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

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

Inside 3GPP Release-13 - Whitepaper by 5G Americas

The following is from the 5G Americas press release:

The summary offers insight to the future of wireless broadband and how new requirements and technological goals will be achieved. The report updates Release 13 (Rel-13) features that are now completed at 3GPP and were not available at the time of the publication of a detailed 5G Americas report, Mobile Broadband Evolution Towards 5G: 3GPP Release 12 & Release 13 and Beyond in June 2015.

The 3GPP standards have many innovations remaining for LTE to create a foundation for 5G.  Rel-12, which was finalized in December 2014, contains a vast array of features for both LTE and HSPA+ that bring greater efficiency for networks and devices, as well as enable new applications and services. Many of the Rel-12 features were extended into Rel-13.  Rel-13, functionally frozen in December 2015 and completed in March 2016, continues to build on these technical capabilities while adding many robust new features.

Jim Seymour, Principal Engineer, Mobility CTO Group, Cisco and co-leader of the 5G Americas report explained, “3GPP Release 13 is just a peek behind the curtain for the unveiling of future innovations for LTE that will parallel the technical work at 3GPP on 5G. Both LTE and 5G will work together to form our connected future.”

The numerous features in the Rel-13 standards include the following for LTE-Advanced:

• Active Antenna Systems (AAS), including beamforming, Multi-Input Multi-Output (MIMO) and Self-Organizing Network (SON) aspects
• Enhanced signaling to support inter-site Coordinated Multi-Point Transmission and Reception (CoMP)
• Carrier Aggregation (CA) enhancements to support up to 32 component carriers
• Dual Connectivity (DC) enhancements to better support multi-vendor deployments with improved traffic steering
• Improvements in Radio Access Network (RAN) sharing
• Enhancements to Machine Type Communication (MTC)
• Enhanced Proximity Services (ProSe)

Some of the standards work in Rel-13 related to spectrum efficiency include:                                                                                                                       

• Licensed Assisted Access for LTE (LAA) in which LTE can be deployed in unlicensed spectrum
• LTE Wireless Local Area Network (WLAN) Aggregation (LWA) where Wi-Fi can now be supported by a radio bearer and aggregated with an LTE radio bearer
• Narrowband IoT (NB-IoT) where lower power wider coverage LTE carriers have been designed to support IoT applications
• Downlink (DL) Multi-User Superposition Transmission (MUST) which is a new concept for transmitting more than one data layer to multiple users without time, frequency or spatial separation

“The vision for 5G is being clarified in each step of the 3GPP standards. To understand those steps, 5G Americas provides reports on the developments in this succinct, understandable format,” said Vicki Livingston, Head of Communications for the association.

The whitepaper as follows:

Related posts:

• Tweets from NGMN Industry Conference & Exhibition 2016
• 3GPP Release-13 whitepapers and presentations
• LTE-Advanced Pro (a.k.a. 4.5G)
• New whitepaper on Narrowband Internet of Things

MCPTT Off-network and UE to UE/Network Relays

3GPP SA6 recently held a workshop on Mission Critical Push To Talk (MCPTT) stage 3 development in Canada. You can look at the meeting report here and download any presentations from here.

An interesting presentation that caught my attention was one on "MCPTT Off-network Architecture". The presentation is embedded below where it is described technically what is meant by Off-network. From my understanding an off-network from MCPTT point of view is one where the UE does not have network coverage.

In such a situation a UE can connect to another UE that can connect to UE/network (if available) to relay the message. Its similar to another technology that I have talked about, Multihop Cellular Networks and ODMA. Anyway, here is the presentation:

Sometimes the standards can take too long to develop a feature and apps can come and deliver a similar service at a very short notice. One such App that does something similar is called Firechat, which played a big role in many protests worldwide. The video explaining it below is worth watching.


The problem with Apps is that they cannot be used by the emergency services or other governmental organisations, unless a standard feature is available. This is the expectation from this Off-network relays. It would work in combination with D2D/ProSe.


For anyone interested in the latest Public Safety (PS), here is a presentation by SA6 chairman from July

LTE Device-to-device (D2D) Use Cases

Device-to-device is a popular topic. I wrote a post, back in March on LTE-Radar (another name) which has already had 10K+ views. Another post in Jan, last year has had over 13K views. In the LTE World Summit, Thomas Henze from Deutsche Telekom AG presented some use cases of 'proximity services via LTE device broadcast'

While there are some interesting use cases in his presentation (embedded below), I am not sure that they will necessarily achieve success overnight. While it would be great to have a standardised solution for applications that rely on proximity services, the apps have already come up with their own solutions in the meantime.



The dating app Tinder, for example, finds a date near where you are. It relies on GPS and I agree that some people would say that GPS consumes more power but its already available today.



Another example is "Nearby Friends" from Facebook that allows to find your friends if they are nearby, perfect for a day when you have nothing better to do.

With an App, I can be sure that my location is being shared only for one App. With a standardised solution, all my Apps have info about location that I may not necessarily want. There are pros and cons, not sure which will win here.

