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📱 | Nothing Phone (1) First Impression – Playful design is the biggest feature


Nothing Phone (1) First Impression – Playful design is the biggest feature

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It also supports Wi-Fi 6, Bluetooth 5.2, and NFC, but FeliCa is not installed.

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    IEEE 802.11

    IEEE 802.11(I Triple E 802.11) isIEEEWidely used by無線 LANIt is one of the related standards.Radio stationlicenseMany are unnecessary and can be used.


    The nominal speed is the instantaneous communication speed between wireless devices.Since the actual exchange of data causes loss for various reasons, the speed (effective speed) measured at speed measurement sites on the Internet is about half-one-third of the nominal speed.[1].

    generationspecificationFormulation timeSecondary modulation methodfrequencybandNominal maximum speedSpatial streamChannel widthRemarks (in Japan)
    1IEEE 802.11April 1997DSSS / FHSS2.4 – 2.5 GHz2 Mbps122 MHzNo license required
    2IEEE 802.11aApril 1999OFDM
    • 5.15 – 5.35 GHz
    • 5.47 – 5.725 GHz
    54 Mbps20 MHz
    • 5.15 – 5.35 GHz: No license required for indoor use only
    • 5.47 – 5.725 GHz: No license required, not only indoors and outdoors
    IEEE 802.11bDSSS / CCK2.4 – 2.5 GHz11 Mbps / 22 Mbps22 MHzNo license required
    3IEEE 802.11gApril 2003OFDM54 Mbps20 MHz
    IEEE 802.11jApril 2004
    • 4.9 – 5.0 GHz
    • 5.03 – 5.091 GHz
    No license required only for terminals within certain restrictions such as license required and power
    4IEEE 802.11nApril 2009
    • 2.4 – 2.5 GHz
    • 5.15 – 5.35 GHz
    • 5.47 – 5.725 GHz
    65 Mbps – 600 Mbps1 a.m. - 4 p.m.20/40 MHzThe maximum nominal speed varies from product to product, with a minimum of 65 Mbps and a maximum of 600 Mbps.
    • 2.4 GHz band: No license required, not only indoors and outdoors
    • 5.15 – 5.35 GHz: No license required for indoor use only
    • 5.47 – 5.725 GHz: No license required, not only indoors and outdoors
    5IEEE 802.11acApril 2014
    • 5.15 – 5.35 GHz
    • 5.47 – 5.725 GHz
    292.5 Mbps – 6.93 Gbps1 a.m. - 8 p.m.80/160 MHz
    • 5.15 – 5.35 GHz: No license required for indoor use only
    • 5.47 – 5.725 GHz: No license required, not only indoors and outdoors
    IEEE 802.11adApril 2013Single carrier / OFDM57 – 66 GHz4.6 Gbps – 6.8 Gbps - Up to 9 GHzNo license required
    6IEEE 802.11axApril 2021, 2[2][3]OFDMA
    • 2.4 GHz band
    • 5 GHz band
    9.6 Gbps1 - 820 / 40 / 80 / 160 MHz
    • 2.4 GHz band
    • 5 GHz band
    • 6 GHz band
    • 5.925 – 6.425 GHz: Available September 2022, 9[4]
    • 6.425 – 7.125 GHz: Not Available
    7IEEE 802.11beXNUM X year X NUM X schedule[5]
    • 2.4 GHz band
    • 5 GHz band
    • 6 GHz band
    46 Gbps1 - 1620/40/80/160/320MHz

    List of IEEE 802.11 task groups

    Standard nameStandard typeEnactment timeRemarks (in Japan)
    802.11Transmission standardApril 1997Defines MAC and frequency hopping and direct sequence modulation schemes. DSSS method.
    802.11aApril 1999A standard that achieves 5 Mbps by using OFDM in the 54 GHz band. It is the second physical layer standard, but it was commercialized in the latter half of 2.
    802.11bThe third standard, but the second to be released as a product. DSSS / CCK method.
    802.11cA standard for bridging between different wireless networks.It was not announced as 802.11c and was absorbed by 802.1D because no significant results were obtained.
    802.11dFormulated procedures for traveling between countries with different radio wave regulations
    802.11eQoS related standardsApril 2005Created an extension of MAC quality of service (QoS)
    802.11F (IAPP)
    802.11gTransmission standard2003Physical layer specifications that use ISM band networks. The OFDM method is applied to the 2.4 GHz band.
    802.11 hNational regulationsStandards for maintaining compatibility between 802.11a and European radio emission regulations
    802.11SecurityEnhanced link layer security
    802.11jNational regulationsAdditional specifications to make 802.11a comply with Japanese Radio Law regulations. j is not an acronym for Japan but a coincidence
    802.11 kStrengthening communicationA standard for exchanging radio resource information within a network to efficiently manage the use of wireless bands.
    802.11mmaintenanceA task group that incorporates 802.11a, 802.11b, 802.11d, and TGc changes into the 802.11 main unit specifications. m means maintenance.
    802.11nTransmission standardCompatible with 2.4 GHz and 5 GHz, achieving high throughput exceeding 100 Mbps in the MAC layer. Supports 40 MHz width and 4 x 4 MIMO.
    802.11papplicationA task group that applies 802.11 in automobiles.ETCUsed in etc.
    802.11rEnhanced roaming performance
    802.11sFor use as a mesh network technology
    802.11TTest / measurementTask group to design 802.11 test and measurement specifications (abandoned standardization)
    802.11uOther network interconnectionSupport interconnection with other network technologies. Passpoint.
    802.11aaVideo transmission
    802.11acTransmission standardApril 2014A standard for achieving a maximum of 5 Gbps using the 6.93 GHz band. Supports 160 MHz width, 8 x 8 MIMO.
    802.11adApril 2012Achieves a throughput exceeding 60 Gbps using the 7 GHz band. Supports 2.1 GHz width.
    802.11afTV white space
    802.11ahSensor network below 1 GHz, smart metering. Based on 11ac, it supports 1 MHz width for IoT.
    802.11aiHigh-speed connection in 10 ms (high-speed initial link setup)
    802.11ajExpand 802.11ad for China. Includes 45 GHz band.
    802.11Wireless LAN bridge method
    802.11aqA standard for knowing the service information supported by the AP before connecting to the AP.
    802.11axApril 2021, 2[2][3]Improved frequency utilization efficiency in high-density environments. Apply OFDMA. 8 GHz width, MU-MIMO support.
    802.11ayA standard for achieving 60 Gbps using the 20 GHz band. Extend 802.11ad.
    802.11azNext-generation positioning method
    802.11baWake up wireless
    • "L", "O", and "Q" are missing because it is easy to mistake L for the number 1 and O / Q for the number 0.
    • It was created in the order of a → z, and after z was aa. It is made in the order of aa → az.
    • Uppercase 802.11F and 802.11T indicate a complete independent document.IEEE 802.1XSame idea.

