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Qualcomm launches C-V2X chip, treading on own 802.11p toes

Qualcomm has unveiled its Cellular-V2X (C-V2X) chipset to market in what looks like a win for the 3GPP Release 14 approach to vehicle-to-everything (V2X) communication. In a white paper about V2X, Qualcomm argues that “the decision for regulators and automakers on V2X is between 802.11p based radio technology and a 3GPP-based Cellular-V2X,” – but this market is far from decided, despite Qualcomm throwing its weight around.

Qualcomm already had an 802.11p chipset, called the QCA65844AU. With the launch of the new C-V2X 9150, Qualcomm is playing both fields – doubling up on the approaches, to suit whatever its customers ask for. In the announcement, Qualcomm counts on Audi, Ford, Peugeot-Citroen (PSA), and SAIC as supporters for its approach.

IEEE 802.11p is a radio protocol that allow cars to communicate when they are in proximity to each other, expected to use 5.9GHz spectrum in America and Europe, and 5.8GHz in Japan. The new C-V2X appears to be in direct competition with 802.11p, and it is not clear if there will be an industry-wide battle to push one approach out of the market, or if peaceful co-existence is on the cards.

Qualcomm is shipping a reference design that combines the C-V2X 9150 (with its integrated GNSS capabilities) with an application processor that will run Qualcomm’s Intelligent Transportation Systems (ITS) software stack – with a Hardware Security Module (HSM) added to provide better system security.

The 3GPP Release 14 C-V2X standard supports both elements of V2X communication – the familiar cellular network-based approach, which travels over the MNO’s network infrastructure, and the direct communications that are blasted to anyone in proximity and don’t require SIM-based connections.

The Rel. 14 spec reuses the established service and application layer specifications that are defined by the automotive industry – specifically, the Society of Automotive Engineers (SAE), and the European Telecommunications Standards Institute’s (ETSI’s) Intelligent Transport Systems group. Notably, LTE-V is not mentioned by Qualcomm in the C-V2X announcement, and it seems that that term has fallen out of favor.

The 9150 C-V2X is a Wi-Fi like radio that can transmit data between vehicles, it cannot connect directly to the LTE network. However, when the C-V2X 9150 is integrated into a module with traditional LTE radios, this can enable a network operator to better manage all the communications taking place across C-V2X.

Under normal conditions, an 802.11p radio would be broadcasting messages across the entire slice of 5.9GHz spectrum until it found a channel that had little interference and could be received by another 802.11p radio – which could offer an MNO the ability to keep the proximity traffic off of its networks, to help ease congestion, better optimized and scheduled to only transmit on clean channels at appropriate times.

IEEE 802.11p has long been the lead technology in V2X, with the IEEE setting up the first Task Group in 2004, and the first version of the standard published in 2010 – ‘Amendment 6: Wireless Access in Vehicular Environments.’ 802.11p radio nodes have been installed in the Cadillac CTS from GM. VW will also be introducing 802.11p radio into the 2019 Golf. Toyota has also deployed 802.11p radio in Japan, but not in any vehicles outside of the country.

Initially, Qualcomm missed out on the 802.11p market. GM chose NXP, Cohda Wireless and Delphi to supply the CTS with 802.11p chipsets. Qualcomm is in the process of acquiring NXP, and will have to begin the consolidation of their portfolios – integrating NXP’s established RoadLINK suite into its own offerings, as it merges with a major player in the automotive space.

Qualcomm was one of the founding members of the 5G Automotive Alliance (5GAA) with Nokia, a group set up to promote and develop C-V2X. The 5GAA now has 54 members including major automakers Audi, BMW, Daimler, Ford, Jaguar Land Rover and SAIC Motor, as well as a number of Tier 1 automotive suppliers, infrastructure vendors and MNO’s. Judging by the list of OEMs involved with 5GAA, C-V2X could well pick up the premium end of the V2X market, potentially leaving 802.11p without LTE-V to be introduced in lower priced vehicles.

Qualcomm argues that C-V2X has some technical advantages over 802.11p, most notably its greater range and better interference management. A V2X approach that relies solely on an 802.11p would require the deployment of new 802.11p network infrastructure to support direct V2I communication, which will come at a significant cost.

802.11p has also been facing challenges since the FCC ruled that normal WiFi could use the DSRC 5.9GHz spectrum the automotive industry was given back in 1999 to develop safety features (spectrum that Europe also set aside, hoping for unification). Normal WiFi broadcasting in that spectrum will cause interference for 802.11p V2V communication and there is a lack of consensus other how to address the issue.

Qualcomm has supported using an approach called re-channelization, which involves moving all safety related DSRC communications to the upper part of the band, and permitting unlicensed devices to share the lower part of the DSRC band, which occupies the upper part of the 5.8GHz ISM band that WiFi uses. Qualcomm asserted that the radio characteristics of DSRC are relatively uniform across DSRC band and thus testing would be straightforward.

Qualcomm ran into criticism from the Alliance of Automobile Manufacturers, whose members represent 77% of all car and light truck sales in the US, in a filing to the FCC, over its position on the testing of DSRC re-channelization. Qualcomm has stated in the past that “re-channelization ensures that Wi-Fi will not interfere with latency-sensitive, safety-of-life DSRC communications.” The AAM is critical of this claim, as Qualcomm provided no test data to support the statement.

Under re-channelization DSRC would see the number of safety channels it can use reduced from 7 channels to 3 channels, moving safety communication closer to sources of interference, and requiring DSRC to use sub-optimal 20 MHz channels. The AAM argues that the reduction in channels could affect the performance of DSRC to a point where it will  require extra testing – slowing any potential adoption of the technology in the US.

It now appears that while all these DSRC-deregulation issues were taking place during 2016, Qualcomm was developing a competitive alternative behind the scenes – C-V2X, with its significantly larger link budget that enables greater ranges and reliability. Based on Qualcomm presentations, it seems that the company thinks C-V2X will completely replace 802.11p down the road, as the new 3GPP standard adds more features in the next releases.

But automakers are very conservative, and despite the performance claims that Qualcomm makes, they are not going to rush their testing process – both at an industry level, and then their own individual testing. It will take several years of testing before such a C-V2X chip would be considered for introduction into a consumer vehicle.

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