Research Challenges for the Advancement of Vehicular Networking

It's been a while since we covered V2X as a topic on this blog. If you are not well versed with CAVs and V2X, we recommend you to watch our tutorials on the 3G4G page here.

The networking channel hosted a seminar on 'Vehicular networking' last month. Quoting from the webinar preview:

Looking back at the last decade, one can observe enormous progress in the domain of vehicular networking. Many ongoing activities focus on the design of cooperative perception, distributed computing, and novel safety solutions. Many projects have been initiated to validate the theoretic work in field tests and protocols are being standardized. We are now entering an era that might change the game in road traffic management. Many car makers already supply their recent brands with cellular and Wi-Fi modems, also adding C-V2X and ITS-G5 technologies. We now intend to shift the focus from basic networking principles to open challenges in cooperative computing support and even on how to integrate so-called vulnerable road users into the picture. Edge computing is currently becoming one of the core building blocks of cellular networks, including 5G, and it is necessary to study how to integrate ICT components of moving systems. The panellists will discuss from an industrial perspective the main research challenges for the advancement of vehicular networking and the novelties that we can expect to see coming in the short term. Panellists with extensive experience in Internet measurements, networks related to sustainable development goals, and highly-localized earth observation networks will discuss these topics and participate in a Q&A session with the audience.

The presentations were not shared but the video of the panel discussion is as follows:

The following speakers presented the following talks:

• Vehicular Networking? by Onur Altintas, Toyota North America R&D (0:04:55)
• Collaborative Perception Sharing for Connected Autonomous Vehicles by Fan Bai, General Motors Global R&D (0:15:00)
• The future of vehicular networking by Frank Hofmann, Robert Bosch GmbH (0:23:25)
• The future of vehicular networks and path to 6G by Dr.-Ing. Volker Ziegler, Nokia (0:35:15)
• Panel Discussion with all speakers and  (0:44:30)

Related Posts: 

• 3G4G: Vehicle to Everything (V2X)
• The 3G4G Blog: An Introduction to Vehicle to Everything (V2X) and Cellular V2X (C-V2X)
• Connectivity Technology Blog: Introduction to Connected and Autonomous Vehicles (CAVs) 

An Introduction to Vehicle to Everything (V2X) and Cellular V2X (C-V2X)

We made an introductory tutorial explaining vehicle to everything. There are 2 different favours of V2X as shown in this tweet below

We have a new section on 3G4G homepage - Vehicle to Everything (V2X) - https://t.co/enOdeIcLE5#3G4G5G #V2V #V2X #V2I #V2P #V2N #CAVs #ConnectedCars #AutonomousCars #3GPP #Specifications #Standards #Whitepapers #Webinars

— 3G4G (@3g4gUK) June 28, 2020

One is based on IEEE 802.11p (802.11bd in future). It is known by different names, DSRC, ITS-G5, etc. The other is the cellular V2X or C-V2X. It started as basic D2D but has evolved over the time. The slides and video are embedded below but this topic will need revisiting with more details.

Intermediate: Vehicle to Everything (V2X) Introduction from 3G4G

Related Posts:

• Connectivity Technology Blog: Introduction to Connected and Autonomous Vehicles (CAVs)
• 3G4G: Vehicle to Everything (V2X)
• The 3G4G Blog: 3GPP Sidelink and its proposed extensions
• The 3G4G Blog: 5G New Radio Standards and other Presentations

R&S Webinar on LTE-A Pro and evolution to 5G

Rohde & Schwarz recently uploaded a webinar video on their YouTube channel. I found it really useful. It's embedded below.

Topics covered:

• LTE-M / NB-IoT
• feMTC
• UE Category M2
• OTDOA based positioning
• UE Categories
• Unlicensed Spectrum Overview
• LTE in Unlicensed Spectrum
• LWA, LWIP
• LAA, eLAA
• Wi-Fi
• LBT
• LWA mobility
• Carrier Aggregation Enhancements
• Multi-user superposition transmission (MUST)
• Single cell - point to multipoint transmission (SC-PTM)
• SC-PTM Channel Structure
• SC-PTM Channel Flow
• Massive MIMO
• V2X Overview
• eNB scheduling - transmission mode 3
• Distributed scheduling - transmission mode 4
• Direct communication
• LTE Advanced Pro (Release 15)
• Further NB-IoT Enhancements
• Even further enhanced MTC - eMTC4 (Rel-15)

Related Posts:

• LTE-Advanced Pro (a.k.a. 4.5G)
• New LTE UE Categories (Downlink & Uplink) in Release-13
• Mission Critical Services update from 3GPP - June 2017

5G New Radio Standards and other Presentations

A recent Cambridge Wireless event 'Radio technology for 5G – making it work' was an excellent event where all speakers delivered an interesting and insightful presentation. These presentations are all available to view and download for everyone for a limited time here.