    Channels available by country

    2.4 GHz band
    ChannelCenter frequency (MHz)North AmericaEuropeJapan
    14248411b only
    5 GHz band
    ChannelCenter frequency (MHz)North AmericaEuropeJapan
    6 GHz band
    ChannelCenter frequency (MHz)North AmericaEuropeJapan
    60 GHz band
    ChannelCenter frequency (GHz)North AmericaJapan

    IEEE 802.11 frames and headers

    The IEEE 802.11 frame has the following structure.

    PLCP preamblePLCP headerIEEE 802.11 headerDataFCS

    Further, the details of the above IEEE 802.11 header are composed of the following fields.

    Frame controlDuration / IDAddress 1Address 2Address 3Sequence controlAddress 4
    • Information indicating the type of frame is entered in the frame control field (the following three types of frames).
      • Management frame (authentication, association request, association response, reassociation request, etc.)
      • Control frame (send request, response confirmation, etc.)
      • Data frame
    • The Duration / ID field contains information such as the reserved time until the frame transmission is completed.
    • Four address fields (the information contained in each address field depends on the communication environment).

    IEEE 802.11

    In English, it is pronounced in the form of "I triple E eight O two dot eleven", and when omitted, it is simply called "dot eleven".JapaneseThen, it is often called "Hachimaru Niiten Ichiichi". The wireless LAN standard that was first unified by the IEEE in 1997.

    It is mainly composed of a physical layer standard and a MAC layer standard, and is characterized by supporting multiple physical layer standards with one MAC layer standard. A standard that supports not only 2.4 GHz band radios but also the physical layer of infrared rays.Specifically, as a physical layerSpread spectrumOf these, three types are specified: frequency hopping (FHSS), direct sequence spread spectrum (DSSS), and infrared.The transmission speed is the theoretical value at the physical layer 3 M, 1 MbpsAchieved.

    For the MAC layerCSMA / CA It is characterized by using the (Carrier Sense Multiple Access with Collision Avoidance) method. The CSMA / CA method is the "Listen Before Talk" method, which is an access control method based on the principle of "listen before speaking" when compared to humans.In other words, if you want to send a packet signal, first check with the antenna whether another device is emitting a packet signal, and then send it. This is an access control method that employs an extremely simple mechanism. be. In the CSMA / CA method, when only 2.4 independent channels can be taken within the range that does not interfere with each other like the 4 GHz band, access points (master stations) other than yourself are autonomously decentralized (that is, in advance with neighboring neighbors). It is a simple and practical access control method for operating without systematic channel setting etc., and is a concept that forms the basis of a series of wireless LAN developments that will be connected after this.

    As an encryption technologyWEPWas supposed to be used.

    IEEE 802.11a

    The IEEE 1997 standard wireless LAN established in 802.11 has a maximum transmission speed of 2 Mbps, and standardization has been carried out since 1997 to increase the transmission speed. Discussions were held on the IEEE 2.4b standard in the 802.11 GHz band and the IEEE 5a standard in the 802.11 GHz band. In the 11b standard, compatibility with the conventional 11 standards was required, but in the 11a standard, physical layer technology using the latest technology at that time was examined without being bound by compatibility, and packet mode.OFDM The physical layer standard (up to 54 Mbps) based on the (Orthogonal Frequency Division Multiple) method was established in 1999. The actual product using IEEE 802.11a is2002Appeared around that time.When it first appeared, the name "Wi-Fi 11" was sometimes used as a contrast to 5b (Wi-Fi).[6].

    In the United States, 5 --5.150 GHz and 5.350 --5.470 GHz, which can be used both indoors and outdoors in the 5.725 GHz band, have been assigned from the beginning.on the other handJapanAt first, the frequency of 5.15 --5.25 GHz band was available for wireless LAN, but since it is also used for mobile satellite communication system,Radio ActIs prohibited from being used outdoors.note that,Automobile,列車Of whichaircraftUse in vehicles such as is not limited to this[7]..After that, in addition to 5.15 --5.25 GHz, 4.9-5 GHz (outdoor license band) and 5.25 --5.35 GHz (indoor unlicensed band) were added in Japan.From now on, as the 2.4 GHz band becomes more crowdedBandwidthIt is expected that the transition to the wide 5 GHz band will progress.

