5G Remote Surgery and Telehealth Solutions

One of the most controversial 5G use cases is the remote surgery. In this post I want to quickly look at the history and what is possible. Before I go to that, here is a short summary video that I am embedding upfront.



As far as I can recall, Ericsson was the first vendor that started talking about remote surgery. This is a tweet from back in 2017.

With #5G and the tactile internet, doctors can perform remote
surgery on a patient anywhere in the world. https://t.co/U81bayv3ws pic.twitter.com/pSXFg1NCJX

— Ericsson (@ericsson) August 28, 2017

Huawei didn't want to be far behind so they did one at MWC Shanghai in 2018. Their tweet with video is embedded below.

Meet the Remote Surgery Robot. At #MWCS18, Huawei stiches together a vivid picture of how #5G’s reliable connection can save lives: https://t.co/cobykl1KKP #WirelessXLabs pic.twitter.com/Pbme8BmcoT

— Huawei (@Huawei) June 28, 2018

In January 2019, South China Morning Post (SCMP) showed a video of a remote surgery on an animal. While the video and the article didn't provide many details, I am assuming this was done by Huawei as detailed here. The video of the surgery below.



This was followed by Mobile World Congress 2019 demo where a doctor used 5G to direct surgery live from a stage at MWC to Hospital Clinic Barcelona over 3 miles away. The team of doctors was removing a cancerous tumor from a patient's colon. This video from that is embedded below.



Vodafone New Zealand had a silly remote surgery of a dog video but looks like they have removed it.  Nothing can beat this Telecom Italia ad embedded below.



There are some realistic use cases. One of them being that with 5G the number of cables / wires in a hospital can be reduced saving on the disinfection.

NTT Docomo showcased 5G Mobile SCOT (Smart Cyber Operating Theater) which is an Innovative solution to enable advanced medical treatment in diverse environments. You can read more details here.

There are lots of other things going on. Here is a short list:

• April 2020: Because of Coronavirus COVID-19, NT Times has an article on Telemedicine Arrives in the U.K.: ‘10 Years of Change in One Week’ - even though this does not involve 5G, it just shows that we are moving in that direction.
• February 2020: 5G-aided remote CT scans used to diagnose COVID-19 patients in China (link)
• February 2020: Verizon teamed with Emory Healthcare to test new 5G use cases for the medical industry at the latter’s Innovation Hub in Atlanta, in a bid to discover how the technology can be used to improve patient care. The collaboration will explore applications including connected ambulances; remote physical therapy; medical imaging; and use of AR and VR for training. (link)
• February 2020: Vodafone 5G Healthcare – Conference & Experience Day (link)
• November 2019: TIM enables first live remote-surgery consultation using 5G immersive reality (link)
• October 2019: Along with a hospital in Malaga, Telefónica has presented what it claims is the first expert assistance system for medical interventions that runs on 5G. (link and video)
• September 2019: Mobile Future Forward 2019 - World's First Remote VR Surgery Demo conducted on Sept 4th, 2019 in Seattle by Chetan Sharma, James Youngquist, Evie Powell, Nissim Hadar, David Colmenares, and Gabe Jones. (link)

Finally, a nice video on Benefits of 5G for Healthcare Technology by T-Mobile



Related Posts:

• The 3G4G Blog: NTT Docomo's Vision on 5G Evolution and 6G
• The 3G4G Blog: 5G eXtended Reality (5G-XR) in 5G System (5GS)
• The 3G4G Blog: Real-life 5G Use Cases for Verticals from China
• The 3G4G Blog: 5G Private and Non-Public Network (NPN)
• The 3G4G Blog: 5G and Industry 4.0
• The 3G4G Blog: Spectrum for 5G NR beyond 52.6 GHz

How the A6 Measurement Event triggers Secondary Cell Change in LTE Carrier Aggregation Calls

Last week I read in Martin Sauter's blog about the LTE RRC A6 measurement event.

Although I am quite interested in RRC measurements I have never seen the A6 event in action. Rather the eNB vendors have implemented carrier aggregation in a way that the UE provides its capabilities and according to the this the maximum possible numbers of component carriers is added to the connection. There is no RRC measurement report before adding secondary LTE cells to the connection. So what is the A6 event good for and is it used at all?

Surprisingly I needed only 2 attempts to find an example of using the A6 event in a live network configuration. It is used when more component carriers are available than the UE can simultaneously handle. E.g. if there are 4 or more cells with different carrier frequencies available in the same antenna sector the A6 event ensures after the initial CA configuration that the cells with the best radio conditions are selected as secondary cells.

Let's have a look at this scenario in detail. Figure 1 shows the report configuration for the A6 event. Keep the reportConfigId = 3 in mind.

Figure 1: Report Configuration for Event A6

The next step is the configuration of the Measurement ID as shown in figure 2. Here the reportConfigId is combined with a measObjectId that represents the carrier frequency of the potential SCell.

Figure 2: Measurement ID for Event A6

Now, if the event A6 is triggered in the UE a RRC Measurement Report with this measId = 3 is sent to the eNB as shown in Figure 3.

Figure 3: RRC Measurement Report for Event A6

There we see the RSRP and RSRQ of the primary cell (PCell) and of the currently serving secondary cells (SCells). By the way the servFreqId stands for the sCellIndex value that was linked to the physical cell ID (PCI) when this SCell was added in a previous RRC Connection Reconfiguration procedure. 

And as one can see the neighbor cell with PCI = 470 has significantly better RSRP and RSRQ to offer than both currently used SCell. 

Consequently the eNB decides to replace the SCell with sCellIndex value 1 with the better cell (PCI 470). This is again done with a RRC Connection Reconfiguration procedure as shown in figure 4. And this is the way how the A6 event is used.

Figure 4: Change of SCell

  

Virve 2.0 - Finland's 4G/5G Public Safety Network

State Security Networks Group Finland (Erillisverkot) safeguards the Finnish society by offering authorities and critical operators engaged in critical infrastructure and services secure and reliable ICT services. Much like in the civilian world, communication between authorities includes transferring images and video material to an increasing degree, which results in ever-growing data transfer volumes and, subsequently, new kinds of demands for all communication networks. 