I blogged about the base station antennas last week but there are other couple of presentations that stood out for me.

The first was an excellent presentation from Sylvia Lu from u-Blox, also my fellow CW Board Member. Her talk covered variety of topics including IoT, IIoT, LTE-V2X and Cellular positioning, including 5G NR Positioning Trend. The presentation is embedded below and available to download from Slideshare

Overview of standardisation status and 3GPP technology evolution trend from 3G4G

The other presentation on 5G NR was one from Yinan Qi of Samsung R&D. His presentation looked at variety of topics, mainly Layer 1 including Massive MIMO, Beamforming, Beam Management, Bandwidth Part, Reference Signals, Phase noise, etc. His presentation is embedded below and can be downloaded from SlideShare.

5G NR: Key features and enhancements from 3G4G

Related Posts:

• Base Station Antenna Considerations for 5G
• Introduction to Fixed Wireless Access (FWA)
• 5G Network Architecture Options (Updated)
• Automated 4G / 5G HetNet Design

Summary of 3GPP Release-14 Work Items

With all focus on 5G (Release-15), looks like Rel-14 has been feeling a bit neglected. There are some important updates though as it lays foundation for other services.

3GPP used to maintain Release Descriptions here for all different releases but have stopped doing that since 2014. For Release-14, a new document "3GPP TR 21.914: Release 14 Description; Summary of Rel-14 Work Items" is now available here.

An executive summary from the document:

Release 14 focusses on the following items:

• Improving the Mission Critical aspects, in particular with the introduction of Video and Data services
• Introducing the Vehicle-to-Everything (V2X) aspects, in particular the Vehicle-to-Vehicle (V2)
• Improving the Cellular Internet of Things (CIoT) aspects, with 2G, 3G and 4G support of Machine-Type of Communications (MTC)
• Improving the radio interface, in particular by enhancing the aspects related to coordination with WLAN and unlicensed spectrum
• A set of uncorrelated improvements, e.g. on Voice over LTE (VoLTE), IMS, Location reporting.

The continuation of this document provides an exhaustive view of all the items specified by 3GPP in Release 14.

I have blogged about the Mission Critical Communications here. 3GPP has also done a webinar on this topic which can be viewed here. I like this slide below that summarizes features in different releases.

Then there are quite a few new features and enhancements for V2X. I have blogged about sidelink and its proposed extensions here.

From the document:

The Work Item on “Architecture enhancements for LTE support of V2X services (V2XARC)”, driven by SA WG2, specifies the V2X architectures, functional entities involved for V2X communication, interfaces, provisioned parameters and procedures in TS 23.285.

Figure above depicts an overall architecture for V2X communication. V2X Control Function is the logical function defined for network related actions required for V2X and performs authorization and provisioning of necessary parameters for V2X communication to the UE via V3 interface.

A UE can send V2X messages over PC5 interface by using network scheduled operation mode (i.e. centralized scheduling) and UE autonomous resources selection mode (i.e. distributed scheduling) when the UE is "served by E-UTRAN" while a UE can send V2X messages over PC5 interface only by using UE autonomous resources selection mode when the UE is "not served by E-UTRAN". 

Both IP based and non-IP based V2X messages over PC5 are supported. For IP based V2X messages over PC5, only IPv6 is used. PPPP (ProSe Per-Packet Priority) reflecting priority and latency for V2X message is applied to schedule the transmission of V2X message over PC5.

A UE can send V2X messages over LTE-Uu interface destined to a locally relevant V2X Application Server, and the V2X Application Server delivers the V2X messages to the UE(s) in a target area using unicast delivery and/or MBMS (Multimedia Broadcast/Multicast Service) delivery.