    Regarding channel layout, etc., in order to make it a globally integrated standard for parts that differ from frequency allocation in Europe and the United States, a new standard has been added.IEEE 802.11jWas stipulated. The j in 11j is not an acronym for "Japan", but just happens to be the "j" th when the standard names are defined in alphabetical order.

    Since the 5 GHz band is used for the frequency, there is an advantage that it is not easily affected by microwave ovens such as 2.4b, 11g, 11n in the 11 GHz band, but the spatial propagation loss of signal strength is proportional to the square of the frequency used for communication. Therefore, it does not propagate as far as the signals of 2b, 2.4g, and 11n in the 11 GHz band.

    It was possible to achieve high transfer speeds with a narrow bandwidth, but it was not very popular.

    Channel change in Japan

    Of the channel used for IEEE 802.11aCenter frequencyHas been changed from the one that has been used in Japan to the one that is internationally standard.[8]..To avoid confusion when making changes, the electronics industry has taken the lead in enacting symbols to facilitate identification.

    • J --Old Japanese domestic standard
    • W --International standard compliant standard
    • Number-Center frequency (eg, "53" has a center frequency of 5.3 GHz)

    From system revision2008(20)5Until now, as a transitional measure, the coexistence of three standards, "J52" (channel arrangement at 5.15 --5.25 GHz), "W52" and "W53" (channel arrangement at 5.15 --5.35 GHz), is allowed, and channel changes are supported. Wireless LAN devices have been released one after another and are beginning to spread.However, it is necessary to be careful because it may happen that the connection cannot be established even if it complies with the standard.

    The client side such as PC card was supposed to be able to support all frequencies (J52, W52, W53), but wireless broadband routers andaccess pointOn the parent device side, it is no longer possible to sell new J52 compatible devices.In addition, for some devices that only support the old standard J52, a method was adopted to make it compatible with W52 by rewriting the firmware.However, some manufacturers do not release W52 / W53 compatible firmware for older products, so such access points cannot communicate with devices that do not support J52.

    When using W52 / W53, there is no interference if the channels are different (the channels used are specified in 4-channel increments).Therefore, up to 8 channels became available, increasing the degree of freedom in installation planning (11b / g is up to 3).

    With the increase in available channels, 11a, which can be installed multiple times on the same floor, was thought to be suitable for corporate use.However, the increasing channel part (W53) is due to DFS (Dynamic Frequency Selection :).Weather radarIt is obligatory to avoid interference with (the avoidance action is performed when interference is detected), and in some cases communication may be interrupted.品質It is not suitable for corporate applications that require continuous operation.[By whom?](Similar operation is not mandatory for W52).

    2007(19)1 OfMinistry of Internal Affairs and CommunicationsDue to the revision of the ministerial ordinance, "W56" (5.47 --5.725 GHz) can be used.This significantly increased the number of channels from 8 to 19. With W56, you can use it outdoors without a license.However, since W56 is also a band used by weather radar, it has the same restrictions as W53.

    Transitional measures have ended2008(20)6After that, the newly released client equipment was also prohibited from supporting "J52", and only the international standard compliant standard of "W5x" was supported.This does not apply to products that were released before that and are still on sale.

    The revised Ministry of Internal Affairs and Communications Ordinance was promulgated on July 2019, 7, and 11ch was added to W56.This made it possible to use 144 + 140ch HT144 / VHT40 (40 MHz width) and 40 + 132 + 136 + 140ch VHT144 (80 MHz width).

    802.11a channel
    periodTypeChannelOutdoorsOperational restrictions due to interference with weather radar
    Until March 2005J5234, 38, 42, 46NoNone
    After February 2005W5236, 40, 44, 48NoNone
    W5352, 56, 60, 64NoThere
    After May 2007, 1W5236, 40, 44, 48NoNone
    W5352, 56, 60, 64NoThere
    W56100, 104, 108, ..., 140YesThere
    After May 2019, 7W5236, 40, 44, 48NoNone
    W5352, 56, 60, 64NoThere
    W56100, 104, 108, ..., 144YesThere

    IEEE 802.11b

    Officially called "IEEE 802.11 High-Rate Direct Sequence". It was formulated by "Task Group B" of "Working Group 802" in the "11 Committee" of the IEEE. 2.4 GHzISM bandUse a frequency band that can be handled without a license. 1997-The standard was deliberated from 1999 to the conventional IEEE 802.11 standard.compatibilityA standard was established that extended the transmission speed from 2 Mbps to a maximum of 11 Mbps (some have 22 Mbps as an option).As a technology, we have achieved high speed by adopting the CCK (Complementary Code Keying) method based on the direct diffusion method (DS method) among the three types of physical layer standards of the IEEE 802.11 standard.

    The 11b standard is a physical layer standard, and the MAC layer standard specified by the conventional IEEE 802.11 is adopted for the MAC layer and commercialized. With the release of wireless LAN cards that cost less than $ 1999 just before the standard was established in 100, the standard has become a catalyst for the wireless LAN market to break at once.computerRelated to the earliest popular無線 LANIt is a standard.

