The article explores the feasibility and design issues for offering 5G connectivity for motorsports.
There was curiosity within the motorsports trade to supply 5G connectivity for the automobiles on observe. Usually, the automobiles use legacy applied sciences like Wi-Fi or digital video broadcast (DVB) to supply the connectivity for backhauling telemetry, video, and audio knowledge from the automobiles again to the pit and media centre for broadcasting. Nonetheless, the present options present a restricted bandwidth, and throughput is within the vary of 10 to 12Mbps. This throughput is inadequate for superior use instances and capabilities like 4K streaming, 360-degree video, and telemetry for the racing automobiles.
The automotive trade can be transferring in the direction of a software program outlined car (SDV) technique, the place the automobiles will want a extremely dependable and low latency connectivity for frequent updates to the software program, and to push gigabytes of information from the a whole lot of various sensors on the automobiles. The transfer to electrification and softwarisation additionally wants a connectivity resolution that’s future-proof and prepared for these necessities and stay related for the following decade.
Therefore the choice of utilizing personal 5G networks to supply connectivity for the motorsports trade automobiles is a beautiful proposition. 5G is an choice for the motorsports trade as it’s designed to beat and mitigate a number of the points concerned in utilizing wi-fi communications applied sciences for the motorsports use instances.
| System Bandwidth Calculations | |||||||||||||||||||||||||||||||||||||||||||||||||
The next desk exhibits the system bandwidth required for a typical racing circuit.
If utilizing a better order 64QAM modulation, the system bandwidth required is approx. 100MHz. | |||||||||||||||||||||||||||||||||||||||||||||||||
Proposed resolution structure
The determine on earlier web page exhibits the proposed ORAN disaggregated structure for the motorsports use case. The answer makes use of the 7.2 break up structure, which is modular and extensible for the motorsports use case.
On this structure, the distributed models (DUs) run a number of the bodily layer algorithms apart from the radio hyperlink management (RLC) and media entry management (MAC) layers. The DUs are housed within the observe aspect models (TSU), which additionally present the ability for the DUs.
The centralised unit (CU) runs the radio useful resource management (RRC) and packet knowledge convergence protocol (PDCP) layers. There’s a redundant 25G fibre ring to backhaul the site visitors from the DU to the CU. The CU and 5G core are centralised on the occasion technical centre.
This break up structure makes the answer scalable because the variety of radios will depend upon the observe structure and dimensions. The CU can management a number of DUs and run the required algorithms particular to the motorsports use instances.
Design issues
Among the design issues and proposed options when utilizing 5G to supply the throughput necessities for racing automobiles are described under.
Excessive pace
The automobiles transfer at a really excessive pace on observe, as much as 350 kilometres an hour. This excessive pace introduces distinctive design challenges within the design of a 5G resolution. The Doppler shift or Doppler unfold is a priority due to the shift within the frequency of the alerts despatched and acquired by the fastened radios from the transferring automobiles. The Doppler shift is instantly proportional to the pace of the automotive. This additionally ends in inter-carrier interference.
Answer. Algorithms should be designed to compensate for the Doppler shift launched because of the pace at which the automobiles are travelling. The Doppler shift relies on the pace and course of motion of the automotive relative to the trackside radio. Thus, the Doppler ends in a rise or a lower within the frequency, relying on the course and pace of motion of the automotive relative to the radio. The transmit frequency is adjusted within the RF entrance finish to compensate for the Doppler shift.
Road circuits
A number of racing tracks, for instance in Components One, are in cities the place there’s infrastructure like buildings, fences, timber, grandstands, and road furnishings. This infrastructure causes interference and scattering of the 5G radio alerts to and from the automobiles, degrading the sign high quality.
Answer. Antenna variety and multipath reception must be carried out to take care of the standard of the acquired alerts on the radio and the UE. The channel state info (CSI) may also be computed and predicted extra continuously to find out the channel situation. Machine language algorithms can be utilized to make a extra correct estimation of the channel situation. This may require a better compute energy on the base station to precisely calculate the CSI and compensate accordingly.
Handover
A novel problem confronted because of the excessive pace at which the automotive travels is that the time for handover between the neighbouring cells is small. It’s of the order of some tens of milliseconds to forestall drops or glitches within the telemetry audio and video knowledge that’s despatched from the automotive. Therefore the seamless handover must be carried out for these racing automobiles.
Answer. Multi-TRxP options like co-ordinated multi-point (CoMP) and multi-panel beamforming can be utilized to cancel out the interference from neighbouring automobiles. CoMP utilises completely different strategies to dynamically coordinate the transmission and reception for a specific UE to and from a number of base stations.
