IEEE 802.11p

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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, so called vehicle-to-everything (V2X) communication, 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. [1] It is also the basis of a European standard for vehicular communication known as ETSI ITS-G5. [2]

Contents

Description

802.11p is the basis for dedicated short-range communications (DSRC), a U.S. Department of Transportation project based on the Communications Access for Land Mobiles (CALM) architecture of the International Organization for Standardization for vehicle-based communication networks, particularly for applications such as toll collection, vehicle safety services, and commerce transactions via cars. The ultimate vision was a nationwide network that enables communications between vehicles and roadside access points or other vehicles. This work built on its predecessor ASTM E2213-03 from ASTM International. [3]

In Europe, 802.11p is used as a basis for the ITS-G5 standard, supporting the GeoNetworking protocol for vehicle to vehicle and vehicle to infrastructure communication. [4] ITS G5 and GeoNetworking is being standardised by the European Telecommunications Standards Institute group for Intelligent Transport Systems. [5]

Context

Because the communication link between the vehicles and the roadside infrastructure might exist for only a short time interval, the IEEE 802.11p amendment defines a method to exchange data through that link without the need to establish a basic service set (BSS), thus without the need to wait on the association and authentication procedures to complete prior to exchanging data. For that purpose, IEEE 802.11p-enabled stations use the wildcard BSSID (a value of all 1s) in the header of the frames they exchange, and may start sending and receiving data frames as soon as they arrive on the communication channel.

Because such stations are neither associated nor authenticated, the authentication and data confidentiality mechanisms provided by the IEEE 802.11 standard (and its amendments) cannot be used. These kinds of functionality must then be provided by higher network layers.

Timing advertisement

This amendment adds a new management frame for timing advertisement, which allows IEEE 802.11p enabled stations to synchronize themselves with a common time reference. The only time reference defined in the IEEE 802.11p amendment is UTC.

Receiver performance

Some optional enhanced channel rejection requirements (for both adjacent and nonadjacent channels) are specified in this amendment in order to improve the immunity of the communication system to out-of-channel interference. They only apply to OFDM transmissions in the 5 GHz band used by the IEEE 802.11a physical layer.

Frequency band

IEEE 802.11p standard typically uses channels of 10 MHz bandwidth in the 5.9 GHz band (5.850–5.925 GHz). This is half the bandwidth, or double the transmission time for a specific data symbol, as used in 802.11a. This allows the receiver to better cope with the characteristics of the radio channel in vehicular communications environments, e.g. the signal echoes reflected from other cars or houses. [6]

History

The 802.11p Task Group was formed in November 2004. Lee Armstrong was chair and Wayne Fisher technical editor. Drafts were developed from 2005 through 2009. By April 2010 draft 11 was approved by 99% affirmative votes and no comments. [7] The approved amendment was published July 15, 2010; its title was "Amendment 6: Wireless Access in Vehicular Environments". [8]

In August 2008, the European Commission allocated part of the 5.9 GHz band for priority transport safety applications [9] and inter-vehicle, infrastructure communications. [10] The intention is that compatibility with the USA will be ensured even if the allocation is not exactly the same; frequencies will be sufficiently close to enable the use of the same antenna and radio transmitter/receiver.

Simulations published in 2010 predict delays of at the most tens of milliseconds for high-priority traffic. [6]

In November 2020, the FCC reallocated the lower 45 MHz half of the DSRC spectrum (5.850–5.895 GHz) for Wi-Fi and other unlicensed uses, [11] arguing that the auto industry had largely failed to make use of the DSRC spectrum in its 21 years of existence, with only 15,506 vehicles in the US –0.0057% of the total –equipped for DSRC. [12]

Implementations

In the Portuguese city of Porto, it is used as a mesh to provide vehicle data between public vehicles and wifi access for its passengers [13]

In Europe, it is foreseen to implement a set of use cases was outlined in the European Commission document "5G Global Developments". [14]

See also

Related Research Articles

<span class="mw-page-title-main">IEEE 802.11</span> Wireless network standard

IEEE 802.11 is part of the IEEE 802 set of local area network (LAN) technical standards, and specifies the set of medium access control (MAC) and physical layer (PHY) protocols for implementing wireless local area network (WLAN) computer communication. The standard and amendments provide the basis for wireless network products using the Wi-Fi brand and are the world's most widely used wireless computer networking standards. IEEE 802.11 is used in most home and office networks to allow laptops, printers, smartphones, and other devices to communicate with each other and access the Internet without connecting wires. IEEE 802.11 is also a basis for vehicle-based communication networks with IEEE 802.11p.

Dedicated short-range communications (DSRC) is a technology for direct wireless exchange of vehicle-to-everything (V2X) and other intelligent transportation systems (ITS) data between vehicles, other road users, and roadside infrastructure. DSRC, which can be used for both one- and two-way data exchanges, uses channels in the licensed 5.9 GHz band. DSRC is based on IEEE 802.11p.