    There are 14 channels available in Japan.That is,Center frequencyFrom 2.412ch of 1 GHz to 2.472ch of 13 GHz, there are 0.005-5ch in 1 GHz (13 MHz) increments and 2,484ch of 14 MHz, for a total of 14ch.However, since the standard for one channel width is 22 MHz, the maximum number of channels that can be communicated without interference is four.The channel design in that case is 4ch, 1ch (6 GHz), 2.437ch (11 GHz), and 2.462ch.However, the legality of using 14ch in 11b is limited to Japan, and there are many masters and slaves that do not support 14ch.In that case, the maximum number of channels that can be communicated without interference is three, which is the same as 14g according to the standard.However, there are also models on the market that can communicate with a channel width narrower than the standard and can use 11ch, 3ch, 1ch, and 5ch at the same time for a total of 9 channels.

    IEEE 802.11g

    IEEE 802.11bDeveloped as an upward compatible standard of, it uses the radio frequency of the ISM band in the same 802.11 GHz band as IEEE 2.4b.

    The maximum communication speed is 54 Mbps, which is faster than the 802.11 Mbps of IEEE 11b.5 GHz band to achieve thatIEEE 802.11aOFDM (OFDM), which is a physical layer standard established inOrthogonal frequency division multiplexing) Is used.

    However, because it uses the ISM band, other equipment (especiallymicrowave, Cordless phones, wireless microphones that use 2.4GHz, Bluetooth, etc.) are more likely to interfere, and the effective speed is lower than that of IEEE 802.11a.

    Also, for IEEE 802.11bcompatibilityTherefore, if even one device that communicates according to the conventional IEEE 802.11b standard is mixed, the operation will be in the IEEE 1b mode accordingly, and the communication speed will be significantly reduced.

    The available channels are a total of 11 channels in the same band as 1-13ch of 13b.The center frequency of each channel is set at intervals of 5 MHz, but the width of one channel is 1 MHz according to the standard, so channels that are not separated by 20 channels or more have overlapping bands, so interference occurs.Therefore, the number of channels that can communicate without any interference even if they are used at the same time is 5 or less.However, models that can use a total of 3 channels of 1ch, 5ch, 9ch, and 13ch by communicating with a channel width narrower than the standard are also on sale.

    For some products, the "" used in 802.11nMIMO (Multiple Input Multiple Output) ”technology has been adopted in advance to enable communication at 108 Mbps, but it is limited to MIMO-compatible devices made by the same manufacturer.

    IEEE 802.11j

    this isIEEE 802.11aIs a modified standard for Japan.However, the letter j does not mean the acronym for Japan, but is accidentally assigned as a project name in the IEEE.

    Of the frequencies allocated for data communication in Japan, near 802.11 GHz used by IEEE 5.2aC bandFrequency is in JapanSatellite communication-Weather radar,Earth observation satelliteBecause it is used in, it cannot be used outdoors[9], Use of 4.9-5.0GHz newly allocated for data communication due to partial revision of the Radio Law and frequency allocation ("5GHz band"Wireless access systemIt was also allowed to be used outdoors.However, a license based on the notification system is required.[10].. ), The IEEE 802.11a is modified to be IEEE 802.11j.

    Initially, 4.4-5.0 GHz was shared with fixed-wire systems for 5 GHz band telecommunications business (such as TV relay).200511から201211Until then, it was used only in the area[11], Because the transition to other frequencies and optical lines was completed by November 2012[12], The regional restrictions have been abolished and it can be used nationwide.

    Since there is no other device using the 4.9 GHz band, there is little radio wave interference.According to the Radio Law, registration of the station is required, but it can be used both indoors and outdoors.With the attached antenna, it is not limited to indoor use, but as a backbone for communication at a distance of about 10 km such as outdoor remote island communication.Digital divideIt is expected to be used for elimination.

    • Frequency band: 4900 MHz --5000 MHz
    • Channel: 4920 MHz / 4940 MHz / 4960 MHz / 4980 MHz total 4ch
    • Channel spacing: 20 MHz / 10 MHz / 5 MHz
    • Antenna power: 250 mW (23.98 dBm) * Reference power decibel display 1 mW = 0 dBm

    Vast construction site / farm / factory[13]On-site LAN such as, or LAN line connecting remote facilities[14][15], Municipality[16][17]·Residents' association[18]Self-employed wireless IP communication such as, wireless internet line provided in areas where it is difficult to draw ADSL / optical line "Skynet V"Ginoza VillageBroadband service Ginoza BB "[19]Used in etc.

    IEEE 802.11n (Wi-Fi 4)

    A standard established to achieve a maximum transmission speed of 2.4 Mbps (5 MHz channel bonding, 600 streams) and an effective speed of 40 Mbps or higher using the 4 GHz / 100 GHz frequency band.

    Compared to IEEE 802.11a / gSubcarrierThe number of lines has increased, and the maximum coding rate has also improved.[20]..Also optional shortGI (400 ns) is now available (802.11 ns for IEEE 800a / g)[21].. Also"MIMO (Multiple Input Multiple Output) ”(for MIMO)Multiple access(See section), transmitting and receiving with multiple antennas (multi-streaming), reviewing communication procedures, and combining multiple channels (bandwidth used for communication).Channel bondingAchieve high speed and stability by (channel coupling).IEEE 802.11a,IEEE 802.11b,IEEE 802.11gCan be interconnected with. Draft version 2006 was formulated in March 3, and draft version 1.0 was formulated in June 2007, and was certified as an official standard in September 6.

    Even if it conforms to the IEEE 802.11n standard, the frequency band used, the number of channels that can be communicated at the same time (the number of spatial streams), and the support for channel bonding differ depending on the individual product.Therefore, even if the product is compatible with IEEE 802.11n, the maximum communication speed differs depending on the product, and whether or not it can be used at the indicated maximum communication speed also depends on the combination of products. Small size to connect to the USB terminalDongleMost of the products are of the type and the products that emphasize portability for use at the hotel where you are staying, up to a speed of about 150 Mbps.

