Short guard interval. By default, all available channels are enabled. Short guard interval

 
 By default, all available channels are enabledShort guard interval 11 guard interval

Jika sudah, maka pilih menu network yang ada di bagian layar Anda. Free Shipping on All Orders. guard-interval (any | long; Default: any) Whether to allow the use of short guard interval (refer to 802. The available channels depend on which IEEE wireless protocol you selected in Band. Enabling the Short Guard Interval increases the Data Rate. 11n 针对 802. This example shows how to set a long guard interval on a 2. Here are some advanced wireless settings selections Geier advises you to make right off the bat: “Short Preamble Length, Short Slot Time, Short Guard Interval, and Frame Aggregation. Re: 400msec - short guard interval. • 64,128,256,512 FFT sizes • Max. When short guard interval is used (400ns GI), a subcarrier carries 312. 11a/b/g used a mandatory 800ns guard interval. However, having a Short Guard Interval (SGI) in office environments, which reduces the interval to 400ns, can increase the data rate by 11%. Other: User entered Guard Interval values between 0 to 1. This option is only available for 2. 11n mode allows for a reduction in this guard interval from the a and g definition of 800 nanoseconds to 400 nanoseconds. • 11 days ago. Short Guard Interval STBC SU beamformer Wi-Fi CERTIFIED™ b Wi-Fi CERTIFIED™ g Wi-Fi CERTIFIED™ n OBSS on Extension Channel Short Guard Interval STBC A-MPDU Tx Wi-Fi Protected Setup™ PIN Pushbutton Page 3 of 4 Wi-Fi CERTIFIED™ Certificate Certification ID: WFA123305 Role: Access PointSystems, methods, and other embodiments associated with single stream wireless communication with greenfield preambles using short guard intervals are described. 64-QAM. (Sorry for bad english) Configure the guard interval for the network by entering this command: config 802. {"payload":{"allShortcutsEnabled":false,"fileTree":{"src/wifi/model":{"items":[{"name":"aarf-wifi-manager. g. Modification. Network performance may be higher when short preamble is enabled. At runtime, the calling function validates object settings for properties. ” 3. Refer to the MCS table for the. A short guard interval of 400 nanoseconds (ns) will work in most office environments as distances between points of reflection, as well as between clients, are short. Ideally, the guard interval is set to just above the delay spread of the channel. This allows you to increase the radio data rate by shortening the guard interval. Pada Wifi, OFDM disediakan 2 Guard Interval o Long GI: 800 ns o Short GI: 400 ns Karena kanal sudah di pecah-pecah menjadi carrier yang kecil-kecil dan saling ortogonal, maka aman jika di terapkan Short GI. 3. 4 GHz than 5 GHz band to make 5 GHz signal stronger than 2. • Helps improve data rate in Up/Down if both AP and STA support Short GI. . 1 is configured to cause the signal processor 130 to process a first guard interval in the data segment 240 of the single stream communication 210 as a long guard interval and subsequent guard intervals based on an indicated type in the SIG field 230 (e. 11, the channel bandwidth was 20MHz with later amendments adding support for 5 and 10MHz bandwidths. 4 microseconds) which leaves 3. Se vanno bene o no. Enabling a short guard interval can decrease network overhead by reducing unnecessary idle time on each access point. • Helps improve data rate in Up/Down if both AP and STA support Short GI. 11n. Select to enable the short guard interval for 802. According to one embodiment, a wireless communication device includes a receiver configured to receive an orthogonal frequency-division multiplexing (OFDM) signal. This option is only available for 5GHz 802. 11n data rates for the MCS for 80 MHz transmissions using a short guard interval. The clients are all 802. 11ac is theoretically capable of data rates up to 6993 Mbps! with 8 spatial streams, 256-QAM, 5/6 coding rate, 160 MHz channel bandwidth, and a 400 ns Short Guard Interval. Scrambler Initialization Range: 0 to 127 Default: 93 Set the initial state of the scrambler in decimal format, which is then turned into 7 bits to feed into the scrambler. Guard Interval is intended to avoid signal loss from multipath effect. 11n, short guard intervals are possible. 802. Here are some advanced wireless settings selections Geier advises you to make right off the bat: “Short Preamble Length, Short Slot Time, Short Guard Interval, and Frame Aggregation. 11, the channel bandwidth was 20MHz with later amendments adding support for 5 and 10MHz bandwidths. Wi-Fi 6 technology is all about better and more efficient use of the existing radio frequency medium. 