802.11j-2004 or 802.11j is an amendment to the IEEE 802.11 standard designed specially for Japanese market. It allows wireless LAN operation in the 4.9–5.0 GHz band to conform to the Japanese rules for radio operation for indoor, outdoor and mobile applications. The amendment has been incorporated into the published IEEE 802.11-2007 standard.

Vehicular communication systems are computer networks in which vehicles and roadside units are the communicating nodes, providing each other with information, such as safety warnings and traffic information. They can be effective in avoiding accidents and traffic congestion. Both types of nodes are dedicated short-range communications (DSRC) devices. DSRC works in 5.9 GHz band with bandwidth of 75 MHz and approximate range of 300 metres (980 ft). Vehicular communications is usually developed as a part of intelligent transportation systems (ITS).

Vehicular ad hoc networks (VANETs) are created by applying the principles of mobile ad hoc networks (MANETs) – the spontaneous creation of a wireless network of mobile devices – to the domain of vehicles. VANETs were first mentioned and introduced in 2001 under "car-to-car ad-hoc mobile communication and networking" applications, where networks can be formed and information can be relayed among cars. It was shown that vehicle-to-vehicle and vehicle-to-roadside communications architectures will co-exist in VANETs to provide road safety, navigation, and other roadside services. VANETs are a key part of the intelligent transportation systems (ITS) framework. Sometimes, VANETs are referred as Intelligent Transportation Networks. They are understood as having evolved into a broader "Internet of vehicles". which itself is expected to ultimately evolve into an "Internet of autonomous vehicles".

Intelligent vehicular ad hoc networks (InVANETs) use WiFi IEEE 802.11p and effective communication between vehicles with dynamic mobility. Effective measures such as media communication between vehicles can be enabled as well methods to track automotive vehicles. InVANET is not foreseen to replace current mobile communication standards.

IEEE 802.11  – or more correctly IEEE 802.11-1997 or IEEE 802.11-1999 – refer to the original version of the IEEE 802.11 wireless networking standard released in 1997 and clarified in 1999. Most of the protocols described by this early version are rarely used today.

IEEE 802.11a-1999 or 802.11a was an amendment to the IEEE 802.11 wireless local network specifications that defined requirements for an orthogonal frequency-division multiplexing (OFDM) communication system. It was originally designed to support wireless communication in the unlicensed national information infrastructure (U-NII) bands as regulated in the United States by the Code of Federal Regulations, Title 47, Section 15.407.

IEEE 802.11b-1999 or 802.11b is an amendment to the IEEE 802.11 wireless networking specification that extends throughout up to 11 Mbit/s using the same 2.4 GHz band. A related amendment was incorporated into the IEEE 802.11-2007 standard.

IEEE 802.11g-2003 or 802.11g is an amendment to the IEEE 802.11 specification that operates in the 2.4 GHz microwave band. The standard has extended link rate to up to 54 Mbit/s using the same 20 MHz bandwidth as 802.11b uses to achieve 11 Mbit/s. This specification under the marketing name of Wi-Fi has been implemented all over the world. The 802.11g protocol is now Clause 19 of the published IEEE 802.11-2007 standard, and Clause 19 of the published IEEE 802.11-2012 standard.

Communications access for land mobiles (CALM) is an initiative by the ISO TC 204/Working Group 16 to define a set of wireless communication protocols and air interfaces for a variety of communication scenarios spanning multiple modes of communications and multiple methods of transmissions in Intelligent Transportation System (ITS). The CALM architecture is based on an IPv6 convergence layer that decouples applications from the communication infrastructure. A standardized set of air interface protocols is provided for the best use of resources available for short, medium and long-range, safety critical communications, using one or more of several media, with multipoint (mesh) transfer.

<span class="mw-page-title-main">Mobile Slotted Aloha</span>

Mobile Slotted Aloha (MS-Aloha) is a wireless network protocol proposed for applications such as vehicle networks.

IEEE 802.11ad is an amendment to the IEEE 802.11 wireless networking standard, developed to provide a Multiple Gigabit Wireless System (MGWS) standard at 60 GHz frequency, and is a networking standard for WiGig networks. Because it uses the V band of millimeter wave (mmW) frequency, the range of IEEE 802.11ad communication would be rather limited compared to other conventional Wi-Fi systems. However, the high frequency allows it to use more bandwidth which in turn enables the transmission of data at high data rates up to multiple gigabits per second, enabling usage scenarios like transmission of uncompressed UHD video over the wireless network.

The Cooperative Adaptive Cruise Control (CACC) is an extension to the adaptive cruise control (ACC) concept using Vehicle-to-Everything (V2X) communication. CACC realises longitudinal automated vehicle control. In addition to the feedback loop used in the ACC, which uses Radar, Camera and/or LIDAR measurements to derive the range to the vehicle in front, the preceding vehicle's acceleration is used in a feed-forward loop. The preceding vehicle's acceleration is obtained from the Cooperative Awareness Messages it transmits using ETSI ITS-G5, DSRC / WAVE technology or LTE-V2X PC5 interface as part of the C-V2X technology. Generally, these messages are transmitted several times per second by future vehicles equipped with ITS capabilities.