    When using the 5 GHz band for the frequency, there is an advantage that it is not easily affected by the microwave oven like 11a, but the spatial propagation loss of the signal strength is proportional to the square of the frequency used for communication, so it is farther from the signal in the 2 GHz band. Does not propagate to.

    In addition, (English edition)The technology called is adopted.Data link layerIn (second layer), to the same destinationフ レ ー ムTo connect and communicate,throughputTo improve.However, only as the frame length becomes longerCommunication pathWill occupy.

    Maximum communication speed of IEEE 802.11n (theoretical value)[22]
    BandwidthMIMO not usedUse 2x2 MIMOUse 3x3 MIMO
    Use 4x4 MIMO
    20 MHz
    72.2 (65.0) Mbps144.4 (130.0) Mbps216.7 (195.0) Mbps288.9 (260.0) Mbps
    40 MHz
    150.0 (135.0) Mbps300.0 (270.0) Mbps450.0 (405.0) Mbps600.0 (540.0) Mbps

    (Modulation method 64QAM, Code rate 5/6, GI 400 (800) ns)

    In Japan, due to restrictions under the Radio Law, only 20 MHz bandwidth (one channel) was available in the original compatible products.2007(19)6Partial amendment of the Radio Law was enforced in Japan, and the bandwidth that can be used simultaneously in wireless communication was increased from the conventional 20 MHz to 40 MHz.[23]..This enables channel bonding (also referred to as dual channel, wide channel, etc.), and the theoretical maximum transmission speed has increased from the conventional 144 Mbps to 300 Mbps.However, if channel bonding is used in the 2.4 GHz band, only two channels can be used without interference from nearby wireless LAN devices.[24]Please note that the radio wave may easily interfere with the wireless LAN installed by another person or another wireless LAN installed by you, and the throughput may decrease.

    2012(24) As of now, the theoretical value of 150 Mbps (MCS index 7) for the products that have been released and use only channel bonding, and the theoretical value of 450 Mbps (MCS index 23) for the products that use both channel bonding and MIMO. Is[25][26][27][28].

    IEEE 802.11n ensures interoperability in the same frequency band as 802.11n draft 2.0 compliant products that were launched before the formal standardization was completed, without changing basic functions.Draft certified equipment meets the core requirements of the final certification program and can be treated as "802.11n certified equipment" without retesting.[29].

    Due to the rapid increase in wireless LAN equipment from around 2012, speed reduction due to radio wave interference began to occur frequently in urban areas, especially in the 2.4 GHz band.[30]..Relatively stable communication is possible in the 5 GHz band, which is still less widespread.5 GHz support for public wireless LANs by major telecommunications carriers is progressing.

    If you are not sure whether the commercially available wireless LAN device supports 5 GHz, 11aIf it is described as a device compatible with / b / g / n, it can be distinguished as 5 GHz compatible, and if it is 11b / g / n, it can be distinguished as only 2.4 GHz compatible.

    IEEE 802.11i

    IEEE 802.11i is not a communication standard itself, but a standard that defines security standards for wireless LAN.WPA (Wi-Fi Protected Access)WPA2Etc. are also standards compliant with IEEE 802.11i.Vulnerability is pointed outWEPInstead, as a standard cryptographic standard, in WPATKIP(Improved version of WEP) in WPA2CCMP(As an encryption algorithmBEA(Use) is adopted.


    The 802.11th generation wireless LAN standard, also known as 802.11vht (5 very high throughput), also known as Gigabit Wi-Fi, is also being researched and developed.Implemented multi-link technology, achieved 1 Gbps or more with dual link connection, and aims to achieve effective speed of 500 Mbps or more even with single link connection.[31]..Research is in full swing all over the world, and JapanNICT(National Institute of Information and Communications Technology) succeeded in developing a high-speed wireless LAN system of 2008 Gbps using the 60 GHz band in 3.[32].

    There are IEEE 802.11ac and IEEE 802.11ad that have already been established as standards.

    IEEE 802.11ac (Wi-Fi 5)

    IEEE 802.11ac is stipulated to provide gigabit throughput in the same 802.11 GHz band as IEEE 802.11a and IEEE 5n. 2.4 GHz is not used.

    80 MHz channel bonding (required)[33], 160 MHz channel bonding, 80 MHz + 80 MHz channel bonding, 256QAM[34], MU-MIMO (above option) is adopted to further increase the transmission speed.

    Since it uses the 5 GHz band for frequency, it has the advantage of being less susceptible to the effects of microwave ovens like 11a, but the spatial propagation loss of signal strength is proportional to the square of the frequency used for communication, so it is farther from the signal in the 2 GHz band. Does not propagate to.

    In addition, the specifications have been simplified compared to IEEE 802.11n.All frames are in A-MPDU format. The MCS set has been reduced from 0-76 to 0-9 by separating the stream count information.BeamformingThe method has also been simplified. Greenfield format frames are obsolete.

    The maximum transmission speed is 1 Gbps for Wave1 (1.3st generation) and 2 Gbps for Wave2 (6.9nd generation) (160 MHz channel bonding, 8 streams).Using the same frequency band as the previous IEEE 802.11a / n,Backward compatibilityBecause there is, it is easy to migrate (upgrade) from the existing wireless LAN.Also developed MIMOMU-MIMOThere are multiple clients using the technology of(English edition)However, the throughput of each client is less likely to decrease.However, since it is necessary to mount two or more antennas on the terminal side and space for the number of terminals is required, the compatible devices in the market are limited to some high-performance models as of 2.

    In 2012, a wireless broadband router compatible with the IEEE 802.11ac draft standard was commercialized. The 11ac standard itself is a standard that uses only the 5 GHz band and is not compatible with the 2.4b / g / n standard that uses 11 GHz, but commercial products have 11n communication functions in addition to 11ac. , Enables a smooth transition from the past 11a / b / g / n equipment.

    Products with a maximum of 2015 Mbps on the market as of 1733 use the 80x2 MIMO specified by Wave 4, which is the second generation standard, while using the bandwidth of 4 MHz.

    Maximum communication speed of IEEE 802.11ac[22]
    BandwidthData rate (Mbps)
    MIMO not used2x2 MIMO3x3 MIMO4x4 MIMO8x8 MIMO (MU-MIMO)[35])
    80 MHz
    160 MHz
    MCS index and data rate


    Modulation methoderror

    Correction rate

    Data rate (Mbps)
    20 MHz width40 MHz width80 MHz width160 MHz width
    800 ns GI400 ns GI800 ns GI400 ns GI800 ns GI400 ns GI800 ns GI400 ns GI

    IEEE 802.11ad

    The specification was finalized as IEEE 2012ad-12 in December 802.11.In 2012, it was announced that the Wi-Fi Alliance would implement a mutual certification program compliant with the WiGig standard, and it was launched in 2013.

    Since the high frequency band of 60 GHz is used, gigabit communication at a short distance of about 10 m without walls or obstacles is assumed.[36].

    Moreover, since the 60 GHz band resonates with oxygen in the air, the propagation attenuation is large.

    The PHY layer requires a single carrier (4620 Mbps) and OFDM is optional (6756.75 Mbps).The maximum transmission speed is 6.8 Gbps.

    The channel width is 2.16 GHz. Uses 57 GHz --66 GHz.The available channels and center frequencies are as follows.

    • CH1: 58.32GHz
    • CH2: 60.48GHz
    • CH3: 62.64GHz
    • CH4: 64.8GHz
    MCSPHYmodulationCode rateTransmission rate (Mbps)
    1Single carrierπ / 2-BPSK1/2385
    6π / 2-QPSK1/21540
    10π / 2-16QAM1/23080

    A PAL layer protocol that does not go through the IP layer is also defined.

    AV-PAL, PCIe, USB3.0 for conversion to Display Port and HDMI, and I / O PAL for protocol conversion to SDIO are defined.

    By using a virtual MAC technology called FastSessionTransfer, the session between 60 GHz and 2.4 GHz or 5 GHz PHY can be switched at high speed.

    In Japan, in November 2015, the Ministry of Internal Affairs and Communications Ordinance No. 11 promulgated a ministerial ordinance to partially revise the Radio Law Enforcement Regulations, and it was classified into the following two types.Those with an antenna power of more than 2 mW are obliged to have a carrier sense function.

    • Certification Rule Article 2, Paragraph 1, Item 19-4-2 60GHz band power saving data communication system radio station (antenna power over 10mW)
    • Certification Rule Article 2, Paragraph 1, Item 19-4-3 Radio station of 60GHz band power saving data communication system (antenna power 10mW or less)

    IEEE 802.11af

    TV white spaceThat is, the empty space of the VHF band (US) and UHF band used for television broadcasting is used.The frequency band for television broadcasting is generally widespread in each country, but there are many free channels that are not used to prevent harmful interference between channels.In addition, it differs for each region / region, such as prefectures and relay station areas.

    This is an attempt to make effective use of such free channels in wireless networks.According to the standard specifications, a WLAN access point uses GPS to locate itself, accesses the geolocation database through the network, and obtains information (including available time) on available channels (white space) at that location. I take the.

    PHY uses OFDM as well as IEEE 802.11ac. In the VHF / UHF band, the propagation loss due to the wall surface of the building is smaller than the 2.4 GHz / 5 GHz band used for Wi-Fi, so the effective reach of radio waves will be expanded.

    802.11af standards are:[37]

    • OFDM channel bandwidth 6/7/8 MHz
    • Transmission speed about 20-30 Mbps
    • Transmission distance about 100-500 m

    IEEE 802.11ax (Wi-Fi 6 / Wi-Fi 6E)

    IEEE 802.11ax[38][39]Is one of the Wi-Fi specification standards aimed at high efficiency wireless. [40] [41],Wi-Fi AllianceByWi-Fi 6Has been certified as.

    When using the 5 GHz or 6 GHz band for the frequency, there is an advantage that it is not easily affected by the microwave oven like 11a, but the spatial propagation loss of the signal strength is proportional to the square of the frequency used for communication, so the 2 GHz band Does not propagate as far as the signal of.

    CES With 2018PresentationIEEE 802.11ax-enabled devices support a total theoretical data rate of 11 Gbit / s[42]..Conventional standard for high-density usage environmentIEEE 802.11acOn the other hand, it is reported that the average throughput is 4 times lower and the delay is 75% lower.[43].

    For more efficient use of frequencies, IEEE 802.11axOrthogonal frequency division multiplexing access (OFDMA),1024-QAMA power control method was introduced to avoid modulation and interference.again,MIMOandMU-MIMOAs a result, the throughput is improved compared to the conventional standard, Target Wake TimeImprovement of power consumption performance by introduction ofWPA3Security has been improved by adopting[44].

    In 2020, the 2.4GHz band will be used in addition to the 5GHz and 6GHz bandsWiFi 6EWas announced[45].

    MCS indexModulation methodError correction rateData rate (Mbps)
    20 MHz width40 MHz width80 MHz width160 MHz width
    1600 nsec800 nsec1600 nsec800 nsec1600 nsec800 nsec1600 nsec800 nsec

    Difference from 802.11ac

    The comparison point with IEEE 802.11ac is[46]

    • Subcarrier interval is 11/4 of 1ac
    • OFDMSymbol length is 4 times (1024QAM support)
    OFDMANot supportedSupport
    Multi-user MIMO (MU-MIMO)Available in the direction.Up to 4 units.Available in downlinks and directions.Up to 8 units.
    Trigger-based random accessNot supportedUL OFDMA transmission by stations to which RU is not directly assigned is possible.
    Spatial frequency reuseNot supportedIt is possible to distinguish between transmission on the terminal's own network and transmission on the neighboring network.

    Adaptive Power and Sensitivity Thresholds can be used to dynamically adjust transmit power and signal detection thresholds to increase space reuse.

    Target Wake Time (TWT)Not supportedsupport.Reduce power consumption and media access competition.
    fragmentationStatic fragmentationDynamic fragmentation
    Guard interval0.4 µs or 0.8 μs0.8 µs, 1.6 µs or 3.2 μs
    Symbol duration3.2 μs12.8 μs

    IEEE 802.11ah

    Sub gigahertz WiFi.The name of the corresponding product isWiFi Halow(Halo).

    Uses the 920 MHz band.Bandwidth must be 1 MHz wide and 2 MHz wide.

    Occupied bandwidth 1 MHz MCS10 with data rate 150 Kbps.Estimated transmission distance up to 1 km.

    Japan916.5 - 927.5 MHz
    米 国902 - 928 MHz
    South Korea917 - 923.5 MHz
    Europe868 - 868.6 MHz

    IEEE 802.11be (Wi-Fi 7)

    IEEE 802.11p

    Formulated for vehicle-to-vehicle communication in 2012[47].. IEEE 802.11p is based on IEEE 802.11aIntelligent transportation system (ITS: Intelligent Transport System) with enhanced functions to support road-to-vehicle (V2I: Vehicle-to-Infrastructure) and vehicle-to-vehicle (V2V: Vehicle-to-Vehicle) communication. In the United States,Physical layerとMAC layerIt is called WAVE (Wireless Access in Vehicular Environments) by combining the IEEE 802.11p of the above and the IEEE 1609 of the upper layer, and in Europe, the specifications of the 5.9 GHz band for the same road-to-vehicle and vehicle-to-vehicle communication as WAVE. Is under development, and Japan is promoting a standard called ARIB STD-T5.8 in the 75 GHz band.[48][49].


