, evaluate and/or
respond to the device data. In between, radio access
establishes physical device connectivity, and the core net-
work manages the actual communication and handles all
subscriber and session data.
The challenge for the core network in an IoT environment
lies in accomodating specific demands on data exchange
protocols, authentication, subscriber and session manage-
ment, and security considerations. It is directly tied to the
breadth of IoT applications, which lead to substantially
diverging communication requirements for the variety of
IoT subscribers.
To illustrate use case differentiation, a closer look at what
types of connectivity are handled in IoT is helpful.
IoT
Core Network
Applications
R
adio Access
Devices

2. 2
The following two polar usage profiles reflect the breadth
of IoT applications:
• Human-like communication requirements:
characterized by long or permanent connectivity, very
frequent client-requests, and transactions with high
bandwidth and low latency, drawing a lot of power.
• Single-purpose M2M communication requirements:
characterized by very short connectivity, inversion of
information flow as there are no client requests to
server/network. Transactions in low bandwidth and high
latency suffice. Low power requirements become a
major factor.
There are many intriguing uses for clients with a human-
like communication profile, including for example con-
nected cars. Nevertheless, when looking at sheer num-
bers, a vast majority of IoT subscribers will be operating
closer to the latter category.
To provide coverage for those subscribers, various LPWAN
(Low Power Wide Area Network) solutions exist. Proprie-
tary (i.e. non-3GPP) technologies include SigFox and LoRa
while LTE-M (LTE Cat-M1) and NB-IoT (Narrow-Band IoT)
represent (3GPP) cellular IoT, operating in the LTE bands.
NB-IoT and LTE-M are shaping up to become complemen-
tary de-facto IoT standards4)
.
IoT technology: 2016 combined MNO partner revenue, number of countries with deployed (non-IoT) networks of
MNO partners, spectrum, and 4G base station upgrade requirements 2) 5)
$578 billion $241 billion $175 billion
~79 countries ~34 countries ~2 countries
Licensed / 3GPP cellular Unlicensed / proprietary Unlicensed / proprietary
Mostly software
upgradable
Hardware upgrades
needed
Hardware upgrades
needed

3. 3
To meet today’s and tomorrow’s demands of MNOs regard-
ing IoT and NB-IoT, Siemens Convergence Creators has
designed a control plane platform that addresses several
key aspects of IoT and NB-IoT networks.
Multiple design goals needed to be considered:
Providing a future proof architecture for data control plane
applications such as AAA or PCRF was one principal objec-
tive, realizing data less front ends running the services
and separate back ends for all associated data was
another.
Furthermore, the solution should have intra site redun-
dancy with no single point of failure. Adding multidimen-
sional scalability including geo-redundancy to the mix, the
platform shall be able to have frontend and backend serv-
ers added without downtime to increase the number of
transactions per second (TPS) and concurrent subscribers/
devices as needed.
All that without complex peer failover configuration,
including reshaping without peer reconfiguration with
only one virtual IP assigned to peers.
While LTE-M is better suited for higher-bandwidth commu-
nication requirements, NB-IoT shines in massive, ultra-low
cost, narrowband deployments and also features improved
indoor coverage. Both have been optimized in 3GPP
Release 13 for low complexity and low device power with
10 years of battery life. NB-IoT additionally offers reduced
device bandwidth of 180kHz and single PRB operation5)
.
Lux Research projects that by 2022, NB-IoT connections
based on LTE 4G networks will dominate low-power wide
area network (LPWAN) connections with over 90 percent
market share2)
.
Siemens IoT Manager
Interfaces to Network Elements
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Siemens IoT Manager
Interfaces
Siemens IoT Manager
3GPP SCEF, MTC-AAA,
MTC-IWF
SCR
LDAP FCAPS, SNMP
VNF-Ve
Files
SMS
(SMS-SC
GMSC, IWMSF)
SGSN MME
AS
SCS
S6t
S6m
S6n
T4 T6b T6a
API or
REST
Tsp
OSS
NFV
 SCR: Siemens Common Repository,
Telco-grade in-memory database for all data
 5G rel15 Evolution not shown (NEF, Network Exposure)
 S6m/S6n can be used with integrated MTC-AAA module
HSS
SCEF, MTC-IWF, and MTC-AAA with 3GPP standards compliance
The race to adapt existing networks or build new opti-
mized ones for NB-IoT is on – and it is about capturing rel-
evant market share – analysts expect a CAGR of 70 to 90
percent for the global NB-IoT market in the next five to
seven years3)
.
To participate in the growth, IoT optimizations to the core
will need to be performed to support a massive number of
devices with very low data rates. This includes deploying a
dedicated core network with IoT specific features, signal-
ling reduction and overload control, and resource and
subscription optimization and scaling.