5kbps × 3. The shortest interval (1/32) provides the lowest protection and the highest data rate; the longest interval (1/4) provides the highest protection but the lowest data rate. The guard interval between each symbol helps receivers overcome the effects of multipath delays. Compared with the traditional OFDM systems, the length of the guard interval for the proposed design can be distinctly reduced, thereby improving the spectral efficiency. What is the 11n guard interval? Intersymbol interference, also known as ISI, is eliminated by the guard interval. B QUESTION: 28 You are reconfiguring an AP to use the short guard interval. This is the router I'm using, Product Vendor: Technicolor Product Name: Technicolor TG784n v3Use either the short guard interval (Short GI) of 400 ns or the long guard interval (Long GI) of 800 ns. Accordingly, the interval select logic 120 of FIG. 8µs) and short GI (0. A guard interval is a period of time between transmissions that allows reflections from the previous data transmission to settle before an AP transmits data again. In wireless transmission, RF signals reach the receiving antenna by two or more paths, if the latter information symbol reaches the antenna too fast, signal may interfere with the earlier symbol (means signal degradation). Guard intervals (GI) are necessary for OFDM to reduce the likelihood of interference between two consecutive Symbols. 802. Short Guard Interval (SGI) is a protocol that lowers the guard interval by 400ns and improves the wireless data rate. On the other hand, if the guard interval is too long, there is increased overhead due to the additional idle time. 11n-2. guard interval guard interval Prior art date 2011-05-18 Legal status (The legal status is an assumption and is not a legal conclusion. . So you're limited to 65mbit per spacial stream. Lack of support for these features can reduce the maximum rate and reduce performance of the Intel® wireless adapters. Command History. Wireless Reliability - Guard Intervals. Short GI NSYM Disambiguation — A bit that indicates if an extra symbol is required when the short GI is used. In one embodiment, the disclosure can define three types of the GI and SC data block, for example, short,. A short guard interval of 400 nanoseconds (ns) works in most office environments as distances between points of reflection, as well as between clients, are short. The guard interval should be 2-4 times the length of the delay spread. Related Commands. Enable SGI (Short guard interval) Client load balancing: Enable Freq handoff and AP handoff for areas with more significant amounts of connected devices (Greater than 20 heavy usage devices. In another embodiment, the short guard interval can be used for short range applications, for example, when the channel impulse of a communication channel response associated with the network has a short duration, such as indoor environments. 900 Mbps (two spatial streams at 80 MHz, short. A sua principal função é a de avisar. This guide covers the steps to set up the wireless network interface, security, SSID groups, VLAN assignment, and more. As same as the legacy IEEE 802. 4 GHz (30%) and 5 GHz (70%) Avoid low transmission rates (802. 8µs กับ Short Guard Interval (SGI) 0. 11b/g used a longer guard interval than 802. According to one embodiment, a wireless communication device includes a receiver configured to receive an orthogonal frequency-division multiplexing (OFDM) signal. 11n, and can cause issues with mixed mode. About This Document. This is kind of half right. SGi (Short Guard Interval) STBC (Space-Time Block Code) 20, 40 MHz bandwidths 2x2 antenna MU-MIMO 5 GHz Wi-Fi features 5 GHz frequency bands Band 1 5150 - 5250 MHz Band 2 5250 - 5350 MHz with DFC Band 3 5470 - 5725 MHz with DFC 5 GHz Wi-Fi power Band 1, 2 up to 23 dBm (200 mW EIRP) Band 3 up to 30 dBm (1000 mW EIRP)As introduced in [5], if the guard interval condition is too short, then ISI and ICI-CIG distortions will occur. Use either the short guard interval (Short GI) of 400 ns or the long guard interval (Long GI) of 800 ns. TX Power Control. Ideally, the guard interval is set to just above the delay spread of the channel. Systems, methods, and other embodiments associated with a single stream wireless communication with a greenfield preamble that uses a short guard interval are described. The standard has been retroactively labelled as Wi-Fi 5 by Wi-Fi Alliance. 