Anyway, the complete presentation is embedded below:

Enabling proximity services via LTE device broadcast from Zahid Ghadialy

For anyone interested in going a bit more in detail about D2D, please check this excellent article by Dr. Alastair Bryon, titled "Opportunities and threats from LTE Device-to-Device (D2D) communication"

Do let me know what you think about the use cases.

LTE Radar - LTE proximity services

Last year, DT gave an interesting presentation on what they termed as 'LTE Radar'. Here is the video to explain the motivation:


The picture below summarises how this will work:

It is interesting to note that these problems are already being solved using Apps and other technologies. Once the 3GPP standard is finalised, it would be a challenge to get this to mass adoption. An example would be Bluetooth based Beacons that I blogged about earlier here. Nevertheless, it would be interesting to see how compelling the use cases would be once this is standardised. The complete DT presentation is embedded below:

LTE proximity services from Zahid Ghadialy

3GPP Rel-12 and Future Security Work

Here is the 3GPP presentation from the 9th ETSI Security workshop. Quite a few bits on IMS and IMS Services and also good to see new Authentication algorithm TUAK as an alternative to the widely used Milenage algorithm.

3GPP Rel-12 Security, and Future 3GPP Security Work from Zahid Ghadialy

3GPP Public Safety focus in Rel-12

Public Safety is still a hot topic in the standards discussion and on this blog as well. Two recent posts containing presentations have been viewed and downloaded like hotcakes. See here and here.

3GPP presented on this topic in the Critical Communications World that took place last month. The following is from the 3GPP press release:

The ’Critical Communications World’ conference, held recently in Paris, has focused largely on the case for LTE standardized equipment to bring broadband access to professional users, by meeting their high demands for reliability and resilience.

Balazs Bertenyi, the 3GPP SA Chair, reported on the latest status of the first 3GPP features for public safety, in particular those covering Proximity services (Direct mode) and Group call. He spoke of the need to strike a balance between more or less customisation, to make use of commercial products while meeting the specific requirements for Public Protection and Disaster Relief (PPDR).

To ensure that these needs are met, Balazs Bertenyi called for the wholehearted participation of the critical communications community in 3GPP groups, by sending the right people to address the technical questions and obstacles that arise during the creation of work items.

A presentation and video from that event is embedded below:

LTE Standards for Public Safety – 3GPP view from Zahid Ghadialy

For more details see here.

Direct Communication in 3GPP Release-12

Here is a presentation from LG on this topic:

Direct Communication in 3GPP from Zahid Ghadialy

And a magazine article from IEEE on this topic:

Design Aspects of Network Assisted Device-to-Device Communications from Zahid Ghadialy

If interested in doing more research on this topic, also see this link.

Related posts:

• Public Safety Communications using LTE
• 3GPP Release-12 and beyond

Public Safety Communications using LTE

Public Safety Communications using LTE from Zahid Ghadialy

Proximity-based Services (ProSe) - New Study Item in 3GPP Rel-12

There is a new Rel-12 WI "Study on Proximity-based Services" with Qualcomm being the main proponent of this. This was earlier known as D2D (Device-to-device). From the 3GPP SP-110638:

Justification: Proximity-based applications and services represent a recent and enormous socio-technological trend. The principle of these applications is to discover instances of the applications running in devices that are within proximity of each other, and ultimately also exchange application-related data. In parallel, there is interest in proximity-based discovery and communications in the public safety community.


Current 3GPP specification are only partially suited for such needs, since all such traffic and signalling would have to be routed in the network, thus impacting their performance and adding un-necessary load in the network. These current limitations are also an obstacle to the creation of even more advanced proximity-based applications.


In this context, 3GPP technology, has the opportunity to become the platform of choice to enable proximity-based discovery and communication between devices, and promote a vast array of future and more advanced proximity-based applications.


Objective: The objective is to study use cases and identify potential requirements for an operator network controlled discovery and communications between devices that are in proximity, under continuous network control, and are under a 3GPP network coverage, for:
1. Commercial/social use
2. Network offloading
3. Public Safety
4. Integration of current infrastructure services, to assure the consistency of the user experience including reachability and mobility aspects
Additionally, the study item will study use cases and identify potential requirements for
5. Public Safety, in case of absence of EUTRAN coverage (subject to regional regulation and operator policy, and limited to specific public-safety designated frequency bands and terminals)


Use cases and service requirements will be studied including network operator control, authentication, authorization, accounting and regulatory aspects.


The study does not apply to GERAN or UTRAN.

In the past I have mentioned about Qualcomm's proprietary Flashlinq technology that seems to contain lots of similarities. There is also this AllJoyn technology that Qualcomm has been showing off since MWC. Here is a video of that:

There is a lot of potential of this proximity marketing technology mostly for marketing purposes and games. In the end it would depend of the Apps, services and charging based around this. There is also a big possibility for TV and VoD services where you start watching something on your device but then transfer it onto a TV or just a bigger screen.