4. 4
The Siemens Control Plane architecture as outlined above
is of course also available virtualized on VMWare and on
KVM/OpenStack including support for an external VNF
Manager.
It supports redundancy with anti-affinity rules, including
Availability, Resiliency, Failover, Scale-out and all other
Siemens Control Plane characteristics.
Virtualization – Siemens Control
Plane Cloud Platform Architecture
Resilience by geographical
distribution
www.siemens.com/convergence-creatorss reserved
Virtual Load Balancer Virtual Load Balancer
vOAM Server vOAM Server
vBackend Server
vFrontend Server
Service 1
vFrontend Server
Service 2
vFrontend Server
Service 3
vFrontend Server
Service 1
vFrontend Server
Service 2
vFrontend Server
Service 3
vBackend Server
Session and user data synchronization in principle takes
place between two, three or more geographically distrib-
uted sites as Active-Active or Active-Passive with auto-
mated or half-manual switch-over and fallback.
Aiming at avoiding complexity wherever possible, the
dynamic session information is synchronized between
sites, which results in substantial bottleneck reduction.
Picking up on established industry trends, a cloud native
approach, centralized subscriber data management and
NFV decomposition are also part of the package.
In general, the use of advanced IP concepts allows to keep
the user plane elements simple, resulting in optimized
inter-site traffic requirements.

5. 5
The Service Capability Exposure Function (SCEF) was
defined to securely expose services and capabilities pro-
vided by 3GPP network interfaces to external IoT/Machine
Type Communications (MTC) applications or servers.
With 3GPP release 13, a new standard for NB-IoT C-SGN
with SCEF was introduced. 3GPP compliant SCEF is part of
the Siemens NB-IoT platform. It is not only used for device
triggers like wake-up or notify user equipment (UE), but
also implements new key IoT functions like APIs to IoT
enterprises, AAA, External ID, Non-IP Data Delivery (NIDD),
UE reachability and Set QoS.
SCEF is a key component of NB-IoT, acting as a bridge between the telco and non-telco worlds, enabling external
IoT applications to communicate via 3GPP network interfaces.
Siemens IoT Manager - overall view
MTC-IWF (inter-working function) and MTC-AAA support is
realized compliant with 3GPP standards (release 12). For
MTC-AAA this includes 3GPP MTC interfaces, device HSS
profiles and device handling, mapping and grouping. Lean
MTC sessions are optimizing memory usage and realize
independent scalability of TPS and number of devices.
MTC-IWF handles server originated device triggers, exter-
nal communication requests from IoT backends with Auth
Service Control System Requests, as well as MSISDN/
device ID to IMSI mappings and integration of online and
offline charging.
SCEF, MTC-IWF and MTC-AAA with
3GPP standards compliance
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Service Capability Exposure Function (SCEF) for Cellular IoT (C-IoT)
UE MME SCEF
Application
Server (AS)
NAS NIDD RESTful
APIs
External ID
group
HSS
Ext. ID
Up to billions of
low-cost, low-power
devices
Need for Low Power
Wide Area (LPWA),
e.g. NB-IoT
Non-IP Data
Delivery
(NIDD)
SCEF
is key component
Secure exposure of network
services and capabilities
* user equipment
Policy AAA
www.siemens.com/convergence-creatorsrestricted © Siemens Convergence Creators Holding GmbH. 2016, All rights reserved
Siemens IoT Manager
Overall view
Siemens IoT Manager
3GPP SCEF, MTC-AAA,
MTC-IWF
SCS
AAA, PCRF
SCR
DB
tbd
Enterprise
Applications
Non IP via NB
small (100kbit)5G Radio 5GC
Enterprise
ApplicationsEnterprise
ApplicationsEnterprise
Applications
ePC
C-SGN
2G/3G
SMS
IP via 4G, LTE-M, 5G, …Mbit/s
NB
4G Radio
+ LTE-M
GSM
LoRa
SigFox
WiFi
device
car
factory
machines