11n data rate. Coding: SU/MU[0] Coding: Possible values: BCC, LDPC, or binary digit (indicating the value of a reserved bit). Select Channel Width. A guard interval is a period of time between transmissions that allows reflections from the previous data transmission to settle before an AP transmits data again. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. When deploying a wireless network in an environment with many obstacles, there will be diffraction, scattering and reflection. The Internet Group Management Protocol (IGMP) is a protocol used by devices and routers to exchange information. 1. ใน Wi-Fi ที่ใช้ OFDM จะใช้ GI อยู่สองตัวคือ GI มาตรฐาน 0. The available channels depend on which IEEE wireless protocol you selected in Band. Auto TX Power Control : Enable automatic adjustment of transmit power. For example, wlanVHTConfig('GuardInterval','Short') specifies a 400-nanosecond guard interval (cyclic prefix) duration. Click this checkbox to enable or disable a short preamble for 802. Using personal security mode for your. When there are too many WiFi router in your neighbour then all of network channel get o. Tính năng Frame Aggregation cho phép gửi nhiều khung dữ liệu trong một lần truyền, nhưng nên sử dụng một cách thận trọng vì. Learn how to create a FortiAP profile for your FortiWiFi and FortiAP devices using the latest configuration guide for version 7. Command introduced. The command is: config 802. When the delays are small. 1. The guard interval prevents Inter-Symbol and Inter-Carrier Interference (ISI, ICI). Ensure to keep at least 6 dB lower value on 2. 5kbps × 3. Configure the guard interval for the network by entering this command: config 802. Single radio/antenna devices do not support mimo and still having trouble with inter symbol interference by multipath, especially in warehouses where barcodescanners are used. Select the channel or channels to include. 802. transmit_optimize. 802. According to one embodiment, a wireless communication device includes a receiver configured to receive an orthogonal frequency-division multiplexing (OFDM) signal. Short Guard Interval (What is Guard Interval?) Guard Interval is used to avoid signal loss from multipath effect. 93Gbps using 160MHz bandwidth,8 spatial streams,MCS9,256QAM,with short guard interval. 11b/g devices use an 800 ns guard interval, while. 11n Introduces Short Guard Interval (SGI) When 802. In the screen shot above you will notice that Short Guard Interval and Aggregation are both disabled. Select to enable the short guard interval. 802. cc. The specification has multi-station throughput of at. Short Guard Interval (SGI), 20 and 40 MHz • Primarily used on AP side to reduce Guard interval between frames to improve performance • Helps improve data rate in Up/Down. 802. IGMP snooping allows. 11ac data rate. 4 μs guard interval which provides about a 10% increase in data rate. The guard interval is a time space between radio symbols (characters) being transmitted that ensures they do not collide in the air. However, if it’s too short, the amount of ISI will increase, and throughput will decrease. It turns out the answer was to disable the "Short Guard Interval" setting. The guard interval can be shortened to increase throughput by up to 10 percent. A guard interval is a period of time between transmissions that allows reflections from the previous data transmission to settle before an AP transmits data again. Systems, methods, and other embodiments associated with a single stream wireless communication with a greenfield preamble that uses a short guard interval are described. An AP identifies any signal content received inside this interval as. Enable or disable use of short (400 ns) guard interval in 20 MHz mode. 11n/ac/ax/be Demod Properties > Format tab The Guard Interval is the ratio of the Cyclic Prefix "CP" time to the inverse FFTtime "T (IFFT). TP-Link announced the world's first 802. The advantage is the shorter wait time (guard interval) between symbols increases throughput. The following example shows how to configure a long guard interval: (Cisco Controller) >config 802. +/- 17° Vertical Scan. S. The need for a long guard interval of 800ns becomes more important as areas become larger, such as in warehouses and in outdoor environments, as reflections and echoes become more likely to continue after the short guard interval would be over. Short Guard-interval : Select to enable the short guard interval. From 802. Short Guard Interval. The 802. When set this cell to OFF, the Guard Interval is 800ns. 11n 针对 802. The long Guard Interval (GI) and short Guard Interval (SGI) are functions built into OFDM that help to mitigate these effects. (Cisco Controller) > config 802. On the WiFi front I would advise you to download a tool such as winfi or WiFi explorer for Mac and check your MCS index, this will notify you of the connected capability of the connection. This field is available only if the selected wireless radio mode includes 802. You’d be missing a valuable opportunity to improve your network’s performance right from the get-go. MU-MIMO is an enhanced form of the MIMO. ap. A preamble of the data unit is. 2. 