Virve is a means of ensuring communication and cooperation between authorities and other partners across organisational borders into the future. It also entails the introduction of a higher service standard, as the transfer to broadband, estimated to take place in 2022, will make it possible to transfer video material, images and data. This will mean that it will be possible to send video material in a reliable and secure way in the case of accidents, for example. The radio network Virve, based on Tetra technology, will reach the end of its lifecycle by the end of the 2020s. The current Virve network will be used simultaneously with the new Virve 2.0 network until, at least, 2025.

Erillisverkot will acquire the broadband Virve 2.0 radio access network as a service from Elisa and the core systems from Ericsson. Separate networks will ensure the continuity of critical communications and operational capability of public safety in all situations in the future.

I would assume this would be MOCN, similar to the UK deployment of ESN networks as shown here.

Virve 2.0 subcribers will use Elisa’s public radio network, which the operator is expanding to become Finland’s largest data and voice network.

About 80 million messages pass through the Virve system every week. Elisa is committed to increasing the coverage, capacity and verification of its mobile network to meet the requirements of Virve 2.0.

The new online services will provide support for critical communication between public authorities and other parties.

The addition of image, video, and other wireless broadband services alongside existing Virve services will enable a better and more up-to-date view of the day-to-day operations of authorities and other actors.

The IoT enables automatic monitoring of rescue personnel and mobile use of surveillance cameras and drones.

The Virve 2.0 radio network service will be in use from 2021 and will include the 4G and 5G technologies and the internet of things. The contract is for ten years.

Finally, a recent advert of Elisa explaining 5G to outside world



Further Study:

• Erillisverkot: Obstacles for MCX Broadband and how to overcome them [PDF]
• Erillisverkot: Virve Broadband Plans for the Future - Critical Communications Europe 2019 [PDF]
• 5G-XCast Whitepaper: Rapidly Deployable Network System for Critical Communications in Remote Locations [PDF]
• Erillisverkot: White paper - Virve 2.0 RFI Summary of responses [PDF]
• Erillisverkot: Factsheet - What is Virve 2.0? [PDF]

Related Posts:

• Operator Watch Blog: Elisa claims "first in world to launch commercial 5G" - technical details and controversy
• The 3G4G Blog - Finland: A country with only Unlimited Data Plans
• The 3G4G Blog: 3GPP Release-16, Release-17 & Beyond...
• The 3G4G Blog: Update from 3GPP on LTE & 5G Mission Critical Communications
• The 3G4G Blog: Update on UK's Emergency Services Network (ESN) from #BAPCO2019
• The 3G4G Blog: A practical use of MOCN in ESN
• Telecoms Infrastructure Blog: Meshing for BYOC (Bring Your Own Coverage)

The Futuristic Concept of 'Smart & Intelligent' Batteries

I did a presentation back in 2013 on the concept of smart batteries. Even though there has been a lot of progress in wireless charging since back then, it hasn't reached even close to the vision that I have. As a result, I converted it into a video to start a discussion on if and when this would be possible. The slides and video are embedded below and I welcome any discussion in comments below.

Misc: The Futuristic Concept of ‘Smart & Intelligent’ Batteries from 3G4G

Comparing S1AP and NGAP UE Context Release

As an addition to my blog post about the 5G RAN Release procedure I would like to have an in-depth view at the details of NGAP UE Context Release Complete message.

Indeed, the S1AP (known from E-UTRAN) and the NGAP are very similar protocols and when reading the 3GPP specs it is obvious that many message names are identical and the procedures fulfill the same purpose when looking at call scenarios.

However, the difference is visible in the details as one can see when looking at the figure below.

While the S1AP UE Context Release Complete message does not contain any additional information we find in the NGAP UE Context Release Complete the identity of the last serving 5G cell, represented by the NR-CGI, the last visited Tracking Area Identity (TAI) and a list with the IDs of the PDU sessions (E-RABs) that have been terminated when the UE context was released.

This additional information in very valuable for network troubleshooting, since in LTE (S1AP) only the ID (ECGI) of the initial serving cell or a new serving cell ID at inter-node handover was signaled. And if you wanted to know how many E-RABs have been terminated with a S1AP UE Context Release procedure it was necessary to look back into the full sequence of call-related S1AP messages starting with the messages for Initial Context Setup.

All in all, with 5G NGAP trace analysis and the life of RAN engineers becomes easier. Thank you, 3GPP! 

Comparision of S1AP and NGAP UE Context Release Complete Messages

A Look into 5G Virtual/Open RAN - Part 3: Connection Release and Suspend

The 3rd post of this series introduces the details of connection release in the 5G RAN.

Indeed, we find most of the release causes known from E-UTRAN in the 5G specs and it is clear that all protocols that have been involved in the connection setup need to be perform a release procedure at the end of the connection.

However, again the split into different virtual functions brings the demand for some addition messages.

This is illustrated in figure 1 for the a release due to "user inactivity", which means: the gNB-CU UP detected that for a define time (typical settings for the user inactivity timer are expected to be between 10 and 20 seconds) no downlink payload packets have been arrived from the UPF to be transmitted.

So the gNB-CU UP sends an E1AP Bearer Context Inactivity Notification message to the gNB-CU CP that triggers the release procedures on NGAP, F1AP, RRC and E1AP. The RRC Releases message is transported over the F1 interface to the gNB-DU where is forwarded across the radio interface to the UE.

Figure 1: Connection Release due to "user inacativity"

An alternative to the connection release is the RRC Suspend procedure shown in figure 2. Here the UE is ordered to switch to the RRC Inactive state, which allows a very quick resume of the RRC connection when necessary.

Figure 2: RRC Connection Suspend

In case of suspending the RRC connection the RRC Release message contains a set of suspend configuration parameters. The probably most important one is the I-RNTI, the (RRC) Inactive Radio Network Temporary Identity.

