I have been asked about the UE Assistance Information (UAI) RRC message a few times before. Generally I have always pointed people back to the LTE/5G specifications but here is a concise video that the telecoms technology training company Mpirical have shared recently:
If you want to dig further into details then please see the RRC specifications: 36.331 for LTE and 38.331 for 5G.
Over the years I have added quite a few short tutorials from Mpirical on this blog, do check them out below.
Ralf Kreher explained EPS Fallback mechanism in his post earlier, which is still quite popular. This post contains couple of videos that also explain this procedure.
The first is a very short and simple tutorial from Mpirical, embedded below:
The second is a slightly technical presentation explaining how 5G system can redirect the 5G VoNR capable device to the 4G system to continue for IMS based VoLTE voice call.
Since the industry realised how the 5G Network Architecture will look like, Network Slicing has been touted as the killer business case that will allow the mobile operators to generate revenue from new sources.
According to global technology intelligence firm ABI Research, 5G slicing revenue is expected to grow from US$309 million in 2022 to approximately US$24 billion in 2028, at a Compound Annual Growth Rate (CAGR) of 106%.
“5G slicing adoption falls into two main categories. One, there is no connectivity available. Two, there is connectivity, but there is not sufficient capacity, coverage, performance, or security. For the former, both private and public organizations are deploying private network slices on a permanent and ad hoc basis,” highlights Don Alusha, 5G Core and Edge Networks Senior Analyst at ABI Research. The second scenario is mostly catered by private networks today, a market that ABI Research expects to grow from US$3.6 billion to US$109 billion by 2023, at a CAGR of 45.8%. Alusha continues, “A sizable part of this market can be converted to 5G slicing. But first, the industry should address challenges associated with technology and commercial models. On the latter, consumers’ and enterprises’ appetite to pay premium connectivity prices for deterministic and tailored connectivity services remains to be determined. Furthermore, there are ongoing industry discussions on whether the value that comes from 5G slicing can exceed the cost required to put together the underlying slicing ecosystem.”
I recently published IDC's first forecast on 5G network slicing services opportunity. Slicing should be an important tool for telcos to create new services, but it still remains many years away in most markets. A very complicated undertakinghttps://t.co/GNY4xiLFBV
Earlier this year, Daryl Schoolar - Research Director at IDC tackled this topic in his blog post:
5G network slicing, part of the 3GPP standards developed for 5G, allows for the creation of multiple virtual networks across a single network infrastructure, allowing enterprises to connect with guaranteed low latency. Using principles behind software-defined network and network virtualization, slicing allows the mobile operator to provide differentiated network experience for different sets of end users. For example, one network slice could be configured to support low latency, while another slice is configured for high download speeds. Both slices would run across the same underlying network infrastructure, including base stations, transport network, and core network.
Network slicing differs from private mobile networks, in that network slicing runs on the public wide area network. Private mobile networks, even when offered by the mobile operator, use infrastructure and spectrum dedicated to the end user to isolate the customer’s traffic from other users.
5G network slicing is a perfect candidate for future business connectivity needs. Slicing provides a differentiated network experience that can better match the customers performance requirements than traditional mobile broadband. Until now, there has been limited mobile network performance customization outside of speeds. 5G network slicing is a good example of telco service offerings that meet future of connectivity requirements. However, 5G network slicing also highlights the challenges mobile operators face with transformation in their pursuit of remaining relevant.
For 5G slicing to have broad commercial availability, and to provide a variety of performance options, several things need to happen first.
Operators need to deploy 5G Standalone (SA) using the new 5G mobile core network. Currently most operators use the 5G non-standalone (NSA) architecture that relies on the LTE mobile core. It might be the end of 2023 before the majority of commercial 5G networks are using the SA mode.
Spectrum is another hurdle that must be overcome. Operators still make most of their revenue from consumers, and do not want to compromise the consumer experience when they start offering network slicing. This means operators need more spectrum. In the U.S., among the three major mobile operators, only T-Mobile currently has a nationwide 5G mid-band spectrum deployment. AT&T and Verizon are currently deploying in mid-band, but that will not be completed until 2023.
5G slicing also requires changes to the operator’s business and operational support systems (BSS/OSS). Current BSS/OSS solutions were not designed to support the increased parameters those systems were designed to support.
And finally, mobile operators still need to create the business propositions around commercial slicing services. Mobile operators need to educate businesses on the benefits of slicing and how slicing supports their different connectivity requirements. This could involve mobile operators developing industry specific partnerships to reach different business segments. All these things take time to be put into place.