802. 11ac will includeConfigure the guard interval for the network by entering this command: config 802. 6 = 277. 11ax has three types of GI – the normal GI (0. Also used in TDMA transmissions. 802. It is a 802. Don’t. These data rates, which are calculated for a 20-MHz channel width using a short guard interval, are available: 0 (7 Mbps) 1 (14 Mbps) 2 (21 Mbps) 3 (29 Mbps) 4 (43 Mbps)If a "short guard interval" isn't working (channel congestion is a common reason for this), the radios may fall back to a standard guard interval, which will reduce throughput as well. 0, making short guard interval mandatory is emphasized as this was a change from 11ac PHY, which caused the confusion. 4. 25 KHz for 802. 11n added optional support for a 0. 5 for 80 MHz. If you're a RF-engineer you know when you can enable. Systems, methods, and other embodiments associated with single stream wireless communication with greenfield preambles using short guard intervals are described. Configure Wireless AP Parameters 4. Enable or disable use of short (400ns) guard interval in 20 MHz mode. 256-QAM. 11 {a |. For normal guard intervals (800 ns): 0 to 32 samples. 11n/ac/ax STAs and APs. 4. Yes — Reduces transmission time to every 400 nanoseconds when communicating with clients that also support the short guard interval. • Modulation Scheme OFDM and DSSS/CCK. Longer guard intervals provide improved performance in environments with multi-path and delay spread. It improves link reliability for longer-range outdoor. Short Guard Interval. Disclosed are a method and a device for transmitting and receiving a frame using a short guard interval. I just called Sonicwall support and the person told me the exact opposite. Next thing is disable fat channels and short guard interval. Delivering Wi-Fi 5 connectivity (802. In networks that experience less than optimum conditions (interference, weak signals, etc. undo short-gi. Now, that provides minimum datarate of 130 Mbps (the minimum is with long guard interval and with 20 MHz channel). dark gray area in figure 1). the Channel 10 guy is an asshole. Short GI — A bit that indicates use of the 400 ns guard interval. SGI is a scalable, extensible, robust protocol that is used for Cisco IOS software. Short Guard interval & Aggregation In the screen shot above you will notice that Short Guard Interval and Aggregation are both disabled. 104 ms Answer (s): AReference: QUESTION: 29 What statement about the beamwidth of an RF antenna is true?The heartbeat interval range is 1 to 20 (100*ms). Scrambler Initialization Range: 0 to 127 Default: 93 Set the initial state of the scrambler in decimal format, which is then turned into 7 bits to feed into the scrambler. Use the VLAN pool when available. 11n bands. The heartbeat interval default is 2 (200 ms). An AP identifies any signal content received inside this interval as. Despite testing it in n-only mode with two laptops, a USB wifi adapter and two phones, connection speeds are less than half of what I see with my 802. 11ac is a wireless networking standard in the IEEE 802. Single radio/antenna devices do not support mimo and still having trouble with inter symbol interference by multipath, especially in warehouses where barcodescanners are used. r/HomeNetworking. The regular guard interval is 800ns. 11n/g/b, and 5GHz 802. Description. For HIPERLAN/2, both 1/4 and 1/8 are selections. Ciao a tutti, volevo un parere sui parametri di configurazione del modem. Description. If the short guard interval does not allow enough time for reflections to settle in your mesh deployment, inter-symbol interference values may increase and degrade. 11n on 5GHz. • Primarily used on AP side to reduce Guard interval between frames to improve performance. We would like to show you a description here but the site won’t allow us. It is referred as HT (High Throughput) specification. 11n radios. Reveal Solution Discussion 1. Observing the received pilot symbol on p-th sub-carrier and on i-th OFDM symbol. 11a/g 所做的改进。 射频芯片在使用 OFDM 调制方式发送数据时,整个帧是被划分成不同的数据块进行发送的,为了数据传输的可靠性,数据块之间会有 GI ,用以保证接收侧能够正确的解析出各个数据块。 A shorter guard interval results in a shorter symbol time, which increases the data rates by about 10% and increase throughput greatly. 