Tutorial: Service Based Architecture (SBA) for 5G Core (5GC)

As a continuation of 'Control and User Plane Separation of EPC nodes (CUPS) in 3GPP Release-14', here is another tutorial on Service Base Architecture (SBA) for the 5G Core.

The slides (with video) is embedded below but there are quite a few tutorials on 5G available on 3G4G page here.

Advanced: 5G Service Based Architecture (SBA) from 3G4G

Further Reading:

• Control and User Plane Separation of EPC nodes (CUPS) in 3GPP Release-14
• 3GPP 5G Specifications
• 5G - 3G4G Webpage
• 2G, 3G, 4G & 5G Training and Tutorial Videos - 3G4G Webpage

3GPP-VRIF workshop on Virtual Reality Ecosystem & Standards in 5G

Its been a year since I last posted about Augmented / Virtual Reality Requirements for 5G. The topic of Virtual Reality has since made good progress for 5G. There are 2 technical reports that is looking at VR specifically. They are:

• 3GPP TR 26.918: Virtual Reality (VR) media services over 3GPP
• 3GPP TR 26.929: QoE parameters and metrics relevant to the Virtual Reality user experience

The second one is work in progress though. 

Anyway, back in Dec. 3GPP and Virtual Reality Industry Forum (VRIF) held a workshop on VR Ecosystem & Standards. All the materials, including agenda is available here. The final report is not there yet but I assume that there will be a press release when the report is published.

While there are some interesting presentations, here is what I found interesting:

From presentation by Gordon Castle, Head of Strategy Development, Ericsson

From presentation by Martin Renschler, Senior Director Technology, Qualcomm

For anyone wanting to learn more about 6 degrees of freedom (6- DoF), see this Wikipedia entry. According to the Nokia presentation, Facebook’s marketing people call this “6DOF;” the engineers at MPEG call it “3DOF+.”

XR is 'cross reality', which is any hardware that combines aspects of AR, MR and VR; such as Google Tango.

From presentation by Devon Copley, Former Head of Product, Nokia Ozo VR Platform

Some good stuff in the pres.

From presentation by Youngkwon Lim, Samsung Research America; the presentation provided a link to a recent YouTube video on this presentation. I really liked it so I am embedding that here:



Finally, from presentation by Gilles Teniou, SA4 Vice chairman - Video SWG chairman, 3GPP

You can check and download all the presentations here.

Further Reading:

• 3GPP 5G Specifications

Satellites & Non-terrestrial networks (NTN) in 5G

Satellites has been an area of interest of mine for a while as some of you know that I used to work as Satellite Applications & Services Programme manager at techUK. I have written about how I see satellites complementing the mobile networks here and here.

Pic Source: The Role of Satellite in 5G - SES

Its good to see that there is some activity in 3GPP going on about satellites & Non-terrestrial networks (NTN) in 5G. While there are some obvious roles that satellites can play (see pic above), the 5G work is looking to cover a lot more topics in details.

Pic Source: Nomor - Overview 3GPP 5G Satellite Activities, Oct 2017

3GPP TR 38.913: Study on scenarios and requirements for next generation access technologies looks at 12 different scenarios, the ones relevant to this topic ate Air to ground, Light aircraft and Satellite to terrestrial.

3GPP TR 38.811: Study on New Radio (NR) to support non terrestrial networks (Release 15) covers this topic a bit more in detail. From looking at how satellites and other aerial networks work in general, it looks at the different NTN architecture options as can be seen above.

People looking to study this area in detail should probably start looking at this TR first.

3GPP also released a news item on this topic last week. It also refers to the above TR and a new one for Release 16. The following from 3GPP news:

The roles and benefits of satellites in 5G have been studied in 3GPP Release 14, leading to the specific requirement to support satellite access being captured in TS 22.261 - “Service requirements for next generation new services and markets; Stage 1”, recognizing the added value that satellite coverage brings, as part of the mix of access technologies for 5G, especially for mission critical and industrial applications where ubiquitous coverage is crucial.