The UE is related to a couple of base station and transmitting/receiving is each on the identical time. The CoMP algorithm resolves duplicate packets acquired. On the cell edge, when transferring from one cell to a different, the handover time could be very low, and the packet loss is minimised. This improves robustness of the transmission, and the connection is extra dependable. This ends in no dropped video frames within the transmission from the automobiles.
Interference
The automobiles usually have a number of sensors that take measurements like acceleration, pace, temperature, vibration, and tire stress. These sensors can create electromagnetic interference, which might hinder the reception and transmission of the 5G radio alerts.
Answer. The antennas should be mounted strategically on the racing automobiles in order that they aren’t susceptible to the interference from different parts within the automotive. The radio frequency circuit must be designed with a excessive degree of tolerance towards spurious alerts.
Bandwidth
The racing automobiles are travelling at a really excessive pace, therefore a decrease modulation and coding scheme (MCS) is required for use to supply a sturdy transmission and reception of alerts. Equally, a sturdy code charge with extra redundant bits is required for the ahead error correction (FEC) to get better from any transmission errors.
Therefore the bandwidth required might be as giant as 200MHz to supply the required throughput for the racing automobiles. This raises the problem of which spectrum to make use of the place a sufficiently giant bandwidth is out there.
Answer
The unlicensed 5GHz or 6GHz bands are an choice the place a big bandwidth can probably be obtainable to be used. Nonetheless, this band is at the moment additionally shared for Wi-Fi, and therefore the reliability and assured availability of this spectrum could also be a problem.
Another choice is to make use of the customized band just like the 10GHz band, which is at the moment utilized by the army for radar stations. The requirement is to maintain the transmit energy low in order that there isn’t any interference to incumbent customers on this band.
Customized radios and trackside infrastructure would should be developed when utilizing these bands to supply the required high quality of service and reliability for the racing automobiles.
| Desk 1 Non-public Use Spectrum | |
| Nation | Band (MHz) |
| Germany | 3700-3800 (100M) |
| USA | 3550-3700 (150M) |
| UK | 3800-4200 (400M) |
| Canada | 3500 deliberate |
| Japan | 4500-4800 (300M) |
| Desk 2 5G NR FR2 Frequency Bands | ||||
| Band | Frequency (GHz) | Widespread Identify | Uplink/Downlink (TDD) | Channel Bandwidth (MHz) |
| n257 | 28 | LMDS | 26.50 – 29.50 | 50, 100, 200, 400 |
| n258 | 26 | Ok-band | 24.25 – 27.50 | 50, 100, 200, 400 |
| n259 | 41 | V-band | 39.50 – 43.50 | 50, 100, 200, 400 |
| n260 | 39 | Ka-band | 37.00 – 40.00 | 50, 100, 200, 400 |
| n261 | 28 | Ka-band | 27.50 – 28.35 | 50, 100, 200, 400 |
5G spectrum
One of many key choices for the answer is the selection of spectrum for use for the 5G system, in order that the system can function in all of the nations whereas offering constant KPIs like throughput and latency. So, following are the choices for the working frequency of the answer, together with the professionals and cons of every choice.
3.5GHz mid band
The three.5GHz mid-band spectrum is crowded and is allotted to the operators in most nations, with the operators having about 20 to 50MHz bandwidth. There are a couple of nations, comparable to Spain, the place the person operators like Telefonica, Vodafone, and Orange have 90 to 100MHz of bandwidth. In Nice Britain the operators have about 20 to 60MHz of bandwidth every. In nations like Bahrain, Canada, Russia, Netherlands, and Turkey the three.5GHz spectrum has not but been auctioned.
Therefore to function within the 3.5GHz band, we would wish to have partnerships with two or extra operators to have the ability to get the 100MHz spectrum wanted. Some nations have reserved a part of spectrum within the mid band for unlicensed and shared use (not obtainable universally), as proven in Desk 1. The obtainable spectrum is primarily for personal indoor use and shouldn’t intervene with incumbents working in the identical frequency band.
mmWave bands
The licensed mmWave spectrum is out there in a couple of completely different bands: 26GHz, 28 GHz, 37GHz, 39GHz, and 47GHz. Usually, the quantity of frequency allotted to every operator within the mmWave bands is increased—from 200MHz to 400MHz or extra. That is perfect by way of a big chunk of bandwidth required for the motorsport resolution. Among the unlicensed bands are:
• USA: 37 to 37.6GHz (3x200MHz) has been allotted by FCC for shared/unlicensed use
• Germany, UK, Australia: 24.25 to 27.5GHz for native licenses
• Japan: 28.3 to 29.1GHz (150MHz out of doors use) for native license
Varadaraj Yatirajula is 5G Answer Architect at Wipro and Distinguished Member of Technical Workers