11a/g 所做的改进。 射频芯片在使用 OFDM 调制方式发送数据时,整个帧是被划分成不同的数据块进行发送的,为了数据传输的可靠性,数据块之间会有 GI ,用以保证接收侧能够正确的解析出各个数据块。 The 802. 11n only, you may. long Enable 802. In the screen shot above you will notice that Short Guard Interval and Aggregation are both disabled. 46 kg) Package (shipping) Weight 1. 11ad router in January 2016. Each transmission burst in 802. 11ax) is the new generation of Wi-Fi technology with a new focus on efficiency and performance. If you. 802. 400 ns B. 6 µs) GI and quadruple (3. Hence, in TGaf capable devices shall support both guard interval modes (short and normal). It indicates that the client stations are currently sleeping in low-power mode. _____ Atheros TP-Link WR740Nv1 ---DD-WRT 53045 WAP. SGI = short guard Interval i = idle or what ever: back in the days i googled those and checked the ddwrt wiki. However for office environments, having a Short Guard Interval (SGI), which lowers the interval to 400ns, can give you an increased data rate of 11%. The available channels depend on which IEEE wireless protocol you selected in Band. Currently short guard interval is not supported for Nv2 protocol. 11n/ac, where the. Select to enable the short guard interval for 802. The guard interval is a period of time inserted between symbols to mitigate the effects of multipath. Cisco supports SGI on a 20MHz channel in the 2. The Other selection inputs a non-standard Guard Interval value between 0 and 1. Not. Enable/disable spectrum analysis to find interference that would negatively impact wireless performance. The Guard Interval time period T (GI) is specified as a fraction (percentage) of the inverse FFT time period T (IFFT). 2 microseconds of data. Short guard interval in 20 MHz Megahertz mode. 11n. ArubaOS 8. N = short guard interval not used in the VHT-Data field. 6 = 277. long Enable 802. Short GI: disabled – Short Guard Interval decreases the time between data characters being sent wirelessly. Short Guard Interval. For short guard intervals (400 ns): 0 to 16 samples. 2. n Data rates of up to 4949 Mbps in 802. MCS: SU MCS/MU. The guard interval is the amount of time that the WAP waits between transmissions, which prevents interference. Lifetime Guarantee. spectrum_analysis. Di IEEE 802. Tick: Enable Short Guard Interval (This would avoid any kind of data loss from wireless interference) or Enable Aggregation (it increases throughput of 802. Refer to the MCS table for the. ) The MCS values correspond to actual data rates. Default. You should be able to see it in a packet capture of the beacon. 802. 67 (MCS Index 9) / 3. Этот интервал помогает при. - 72969 This website uses cookies. 无线信号. Enclose each property name in quotation marks. 11n you can choose between a short guard interval and a long guard interval. Short GI: whether short guard interval is used. 11n devices. C. According to one embodiment, a wireless communication device includes a transmitter configured to generate an orthogonal frequency-division multiplexing (OFDM) signal that. 4). The intention of PHY submission was to make short GI a mandatory feature in addition to normal guard interval. . 室内环境干扰因素小. In draft 2. 8- Short Guard Interval: این گزینه باید حتما تیک زده شود و یا فعال شود ( با فعال کردن این گزینه پهنای باند شبکه وایرلس به طور متعادل در فضا پخش میشود و تمام قدرت روی کیفیت و تبادل اطلاعات متمرکز میشود ). A guard interval is a period of time between transmissions that allows reflections from the previous data transmission to settle before an AP transmits data again. Short Guard Interval (400ns), który to parametr tylko w teorii pozwala nam na osiągniecie. A method for receiving a beacon frame comprises the steps of: receiving a first beacon frame which contains guard interval type information; determining a second beacon frame which is to be received after the first beacon frame on the basis of the guard interval type information; and receiving the second beacon frame, wherein the guard interval type. Hello, because our wireless analyzer can't capture packages transmitted in Short-GI model, we want to disable the Short-GI (guard interval) for AP/AC, we didn't find the configure for disable short-GI in the configuration tools for AP/AC. Otherwise said, you should set a relatively short amount of time between the transmission of. The ratified version includes support for features such as short guard interval and frame aggregation. B. Normally this is an 800ns timer that. It is not to be confused with the space between packets, which is the inter-frame space (IFS). ssid AeroHive-guest. Scrambler Initialization Range: 0 to 127 Default: 93 Set the initial state of the scrambler in decimal format, which is then turned into 7 bits to feed into the scrambler. 