Satellites refer to Spaceborne vehicles in Low Earth Orbits (LEO), Medium Earth Orbits (MEO), Geostationary Earth Orbit (GEO) or in Highly Elliptical Orbits (HEO).

Beyond satellites, Non-terrestrial networks (NTN) refer to networks, or segments of networks, using an airborne or spaceborne vehicle for transmission. Airborne vehicles refer to High Altitude Platforms (HAPs) encompassing Unmanned Aircraft Systems (UAS) - including tethered UAS, Lighter than Air UAS and Heavier than Air UAS - all operating at altitude; typically between 8 and 50 km, quasi-stationary.

These Non-terrestrial networks feature in TSG RAN’s TR 38.811 “Study on NR to support non-terrestrial networks”. They will:

• Help foster the 5G service roll out in un-served or underserved areas to upgrade the performance of terrestrial networks
• Reinforce service reliability by providing service continuity for user equipment or for moving platforms (e.g. passenger vehicles-aircraft, ships, high speed trains, buses)
• Increase service availability everywhere; especially for critical communications, future railway/maritime/aeronautical communications
• Enable 5G network scalability through the provision of efficient multicast/broadcast resources for data delivery towards the network edges or even directly to the user equipment

The objective of TR 38.811 is to study channel models, to define the deployment scenarios as well as the related system parameters and to identify and assess potential key impact areas on the NR. In a second phase, solutions for the identified key impacts on RAN protocols/architecture will be evaluated and defined.

A second study item, the “Study on using Satellite Access in 5G” is being addressed in Working Group SA1.  It shall lead to the delivery of the corresponding Technical Report TR 22.822 as part of Release 16.

This study will identify use cases for the provision of services when considering the integration of 5G satellite-based access components in the 5G system. When addressing the integration of (a) satellite component(s), use cases will identify new potential requirements for 5G systems addressing:

• The associated identification of existing / planned services and the corresponding modified or new requirements
• The associated identification of new services and the corresponding requirements
• The requirements on set-up / configuration / maintenance of the features of UE’s when using satellite components related features as well for other components from the 5G system
• Regulatory requirements when moving to (or from) satellite from (or to) terrestrial networks

Related Posts:

• An Introduction to Non-Terrestrial Networks (NTN)
• Connectivity on Planes
• Connectivity Technology Blog: TIP has launched 'Non-Terrestrial Connectivity Solutions' Group
• 3G4G Small Cells Blog: Flying Small Cells are here...

The small detail about 5G you may have missed...

While going through the latest issue of CW Journal, I came across this article from Moray Rumney, Lead Technologist, Keysight. It highlights an interesting point that I missed out earlier that 5G also includes all LTE specifications from Release 15 onwards.

I reached out to our CW resident 3GPP standards expert Sylvia Lu to clarify and received more details.

There is a whole lot of detail available in RP-172789.zip. Here RIT stands for Radio Interface Technology and SRIT for Set of RIT.

Indeed, NB-IoT and Cat-M will also be part of the initial IMT-2020 submissions early next year.. watch the space

— Sylvia Lu (@SylviaLuUk) December 22, 2017

In fact at Sylvia clarified, NB-IoT and Cat-M will also be part of the initial IMT-2020 submissions early next year. Thanks Sylvia.

There is also this nice presentation by Huawei in ITU (here) that describes Requirements, Evaluation Criteria and Submission Templates for the development of IMT-2020. It is very helpful in understanding the process.

Coming back to the question I have often asked (see here for example),
1. What features are needed for operator to say they have deployed 5G, and
2. How many sites / coverage area needed to claim 5G rollout

With LTE Release-15 being part of 5G, I think it has just become easy for operators to claim they have 5G.

What do you think?