Because of the enormity of the tasks needed to make 5G network slicing a commercial success, IDC currently has a very conservative outlook for this service through 2026. IDC believes it will be 2023 until there is general commercial availability of 5G network slicing. The exception is China, which is expected to have some commercial offerings in 2022 as it has the most mature 5G market. Even then, it will take until 2025 before global revenues from slicing exceeds a billion U.S. dollars. In 2026 IDC forecasts slicing revenues will be approximately $3.2 billion. However, over 80% of those revenues will come out of China.
The 'Outspoken Industry Analyst' Dean Bubley believes that Network Slicing is one of the worst strategic errors made by the mobile industry, since the catastrophic choice of IMS for communications applications. In a LinkedIn post he explains:
At best, slicing is an internal toolset that might allow telco operations or product teams (or their vendors) to manage their network resources. For instance, it could be used to separate part of a cell's capacity for FWA, and dynamically adjust that according to demand. It might be used as an "ingredient" to create a higher class of service for enterprise customers, for instance for trucks on a highway, or as part of an "IoT service" sold by MNOs. Public safety users might have an expensive, artisanal "hand-carved" slice which is almost a separate network. Maybe next-gen MVNOs.
(I'm talking proper 3GPP slicing here - not rebranded QoS QCI classes, private APNs, or something that looks like a VLAN, which will probably get marketed as "slices")
But the idea that slicing is itself a *product*, or that application developers or enterprises will "buy a slice" is delusional.
Firstly, slices will be dependent on [good] coverage and network control. A URLLC slice likely won't work reliably indoors, underground, in remote areas, on a train, on a neutral-host network, or while roaming. This has been a basic failure of every differentiated-QoS monetisation concept for many years, and 5G's often-higher frequencies make it worse, not better.
Secondly, there is no mature machinery for buying, selling, testing, supporting. price, monitoring slices. No, the 5G Network Exposure Function won't do it all. I haven't met a Slice salesperson yet, or a Slice-procurement team.
Thirdly, a "local slice" of a national 5G network will run headlong into a battle with the desire for separate private/dedicated local 5G networks, which may well be cheaper and easier. It also won't work well with the enterprise's IT/OT/IP domains, out of the box.
Also there's many challenges getting multi-operator slices, device OS links to slice APIs, slice "boundary controllers" between operators, aligning RAN and core slices, regulatory questionmarks and much more.
There are lots of discussion in the comments section that may be of interest to you, here.
My belief is that we will see lots of interesting use cases with slicing in public networks but it will be difficult to monetise. The best networks will manage to do it to create some plans with guaranteed rates and low latency. It would remain to be see whether they can successfully monetise it well enough.
For technical people and newbies, there are lots of Network Slicing resources on this blog (see related posts 👇). Here is another recent video from Mpirical:
I looked at IMS briefly in my LTE voice tutorial here. The Nokia Lectures covered IMS in-depth in part 5 of the video. I recently came across a short overview of IMS for SBA. You can see our old tutorial on Service Based Architecture (SBA) for 5G Core (5GC) here.
I came across this short video from Mpirical that nicely explains the IMS support for SBA. It's embedded below. The related posts at the bottom may also be worth checking out.
Google announced that its latest smartphone OS will include support for 5G network slicing. Last week Telecom TV brought this news to my attention. The article explains:
It's a move designed to leverage its expertise in devices in order to give it the edge over its rival hyperscalers.
It comes in two flavours. The first is for enterprise-owned handsets, and routes all data sent and received by a device over the network slices provided by that company's mobile operator. Android 12 gives operators the ability to manage slices using a new dynamic policy control mechanism called User Equipment Route Selection Policy (URSP). URSP enables devices to automatically switch between different network slices according to which application they are using. For example, someone working for a financial institution might require a highly-secure network slice for sending and receiving sensitive corporate data, but will then require a reliable, high-throughput, low-latency slice so they can participate in a video meeting.
The second flavour is implemented in the work profile. For years, enterprises have had the option of creating work profiles on Android devices – irrespective of whether they are owned by the organisation or the individual – to use as a separate repository for enterprise apps and data. When Android 12 comes out next year, enterprises will be able to route data to and from that repository over a network slice.
Google said it has already carried out network slicing tests with both Ericsson and Nokia using test versions of its recently released Pixel 6 smartphone running on the as-yet-unreleased Android 12 OS.
It's a replacement for enterprise APNs for now. So not earth-shattering, but a start nonetheless.
Perhaps indicates that enterprise privacy/security/policy might be the major use-case for slicing for the foreseeable future?