    [How to use footnotes]
    1. ^ Annoying wireless LAN speed notation(Nikkei BPCompany, ITpro)
    2. ^ a b "IEEE SA Standards Board Approvals --09 / 10 February 2021". www.ieee.org (September 2021, 2). April 2021, 6Browse.
    3. ^ a b "IEEE 802.11ax-2021 --IEEE Approved Draft Standard for Information technology ...". www.ieee.org (September 2021, 5). April 2021, 6Browse.
    4. ^ "Wi-Fi 6E" finally lifted-The Ministry of Internal Affairs and Communications promulgates a ministerial ordinance that allows the use of wireless LAN in the 6 GHz band.
    5. ^ "OFFICIAL IEEE 802.11 WORKING GROUP PROJECT TIMELINES" (English). IEEE Std P802.11be. IEEE (September 2021, 6). April 2021, 6Browse.
    6. ^ Agilent Technologies establishes accreditation body for wireless LAN interoperability --Tech Village ・ May 2002, 5
    7. ^ Ministry of Internal Affairs and Communications Radio Wave Usage Homepage | Others | About outdoor use of wireless LAN --Ministry of Internal Affairs and Communications, February 2020, 2
    8. ^ Guidelines for "Frequency change of 5GHz band wireless LAN" XNUMXrd edition (PDF)
    9. ^ Information and Communication Council Information and Communication Technology Subcommittee 5GHz Band Wireless Access System Committee "5GHz band wireless access system committee working group study result reportNovember 2006, 11, Ministry of Internal Affairs and Communications
    10. ^ "5GHz band wireless access system"Ministry of Internal Affairs and Communications Radio Wave Usage Homepage" Ministry of Internal Affairs and Communications
    11. ^ Special Feature What you can expect / cannot expect to open the outdoor use of 5GHz band wireless access"INTERNET Watch" July 2002, 7, Impress Co., Ltd.
    12. ^ "As a result of soliciting opinions on revisions such as notifications regarding the expansion of the use of wireless stations in 5GHz band wireless access systems"Ministry of Internal Affairs and Communications" March 2012, 11, Ministry of Internal Affairs and Communications
    13. ^ "Introduction case ZEON CORPORATION"Fujitsu Network Solutions" Fujitsu Network Solutions
    14. ^ "Solution case study Wireless data communication between head office and branch offices"DENGYO Nippon Electric Works Co., Ltd." Nippon Electric Works Co., Ltd.
    15. ^ "Solution case study Broadcast video / FM broadcasting station temporary transmission line"DENGYO Nippon Electric Works Co., Ltd." Nippon Electric Works Co., Ltd.
    16. ^ "Introduction case Tadami Town, Fukushima Prefecture"Fujitsu Network Solutions" Fujitsu Network Solutions
    17. ^ "Onna village long-distance wireless LAN construction"Riuden Co., Ltd." Riuden Co., Ltd.
    18. ^ "Next-generation wireless network system Proposal of 5GHz band wireless access system"Toa Toa Corp." February 2013, Toa Corp., page 2
    19. ^ "Okinawa Prefecture Ginoza Village Area Limited Broadband Service"Ginoza Village" Ginoza Village, Kunigami District, Okinawa Prefecture
    20. ^ サブキャリアの本数は52→56(ただしうち4本はパイロット信号用のため、実質的には48→52)に増え、最大の符号化率は3/4→5/6に向上した。これに伴い、最大伝送速度の理論値は52/48 × (5/6)/(3/4) = 65/54倍になった。
    21. ^ Since the data transmission time per symbol is 1 ns, this option further increases the theoretical maximum transmission rate by (3200 + 3200) / (800 + 3200) = 400/20 times.
    22. ^ a b Modulation method 256QAM, Code rate 5/6, GI At 400 ns.Blue characterIs added in the Wave2 standard.
    23. ^ Ministry of Internal Affairs and Communications amends Radio Law to speed up wireless LAN - ITpro(March 2007, 6) Retrieved March 29, 2013.
    24. ^ Now is the time to buy! IEEE802.11n compatible wireless LAN equipment ― 1st Why did IEEE802.11n reach a speed of 300 Mbps at once? - ASCII.jp(March 2010, 1) Retrieved March 14, 2013.
    25. ^ http://www.pro.logitec.co.jp/pro/g/gLAN-WH450NGR/
    26. ^ Leave your PC, home appliances and games to us with IEEE 802.11n!Let's buy a new high-speed & easy-to-use latest wireless LAN router INTERNET Watch June 2010, 3
    27. ^ IEEE 802.11n-2009See English version
    28. ^ 2011(23) Currently, wireless LAN routers with a maximum transmission speed of 300 Mbps are sold as "11n compliant", and wireless LAN routers with a maximum transmission speed of 150 Mbps are sold as "n (11n) technology compatible".
    29. ^ http://www.wi-fi.org/pressroom_overview.php?newsid=835
    30. ^ Hiroto Kaneko (May 2012, 5). "Is this okay?" Dirty "wireless LAN". Nikkei BP PC Online. http://pc.nikkeibp.co.jp/article/trend/20120329/1044715/ April 2012, 12Browse. 
    31. ^ Anatomy!Gigabit wireless LAN (1): 11 times more than 10n!What is 802.11ac for next-generation wireless LAN? - @IT(March 2013, 03) Retrieved March 11, 2013.
    32. ^ Up to 60 Gbps using 3 GHz band, NICT et al. Ultra-high-speed wireless LAN system - INTERNET Watch(March 2008, 11) Retrieved March 4, 2013.
    33. ^ Compared to 40n during 802.11 MHz channel bonding, the number of data signal subcarriers increases from 108 to 234, so the maximum transmission speed is 234/108 = 13/6 times.
    34. ^ Compared to 64QAM, the number of bits per symbol increases from 1bit to 6bit, so the maximum transmission speed is 8/8 = 6/4 times.
    35. ^ Since there are a maximum of 1 streams for one user, the maximum speed for one terminal is equivalent to 4x1 MIMO.The following values ​​are the theoretical values ​​of the total communication speed on the master unit side.
    36. ^ << Wireless communication that can be understood by illustration >> [IEEE 802.11ad / WiGig] High-speed communication between short-distance devices using the 60 GHz band --PC Online (August 2012, 8) Retrieved November 6, 2013.
    37. ^ http://iwparchives.jp/files/pdf/iwp2014/iwp2014-ch04-03-p201.pdf
    38. ^ Wi-Fi Alliance introduces Wi-Fi 6
    39. ^ Here come Wi-Fi 4, 5 and 6 in plan to simplify 802.11 networking names
    40. ^ Goodwins.Next-generation 802.11ax wi-fi: dense, fast, delayed" (English). ZDNet. April 2019, 2Browse.
    41. ^ Gold, Jon. “FAQ: What you need to know about 802.11ax, the next big Wi-Fi standard” (English). Network world. https://www.networkworld.com/article/3048196/mobile-wireless/faq-802-11ax-wi-fi.html April 2017, 8Browse. 
    42. ^ Dignan, Larry (May 2018, 1). “D-Link, Asus tout 802.11ax Wi-Fi routers, but you'll have to wait until later in 2018”.zdnet. https://www.zdnet.com/article/d-link-asus-tout-802-11ax-wi-fi-routers-but-youll-have-to-wait-until-later-in-2018/ April 2018, 4Browse. 
    43. ^ Goodwins.Next-generation 802.11ax wi-fi: dense, fast, delayed" (English). ZDNet. April 2019, 2Browse.
    44. ^ Goodwins.Next-generation 802.11ax wi-fi: dense, fast, delayed" (English). ZDNet. April 2019, 2Browse.
    45. ^ "Wi-Fi Alliance® brings Wi-Fi 6 into 6 GHz | Wi-Fi Alliance". www.wi-fi.org. April 2022, 8Browse.
    46. ^ http://www.ni.com/white-paper/53150/ja/
    47. ^ IEEE 802.11p, http://www.de-pro.co.jp/2016/11/22/8959/ 
    48. ^ (PDF) ITS standardization 2015, http://www.jsae.or.jp/01info/its/2015_bro_j.pdf 
    49. ^ WIRELESS JAPAN 2006 – Development and standardization trends of mobile and wireless LAN related standards 2 IEEE 802.11a that communicates between vehicles based on 802.11a, http://news.mynavi.jp/articles/2006/07/20/wj1/001.html 

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