5G Dual Connectivity, Webinar and Architecture Overview

One of the things that will come as a result of NSA (Non-StandAlone) architecture will be the option for Dual Connectivity (DC). In fact, DC was first introduced in LTE as part of 3GPP Release 12 (see 3G4G Small Cells blog entry here). WWRF (Wireless World Research Forum) has a good whitepaper on this topic here and NTT Docomo also has an excellent article on this here.

A simple way to understand the difference between Carrier Aggregation (CA) and Dual Connectivity (DC) is that in CA different carriers are served by the same backhaul (same eNB), while in DC they are served by different backhauls (different eNB or eNB & gNB).


We have produced a short video showing different 5G architectures, looking mainly at StandAlone (SA) and Non-StandAlone (NSA) architectures, both LTE-Assisted and NR-Assisted. The video is embedded below:

Finally, 3GPP has done a short webinar with the 3GPP RAN Chairman Balazs Bertenyi explaining the outcomes from RAN#77. Its available on BrightTalk here. If you are interested in the slides, they are available here.

Related posts:

• 5G Core Network, System Architecture & Registration Procedure
• 5G: Architecture, QoS, gNB, Specifications - April 2017 Update
• 5G Security Updates - July 2017
• Enhanced 5G Security via IMSI Encryption
• 5G – Beyond the Hype
• Network Sharing is becoming more relevant with 5G

Mission Critical Services update from 3GPP - June 2017

3GPP has published an overview of what has been achieved so far in the Mission Critical and also provides an outlook of what can be expected in the near future. A more detailed paper summarizing the use cases and functional aspects of Rel-13, Rel-14 and upcoming Rel-15 will be published later this year.

Mission Critical Services – Detailed List of Rel-13, Rel-14 and Rel-15 Functionalities

Rel-13 MCPTT (completed 2016)

• User authentication and service authorization
• Configuration
• Affiliation and de-affiliation
• Group calls on-network and off-network (within one system or multiple systems, pre-arranged or chat model, late entry, broadcast group calls, emergency group calls, imminent peril group calls, emergency alerts)
• Private calls on-network and off-network (automatic or manual commencement modes, emergency private calls)
• MCPTT security
• Encryption (media and control signalling)
• Simultaneous sessions for call
• Dynamic group management (group regrouping)
• Floor control in on-network (within one system or across systems) and in off-network
• Pre-established sessions
• Resource management (unicast, multicast, modification, shared priority)
• Multicast/Unicast bearer control, MBMS (Multimedia Broadcast/Multicast Service) bearers
• Location configuration, reporting and triggering
• Use of UE-to-network relays

Rel-14 MC Services (completed 2017)

MC Services Common Functionalities:

• User authentication and service authorization
• Service configuration
• Affiliation and de-affiliation
• Extended Location Features
• (Dynamic) Group Management
• Identity management
• MC Security framework
• Encryption (media and control signalling)

MCPTT Enhancements:

• First-to-answer call setup (with and without floor control)
• Floor control for audio cut-in enabled group
• Updating the selected MC Service user profile for an MC Service
• Ambient listening call
• MCPTT private call-back request
• Remote change of selected group

MCVideo, Common Functions plus:

• Group Call (including emergency group calls, imminent peril group calls, emergency alerts)
• Private Call (off-network)
• Transmission Control

MCData, Common Functions plus:

• Short Data Service (SDS)
• File Distribution (FD) (on-network)
• Transmission and Reception Control
• Handling of Disposition Notifications
• Communication Release

Rel-15 MC Services (in progress)

MC Services Common Functionalities Enhancements:

• Enhanced MCPTT group call setup procedure with MBMS bearer
• Enhanced Location management, information and triggers
• Interconnection between 3GPP defined MC systems
• Interworking with legacy systems

MCPTT Enhancements:

• Remotely initiated MCPTT call
• Enhanced handling of MCPTT Emergency Alerts
• Enhanced Broadcast group call
• Updating pre-selected MC Service user profile
• Temporary group call - user regroup
• Functional alias identity for user and equipment
• Multiple simultaneous users