Last week Taiwanese operator Far EasTone (FET) and Ericsson announced they have completed the world’s first proof of concept (PoC) for simultaneously connecting multiple network slices per device running on Android 12 commercial release. The press release said:
The trial, carried out on FET’s 5G standalone (SA) infrastructure built on Ericsson’s radio access network and cloud-native Core network, successfully demonstrated the 5G user equipment slicing policy feature (User Equipment Route Selection Policy, or URSP) on multiple Android devices. This marks a breakthrough in network slicing capabilities on a 5G standalone network and paves the way for further ecosystem development in this important area.
With more 5G networks evolving to standalone architecture around the globe, end-to-end network slicing, which includes Ericsson RAN Slicing to secure Quality of Service (QoS) differentiation, plays a key role in enabling new services for end users, with which multiple virtual 5G networks are created on top of one physical network. The 5G trial, in collaboration with FET, Ericsson and Android, went even further in network slicing capabilities by introducing and demonstrating 5G user equipment (UE) slicing policy (URSP) features that allow devices to simultaneously operate on dynamic policy control and selection between multiple 5G network slices. This enables the steering of applications and services with specific requirements to defined slices without switching devices.
Multiple slices allow devices to have multiple profiles to secure different levels of experience, security, and privacy requirements, based on the needs of the different applications and in correspondence with the user profile. For instance, a device can have a personal profile with private data from apps or off-work entertainment, and a work profile with enterprises productivity apps. With URSP features, employers can customize the work profile with increased security and enable better use of RAN Slicing with QoS so that enterprise-related apps can work even during network congestion.
Some security-sensitive apps, such as mobile banking, can also benefit from different routing mechanisms of the traffic enabled by URSP. For instance, the banking app would not need to send its traffic to the internet and then to the app server as it does today. Instead, it could go straight to the app server and avoid the routing through internet. With the shortest route by connecting to a defined slice, users could reduce the risk of being attacked by hackers.
Along with the concept of network slicing and features in the RAN and Core network, UE Route Selection Policy (URSP) is introduced as a way to manage network slice information for the UE. URSP is a network slice feature enabled by the PCF which informs the network slice status to the UE via the AMF. In 4G network systems, it was near impossible to install new services in the network for a UE. But through the URSP feature, 5G network operators can easily configure new service for a UE. Figure 12 (top of this blog post) shows the difference in network slice selection in 4G and 5G Network. In 5G network, slice selection policy can be configured dynamically through URSP, while slice selection policy is pre-defined and cannot be changed dynamically in 4G network.
URSP contains OSId, AppId, IP descriptors to define the application and Single-Network Slice Selection Assistance Information (S-NSSAI), Data Network Name (DNN), Session and Service Continuity (SSC) mode information for the application and network slice mapping.
The S-NSSAI identifies each network slice service and provides information to properly assign network slice/functions. An S-NSSAI is comprised of:
A Slice/Service type (SST), which refers to the expected network slice behavior in terms of features and services;
A Slice Differentiator (SD), which is an optional information that complements the Slice/Service type(s) to differentiate amongst multiple network slices of the same Slice/Service type.
3GPP allows the use of the Slice Differentiator (SD) field that can build customized network slices. The SD field can be used to describe services, customer information and priority.
Here is a short video from Mpirical explaining 5G UE Route Selection.
It it worth reminding here that this feature, like many of the other 5G features, is dependent on 5G Core. We hope that the transition to 5G Standalone Networks happens as soon as possible.
We looked at the 5G Enhanced URLLC (eURLLC) earlier. One of the ways to improve reliability is to have redundancy in the user plane. This can use different approaches like:
Duplicating N3
Adding a secondary gNB using Dual connectivity
Introducing another UPF
Two anchor UPFs
In fact they are all built on top of each other so you can decide how critical are your user plane redundancy needs.
I came across this short video from Mpirical embedded below that covers this topic nicely. In case you want to refresh your 5G Core Network architecture, jump to our old tutorial here.
Earlier this year, MediaTek had announced that its MT2625 NB-IoT chip has been validated for LwM2M over NIDD on SoftBank Corp.’s cellular network across Japan. This achievement marks the first global commercial readiness of LwM2M over NIDD; a secure, ultra-efficient IoT communications technique that is being adopted by operators worldwide. The benefits of LwM2M over NIDD include security improvements, cost-efficient scalability and reduced power consumption.
LwM2M over NIDD is a combination of the communication technology "NIDD (Non-IP Data Delivery)" that does not use an IP address in LTE communication NB-IoT for IoT and the device management protocol "LwM2M (Lightweight M2M)" advocated by the Open Mobile Alliance. It's been a while since I wrote about Open Mobile Alliance on this blog. OMA SpecWorks is the successor brand to the Open Mobile Alliance. You can read all about it here.
