今天通过Wi-Fi实现千兆连接

Content Conclusion Executive The Digital Decade Policy Programme (DDPP) sets concrete targets and objectives for 2030to guide Europe’s digital transformation. Digital infrastructure is one of the cardinal pointsfocusing on improving and developing mobile and fiber network infrastructures. The goalis to ensure Gigabit connectivity for everyone and achieve high-speed mobile coverage (atleast 5G) everywhere” [1]. The Commission sets the Gigabit connectivity target for fixedbroadband connections delivered to the home [2]. Fixed broadband connectivity is typically There are diverging views on how to prevent Wi-Fi from becoming a bottleneck in deliveringGigabit connectivity to consumers. Some request additional spectrum in the upper 6 GHzband [3] while others point to efficiency deficits and argue for more efficient usage of the We have analyzed Wi-Fi performance in an apartment building, considering the mostcommon channel allocation in Europe, namely the 5 GHz and lower 6 GHz bands, for •Speeds significantly higher than 1 Gbps can be achieved today with current Wi-Fitechnology.•The best performance is achieved when combining efficient reuse of the available Further emphasis should be put on optimizing operation in dense scenarios withappropriate channel bandwidth and features, rather than overprovisioning of spectrum. Spectrumavailability Historically, Europe has had two spectrum ranges where Wi-Fi technologies can bedeployed: 2.4 GHz, 2400-2483.5 GHz [5] and 5 GHz, 5150-5350 MHz and 5470-5725 MHz[6]. Wi-Fi standards Wi-Fi is the most common technology being deployed under “license-exempt” authorizationregimes, and its operation in these bands is at the core of the underlying standard, IEEE In 1997, the first version of the standard [11] supported up to 2 Mb/s throughput usinginfrared or radio transmissions in the 2.4 GHz band. In 1999, IEEE 802.11a rapidlyincorporated the use of the newly available license-exempt 5 GHz band, supportingdata rates of up to 54 Mb/s. Accessing a channel from the begining of the standards isfundamentally based on the principle that a user first senses if someone else is transmittingbefore starting its own transmission. If someone else is transmitting, the user defers. This A significant improvement was witnessed in 2009, when the amendment "n" (knownas Wi-Fi 4) introduced multi-antenna transmissions and the doubling of the channelbandwidth to 40 MHz, increasing the maximum raw data rate to 600 Mb/s. At this rate, atransmission of 1000 B takes about 126 μs (14.4μs for the transmission of 4 OFDM symbolscontaining the data, plus 52μs for the preamble, 16μs inter-frame space, and 44μs for theacknowledgment). However, the channel access procedure on average roughly doubles thisduration to 236 μs. This large overhead for every frame significantly results in an achieved This principle continues in the subsequent standard amendment "ac" (known as Wi-Fi5): the raw data rate is increased by quadrupling the maximum channel bandwidth to160 MHz and stuffing more bits into one transmitted symbol, allowing a maximum rawdata rate of 7 Gb/s – resulting in an even lower efficiency for small frames as the channelaccess procedure before the transmission again remained unchanged. As in the previous The amendment "ax" or Wi-Fi 6 then introduced orthogonal frequency-division multipleaccess (OFDMA), which allows transmissions to or from up to 74 users at the same time byassigning different frequency parts of the current channel bandwidth to them. Surprisingly,this amendment was the first of the major amendments that did not enlarge the channel The latest Wi-Fi generation, Wi-Fi 7, based on the amendment "be", further enlarges themaximum channel bandwidth to 320 MHz, resulting in a maximum raw data rate of up to23 Gb/s. The improvements in aggregation were achieved through the ability to parallelize This overview of Wi-Fi's generations offers a simplified perspective on its developments asit does not account for the numerous other minor amendments that have been introducedsince 1997. However, it is sufficient to show the general trend of the development: Widerchannel bandwidths (from 20 MHz in the beginning to now 320 MHz) increase the raw data Although the new features that came with each generation are impressive, the basicchannel access mechanism based on CSMA/CA remains untouched and thus is still the Detailed analysis:Today's Wi-Fioffers Gigabitspeeds through5 GHz and lower In the following sections, we analyze what speeds Wi-Fi can deliver today, deployingspectrum in the 5 GHz and lower 6 GHz bands. Model scenario We conduct system-level simulations of a multi-user, multi-cell Wi-Fi installation in anapartment building. In particular, we simulate a smaller version of the residential scenariodescribed in [12], which is also used in previous studies [13, 3]. The residential scenario consists of a building of three floors with 10 apartments per floor, resulting in a total of 30apar