Best explanation for 5G architecture using a CallFlow diagram. Read NOW!

5G network architecture is a change to cloud from dedicated hardware (specialized hardware). 5G core network moves from 3/4G dedicated hardware to cloud or virtual machines. Radio also moves from dedicated hardware BaseBand Units to CloudRAN or OpenRAN.

Now Mobile Network Operators are not constrained to a single vendor.

Mobile operators can also roll out features faster with a simple software upgrade.

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What is a 5G Core network?

5G Core network architecture was implemented as software as to remove dedicated hardware and also improve performance. This new 5G Core network architecture allows the possibility of rapidly introducing new network functionalities. It also allows running software upgrades that make it possible to create and deploy new services quickly.

Benefits of 5G Core Architecture

Why should you move to a 5G core network? See the main benefits of using 5G core network below:

lowering the cost
allow development of new functionalities
allow software updates
improved network capabilities
growing number of connections
more secure connectivity

Lowering the cost

One of the biggest benefits of using 5G core network is cost decrease for mobile operators. This decrease is possible because the 5G core network is created to replace the dedicated hardware with commercial off-the-shelf solution. These solutions are created to have easy maintenance, allowing new features and software updates to an initial solution and to be accessed remotely for different actions.

All of these combined produce a lower cost for mobile operators for a 5G core network than a previous core network.

Improving the performance

See below some examples that indicate performance improvement for 5G networks compared to 4G networks.

Running on commercial off-the-shelf hardware, it is easier to develop new functionalities that can be integrated into the product using software updates than for other networks that work with dedicated hardware.

One fundamental capability is that it allows vendors to provide internet services as ISPs due, encouraging competition between internet providers.
The network operators can also offer new services to new categories of users. For example, you can use 5G in different fields such as transportation or healthcare to develop new solutions like self-driving cars, connected cars or connected healthcare systems.

5G has greater bandwidth, meaning it can handle many more connected devices than 4G networks. According to global reports the number of connected devices will grow from about 18 billion in 2018 to more than 29 billion in 2023.
This increase is mainly due to the increase of IoT usage in different fields of activity.

Here are some examples of IoT applications, which include location tracking or real-time data collected from moving devices:

The user authentication, data encryption and roaming encryption have been improved for 5G networks.
5G already uses the best 4G defensive technology and it has also implemented new security protocols for previously unresolved problems.

What are the subscribers benefits from this new 5G architecture?

See exactly what a 5G Core network does below:

provides IP service for subscribers (both smartphones and IoT devices)
accepts NGAP connections from gNB
performs registration requests coming from UE
establishes data sessions, taking into account subscription
performs deregistration on UE or network requests
supports authorization and changing of data sessions
supports cell reselection (service request from new gNB from same UE)
supports Voice over NR

The architecture components of a 5G core network

A standard 5G core network contains the following components:

The AMF

The Access and Mobility Management Function (AMF) is responsible from mobility management. The AMF makes the signaling connection with UE and helps UE to register.

The AMF supports :

UE authentication (using 5G AKA) toward AUSF
UE registration in UDM
Subscription to UE data change (AMF data and SMF selection data) in UDM
PDU session management in SMF
AP selection, ODB enforcement (on session and subsequent, UDM pushed, cheanges)
MO / MT SMS using CAPIF
Subscription to UE reachability event

The UDM

The Unified Data Repository (UDM) stores subscriber data and location for the 5G network.

The UDM supports:

AMF registration for 3GPP access (create / update / purge)
5G AKA auth generation (from AUSF)
Retrieval and subscription (create/update/delete) to AM / SM / SMF select / SMS data / SMS management data subscription data. Notify data change to subscribed nodes
SMSF registration, return SMSF GT in SRI-SM, subscribe to UE reachability event in AMF when MT SMS is pending

The AUSF

The Authentication Server Function (AUSF) provides subscriber authentication, normally based on SIM.

The SMF

The Session Management Function (SMF) control of the data sessions. Together, the AMF and SMF are roughly equivalent to 4G MME.

The SMF supports:

Session management from access network: create / update / remove SM context
Obtain / subscribe to SM data in UDM
User plane: Local PDN or GTP toward PGW. Uses gNB IP provided by AMF (using UCN extension of CAPIF) to select GTP-U endpoint
Notify session released to access network using provided callback URI

The NRF

The Network Repository Function (NRF) is the network node(s) repository (database).

Description:

The NRF implements registration and discovery of various other 5G network services, either in local or a remote network.
The NRF also provides a service for requesting OAuth2 access tokens.
Support for 5G roaming is provided via a Security Proxy that transports requests between networks.
Its function is similar to those provided to 2/3/4G by SS7 STP, Diameter DRA and data services DNS.
NRF services don’t include request forwarding, only register/discover/subscribe/notify.
Starting with rel. 16 a new node, SCP (Service Communication Proxy) will be described. It will forward requests to destination based on NRF interaction.

The NRF allows any other network nodes to:

NF node register / update / unregister. NOTE: update is only supported for heartbeat
Node discovery. Supported query parameters: target type, instance
Bootstrapping interface: allow a node to obtain NRF's URIs for services including their version
Obtain authentication token

The UPF

The User Plan Function (UPF) deals with User Plane data under the control of SMF. It is roughly equivalent to 4G SGW and PGW.

The SEPP

The Security Edge Protection Proxy (SEPP) is a non transparent HTTP proxy. Each SEPP uses a N32 connection toward peer SEPP.

The SEPP supports:

N32-c

The following N32 handshake procedures are specified.

The 5G Call Flow process

5G Core network Non-Roaming diagram

5G Core network Roaming diagram

MiniCore5G
MiniCore is a Software-defined compact Core Network that can be used as a test 5G network, LTE/IMS or GSM/GPRS Core Network.
See the product here ››

5G Architecture