If the RRC connection is suspended, F1AP and E1AP Contexts are released, but the NGAP UE Context remains active. Just NGAP RRC Inactivity Transition Report is sent to the AMF.

Related Posts:

• A Look into 5G Virtual/Open RAN - Part 4: Intra-gNB DU Handover
• 3G4G: Open RAN, OpenRAN and O-RAN

A Look at the same RRC Message in LTE and 5G Stand-alone Call Scenarios

Some weeks ago the differences in 4G LTE RRC (3GPP 36.331) and 5G NR RRC (3GPP 38.331) and how both protocols interact in EN-DC call scenarios have been discussed in another blog post.

Now I would like to share a visual comparison of the RRC (Connection) Setup Complete message as it is seen in LTE (including EN-DC) and 5G stand-alone (SA) radio connections.

From the figure below one can see that although this message fulfills the same purpose in both radio access technologies its particular contents may look quite differently.

Different variants of RRC (Connection) Setup Complete message in LTE and 5G stand-alone call scenarios

SCF Releases 5G Functional API to Enable Open Small Cells Ecosystem

The Small Cell Forum (SCF) announced the publication of documents focused on stimulating a competitive ecosystem for vendors of 5G-era small cell hardware, software and equipment. The expanded set of specifications contained in these documents are:

• SCF222 - 5G FAPI: PHY API Specification
• SCF223 - 5G FAPI: RF and Digital Frontend Control API
• SCF224 - 5G FAPI: Network Monitor Mode API

According to the press release:

Expanding upon the 5G Physical Layer API specification, published in July 2019, the new specifications enable small cells to be constructed piece-by-piece using components from different vendors, in order to address the diverse mixture of 5G use cases relatively easily, a common goal to all of the specifications made by Small Cell Forum.

The new release also includes two completely new specifications, SCF223: 5G NR FAPI P19 FrontEnd Interface Specification and SCF224: Network Monitor Mode API for Small Cells.

According to Dr. Prabhakar Chitrapu, Chair of SCF, “FAPI helps Equipment Vendors to mix PHY & MAC Software from different suppliers via this open FAPI interface. So, FAPI is an 'internal' interface.”

“5G-nFAPI (network FAPI) is a 'network' interface and is between a Distributed Unit and Centralised Unit  of a Split RAN/Small Cell network solution. An open specification of this interface (nFAPI) will help network architects by allowing them to mix distributed and central units from different vendors.”

SCF nFAPI is enabling Open RAN ecosystem in its own way by allowing any small cell CU/DU (S-CU / S-DU) to connect to any small cell radio unit (S-RU)

Here is a video playlist from SCF that explains the new API's



Related Posts:

• Telecoms Infrastructure Blog: Small Cell Forum Releases 5G FAPI API Specifications
• The 3G4G Blog: A quick tutorial on Open RAN, vRAN & White Box RAN
• Telecoms Infrastructure Blog: SuperMicro's 5G Pole-Mounted DU Server Solution

Mobility Analysis: Austrians Stay at Home

The Austrian company Invenium Data Insights GmbH has partnered with the mobile network operator A1 to analyze and visualize subscriber mobility pattern on a public dashboard to illustrate the impact of the severe restrictions on people’s mobility (and its expected reversal) due to the COVID-19 pandemic.

Screenshot of the public dashboard (click picture to enlarge)

In a side note (in the screenshot highlighted in yellow) and in their blog the partners guarantee that the underlying data is fully anonymous and not derived from customer data. This was certified by TüV, an independent Technical Inspection Association.

Although I have no insight into this particular project I assume that the underlying raw data is provided by eNBs using the 3GPP-defined maximum detail level cell trace according to 3GPP 32.423.

This means that the trace collection entity gets the full ASN.1 contents of all RRC, S1AP and X2AP messages, but NAS messages - if provided at all - are encrypted. Also the eNB has not insight into any user plane applications since it has no means to decode the IP payload. This guarantees that neither IMSI, IMEI, web addresses nor phone numbers are found in the raw data.

The key for a meaningful mobility analysis using this data might be the fact that the S-TMSI value in E-UTRAN rarely changes and due to user inactivity settings each subscriber generates multiple RRC connections per hour. Within these RRC connections we find RRC Measurement Reports and typically also some vendor-specific events providing other important radio parameters from the radio interface lower layers including uplink radio quality measurements like PUSCH SINR.

By looking at multiple RRC connections of the same S-TMSI and the reported air interface measurements it is possible to determine if the subscriber remains at the same place or moves around. It it also possible to determine if a subscriber is located indoor or outdoor.

The trace collection entity writes the analysis results into a comprehensive data set that can be used to mask and scramble even S-TMSI values for additional data privacy. The raw data is deleted.

At the end this methodology allows a highly reliable mobility analysis while simultaneously protecting the data privacy of subscribers. The key difference in comparison to statistics based on crowd-sourced data as published e.g. by umlaut is the fact that the 3GPP cell trace provides data for all RRC connections in the network while crowd-sourced data collection requires the installation of certain apps (in case of umlaut only Android apps are supported) and the subscriber's confirmation to collect the data.

However, it must be mentioned that the 3GPP cell trace cannot be used as a data source for the widely discussed Corona contact tracking apps that allow to identify subscribers that have been in close proximity with someone who has been tested positive for COVID-19. For this purpose cell trace data lacks the necessary accuracy to determine the subscriber's and its neighbor's positions.

Spectrum for 5G NR beyond 52.6 GHz

3GPP TR 38.807: Study on requirements for NR beyond 52.6 GHz has recently been revised with all the new information post WRC-19. There is a section that details potential use cases for this new spectrum.

New spectrum above 52.6 GHz – Potential use cases and deployment scenarios from a presentation by Kari Pajukoski, Oskari Tervo and Jari Hulkkonen, Nokia at the #6GSummit https://t.co/BqYPK7xpcz #Free5GTraining pic.twitter.com/6gqz0jCL3A

— 5G Training (@5Gtraining) January 16, 2020

Quoting from the specs:

The relatively underutilized millimeter-wave (mmWave) spectrum offers excellent opportunities to provide high speed data rate, low latency, and high capacity due to the enormous amount of available contiguous bandwidth. However, operation on bands in frequencies above 52.6GHz will be limited by the performance of devices, for example, poor power amplifier (PA) efficiency and larger phase noise impairment, the increased front-end insertion loss together with the low noise amplifier (LNA) and analog-to-digital converter (ADC) noise. In addition, bands in frequencies above 52.6GHz have high propagation and penetration losses challenge. Even so, various use cases are envisioned for NR operating in frequencies between 52.6GHz and 114.25GHz. Some of the use cases are illustrated in Figure 5.1-1 and following section provide detailed description of the uses cases. It should be noted that there is not a 1-to-1 mapping of use cases and wireless interfaces, e.g. Uu, slidelink, etc. Various wireless interfaces could be applicable to various uses cases described.

• High data rate eMBB
• Mobile data offloading
• Short-range high-data rate D2D communications
• Vertical industry factory application
• Broadband distribution network
• Integrated access backhaul (IAB)
• Factory automation/Industrial IoT (IIoT)
• Augmented reality/virtual reality headsets and other high-end wearables
• Intelligent Transport Systems (ITS) and V2X
• Data Center Inter-rack Connectivity
• Smart grid automation
• Radar/Positioning
• Private Networks
• Critical medical communication

There is quite detailed information for each use case in the document that I am not detailing here.

Getting ready for our 5G training next week - https://t.co/6YXW3YlDvD - this picture summarises the 5G mmWave frequency proposals pre #WRC15, approved for study at WRC-15 and available for IMT post #WRC19#3G4G5G #CWTechTrain #5G #Spectrum #5GTraining @cambwireless @UK_5G pic.twitter.com/KoWEpD89Pz

— 3G4G (@3g4gUK) March 3, 2020

It also details information on the allocation within the frequency range 52.6 GHz to 116 GHz in ITU Radio Regulation (see table below). The column with comments contains (a subset of) information on protection requirements for incumbent services. For the full details please refer to the Radio Regulations.

Quoting from the specs:

Within the range 52.6 to 116 GHz, the frequency bands 66-76 GHz (including 66-71 and 71-76 GHz) and 81-86 GHz are being studied under WRC-19 Agenda Item 1.13 for potential IMT identification. Results of sharing and compatibility studies, potential technical and regulatory conditions are included in Draft CPM Report, and the final decisions are to be made in WRC-19 with respect to IMT identification or no IMT identification, along with the corresponding technical and regulatory conditions.

For 66-71 GHz, Studies were carried out for the ISS, MSS (Earth-to-space) indicating that sharing is feasible, with a need for separation distance in the order of few kilometers for the case of MSS (space-to-Earth). The need for studies addressing interference from IMT towards RNS is still under debate. Thus, final conclusions in the regulatory and technical conditions for this band cannot be drawn.

For 71-76 GHz, studies were carried out for the FS, RLS and FSS (space-to-Earth) indicating that sharing with FS and FSS is feasible. However, additional limits of the IMT BS and UE unwanted emissions is needed to protect RLS in the adjacent frequency band 76-81 GHz.

For 81-86 GHz, studies were carried out for the FS, FSS (Earth-to-space), RAS (in band and adjacent band), EESS (passive) and RLS. Studies are not needed for the SRS (passive), as this service is dealing with sensors around other planets and no interference issue is expected. Studies were also not carried out for the MSS. The results of those studies indicate that sharing with FS, FSS and RAS (in band and adjacent band) is feasible. Notice that additional limits of the IMT BS and UE unwanted emissions would be needed to ensure protection of EESS (passive) in the adjacent frequency band 76-81 GHz and RLS in the adjacent frequency band 86-82 GHz.

An interesting paper looking at Waveforms, Numerology, and Phase Noise Challenge for Mobile Communications Beyond 52.6 GHz is available here.


Related Posts:

• The 3G4G Blog: Examples of 5G Use Cases & Applications
• The 3G4G Blog: 5G Private and Non-Public Network (NPN)
• The 3G4G Blog: 5G Integrated Access and Backhaul (IAB) Enhancements in Rel-17
• The 3G4G Blog: What is Industrial IoT (IIoT) and how is it different from IoT?
• The 3G4G Blog: 5G and Industry 4.0
• Connectivity Technology Blog: 5G Indoor Precise Positioning
• The 3G4G Blog: 5G eXtended Reality (5G-XR) in 5G System (5GS)

5G eXtended Reality (5G-XR) in 5G System (5GS)

We have been meaning to make a tutorial on augmented reality (AR), virtual reality (VR), mixed reality (MR) and extended reality (XR) for a while but we have only managed to do it. Embedded below is video and slides for the tutorial and also a playlist of different use cases on XR from around the world.

If you are not familiar with the 5G Service Based Architecture (SBA) and 5G Core (5GC), best to check this earlier tutorial before going further. A lot of comments are generally around Wi-Fi instead of 5G being used for indoors and we completely agree. 3GPP 5G architecture is designed to cater for any access in addition to 5G access. We have explained it here and here. This guest post also nicely explains Network Convergence of Mobile, Broadband and Wi-Fi.

Intermediate: 5G and Extended Reality (XR) from 3G4G

XR use cases playlist



A lot of info on this topic is from Qualcomm, GSMA, 3GPP and 5G Americas whitepaper, all of them in the links in the slides.


Related Posts:

• The 3G4G Blog - Tutorial: Service Based Architecture (SBA) for 5G Core (5GC)
• The 3G4G Blog: 5G and Fixed-Mobile Convergence (FMC)
• The 3G4G Blog: Introduction to 5G ATSSS - Access Traffic Steering, Switching and Splitting
• Guest Post by Ben Toner - Exploring Network Convergence of Mobile, Broadband and Wi-Fi
• Connectivity Technology Blog: 5G Indoor Precise Positioning
• Operator Watch Blog: NTT Docomo presentation on 5G Launch Plans and Use Cases Solutions Partnership
• 3G4G: 3GPP 5G Specifications
• 3G4G: 5G (IMT-2020) Wireless

A Look into 5G Virtual/Open RAN - Part 2

In the first blog post of this series the different virtual RAN functions, interfaces and protocols have been discussed. Now it is time to have a look at a set of procedures that are required for the establishment of an UE connection in virtual 5G RAN.

The Big Picture

In 5G standalone RAN the crucial elements for user plane payload transport of an UE connection are  GTP/IP transport tunnels and a dedicated radio bearer on the radio interface.

When looking at the 5G RAN there are two of such tunnels: one on NG-U (aka N3) that is controlled by NGAP, and one on F1-U that is controlled by F1AP - see figure 1.

On behalf  of these two tunnels payload data can be transported between the 5G core network User Plane Function (UPF) to the gNB Distributed Unit (gNB-DU) and vice versa. For the transport over the 5G RAN fronthaul (realized e.g. as eCPRI) and across the radio interface a dedicated radio bearer (DRB) for the user plane transport must be configured by the gNB Central Unit for the Control Plane (gNB-CU CP).

As in LTE it is the RRC protocol that establishes this DRB. However, due to the virtualization the different protocol layers for the air interface are also distributed and the gNB-DU is in charge of all the lower layer PHY/RLC/MAC parameters (e.g the c-RNTI), while the gNB-CU CP assigns higher layer parameters of PDCP and RRC like the DRB-ID. Since only the gNB-CU CP can send downlink RRC messages to the UE the lower layer parameters from the DU first need to be sent in uplink direction to the gNB-CU CP.

Beside this parameter exchange the F1AP is also responsible for the tunnel management of the F1-U Tunnel.

The downlink tunnel endpoint information is provided by the gNB-DU using F1AP, but the uplink tunnel endpoint terminates at the gNB-CU UP and thus, its endpoint parameters are received by the gNB-CU CP when it exchanges information with the gNB-CU UP on behalf of the E1AP protocol.

Figure 1: Network Functions, Protocols and Parameters involved in Setup of User Plane Data Transmission Resources
(click on the image to see full size)

A similar situation we see for the NG-U tunnel that is controlled by NGAP, the protocol for communication between gNB-CU CP and the Access and Mobility Management Function (AMF) in the 5G core. Neither the gNB-CU CP nor hte AMF have direct access to the NG-U tunnel endpoints. Hence, E1AP is used again to transmit the downlink tunnel parameters to the gNB-CU CP while the uplink tunnel endpoint parameters must be sent by the UPF to the Session Management Function (SMF) using the Packet Forwarding Control Protocol (PFCP) and later by the SMF to the AMF over the service-based interface where the tunnel endpoint parameters are embedded in a JavaScript Object Notation (JSON) container.

By the way, JSON is a quite generic format for exchanging and storing different kind of data. Between the AMF and the SMF JSON is used to transport Non-Access Stratum Session Management messages (defined in 3GPP 24.501).

The Ladder Diagram

Having the Big Picture in mind it is now easier to look at the ladder diagram with the individual RAN messages for UE connection setup - shown in Figure 2.

It looks complicated, because the F1AP messages carry RRC plus NAS messages in uplink and downlink direction, but when understanding the underlying logic it is easy.

Figure 2: 5G VRAN Successful UE Connection Setup
(click on the image to see full size)

The very first step (in the figure: step 0) is the random access procedure executed on the MAC layer involving the UE and the gNB-DU.

After successful random access the UE sends the NR RRC Setup Request message. This is the Initial UL RRC Message transported by the F1AP from the gNB-DU to the gNB-CU CP. Actually the F1AP carries PDCP transport blocks and inside the PDCP the NR RRC messages are found, but to keep it simple I do not show the PDCP header in the ladder diagram.

Beside RRC Setup Request there are also some other initial NR RRC messages and RRC response messages possible (see step 1 and 2).

More RRC messages are transported over F1AP until the RRC Connection establishment is complete.

The NR RRC Setup Complete message also transports the initial NAS message and the reception of this message by the gNB-CU CP triggers the setup of a F1AP UE context. The concept of UE context management in F1AP is the same as in NGAP or - when looking back into the E-UTRAN - in S1AP.

The GTP/IP transport tunnel on F1-U is established during F1AP UE Context Setup assisted by E1AP Bearer Context Setup procedure that provides the necessary tunnel endpoint parameters.

In the same manner the NG-U tunnel is established by the NGAP Initial UE Context Setup procedure.

Additional NAS messages (especially for session management) and NR RRC Reconfiguration are exchanged to establish the end-to-end UE connection through the core network. And that's it.

Related Posts:

• A Look into 5G Virtual/Open RAN - Part 3: Connection Release and Suspend
• 3G4G: Open RAN, OpenRAN and O-RAN

Mobile Voice Communications is neither Dying, nor Dead!

If you have been following the mobile industry for a long time, you could be forgiven for thinking that voice communications is dead. This 2013 article for example talks about the impending death of voice and this 2018 article talks about how smartphones have killed the art of conversation. These are just examples and I have read many similar articles in the last 5-10 years.

The thing is that a lot of unnecessary calls became SMS and messages once the price of SMS and data went down. Similarly, voice ceased to be a differentiator in many markets so they started offering unlimited voice and/or SMS locally. This does not necessarily solve my requirements for international calling so I moved on to Viber, WeChat and WhatsApp.

The annual TeleGeography Report and Database update (just released) estimates that international over-the-top (OTT) voice traffic reached 1 trillion minutes in 2019, compared to just 432 billion minutes of international carrier traffic.

Anyway, with the lockdown in many countries because of coronavirus COVID-19, people have re-discovered the use of voice communications again. While I prefer having meetings on the internet, sometimes it's just simpler to call using your phone. A friend discovered that while she has some 40 GB data allowance that was generally more than enough, working from home means that she is having to use her device as a hotspot that is using up all her data. Switching from OTT calling to unlimited voice calling in her package means that she doesn't have to worry about voice calls eating her data package.