IEEE 802.11ah is a wireless networking protocol published in 2017 called Wi-Fi HaLow as an amendment of the IEEE 802.11-2007 wireless networking standard. It uses 900 MHz license-exempt bands to provide extended-range Wi-Fi networks, compared to conventional Wi-Fi networks operating in the 2.4 GHz and 5 GHz bands. It also benefits from lower energy consumption, allowing the creation of large groups of stations or sensors that cooperate to share signals, supporting the concept of the Internet of things (IoT). The protocol's low power consumption competes with Bluetooth, LoRa, and Zigbee, and has the added benefit of higher data rates and wider coverage range.

IEEE 802.11ax, officially marketed by the Wi-Fi Alliance as Wi-Fi 6 and Wi-Fi 6E (6 GHz), is an IEEE standard for wireless local-area networks (WLANs) and the successor of Wi-Fi 5 (802.11ac). It is also known as High EfficiencyWi-Fi, for the overall improvements to Wi-Fi 6 clients in dense environments. It is designed to operate in license-exempt bands between 1 and 7.125 GHz, including the 2.4 and 5 GHz bands already in common use as well as the much wider 6 GHz band.

<span class="mw-page-title-main">Vehicle-to-everything</span> Communication between a vehicle and any entity that may affect the vehicle

Vehicle-to-everything (V2X) is communication between a vehicle and any entity that may affect, or may be affected by, the vehicle. It is a vehicular communication system that incorporates other more specific types of communication as V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), V2V (vehicle-to-vehicle), V2P (vehicle-to-pedestrian), V2D (vehicle-to-device).

The 5G Automotive Association (5GAA) is a corporate coalition to develop and promote standardized protocols for automotive vehicles utilizing 5G communications. It serves as a lobbying group for the European Union on behalf of its membership. Their interests are government investments in the widespread deployment of short-range 5G wireless technology dubbed Cellular V2X.

Cellular V2X (C-V2X) is a 3GPP standard for V2X applications such as self-driving cars. It is an alternative to 802.11p, the IEEE specified standard for V2V and other forms of V2X communications.

References

  1. ↑ "IEEE 1609 - Family of Standards for Wireless Access in Vehicular Environments (WAVE)". U.S. Department of Transportation. April 13, 2013. Retrieved 2014-11-14.
  2. ↑ EN 302 663 Intelligent Transport Systems (ITS); Access layer specification for Intelligent Transport Systems operating in the 5 GHz frequency band (https://www.etsi.org/deliver/etsi_en/302600_302699/302663/01.03.01_30/en_302663v010301v.pdf)
  3. ↑ E2213-03 Standard Specification for Telecommunications and Information Exchange Between Roadside and Vehicle Systems (Report). ASTM International. doi:10.1520/E2213-03R10 . Retrieved July 15, 2007.
  4. ↑ "Final draft ETSI ES 202 663 V1.1.0 (2009-11)" (PDF). European Telecommunications Standards Institute . Retrieved 2013-04-16.
  5. ↑ "Intelligent Transport Systems". Web site. ETSI. Archived from the original on April 14, 2013. Retrieved September 9, 2013.
  6. 1 2 Sebastian Grafling; Petri Mahonen; Janne Riihijarvi (June 2010). "Performance evaluation of IEEE 1609 WAVE and IEEE 802.11p for vehicular communications". 2010 Second International Conference on Ubiquitous and Future Networks (ICUFN). pp. 344–348. doi:10.1109/ICUFN.2010.5547184. ISBN   978-1-4244-8088-3. S2CID   18350900.
  7. ↑ "Status of Project IEEE 802.11 Task Group p: Wireless Access in Vehicular Environments". IEEE. 2004–2010. Retrieved August 10, 2011.
  8. ↑ "Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 6: Wireless Access in Vehicular Environments" (PDF). IEEE 802.11p published standard. IEEE. July 15, 2010. Retrieved August 10, 2011.
  9. ↑ 2008/671/EC: Commission Decision of 5 August 2008 on the harmonised use of radio spectrum in the 5875 - 5905 MHz frequency band for safety-related applications of Intelligent Transport Systems (ITS)
  10. ↑ "Cars that talk: Commission earmarks single radio frequency for road safety and traffic management". European Commission. 2008-08-05. Retrieved 2008-08-23.
  11. ↑ "FCC Modernizes 5.9 GHz Band to Improve Wi-Fi and Automotive Safety". Federal Communications Commission. 2020-11-18. Retrieved 2022-04-27.
  12. ↑ "FCC takes spectrum from auto industry in plan to "supersize" Wi-Fi". 18 November 2020.
  13. ↑ "Mission for Growth Portugal – B2B Meetings". B2match.eu. Archived from the original on 2015-01-11. Retrieved 2016-05-16.
  14. ↑ 5G Global Developments – SWD (2016) 306, page 9 (http://ec.europa.eu/newsroom/dae/document.cfm?doc_id=17132)
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