OMA SpecWorks’ LightweightM2M is a device management protocol designed for sensor networks and the demands of a machine-to-machine (M2M) environment. With LwM2M, OMA SpecWorks has responded to demand in the market for a common standard for managing lightweight and low power devices on a variety of networks necessary to realize the potential of IoT. The LwM2M protocol, designed for remote management of M2M devices and related service enablement, features a modern architectural design based on REST, defines an extensible resource and data model and builds on an efficient secure data transfer standard called the Constrained Application Protocol (CoAP). LwM2M has been specified by a group of industry experts at the OMA SpecWorks Device Management Working Group and is based on protocol and security standards from the IETF.
You can get all the LwM2M resources here and the basic specs of 'Lightweight M2M 1.1: Managing Non-IP Devices in Cellular IoT Networks' here.
The 5G Americas whitepaper 'Wireless Technology Evolution Towards 5G: 3GPP Release 13 to Release 15 and Beyond' details how Current Architecture for 3GPP Systems for IOT Service Provision and Connectivity to External Application Servers. It also talks about Rel-13 Cellular IoT EPS Optimizations which provide improved support of small data transfer over control plane and user plane. Control Plane CIoT EPS Optimization transports user data (measurements, ID, status, etc.) via MME by encapsulating user data in NAS PDUs and reduces the total number of control plane messages when handling a short data transaction. Control Plane CIoT EPS optimization, designed for small infrequent data packets, can also be used for larger data bursts depending in UE Radio capability.
User data transported using the Control Plane CIoT EPS Optimization, has special characteristics, as different mobility anchor and termination nodes.
Therefore, the Preferred Network Behavior signaling must include information on:
Whether Control Plane CIoT EPS optimization is supported
Whether User Plane CIoT EPS optimization is supported
Whether Control Plane CIoT EPS optimization is preferred or whether User Plane CIoT EPS optimization is preferred
These optimizations have enabled:
Non-IP Data Delivery (NIDD) for both: mobile originated and mobile terminated communications, by using SCEF (Service Capability Exposure Function) or SGi tunneling. However, it has to be taken into account that Non-IP PDUs may be lost and its sequence is not guaranteed
For IP data, the UE and MME may perform header compression based on Robust Header Compression (ROHC) framework
NB-IoT UE can attach but not activate any PDN connection
High latency communication handled by the buffering of downlink data (in the Serving GW or the MME)
SMS transfer
EPS Attach, TA Update and EPS Detach procedures for NB-IoT only UEs, with SMS service request
Procedures for connection suspend and resume are added
Support for transfer of user plane data without the need for using the Service Request procedure to establish Access Stratum context in the serving eNodeB and UE
When selecting an MME for a UE that is using the NB-IoT RAT, and/or for a UE that signals support for CIoT EPS Optimizations in RRC signaling, the eNodeB’s MME selection algorithm shall select an MME taking into account its Release 13 NAS signaling protocol.
Mpirical has a nice short video explaining 5G Non IP Data Delivery. It is embedded below.
IoT has not taken off as expected and prophesised for years. While the OMASpecWorks is doing some fantastic work by defining simplified approach for IoT deployment, its current member list doesn't have enough operators to drive the uptake required for its spec adoption. They would argue that it doesn't matter how many members there are as the NIDD approach is completely optional and over-the-top. Let's wait and see how it progresses.
One of the interesting features of 5G is Ultra-Reliability and Low-Latency Communication or URLLC. It has been enhanced as part of 3GPP Release-16. A summary of the changes in eURLLC can be seen in the picture above.
This ATIS webinar that I blogged about last week covered this topic as well. For example L1/L2 changes have been summarised nicely in this Qualcomm slide above while the slide from Intel speaker below looks at redundant transmission and session continuity.
Redundant transmission in the user plane is an extremely useful feature, especially if the packets are mission critical and have to reach from the source to their destination in a guaranteed time / reliability.
Dual connectivity will enable this redundant path when required to meet a guaranteed reliability.
Here is a short video from the training company Mpirical, explaining the the 5G eURLLC feature:
Within 5GC, SMS Function (SMSF) supports SMS over NAS (SMSoNAS) defined in 3GPP TS 23.501. Besides, SMSoIP can also be considered as IMS based SMS solution under 5G network. SMSoIP can be deployed simultaneously with voice service over IMS to provide both voice and short message service. It is recommended to use SMSoNAS solution if voice services over IMS is not supported or for a 5G data card/Machine Type Communications (MTC)/Non-IMS device without voice service. The network architecture of SMSoIP and SMSoNAS is shown in Figure.
Mpirical explains it in the video as embedded below:
You may also find "5G SMS is Very Real and Here to Stay" by William Dudley useful. It covers a lot of technical details and signalling. It's available here.