She is not alone. Operators all over are reporting the rise in voice communications:

• 27 Mar 2020 - O2 UK reported, "Since March 16th we have seen approximately 57% more voice traffic at the busiest point of the day. Typically voice traffic increases 5% year on year, and in a week we have experienced an increase of voice traffic comparable to nine years of regular demand." (link)
• 26 Mar 2020 - Official numbers reported by CTIA from Verizon, AT&T, T-Mobile, Sprint and U.S. Cellular stated that mobile voice traffic was up 24.3% while mobile data traffic was up 9.2% (see photo above - link)
• 24 Mar 2020 - Telenor Norwar tweeted, "Traffic has increased sharply since the coronary smith was seriously registered in this country. 50% increase in mobile voice, 25% increase in mobile data and 30-40% increase in fixed broadband"
• 24 Mar 2020 - T-Mobile USA released some interesting stats including gaming, etc. With regards to voice, their announcement said, "People are talking and texting more. Messaging is up dramatically, with a 26% increase in SMS (texting) and a 77% increase in MMS (pictures, multi-party texts, etc.). And, the amount of time people spend on calls has increased 17% nationwide." (link)
• 20 Mar 2020 - Telia in Denmark reported, "Thursday, March 12, the volume of speech in the network thus increased by 24% compared to the day before. Over the weekend 50% more was spoken - obviously due to a need to gain status on family and friends in the new situation. In the past working week, about 60% more has been spoken on the phone than on a normal week in March." (translated from original)

Is voice important for an operator? Probably not very much in the developed markets where users pay a good amount for data packages. In developing countries, voice is still a good source of revenue. At the TIP summit last year, Malaysian telecom giant Axiata said that ""every gigabyte costs about $1.40 to manufacture...generates only 80 cents in revenue...The 2G voice business currently funds any losses". This is not a long term sustainable model for these operators.

Of the 1000 people surveyed, top 5 things people in the USA want from 5G:
• Faster data speeds
• Improved coverage – fewer dead spots
• Clearer voice quality 🤔
• better battery life
• lower cost servicehttps://t.co/aK4ym25seW

— Zahid Ghadialy (@zahidtg) March 23, 2018

Funnily I just remembered that in a survey of over 1000 people in the USA regarding what they want from 5G, the third most important thing was "clearer voice quality". If you want to understand how voice quality is measured that see this tweet below

How do you measure voice quality! pic.twitter.com/a9aNBVMa9L

— 3G4G (@3g4gUK) May 2, 2017

We may keep on seeing a boom in voice traffic as more lockdowns occur and they are even stricter. We will have to wait and see of this habit of talking sticks or it's just for this unusual situation.

Related Posts:

• The 3G4G Blog: A quick starter on 4G voice (for beginners)

Real-life 5G Use Cases for Verticals from China

GSMA have recently published a series of reports related to China. This includes the 'The Mobile Economy China' report as well as reports on ‘Impacts of mmWave 5G in China’, ‘5G use cases for verticals China 2020’ and ‘Powered by SA case studies’. They are all available here.

China currently has 1.65bn subscribers (Excluding licensed cellular IoT) which is expected to grow to 1.73bn in 2025. The report quotes 1.20bn unique mobile subscribers that is expected to grow to 1.26bn by 2025. With a population of 1.44 billion, this would be assuming everyone over 10 years has a smartphone. 2G and 3G is being phased out so only 4G and 5G will be around in 2025. This would be different for IoT.

The 5G Use Cases for Verticals China 2020 report is comprised of 15 outstanding examples of 5G-empowered applications for verticals, ranging from industrial manufacturing, transportation, electric power, healthcare, education, to content creation, and zooms into the practical scenarios, technical features, and development opportunities for the next generation technology. Every use case represents the relentless efforts of 5G pioneers who are open, cooperative, and innovative.

1. Flexible Smart Manufacturing with 5G Edge Computing (RoboTechnik, China Mobile, Ericsson)
2. 5G Smart Campus in Haier Tianjin Washing Machine Factory (China Mobile, Haier)
3. Aircraft Surface Inspection with 5G and 8K at Commercial Aircraft Corporation of China (Comac, China Unicom, Huawei)
4. Xinfengming Group’s Smart Factory Based on MEC Technology (Xinfengming, China Mobile, ZTE)
5. SANY Heavy Industry 5G and Smart Manufacturing (Sany, China Mobile, China Telecom, ZTE)
6. Xiangtan Iron & Steel's 5G Smart Plant (Xisc, China Mobile, Huawei)
7. The Tianjin 5G Smart Port (Tianjin, China Unicom, ZTE, Trunk)
8. 5G Intelligent Connected Vehicle Pilot in Wuhan (China Mobile, Huawei, et al.)
9. 5G BRT Connected Vehicle-Infrastructure Cooperative System (China Unicom, DTmobile, et al.)
10. 5G for Smart Grid (China Mobile, Huawei, et al.)
11. Migu's "Quick Gaming" Platform (China Mobile, et al.)
12. 5G Cloud VR Demonstration Zone in Honggutan, Nanchang, Jiangxi Province (Besttone, China Telecom, Huawei)
13. 5G Cloud VR Education Application Based on AI QoE (China Telecom, Nokia, et al.)
14. China MOOC Conference: 5G + Remote Virtual Simulation Experiment (China Unicom, Vive HTC, Dell Technologies, et al.)
15. 5G-empowered Hospital Network Architecture Standard (CAICT, China Mobile, China Telecom, China Unicom, Huawei, et al.)

They are all detailed in the report here.

I have written about 5G Use Cases in a blog post earlier, which also contains a video playlist of use cases from around the world. Not many from China in there at the moment but should be added as and when they are available and I discover them.


Related Posts:

• Operator Watch Blog: China Allocates Shared Spectrum for Indoor Use, CBN gets Third Spectrum for 5G Network
• The 3G4G Blog: Examples of 5G Use Cases & Applications
• The 3G4G Blog: 5G Private and Non-Public Network (NPN)
• The 3G4G Blog: 5G and Industry 4.0
• The 3G4G Blog: What is Industrial IoT (IIoT) and how is it different from IoT?
• 3G4G: M2M, MTC & IoT
• Operator Watch Blog: China's Synchronized 5G Launch

How Cellular IoT and AI Can Help to Overcome Extreme Poverty in a Climate-resilient Way

The Democratic Republic ofthe Congo (DRC) is the second largest country in Africa and it has a significant potential for agricultural development as the country has more land (235 million hectares) than Kenya, Malawi, Tanzania, and Zambia, combined, of which only 3.4% is cultivated.

Despite this, around 13 millions of Congolese live in extreme food insecurity, among them 5 millions acutely malnourished children. Current assessments show the trend is increasing.

In the southern provinces formerly known as "Katanga" the needs in maize for human consumption sum up to 700,000 tons per year, while the local production barely amounts to 120,000 tons per year. This means the provinces have to resort to importing food from neighboring countries, which represents a huge burden on the region's economy.

Another aspect of the problem is that 80% of the local production is made by women farmers, and the biggest challenge they face is the lack of daily agronomic monitoring and guidance. There is only a limited amount of agriculture experts in the region and without assistance, the farmers’ average output is at best one ton per hectare. However, field trials have proven that by using smart farming technology they can easily produce up to 6 tons per hectare year over year with the right sustainable approach and support. Artificial intelligence (AI), the Internet of Things (IoT) and big data analytics underpinned by mobile connectivity can even do more. They bring significant potential for capturing carbon, optimizing water, pesticide and fertilizer usage, and reducing soil erosion. Thus, African women can not only provide the solution to the local food gap/insecurity but also become the primary protectors of their environment.

The basic technical concept is not new. Back in 2016 Ooredoo Myanmar launched Site Pyo, a mobile agriculture information service for smallholder farmers. At its core Site Pyo is a weather forecast app that was enhanced with weather-dependent advice for ten crops, from seed selection to harvesting and storage. In addition the app displays the actual market prices for these crops. GSMA as a co-funder of the project celebrates Site Pyo as a big success, but it seems to be limited to Myanmar. Why?

„A lot of customization needs to be done to adapt the application functionality for a particular region“, says Dieu-Donné Okalas Ossami, CEO of „e-tumba“, a French Start-up specialized in smart farming solutions for Sub-Sahara Africa. His company partners with iTK, a spin-off from CIRAD, the French Institute for tropical agronomy. The iTK crop-specific predictive models are based on years of agronomic data, but have originally been designed for big farmers. To meet the demands of women in Katanga requires more granular data for both, input and output.

As in case of Site Pyo weather predictions are important, but in addition there are data feeds from sensors on the spot. Weather stations measure constantly temperature and rainfall while sensors in the soil report its saturation with water, nitrogen and potassium.

„A typical real-time advice that our software provides is to delay the harvest for some additional days to maximize the yield“, explains Okalas Ossami. „However, even for two neighboring fields the particular advices are often different.“ 

Also the communication channels need to be taylored. Many women farmers are illiterate. For them the advice must be translated into the local language they speak and transmitted to their phones as a voice message. Those who can read and write will receive the notifications through short message service.

The mobile connectivity that links all elements of the system is realized by the mobile network operators present in the region.

Infographic: The Technical Environment Behind the Project

„Actually NB-IoT would fit to our use case“, says Okalas Ossami, „but it is not available. And there is neither LoRa nor SigFox.“ Hence, the sensors are using data connections of 3G and 4G radio access technology. In case of network outage or missing coverage a local field technician must collect the sensor data manually and transfer it to the data center through alternative channels.

It is the same field technician who installs the sensors. The woman farmers receive a basic training to understand how the system works, but they do not need to care about technical components - except keeping their mobile phones charged.

Here comes another important aspect into the game: How can the women trust this technical environment?

In case of Site Pyo the operator Ooredoo observed a quickly increasing user community measured by the number of app downloads. However, there was no indication to which extend the Myanmar farmers really used the app. The e-tumba solution addresses this gap by partnering with the non-government organization „Anzafrika“.

Anzafrika is present in the villages where the people live. One of its major targets is to overcome the extreme poverty by developing the regional economy. A key factor for this is that the smallholder farmers do not just see the market prices for their crops, but get real access to large, stable and long-term markets where these prices are paid. Anzafrika is brokering contracts between the woman farmers and large multinational corporations committed to the Economics of Mutuality, growing human, social and natural capital. The business model behind this concept was outlined by Bruno Roche and Jay Jakub in their book „Completing Capitalism:Heal Business to Heal the World“. Instead of focusing on greenhouse gas emissions (output) they insist that climate-resilient business models must measure the input needed for manufacturing goods. As an example: For one hot cup of coffee the greenhouse gas emissions are extremely low, but 3.4 liters of water are needed (most for packaging, processing and drinking) and 12 gram of top soil will be eroded. These are (among others) the expenses paid by the planet that are not taken into account by a carbon tax.

Coffee plantations are monocultures with all the known disadvantages resulting form this kind of farming. In the past the Congolese women farmers have grown maize as a monoculture. Now, with advice from Anzafrika and e-tumba they transitioned from an „all-maize“ sustenance crop to a semi-industrial „maize-sorghum“ production. This helps to minimize the top soil erosion and thus, to remunerate the natural capital involved in the process.  

Regarding the human and social capital Anzafrika monitors how the overall situation in the villages  is improving. The focus is on progress in well-beeing, satisfaction and health not just for the women farmers, but for their entire communities.

In 2019 smart farming technology have been tested and deployed with a group of 150 women in the province of Lualaba. Now, in 2020, their number is expected to rise to 500 and after 6 years the stunning target of 100,000 participants shall be met. A look at the download numbers of Site Pyo (206,000 in the course of one year) shows that these numbers are not over-optimistic.

The partnership between Anzafrika, e-tumba and iTK is now considered as a best international practice, as indicated by Patrick Gilabert, UNIDO Representative to the European Union in Brussels. It fully aligns with the development of new comprehensive strategies for Africa that aim at creating a partnership of equals and mutual interest through agriculture, trade and investment partnerships.

UNIDO, as the UN convener for the implementation of the “Industrial Decade for Development of Africa” (IDDA 3) is always ready to join forces with innovative partners.

How LTE RRC (4G) and NR RRC (5G) Protocols are used in Parallel in EN-DC (5G NSA)

Last week I had a fruitful discussion with a fellow blogger on the web, Martin Sauter (@mobilesociety) regarding a post in which he compared features of LTE RRC (3GPP 36.331) and NR RRC (3GPP 38.331).

It was Martin's impression that the NR RRC protocol is primarily designed to be used in the 5G standalone mode. However, as I wrote in a comment to his post the NR RRC protocol is already used in EN-DC radio connections.

The reason is that the UE must be informed about Hundreds of lower layer 5G parameters (physical, MAC, RLC) that are needed for the payload transmission over 5G frequencies. Indeed, when it comes to user plane data transmission the gNB works almost independently and the UE must handle LTE and NR radio links in parallel.So it has two different radio units (even if combined into a single radio chip set). This double-functionality is also one important reason why 5G smartphones are quite expensive. It is a lot of software and know-how that sits inside these chips.

How much surplus code is really necessary to enable 5G technology becomes visible when looking at trace data using a state-of-the-art protocol test and monitoring tool.

When reading the 3GPP 36.331 (LTE RRC) standard document one might have the impression that just a few 5G parameters have been incorporated into this protocol to support EN-DC connections.

However, when looking into the details of e.g. the nr-SecondaryCellGroupConfig-r15 it turns out that some this single information element is indeed a huge block of NR information (total size: 1111 Byte)

It is an entire 5G RRC message (rRCReconfiguration) that is piggybacked by the LTE rrcConnectionReconfiguration message, because in 5G non-standalone mode this is the only way to transmit 5G signaling information to the UE. And as highlighted in the upper part of the screenshot there are a couple of NR RRC messages transported in so-called NR-RRCContainers* during the EN-DC Establishment Procedure.

And what about 5G standalone mode? For this radio access technology the 3GPP 38.331 Rel. 15 protocol is suitable as well. Hence, some parameters mentioned in the standard paper will never be seen in EN-DC. A perfect example is S-NSSAI (Single Network Slice Selection Assistance Information), because network slicing requires the connection with a 5G core network as a prerequisite. 

(click on image for larger version)

* This is not an 3GPP term, but coined by the developers of the decoding engine.

A Look into 5G Virtual/Open RAN - Part 1

Although it is understood in general that virtualization and increasing complexity are inherent characteristics of 5G networks many people are surprised when they realize the significant differences of 5G RAN architecture and signaling procedures compared to what they know from LTE or UTRAN.

In this blog post series I want to highlight some details that are not immediately visible when reading the 3GPP specs.

Figure 1 shows a virtualized gNB and the protocols it uses to communicate with its internal entities as well as with the UE and peer entities in neighbor network elements/functions.

Figure 1: Virtual Network Functions and Protocols in 5G RAN
(click on the image to see full size)

The core of the whole thing is the gNB-Central Unit for the Control Plane (gNB-CU CP). This function communicates directly with the UE using the NR RRC protocol. It also "talks" to the 5G Core Network represented by the AMF using the NGAP, a protocol very similar to the S1AP known from E-UTRAN. Neighboring 5G base stations are contacted using the XnAP, neighboring eNBs can be reached by using X2AP.

The other virtual functions of the gNB are the Central Units for User Plane (gNB-CU UP) and the Distributed Units (gNB-DU). While the gNB-CU UP is responsible for handling the transport of payload the gNB-DUs deal with all the allocation of radio resources, especially the scheduling. As a result the lower layer radio interface protocols, especially RLC and MAC terminate in the gNB-DUs.

For the RAN monitoring tools and the 3GPP Minimization of Drive Test (MDT) feature this means that RRC and Logged Measurement Reports sent by UEs will be available at gN-CU CP while all uplink radio quality measurements and call-related user plane metrics is only available at the gNB-DU - see figure 3.

Figure 2: Distribution of un-correlated RAN measurement tasks among different gNB virtual functions
(click on the image to see full size) 

And today, there is no 3GPP-standardized procedure to correlate this measurement information collected by different virtual gNB functions.

The full impact of the 5G RAN virtualization becomes even more evident when looking at Figure 3. It shows a single gNB-CU CP in charge of controlling several gNB-CU UPs and gNB-DUs.

In a live network deployment a single gNB-CU CP will control hundreds of gNB-DUs and maybe several gNB-CU UPs. This is why it is misleading to compare the connectivity of a gNB-CU CP with that of a LTE eNB. Rather it could be compared with a UTRAN RNC controlling a similar number of 3G base stations.

Figure 3: 5G RAN Connectivity
(click on the image to see full size)

Looking back into figure 1 we see that the F1AP is used for communication between gNB-CU CP and its gNB-DUs while the E1AP is the protocol that connects the gNB-CU CP with surrounding gNB-CU UPs.

Call-related control plane procedures of F1AP and E1AP are very similar to what is known from NGAP. There is a UE context established between the gNB-CU CP and the gNB-DU. On F1-U a GTP tunnel is established for user plane transport. At the same time an E1 Bearer Context in gNB-CU CP and gNB-CU UP keeps track of the most relevant user plane transport parameters.

All in all for setting up a single subscriber connection in the virtualized 5G RAN there are significantly more signaling transactions necessary than in E-UTRAN. Figure 4 shows a practical example.

Figure 4: 5G RAN Call Trace in NETSCOUT Session Analyzer
(click on the image to see full size)

The volume and complexity of signaling information is increasing when the UE moves or is redirected to virtual functions within one gNB e.g. due to load balancing.

The next blog post of this series will dive deeper into details of such call scenarios.

Stay tuned...

Related Posts:

• The 3G4G Blog: A Look into 5G Virtual/Open RAN - Part 2
• 3G4G: Open RAN, OpenRAN and O-RAN