Both IP based and non-IP based V2X messages are supported for V2X communication over LTE-Uu. In order to transmit non-IP based V2X messages over LTE-Uu, the UE encapsulates the V2X messages in IP packets.

For latency improvements for MBMS, localized MBMS can be considered for localized routing of V2X messages destined to UEs.

For V2X communication over LTE-Uu interface, the V2X messages can be delivered via Non-GBR bearer (i.e. an IP transmission path with no reserved bitrate resources) as well as GBR bearer (i.e. an IP transmission path with reserved (guaranteed) bitrate resources). In order to meet the latency requirement for V2X message delivery, the following standardized QCI (QoS Class Identifier) values defined in TS 23.203 can be used:

• QCI 3 (GBR bearer) and QCI 79 (Non-GBR bearer) can be used for the unicast delivery of V2X messages.
• QCI 75 (GBR bearer) is only used for the delivery of V2X messages over MBMS bearers. 

There are updates to cellular IoT (CIot) which I have blogged about here.

There are some other interesting topic that are enhanced as part of Release14. Here are some of them:

S8 Home Routing Architecture for VoLTE

• Robust Call Setup for VoLTE subscriber in LTE
• Enhancements to Domain Selection between VoLTE and CDMA CS
• MBMS improvements
• eMBMS enhancements for LTE
• IMS related items
• Evolution to and Interworking with eCall in IMS
• Password-based service activation for IMS Multimedia Telephony service
• Multimedia Priority Service Modifications
• Enhancements to Multi-stream Multiparty Conferencing Media Handling
• Enhancement for TV service
• Improved Streaming QoE Reporting in 3GPP (IQoE)
• Quality of Experience (QoE) Measurement Collection for streaming services in UTRAN
• Development of super-wideband and fullband P.835
• Enhancements to User Location Reporting Support
• Enhancing Location Capabilities for Indoor and Outdoor Emergency Communications
• Further Indoor Positioning Enhancements for UTRA and LTE
• Improvements of awareness of user location change
• Terminating Access Domain Selection (T-ADS) supporting WLAN Access
• Enhanced LTE-WLAN Aggregation (LWA)
• Enhanced LTE WLAN Radio Level Integration with IPsec Tunnel (eLWIP)
• Positioning Enhancements for GERAN
• New GPRS algorithms for EASE
• RRC optimization for UMTS
• Multi-Carrier Enhancements for UMTS
• DTX/DRX enhancements in CELL_FACH
• LTE radio improvements
• Enhancements on Full-Dimension (FD) MIMO for LTE
• Downlink Multiuser Superposition Transmission for LTE
• Performance enhancements for high speed scenario in LTE
• Control and User Plane Separation (CUPS) of EPC nodes
• Paging Policy Enhancements and Procedure
• Shared Subscription Data Update
• Service Domain Centralization
• Control of Applications when Third party Servers encounter difficulties
• PS Data Off Services
• Enhancement to Flexible Mobile Service Steering 
• Sponsored data connectivity improvements
• Group based enhancements in the network capability exposure functions
• Improved operator control using new UE configuration parameters
• Charging and OAM stand alone improvements
• Rel-14 Charging
• ...

Further Reading:

• 3GPP Release 14 - Techplayon
• Enhanced Television Services over 3GPP eMBMS
• RAN Evolution of LTE in Release 14
• 3GPP announces RAN work programme for R14
• LTE System Information According to Release 14 (3GPP TS 36.300 V14.3.0 )

3GPP Sidelink and its proposed extensions

In an earlier post I discussed briefly about the sidelink: V2V communications are based on D2D communications defined as part of ProSe services in Release 12 and Release 13 of the specification. As part of ProSe services, a new D2D interface (designated as PC5, also known as sidelink at the physical layer) was introduced and now as part of the V2V WI it has been enhanced for vehicular use cases, specifically addressing high speed (up to 250Kph) and high density (thousands of nodes).

Before going further, lets just quickly recap the different V2x abbreviations:

• V2X = Vehicle-to-Everything
• V2V = Vehicle-to-Vehicle
• V2I = Vehicle-to-Infrastructure 
• V2P = Vehicle-to-Pedestrian 
• V2H = Vehicle-to-Home
• eV2X = enhanced Vehicle-to-Everything

I came across this interesting presentation from ITRI that provides lot more details on sidelink and its proposed extension to other topics including eV2X and FeD2D (Further enhanced Device-to-Device).