MCVideo Additions:

• Video push
• Video pull
• Private call (on-network)
• Broadcast Group Call
• Ambient Viewing Call
• Capability information sharing
• Simultaneous Sessions
• Use of MBMS transmission
• Emergency and imminent peril private communications
• Primary and Partner MC system interactions for MCVideo communications
• Remote video parameters control capabilities

MCData Additions:

• MCData specific Location
• Enhanced Status
• Accessing list of deferred communications
• Usage of MBMS
• Emergency Alert
• Data streaming
• File Distribution (FD) (off-network)
• IP connectivity

Release-14 features will be available by end of September 2017 and many Release-15 features, that is being hurried due to 5G will be available by June 2018.

For more details, follow the links below:

• Mission Critical Services in 3GPP
• 3GPP TSG-SA WG6 Meeting #17 - Agenda, Documents and Reports

5G: Architecture, QoS, gNB, Specifications - April 2017 Update

The 5G NR (New Radio) plan was finalised in March (3GPP press release) and as a result Non-StandAlone (NSA) 5G NR will be finalised by March 2018. The final 3GPP Release-15 will nevertheless include NR StandAlone (SA) mode as well.

NSA is based on Option 3 (proposed by DT). If you dont know much about this, then I suggest listening to Andy Sutton's lecture here.

3GPP TR 38.804: Technical Specification Group Radio Access Network; Study on New Radio Access Technology; Radio Interface Protocol Aspects provides the overall architecture as shown above

Compared to LTE the big differences are:

• Core network control plane split into AMF and SMF nodes (Access and Session Management Functions). A given device is assigned a single AMF to handle mobility and AAA roles but can then have multiple SMF each dedicated to a given network slice
• Core network user plane handled by single node UPF (User Plane Function) with support for multiple UPF serving the same device and hence we avoid need for a common SGW used in LTE. UPF nodes may be daisy chained to offer local breakout and may have parallel nodes serving the same APN to assist seamless mobility.

Hat tip Alistair Urie.

Notice that like eNodeB (eNB) in case of LTE, the new radio access network is called gNodeB (gNB). Martin Sauter points out in his excellent blog that 'g' stands for next generation.

3GPP TS 23.501: Technical Specification Group Services and System Aspects; System Architecture for the 5G System; Stage 2 provides architecture model and concepts including roaming and non-roaming architecture. I will probably have to revisit as its got so much information. The QoS table is shown above. You will notice the terms QFI (QoS Flow Identity) & 5QI (5G QoS Indicator). I have a feeling that there will be a lot of new additions, especially due to URLLC.

Finally, here are the specifications (hat tip Eiko Seidel for his excellent Linkedin posts - references below):
5G NR will use 38 series (like 25 series for 3G & 36 series for 4G).

RAN3 TR 38.801 v2.0.0 on Study on New Radio Access Technology; Radio Access Architecture and Interfaces

RAN1 TR 38.802 v2.0.0 on Study on New Radio (NR) Access Technology; Physical Layer Aspects

RAN4 TR 38.803 v2.0.0 on Study on New Radio Access Technology: RF and co-existence aspects

RAN2 TR 38.804 v1.0.0 on Study on New Radio Access Technology; Radio Interface Protocol Aspects

38.201 TS Physical layer; General description
38.211 TS Physical channels and modulation
38.212 TS Multiplexing and channel coding
38.213 TS Physical layer procedures
38.214 TS Physical layer measurements
38.21X TS Physical layer services provided to upper layer
38.300 TS Overall description; Stage-2
38.304 TS User Equipment (UE) procedures in idle mode
38.306 TS User Equipment (UE) radio access capabilities
38.321 TS Medium Access Control (MAC) protocol specification
38.322 TS Radio Link Control (RLC) protocol specification
38.323 TS Packet Data Convergence Protocol (PDCP) specification
38.331 TS Radio Resource Control (RRC); Protocol specification
37.3XX TS [TBD for new QoS]
37.3XX TS Multi-Connectivity; Overall description; Stage-2
38.401 TS Architecture description
38.410 TS NG general aspects and principles
38.411 TS NG layer 1
38.412 TS NG signalling transport
38.413 TS NG Application Protocol (NGAP)
38.414 TS NG data transport
38.420 TS Xn general aspects and principles
38.421 TS Xn layer 1
38.422 TS Xn signalling transport
38.423 TS Xn Application Protocol (XnAP)
38.424 TS Xn data transport
38.425 TS Xn interface user plane protocol
38.101 TS User Equipment (UE) radio transmission and reception
38.133 TS Requirements for support of radio resource management
38.104 TS Base Station (BS) radio transmission and reception
38.307 TS Requirements on User Equipments (UEs) supporting a release-independent frequency band
38.113 TS Base Station (BS) and repeater ElectroMagnetic Compatibility (EMC)
38.124 TS Electromagnetic compatibility (EMC) requirements for mobile terminals and ancillary equipment
38.101 TS User Equipment (UE) radio transmission and reception
38.133 TS Requirements for support of radio resource management
38.104 TS Base Station (BS) radio transmission and reception
38.141 TS Base Station (BS) conformance testing

Note that all specifications are not in place yet. Use this link to navigate 3GPP specs: http://www.3gpp.org/ftp/Specs/archive/38_series/

Further reading:

• 3GPP 5G Specifications - Jan 2018 update
• Qualcomm: 3GPP agrees on plan to accelerate 5G NR – the global 5G standard – for 2019 deployments
• 3GPP 5G Study completed by RAN --- Let's look at the Technical Reports
• Structure of the 3GPP NR (5G) Specification

3GPP Release-14 & Release-15 update

3GPP is on track for 5G as per a news item on the 3GPP website. In 5G World in London in June, Erik Guttman, 3GPP TSG SA Chairman, and Consultant for Samsung Electronics spoke about progress on Release-14 and Release-15. Here is his presentation.

According to 3GPP:

The latest plenary meeting of the 3GPP Technical Specifications Groups (TSG#72) has agreed on a detailed workplan for Release-15, the first release of 5G specifications.

The plan includes a set of intermediate tasks and check-points (see graphic below) to guide the ongoing studies in the Working Groups. These will get 3GPP in a position to make the next major round of workplan decisions when transitioning from the ongoing studies to the normative phase of the work in December 2016:- the start of SA2 normative work on Next Generation (NexGen) architecture and in March 2017:- the beginning of the RAN Working Group’s specification of the 5G New Radio (NR).

3GPP TSG RAN further agreed that the target NR scope for Release 15 includes support of the following:

• ■ Standalone and Non-Standalone NR operation (with work for both starting in conjunction and running together)
  • ■ Non-standalone NR in this context implies using LTE as control plane anchor. Standalone NR implies full control plane capability for NR.
  • ■ Some potential architecture configuration options are shown in RP-161266 for information and will be analyzed further during the study

• ■ Target usecases: Enhanced Mobile Broadband (eMBB), as well as Low Latency and High Reliability to enable some Ultra-Reliable and Low Latency Communications (URLCC) usecases
• ■ Frequency ranges below 6GHz and above 6GHz

During the discussion at TSG#72 the importance of forward compatibility - in both radio and protocol design - was stressed, as this will be key for phasing-in the necessary features, enabling all identified usecases, in subsequent releases of the 5G specification.


Telecom TV has posted a video interview with Erik Guttman which is embedded below:



Related posts:

• 5G Study Item (SI) for RAN Working Groups Approved
• NTT Docomo's 5G Treasure Trove
• Feasibility Study on New Services and Markets Technology Enablers for 5G
• 5G and Future Technologies from Johannesberg Summit
• Antenna evolution: From 4G to 5G

Updates from the 3GPP RAN 5G Workshop - Part 1

3GPP held a 5G Workshop in Phoenix last week. 550 delegates and over 70 presentations contributed to the discussion, which covered the full range of requirements that will feed TSG RAN work items for the next five years. I will eventually look at all the presentations and highlight the ones that I find interesting as a part of this blog. Due to the vast number of presentations, I will split them into a few blog posts.

Lets start with the chairman summary. The chair highlighted three high level use cases that 5G needs to address (This has been highlighted in many presentations, see here for example):

• Enhanced Mobile Broadbandare 
• Massive Machine Type Communications
• Ultra-reliable and Low Latency Communications

As can be seen in the picture above, 3GPP is planning to split the 5G work into two phases. Phase 1 (Rel-15) will look at a subset of requirements that are important for the commercial needs of the day. Phase 2 (Rel-16) will look at more features, use cases, detailed requirements, etc.

Here is the chair summary of the workshop:

The presentation (RWS-150002) from Motorola/Lenovo highlighted the need to handle different spectrum. For sub-6GHz, the existing air interface could work with slight modifications. For spectrum between 6GHz and 30GHz, again a similar air interface like 4G may be good enough but for above 30GHz, there is a need for new one die to phase noise.

The presentation by CATT or China Academy of Telecommunication Technology (RWS-150003) is quite interesting and is embedded below. They also propose Pattern Division Multiple Access (PDMA).

Orange (RWS-150004) has definitely put a thought into what good 5G would be. Their presentation is embedded below too:

The presentation from Huawei (RWS-150006) introduced the concept of Unified Air Interface, UAI.



They presentation also explains the concept of Adaptive Frame structures and RAN slicing very well. For those who may be wondering, uMTC stands for ultra-reliable MTC and mMTC stands for massive MTC. RAN slicing enables the RAN to be partitioned such that a certain amount of carriers are always dedicated to a certain services independently of other services. This ensures that the service in the slice is always served reliably.

The final presentation is the vision and priorities by 5GPPP as follows:

3GPP Release-13 work started in earnest

The 3GPP news from some months back listed the main RAN features that have been approved for Release-13 and the work has already started on them. The following are the main features (links contain .zip files):

• LTE in unlicensed spectrum (aka Licensed-Assisted Access) - RP-150055
• Carrier Aggregation enhancements - RP-142286
• LTE enhancements for Machine-Type Communications (MTC) - RP-141865
• Enhancements for D2D - RP-142311
• Study Item Elevation Beamforming / Full-Dimension MIMO - RP-141831
• Study Item Enhanced multi-user transmission techniques - RP-142315
• Study Item Indoor positioning - RP-141102
• Study Item Single-cell Point-to-Multipoint (SC-PTM) - RP-142205

Another 3GPP presentation from late last year showed the system features that were being planned for Rel-13 as shown above.

I have also posted a few items earlier relating to Release13, as follows:

• LTE Category-0 low power M2M devices
• Update on Public Safety and Mission Critical communications
• 3GPP Rel-12 and Future Security Work
• Elevation Beamforming / Full-Dimension MIMO
• LA-LTE and LAA
• LTE-Hetnet (LTE-H) a.k.a. LTE Wi-Fi Link Aggregation (LWA)

Ericsson has this week published a whitepaper on release 13, with a vision for 'Networked Society':

The vision of the Networked Society, where everything that benefits from being connected will be connected, places new requirements on connectivity. LTE is a key component in meeting these demands, and LTE release 13 is the next step in the LTE evolution.

Their whitepaper embedded below:

It should be pointed out that 5G work does not start until Release-15 as can be seen from my tweet

Nice picture of "5G Radio Interface development timeline" by @alainmouradUK pic.twitter.com/ANFfujJGS5
— Zahid Ghadialy (@zahidtg) April 4, 2015

xoxoxo Added Later (26/04/2015) xoxoxo
I came across this presentation from Keysight (Agilent) where Moray Rumney has provided information in much more detail.