6. 6
SCEF authentication and load
handling
SCEF Use Cases
Before an NIDD transfer via SCEF is initiated, two different
registration steps are required by the application server
(AS) and UE.
As part of the registration procedures, SCEF uses both the
S6t-interface to the HSS and the T6 interface to MME/C-
SGN as part of the registration procedures.
APIs for NIDD are not yet defined and may be optionally
secured by SCEF and the AS with a secure server. Further-
more, SCEF can downgrade the load information in case
Most of the use cases for SCEF are based on the expecta-
tion that the number of devices will grow exponentially
and data size per device remains small. In addition, to be
the specified load exceeds the local limits maintained in
the SCEF’s configuration.
Once the authentication is successfully concluded, NIDD
transfer between AS and UE is possible in both directions.
Should a delivery attempt fail, there are multiple available
courses of action. For example, in case the UE is not regis-
tered, SCEF can buffer the data and deliver it later when
conditions become suitable. Alternatively, the SCEF may
use SMS to cause the UE to attach to the mobile network.
able to handle the requirements stipulated by Infrequent
Small Data Transmissions, future optimization of the EPC
might also be required.
Mobile Autonomous Report-
ing (MAR) exception report
• smoke alarm detectors: alarms
• smart meters: failure notifica-
tions (e.g. power failure)
• any devices: tamper notifications
a few
bytes
(~20)
sporadic, rare
(a few times
per year)
not
required
Mobile Autonomous Report-
ing (MAR) periodic reports
• sensors: periodic sensor data
(weather, traffic, etc.)
• smart meters: periodic metering
reports
20 – 200
bytes
1 day (40%),
2 hours (40%),
1 hour (15%),
and 30 min-
utes (5%)
not
required
Network Triggered Action
(Network Commands)
• switch on/off (standby)
• request for meter reading
• trigger to send uplink report
a few
bytes
(0 – 20)
1 day (40%),
2 hours (40%),
1 hour (15%),
and 30 min-
utes (5%)
required in
some cases
Software update/reconfigu-
ration model
large
( 2000
bytes)
twice per year required
SCEF Use Cases
General
Examples Response
Data Size
(typical)
Frequency
(typical)

7. 7
Usage Control via Gy interface
• Device exceeds the subscribed uplink or downlink rate
• Device exceeds the number of attachments for the time period
• Device exceeds the quota of event subscription/notification
• Device exceeds the quota of NIDD subscription
Changing the billing party of a session
• An enterprise offering a client to pay for an online session after cli-
ent purchases a product
• Free connection services
Information to 3rd parties about network issues
In case of non-reachability of the UE the SCEF informs the
enterprise whether this is due to the network or the UE itself.
3rd party interaction for UE Patterns
The enterprise can inform the Operator of patterns of a UE,
so the Operator can better tune the network, used for differen-
tiation between fixed and mobile devices.
Infrequent Small Data Transmissions
Highly efficient handling of infrequent small data transmis-
sions for ultra-low complexity, power constrained, and low
data-rate ‘Internet of Things’ devices (Cellular IoT devices).
Tracking Devices
Highly efficient handling of tracking devices using small data
transmissions for ultra-low complexity, power constrained, and
low data-rate ‘Internet of Things’ devices (Cellular IoT devices).
SCEF Use Cases Billing/Control
SCEF Use Cases Technical
Examples
Examples / Description
Would you like to find out more about the capabilities of the Siemens Platform for IoT, NB-IoT and SCEF?
Contact Siemens Convergence Creators with your questions or to arrange a demo:
Oliver Korfmacher
Product Line Manager
LTE Business Unit
info@siemens-convergence.com
Sources:
1)
https://www.forbes.com/sites/louiscolumbus/2017/01/29/internet-of-things-market-to-reach-267b-by-2020
2)
http://www.luxresearchinc.com/news-and-events/press-releases/read/
nb-iot-standard-poised-take-90-share-low-power-wide-area
3)
http://www.marketsandmarkets.com/PressReleases/narrowband-iot-enterprise-application.asp,
http://www.prnewswire.com/news-releases/global-narrowband-iot-market-forecast-2017-2024-300434777.html
4)
https://www.qualcomm.com/news/onq/2015/09/28/harmonizing-industry-narrowband-iot-specification
5)
Nokia: LTE evolution for IoT connectivity - https://resources.ext.nokia.com/asset/200178

8. All hardware and software names used
are brand names and/or trademarks of their
respective holders.
© Siemens Convergence Creators GmbH, 2017.
All rights reserved.
SCVC-PGCON-CORE-B-EN-201707-R01.1
Subject to change without prior notice. The infor-
mation in this document contains general
descriptions of the technical options available,
which may not apply in all cases.
The required technical options should therefore
be specified in the contract.
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