There are quite a few references in the document that provides more details on sidelink and its operation and extension to other devices like wearables.

There are also details on synchronization and eV2X services.

There is also a very nice D2D overview presentation by Orange that I am embedding below (download from slideshare)

LTE, 5G and V2X

3GPP has recently completed the Initial Cellular V2X standard. The following from the news item:

The initial Cellular Vehicle-to-Everything (V2X) standard, for inclusion in the Release 14, was completed last week - during the 3GPP RAN meeting in New Orleans. It focuses on Vehicle-to-Vehicle (V2V) communications, with further enhancements to support additional V2X operational scenarios to follow, in Release 14, targeting completion during March 2017.

The 3GPP Work Item Description can be found in RP-161894.

V2V communications are based on D2D communications defined as part of ProSe services in Release 12 and Release 13 of the specification. As part of ProSe services, a new D2D interface (designated as PC5, also known as sidelink at the physical layer) was introduced and now as part of the V2V WI it has been enhanced for vehicular use cases, specifically addressing high speed (up to 250Kph) and high density (thousands of nodes).

...

For distributed scheduling (a.k.a. Mode 4) a sensing with semi-persistent transmission based mechanism was introduced. V2V traffic from a device is mostly periodic in nature. This was utilized to sense congestion on a resource and estimate future congestion on that resource. Based on estimation resources were booked. This technique optimizes the use of the channel by enhancing resource separation between transmitters that are using overlapping resources.

The design is scalable for different bandwidths including 10 MHz bandwidth.

Based on these fundamental link and system level changes there are two high level deployment configurations currently defined, and illustrated in Figure 3.

Both configurations use a dedicated carrier for V2V communications, meaning the target band is only used for PC5 based V2V communications. Also in both cases GNSS is used for time synchronization.

In “Configuration 1” scheduling and interference management of V2V traffic is supported based on distributed algorithms (Mode 4) implemented between the vehicles. As mentioned earlier the distributed algorithm is based on sensing with semi-persistent transmission. Additionally, a new mechanism where resource allocation is dependent on geographical information is introduced. Such a mechanism counters near far effect arising due to in-band emissions.

In “Configuration 2” scheduling and interference management of V2V traffic is assisted by eNBs (a.k.a. Mode 3) via control signaling over the Uu interface. The eNodeB will assign the resources being used for V2V signaling in a dynamic manner.

5G Americas has also published a whitepaper on V2X Cellular Solutions. From the press release:

Vehicle-to-Everything (V2X) communications and solutions enable the exchange of information between vehicles and much more - people (V2P), such as bicyclists and pedestrians for alerts, vehicles (V2V) for collision avoidance, infrastructure (V2I) such as roadside devices for timing and prioritization, and the network (V2N) for real time traffic routing and other cloud travel services. The goal of V2X is to improve road safety, increase the efficiency of traffic, reduce environmental impacts and provide additional traveler information services. 5G Americas, the industry trade association and voice of 5G and LTE for the Americas, today announced the publication of a technical whitepaper titled V2X Cellular Solutions that details new connected car opportunities for the cellular and automotive industries.

The whitepaper describes the benefits that Cellular V2X (C-V2X) can provide to support the U.S. Department of Transportation objectives of improving safety and reducing vehicular crashes. Cellular V2X can also be instrumental in transforming the transportation experience by enhancing traveler and traffic information for societal goals.

C-V2X is part of the 3GPP specifications in Release 14. 3GPP announced the completion of the initial C-V2X standard in September 2016. There is a robust evolutionary roadmap for C-V2X towards 5G with a strong ecosystem in place. C-V2X will be a key technology enabler for the safer, more autonomous vehicle of the future.

The whitepaper is embedded below:

Related posts:

• Feasibility Study on New Services and Markets Technology Enablers for 5G
• Connected and Autonomous vehicles: Beyond Infotainment and Telematics
• Connected and Autonomous Car Revolution

Further Reading:

• Personal View: LTE V2X Specifications approved by 3GPP RAN plenary – Eiko Seidel

Connected and Autonomous vehicles: Beyond Infotainment and Telematics

An interesting presentation from the recent Cambridge Wireless Future of Wireless International Conference 2016, delivered by David Wong of SMMT. The presentation and video of this talk is embedded below.