11n added optional support for a 0. • Primarily used on AP side to reduce Guard interval between frames to improve performance. Ttr creates a small overlap between consecutive subsections in order to smooth the transitions between them. If you are using 802. The guard interval in a typical 802. It can be observed that while there is a steady. 4 GHz 5 GHz Spectrum Capabilities 20 MHz Channel Width in 5 GHz 40 MHz Channel Width in 5 GHz 80 MHz Channel Width in 5 GHz Protected Management Frames WMM® WPA2™. 11n, and can cause issues with mixed mode. ap (config-if)#interface dot11radio0. The Connect with Intel® Centrino® processor technology program tests and verifies routers. As discussed earlier, OFDMA combines sub-carriers to form resource units (RUs), or sub-channels, of different widths. 5 Mbit/s per MHz and spatial stream, or slightly more than half the advertised bitrate. Channel width multiplication factors are 1 for 20MHz BW, 2. 11 operation, the guard interval is 800 ns. Enabling a short guard interval can decrease network overhead by reducing unnecessary idle time on each access point. 11n specifies two guard intervals: 400ns (short) and 800ns (long). Short Guard Interval Supported : Protection : Beacon Interval (Msec, Range: 20 - 2000) DTIM Period (Range: 1-255) Fragmentation Threshold (Range: 256-2346, Even Numbers) RTS Threshold (Range: 0-2347) Maximum Stations (Range: 0-200) Transmit Power : Fixed Multicast Rate. The 802. You, as the designer of an OFDM system, define the length of the CP based on your requirements. 160 MHz channel, 1 spatial stream, short guard interval, VHT, MCS7 (up to 650 Mbps). Short Guard Interval Choice: On|Off Default: Off Determine whether the OFDM symbols adopt the short guard interval which is 400ns. Channels. since 802. The guard interval (GI) are necessary for prevention of inter-symbol and Inter-carrier. TX PowerSystems, methods, and other embodiments associated with a single stream wireless communication with a greenfield preamble that uses a short guard interval are described. 2 µs Extended guard interval durations allow for better protection against signal delay spread as it occurs in outdoor environments. Note: The Linksys USB600N does not reliably collect 11n packets with short guard interval. You should be able to see it in a packet capture of the beacon. Lower the delay, the. Command Information. MU-MIMO is short for Multi-User, Multiple-Input, Multiple-Output. 1 Channelization When the OFDM PHY was introduced to 802. 11n was released it included an optional Short Guard Interval (SGI) function that reduced the amount of delay spread protection by half, from 800 ns to 400 ns (. 2us cyclic prefix) Highest Modulation. 11, the channel bandwidth was 20MHz with later amendments adding support for 5 and 10MHz bandwidths. Symbols are what carry the bits (0s and 1s). If you are using 802. The standard symbol guard interval used in 802. This parameter is enabled by default. GUARD INTERVAL The Symbol Period for Wi-Fi is 1/250,000th of a second or 4000ns Of that 4000ns, by default, 3200ns of it is used for transmission, 800ns is used for silence between symbols. Configure Wireless Client Parameters 3. 4 GHz and 5 GHz. Training. The regular guard interval is 800ns. 4 W) Maximum FAP Power. The Guard Interval time period T (GI) is specified as a fraction (percentage) of the inverse FFT time period T (IFFT). Guard Interval: 800ns: Security Settings: WPA2-PSK/WPA2-Enterprise: WPA Encryption: AES: WIFI 5G. With 802. For each VAP you add you need to increase Beacon Interval by 100. Select to enable the short guard interval. The short guard interval time is 400ns, or half of what it used to be. By default, all avail-. Some outdoor deployments, may, however require a longer guard interval. A shorter guard interval results in a shorter symbol time, which increases the data rates by about 10% and increase throughput greatly. 11 {a | b} 11nsupport rifs rx {enable | disable} Save your changes by entering this command: save config Ensure to keep at least 6 dB lower value on 2. 4/0. If fix the capability to 40MHz channel width with long guard interval, I see almost all (around 85%) packets with 20MHz channel width. Software-configurable dual radio supports 5 GHz (Radio 0) and 2. 11n also use 800 nanoseconds as the default guard interval. 间隔时间越小,传输效率越高,间隔时间越大,抗干扰能力越强。. In IEEE 802. The higher the MCS index is, the more throughput is supported by the corresponding modulation schema.