You can view many presentations from #FWIC16 at Cambridge Wireless page here and videos here.

Feasibility Study on New Services and Markets Technology Enablers for 5G

3GPP SA1 (see tutorial about 3GPP if you dont know) recently released four new Technical Reports outlining the New Services and Markets Technology Enablers (SMARTER) for next generation mobile telecommunications.

3GPP TR 22.891 has already identified over 70 different which are into different groups as can be seen in the picture above. These groups are massive Internet of Things (MTC), Critical Communications, enhanced Mobile Broadband, Network Operation and Enhancement of Vehicle-to-Everything (eV2X).

The first 4 items have their own technical reports (see below) but work on the last item has only recently started and does not yet have a TR to show to the outside world. It is foreseen that when there are results from the eV2X study these will be taken on board in the Smarter work. (thanks to Toon Norp for this info)

The four Technical Reports (TR) are:

• TR 22.861, FS_SMARTER – massive Internet of Things (MTC): Massive Internet of Things focuses on use cases with massive number of devices (e.g., sensors and wearables). This group of use cases is particularly relevant to the new vertical services, such as smart home and city, smart utilities, e-Health, and smart wearables.
• TR 22.862, FS_SMARTER – Critical Communications: The main areas where improvements are needed for Critical Communications are latency, reliability, and availability to enable, for example, industrial control applications and tactile Internet. These requirements can be met with an improved radio interface, optimized architecture, and dedicated core and radio resources.
• TR 22.863, FS_SMARTER – enhanced Mobile Broadband: Enhanced Mobile Broadband includes a number of different use case families related to higher data rates, higher density, deployment and coverage, higher user mobility, devices with highly variable user data rates, fixed mobile convergence, and small-cell deployments.
• TR 22.864, FS_SMARTER – Network Operation: The use case group Network Operation addresses the functional system requirements, including aspects such as: flexible functions and capabilities, new value creation, migration and interworking, optimizations and enhancements, and security.

Embedded below is 3GPP TR 22.891 which has a lot of interesting use cases and makes a useful reading.

Connected and Autonomous Car Revolution

Last week we had the Automotive and Transport SIG event in Cambridge Wireless. There is already some good writeup on that event here and here. In this post my interest in looking at the technologies discussed.

R&S (who were the sponsors) gave their introduction presentation quite well highlighting the need and approaches for the connected car. He also introduced the IEEE 802.11p to the group.

As per Wikipedia, "IEEE 802.11p is an approved amendment to the IEEE 802.11 standard to add wireless access in vehicular environments (WAVE), a vehicular communication system. It defines enhancements to 802.11 (the basis of products marketed as Wi-Fi) required to support Intelligent Transportation Systems (ITS) applications. This includes data exchange between high-speed vehicles and between the vehicles and the roadside infrastructure in the licensed ITS band of 5.9 GHz (5.85-5.925 GHz). IEEE 1609 is a higher layer standard based on the IEEE 802.11p."

Back in December, Dr. Paul Martin did an equally useful presentation in the Mobile Broadband SIG and his presentation is equally relevant here as he introduced the different terms live V2X, V2i, V2V, V2P, etc. I have embedded his presentation below:

Roger Lanctot from Strategy Analytics, gave us some interesting facts and figures. Being based in the US, he was able to give us the view of both US as well as Europe. According to him, “LTE is the greatest source of change in value proposition and user experience for the customer and car maker. Bluetooth, Wi-Fi, NFC and satellite connectivity are all playing a role, but LTE deployment is the biggest wave sweeping the connected car, creating opportunities for new technologies and applications.” His officially released presentation is embedded below (which is much smaller than his presentation on that day.

There were also interesting presentations that I have not embedded but other may find useful. One was from Mike Short, VP of Telefonica and the other was from Dr. Ireri Ibarra of MIRA.

The final presentation by Martin Green of Visteon highlighted some interesting discussions regarding handovers that may be required when the vehicle (and the passengers inside) is moving between different access networks. I for one believe that this will not be an issue as there may be ways to work the priorities of access networks out. Anyway, his presentation included some useful nuggets and its embedded below: